Tech4Biowaste - User contributions [en]

Hydrolysis

2023-03-03T15:51:20Z

Anna Alessi: /* Biorenewables Development Centre */

{{Infobox technology|Name=Hydrolysis|Category=[[Pre-processing]] ([[Pre-processing#Chemical_processes_and_technologies|Chemical processes and technologies]])|Feedstock=Lignocellulosic biomass|Product=Sugars and organic acids}}
<onlyinclude>'''Hydrolysis''' (/haɪˈdrɒlɪsɪs/; from Ancient Greek ''hydro-'' 'water', and ''lysis'' 'to unbind') is a chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions that use water as the reagent.<ref>{{Cite web|year=2002|title=Hydrolysis|e-pub date=2002|date accessed=2021|url=https://en.wikipedia.org/wiki/Hydrolysis|Author=Wikipedia}}</ref> In lignocellulosic biomass, the cellulose and hemicellulose breaks down into individual sugars. Hemicellulose is easier to hydrolyse than cellulose.<ref>{{Cite journal|title=Dilute acid hydrolysis of lignocellulosic biomass|year=2010-01-15|author=P. Lenihan, A. Orozco, E. O’Neill, M.N.M. Ahmad, D.W. Rooney, G.M. Walker|journal=Chemical Engineering Journal|volume=156|issue=2|page=395–403|doi=10.1016/j.cej.2009.10.061}}</ref> The result of hydrolysing hemicellulose and cellulose are sugars (glucose, mannose, galactose, (C6) and xylose, arabinose (C5)) and organic acids (formic acid and acetic acid).<ref>{{Cite journal|title=Acid Hydrolysis of Lignocellulosic Biomass: Sugars and Furfurals Formation|year=2020-04-17|author=Katarzyna Świątek, Stephanie Gaag, Andreas Klier, Andrea Kruse, Jörg Sauer, David Steinbach|journal=Catalysts|volume=10|issue=4|page=437|doi=10.3390/catal10040437}}</ref> </onlyinclude>

== Feedstock ==

=== Origin and composition ===
Hydrolysis can be performed as a pretreatment on any biowaste with a high lignocellulose content. Lignocellulose is typically the nonedible part of a plant, composed of a complex of cellulose, hemi-cellulose and lignin. Suitable feedstocks include grasses, straw, leaves, stems, shells, manure, paper waste, and others. The ratio between cellulose, hemi-cellulose and lignin varies wildly depending on the specific feedstock.<ref name=":1" />

=== Structural features ===

==== Cellulose ====
''Explain structure of cellulose''

==== Hemicellulose ====
''Explain structure of hemi-cellulose''

==== Lignin ====
''Explain structure of Lignin''

== Process and technologies ==

=== Chemical hydrolysis===
Chemical pretreatments have been used extensively for removal of lignin surrounding cellulose and for destroying its crystalline structure. Even though chemical pretreatments are usually effective, they have disadvantages which should not be ignored [10]. These include use of specialized corrosion resistant equipment, need for extensive washing, and disposal of chemical wastes. Various chemical methods are discussed under several headings, namely, alkalis, acids, gases, oxidizing agents, cellulose solvents, extraction, and swelling agents.

==== Acid ====
'''Acid hydrolysis''' is a hydrolysis process in which a protic acid is used to catalyze the hydrolysis reaction. Acids are used mainly for hydrolysis of cellulose [10]. A strong acid, such as formic, hydrochloric, nitric, phosphoric, or sulphuric acid can be used in concentrated or diluted form. '''Concentrated acid''' (10-30 %) can penetrate the lignin structure and break down the cellulose and hemicellulose to individual sugars at low temperature and with high yield. Downsides are the high acid consumption and high corrosion potential. These downsides are circumvented with the use of '''diluted acid''' (2-5 %). However, in the latter case, higher temperature is required, which can lead to side product formation such as furfural and 5-hydroxymethyl-furfural.<ref name=":1">{{Cite book|author=Alessandra Verardi, Isabella De Bari, Emanuele Ricca and Vincenza Calabrò|year=2012|section_title=Hydrolysis of Lignocellulosic Biomass: Current Status of Processes and Technologies and Future Perspectives|editor=Marco Aurelio Pinheiro Lima and Alexandra Pardo Policastro Natalense|book_title=Bioethanol|publisher=IntechOpen}}</ref>

Acid hydrolysis can be further improved by the addition of salts, such as metal salts or suphite salts. Metals such as aluminium, calcium, copper, iron and zincnc can be used to increase the sugar yield [6]. Similar to [[Pulping and fractionation#Sulphite pulping|sulphite pulping]], sulphites can be added to aid in lignin removal.

===== Sulfuric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Hydrochloric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Phosphoric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

==== Alkali ====
'''Alkaline hydrolysis''' refers to hydrolysis reactions using hydroxide, commonly from sodium hydroxide or calcium hydroxide. The hydroxide breaks down the lignin bonds to make the cellulose more accessible. The reaction proceeds at lower temperature and pressure and residual alkali can be recycled. However, the pretreatment does result in irrecoverable salts in the product.<ref>{{Cite journal|title=Pretreatment of lignocellulosic sugarcane leaves and tops for bioethanol production|year=2020-01-01|journal=Lignocellulosic Biomass to Liquid Biofuels|page=301–324|doi=10.1016/B978-0-12-815936-1.00010-1|author=S. Niju, M. Swathika, M. Balajii|volume=}}</ref>

===== Sodium hydroxide =====
Dilute sodium hydroxide (NaOH) treatment of lignocellulosic material causes swelling, leading to an increase in internal surface area, decrease in the degree of polymerization, decrease in crystallinity, separation of structural linkages between lignin and carbohydrates, and disruption of the lignin structure [10].

''Elaborate more the reactions conditions and give some examples from literature.''

===== Ammonia =====
Liquid or gaseous ammonia acts as a strong swelling agent for cellulose [1].

''Elaborate more the reactions conditions and give some examples from literature.''

===== Ammonium sulfite =====
Ammonium sulfite is used mainly in a conventional pulping process.

''Elaborate more the reactions conditions and give some examples from literature.''

==== Solvent ====
Solvents can be added to improve the hydrolysis process. This is similar to [[Pulping#Dissolving pulp and organosolv|organosolv pulping]], but without the delignification as goal.<ref name=":2">{{Cite journal|title=Biomass pretreatment: Fundamentals toward application|year=2011-11|author=Valery B. Agbor, Nazim Cicek, Richard Sparling, Alex Berlin, David B. Levin|journal=Biotechnology Advances|volume=29|issue=6|page=675–685|doi=10.1016/j.biotechadv.2011.05.005}}</ref>

===== Organosolv (lignin hydrolysis) =====
Organosolv pretreatment is the process to extract lignin from lignocellulosic feedstocks with organic solvents or their aqueous solutions.

In an '''organosolv hydrolysis''' organic solvents are added to the process, usually performed at high temperatures (100-250 °C). This can be combined with a catalyst such as HCl or H2SO4.<ref name=":2" /> For example, in '''acid-acetone''' pre-treatment biowaste is treated with an acid such as phophoric acid and then mixed with pre-cooled acetone.<ref name=":0">{{Cite journal|title=A comprehensive review on pre-treatment strategy for lignocellulosic food industry waste: Challenges and opportunities|year=2016-01-01|journal=Bioresource Technology|volume=199|page=92–102|doi=10.1016/j.biortech.2015.07.106|author=Amit K. Jaiswal, Rajeev Ravindran}}</ref>

===== Ionic Liquids=====
Ionic liquids are '''solvents''' that can be used for biomass pretreatment, fractionation, and dissolution. During ionic liquid pretreatment, a cellulose-rich fraction can be generated through the degradation and removal of a large portion of lignin and hemicellulose <ref>{{Cite web|Author=Moyer, P., Kim, K., Abdoulmoumine, N. et al.|year=2018|title=Structural changes in lignocellulosic biomass during activation with ionic liquids comprising 3-methylimidazolium cations and carboxylate anions|e-pub date=27/09/2018|date accessed=06/12/2021|url=https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-018-1263-0}}</ref>

==== Subcritical water ====
Subcritical water hydrolysis (SWH), also called h''ydrothermal liquefaction'', ''hydrothermolysis'', or ''aquathe''rmolysis, has potential for breaking down the cellulose and hemicellulose biopolymers into simple sugars and small molecules. The technique uses water at high temperatures and pressures to keep it in a liquid form. SWH can reduce reaction time and thereby degradation product formation, generates less waste water and lower corrosion requirements.<ref>{{Cite journal|title=Subcritical water hydrolysis of sugarcane bagasse: An approach on solid residues characterization|year=2016-02-01|author=D. Lachos-Perez, F. Martinez-Jimenez, C. A. Rezende, G. Tompsett, M. Timko, T. Forster-Carneiro|journal=The Journal of Supercritical Fluids|volume=108|page=69–78|doi=10.1016/j.supflu.2015.10.019}}</ref>

=== Enzymatic hydrolysis ===
Enzymatic hydrolysis is a catalytic decomposition of a chemical compound by reaction with water, such as the conversion of lignocellulosic materials, by the addition of specific enzymes.

==== Cellulase enzymes ====
The hydrolysis of cellulose in native lignocellulosic material is slow and is primarily governed by structural features of the lignocellulosic biomass:

1. cellulose present in biomass possesses highly resistant crystalline structure;

2. lignin surrounding the cellulose forms a physical barrier;

3. The sites available for enzymatic attack are limited.

The cellulose present in lignocellulosic materials is composed of crystalline and amorphous components. The amorphous component is more susceptible to enzymatic attack than the crystalline component. The presence of lignin forms a physical barrier for enzymatic attack; therefore, treatments causing disruption of the lignin seal will increase the accessibility of cellulose to enzyme molecules and eventually its hydrolysis rate. The limitation of available sites for enzymatic attack stems from the fact that the average size of the capillaries in biomass is too small to allow the entry of large enzyme molecules; and thus, enzymatic attack is confined to the external surface [10].

Pretreatment, therefore, is an essential prerequisite to enhance the susceptibility of lignocellulosic materilas to enzyme action. An ideal pretreatment would accomplish reduction in lignin content, concommitant with a reduction in crystallinity, and an increase in surface area. The variety of pretreatments can be classified into physical, chemical, and biological depending on the mode of their action [10].

......

==== Hemicellulase enzymes ====
........

==== Ligninolytic enzymes ====
.... (See reference 11)

=== Biological hydrolysis ===
Lignin degradation can also occur through the action of lignin degrading enzymes secreted by microorganisms (e.g. fungi).

== Product==
Hydrolysis is generally performed on cellulose and hemi-cellulose, which results in different sugars: glucose, mannose, and galactose as C6 sugars, and xylose and arabinose asC5 sugars. Next to these, organic acids are often formed in formic acid and acetic acid.

=== Post-treatment ===
Currently no post-treatment has been identified.

== Technology providers ==
{| class="wikitable sortable mw-collapsible"
|+'''Technology comparison'''
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Company name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Country
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology category
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| TRL
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Capacity [kg/h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Catalyst loading [wt %]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| pH
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Pressure [bar]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Reactor
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Residence time [h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Temperature [°C]
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Food waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Garden & park waste
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
!
!
|-
| [[Hydrolysis#Biorenewables Development Centre|Biorenewables Development Centre]]
| United Kingdom
|
|Pre-treatment vessel
|5
|
|
|
|12
|Stainless vessel grade
|
|< 180
|
|
|-
| [[Hydrolysis#Hysytech S.R.L.|Hysytech S.R.L.]]
| Italy
|
|Compost hydrolysis
|7
|1 m3/h
|
|
|1
|Continuous reactor, Cone bottom
|
|>60
|
|
|-
|[[Hydrolysis#Lule.C3.A5 University of Technology LTU|Luleå University of Technology LTU]]
|Sweden
|
|Organosolv pre-treatment
|6-7
|0,7 l/min (biomass)
|≤0.25 % sulfuric acid
|
|30
|Continuous organosolv reactor
|
|≤ 230 °C
|
|
|-
|[[Hydrolysis#Valmet%20Oyj|Valmet Oyj]]
|Finland
|
|BioTrac
|9
|800 tonne/day
|
|
|
|Horizontal tube reactor
|
|
|
|
|}

=== Biorenewables Development Centre ===
{{Infobox provider-hydrolysis|Company=Biorenewables Development Center|Country=United Kingdom|Image=Cropped-logo1.png|Webpage=http://www.biorenewables.org|Contact=Anna Alessi|Technology name=Pre-treatment vessel|TRL=5|Temperature=up to 180|Processable volume=100|Agitator=variable}}

The Biorenewables Development Centre (BDC) has a range of pre-processing equipment capable of processing a variety of biomass materials. Our custom-made pre-treatment vessel is used for biomass pre-treatments and enzymatic hydrolysis. Our pre-treatmnet vessel is a 100 L stainless steel vessel grade 316L capable of operating at up to 12 bar and around 180 °C, thereby allowing acid, base, peroxide, enzyme, heat, pressure and fibre expansion (aka steam explosion) treatments to be carried out. A variable speed agitator allows for good mixing of the solid and liquid fractions. The vessel is jacketed and heated with Texotherm HT22 oil from an external HTF250e Tricool Thermal Heater. This vessel can be used for the pre-treatment of different types of biomass (e.g. wheat straw, wood and Miscanthus) and the fibre expansion vessel is also capable of doing explosion (i.e. rapid release of the pressure inside the vessel to open the structure of biomass).

=== CENER (ES) ===
{{Infobox provider-hydrolysis|Company=CENER BIO2C|Controlled parameters=Temperature, pressure, pH|Feedstock=High flexibility in feedstocks: lignocellulosic feedstocks such herbaceous and woody, considering as well the OFMSW, agri-food waste.|Other=More info: https://www.bio2c.es/biochemical-unit/|Reactor material=Stainless steel|Safety restrictions=no atex, maximum working pressure 2 bar.|Reactor=High solids enzymatic hydrolysis stirred tank reactor.|Processable volume=200L, 3000L|Temperature=20-80ºC (Ambient temperature up to 130 ºC (sterilizable))|Catalyst=Enzymes|Image=Logo-cener-bio2c-english-1.png|Atmosphere=Environment|Agitator=Coaxial Industrial mixer|Capacity=Enzymes|TRL=6-7|Technology name=BIO2C – Enzymatic Hydrolysis|Webpage=https://www.bio2c.es/pretreatment-unit/|Contact=Goizeder Barberena, info@cener.com|Country=Spain|Product=Hydrolysed product}}
'''CENER Biomass Department''' performs applied research activities in the field of biomass, providing R&D services and technical assistance to all agents of the sector. The area is focused on the development & optimization of production processes of bioproducts, solid biofuels, advanced liquid or gaseous biofuels, as well as biorefinery concepts. Indeed, the main pillars are focused on '''solid biofuels, bioprocesses and comprehensive sustainability assessment'''. The main infrastructures in this department include the '''Biomass Laboratory''' (biomass & biofuels characterization and process development at lab scale), as well as the '''Biorefinery and Bioenergy Centre (BIO2C)'''.

=== Hysytech S.R.L. ===
{{Infobox provider-hydrolysis|Company=Hysytech Srl|Controlled parameters=pH and Temperature|Feedstock=Compost|Safety restrictions=None|Reactor material=Stainless steel|Reactor=Continuous reactor. Cone bottom.|Processable volume=400|Temperature=>60|Atmosphere=Environment|Country=Italy|Catalyst=Base|Capacity=1 m3/h|Agitator=None. Pump recirculation|TRL=7|Technology name=Compost hydrolysis|Webpage=www.hysytech.com|Contact=massimiliano.antonini@hysytech.com; Simone.solaro@hysytech.com; freddy.liendo@hysytech.com|Product=Hydrolyzed product}}

=== Luleå University of Technology LTU ===
{{Infobox provider-hydrolysis|Company=Luleå University of Technology|Country=Sweden|Contact=Tobias Wretborn tobias.wretborn@ltu.se|Image=DownloadLTU.png|Webpage=https://www.ltu.se/|Processable volume=0,7 l/min (biomass)|Controlled parameters=Pressure, Temperature, Time, Solvent concentration, Solvent to biomass ratio|Atmosphere=Saturated, at pressures up to 30 bar|Capacity=0,7 l/min (biomass)|Reactor material=EN 1.4301|Agitator=Hydraulic augers|Temperature=≤ 230 °C|Catalyst=≤0.25 % sulfuric acid|TRL=6-7|Technology name=Organosolv pre-treatment|Product=Cellulose rich pulp, Lignin and Hemicellulose rich process liquor|Feedstock=Lignocellulosic biomass|Reactor=Continuous organosolv reactor|Safety restrictions=not relevant|Other=not relevant}}
Department of Civil, Environmental and Natural Resources Engineering: Humanity faces enormous challenges in the areas of energy, environment, raw materials, water resources and security. By research and education in the areas of mining, civil and environmental engineering, we take responsibility for the development of a sustainable society. We are about 400 people of about 50 nationalities, of which 200 are doctoral students and just over 50 professors. You will find us in the T-pavilion and the C-house on the university campus in Luleå. You will find our Lab activities in the F-house and the C-house. Our research and education are characterized by a strong experimental and applied profile with several large and well-equipped laboratories. All activities are quality assured by our dedicated professors and lecturers in an exclusive and successful collaboration with industry and the public sector. 65% of our research is externally funded and we have well-developed international collaborations with universities in all continents.
=== Valmet Oyj ===
{{Infobox provider-hydrolysis|Company=Valmet Oyj|Webpage=https://www.valmet.com/|Country=Finland|Technology name=BioTrac|Technology category=Chemical processes and technologies|TRL=9|Capacity=biomass feed up to 800 tonne/day|Reactor=Horizontal tube reactor|Temperature=High|Catalyst=Acidic conditions|Feedstock=All lignocellulosic biomass, including wood and forestry residues, wheat straw, corn stover and bagasse}}

== Open access pilot and demo facility providers ==
[https://biopilots4u.eu/database?field_technology_area_data_target_id=107&field_technology_area_target_id%5B85%5D=85&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database]

== Patents ==
Currently no patents have been identified.

== References ==
<references />10. The Nature of Lignocellulosics and Their Pretreatments for Enzymatic Hydrolysis L. T. Fan, Young-Hyun Lee and M. M. Gharpuray Department of Chemical Engineering Kansas State University Manhattan, KS 66506/U.S.A.

11. Enzymatic hydrolysis of lignin by ligninolytic enzymes and analysis of the hydrolyzed lignin products Sitong Zhang, Jianlong Xiao, Gang Wang, Guang Chen
[[Category:Pre-processing]]
[[Category:Technologies]]

Anaerobic digestion

2023-02-06T14:56:50Z

Anna Alessi: /* Biorenewables Development Centre */

{{Infobox technology|Name=Anaerobic digestion|Category=[[Conversion]] ([[Conversion#Biochemical_processes_and_technologies|Biochemical processes and technologies]])|Feedstock=[[Biowaste]] in general, [[Food waste]], [[Garden and park waste]] (wood, leaves)|Product=Biogas and digestate}}
<onlyinclude>'''Anaerobic digestion''' is a process through which micro-organisms break down organic matter, such as animal manure, wastewater biosolids, and food wastes, in the absence of oxygen. Anaerobic digestion intended for biogas production takes place in a sealed tank (called an anaerobic digester), which is designed and constructed in various shapes and sizes specific to the site and feedstock conditions. These sealed vessels contain complex microbial communities that break down the waste and produce biogas and digestate (i.e., the solid and liquid material end-products of the process). The biogas can be used as a source of energy. The remaining digestate can be used as a fertiliser, or it can be post-treated according to its intended use, e.g. by drying or composting to use it as a soil improvement agent.</onlyinclude>

== Feedstock ==
=== Origin and composition ===
Multiple organic materials can be combined in one digester, a practice called co-digestion. Co-digested materials include, amongst others, manure, food waste, energy crops, crop residues, and fats, oils, and greases (FOG) from restaurant grease traps.

=== Pre-treatment ===
Biomass is first separated from impurities as stones and glass. An agitator provides a good mixing between different biomass types to avoid strong changes in composition. The feed is a stirrable mixture and the dry matter content may be a maximum of 15-20% of the slurry. Co-substrates are often reduced in size by shredding before they are fed in order to make the contact surface of the biomass as large as possible.

For residual flows from the food industry, crop residues and manure, thermal and chemical pre-treatments are mainly applied. The most important effects of thermal pre-treatment are: reducing particle size, increasing solubility and improve the biodegradability. Additional advantages of thermal pre-treatment are: (1) higher loading of the digester is possible, (2) lower viscosity of the treated material which results in lower energy input for mixing the digester, (3) improved dewaterability of digestate and (4) sanitised product.

The following pre-treatments may be considered :

* [[Membrane filtration]]
*[[Sieving]]
* [[Sizing]] (e.g. chipping, grinding)
* Thermal pre-treatment

== Process and technologies ==
=== Process ===
There are three basic anaerobic digestion processes, namely psychrophilic, mesophilic, and thermophilic, which take place over different temperature ranges. Psychrophilic digestion is a low temperature (<20°C) process. Mesophilic digestion takes place between 20 and 45°C, which can take a month or two to complete, and thermophilic digestion between 45 and 65°C, which is faster, but its micro-organisms are more sensitive. The majority of the agricultural biogas plants are operated at mesophilic temperatures. Thermophilic temperatures are applied mainly in large-scale centralised biogas plants with co-digestion<ref>{{Cite web|year=2021|title=Anaerobic digestion|e-pub date=2021|date accessed=6/9/2021|url=https://www.eubia.org/cms/wiki-biomass/anaerobic-digestion/}}</ref>. The process of anaerobic digestion takes place through four successive stages: hydrolysis, fermentation, acetogenesis, and methanogenesis.<ref>{{Cite journal|author=Junye Wang|year=2014|title=Decentralized biogas technology of anaerobic digestion and farm ecosystem: opportunities and challenges|journal=Fronties in Energy Research|volume=2|page=|doi=10.3389/fenrg.2014.00010}}</ref> In the hydrolysis step, the feedstock is broken down into soluble substrates (e.g., sugar and amino acids) by enzymes. Fermentation involves the conversion of sugar, amino acids, and fatty acids into ammonia, organic acids, hydrogen (H2) and CO2. In the acetogenesis step, volatile fatty acids are broken down into acetic acids, CO2 and H2. Finally, methanogenesis step converts acetate, formaldeyde, and H2 to CH4 and water<ref>{{Cite journal|author=Jay N. Meegoda, Brian Li, Kush Patel, Lily B. Wang|year=2018|title=A review of the Processes, Parameters, and Optimization of Anaerobic Digestion|journal=International Journal of Environmental Research and Public Health|volume=15|page=|doi=10.3390/ijerph15102224}}</ref>.
[[File:Anaerobic stages.png|thumb|Simplified scheme of pathways in anaerobic digestion (not own work)]]

Usually, the produced biogas must be dried and drained for condense water and biological or chemical cleaned for H2S, NH3 and trace elements. Further upgrading of the biogas to increase the CH4 content could be realized by membrane separation of CO2 and pressurising the biogas.
== Product ==
Anaerobic digestion produces two valuable outputs, namely biogas and digestate. Biogas is composed of methane (CH4), which is the primary component of natural gas, at a relatively high percentage (50 to 75%), carbon dioxide (CO2), hydrogen sulfide (H2S), water vapor, and trace amounts of other gases. The energy in biogas can be used like natural gas to provide heat, generate electricity, and power cooling systems. Biogas can also be purified by removing the inert or low-value constituents (CO2, water, H2S, etc.) to generate renewable natural gas (RNG). This can be sold and injected into the natural gas distribution system, compressed and used as vehicle fuel, or processed further to generate alternative transportation fuel or other advanced biochemicals and bioproducts.

The digestate can be used in many beneficial applications provided that is is appropriately treated post processing. This could be in form of animal bedding, nutreint-rich fertilizer, organic-rich compost, or as soil amendment.

=== Post-treatment ===
The remaining digestate can be post-treated according to its intended use, e.g. by drying or composting to use it as a soil improvement agent.

== Technology providers ==
{| class="wikitable sortable mw-collapsible mw-collapsed"
|+'''Technology comparison'''
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Company name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Country
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology category
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| TRL
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Capacity [kg/h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Processable mass [kg]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Temperature [°C]
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Food waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Garden & park waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Product: biogas
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Product: Renewable natrual gas (RNG)
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
|-
| [[Anaerobic digestion#Biogas Plus|Biogas Plus]]
| The Netherlands
| -
| Compact Plus
| 9
| -
| -
| -
|
|
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|
|-
| [[Anaerobic digestion#BioRenGaz|BioRenGaz]]
| France
| -
| Bioreactor
| 7
| -
| -
| -
|
|
|
|
|-
|[[Anaerobic digestion#Dranco|Dranco]]
|Belgium
|
|DRANCO Dry anaerobic digestion
| -
|5000
| -
| -
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|
|
|
|-
|[[Anaerobic digestion#Planet Biogas|Planet Biogas]]
|Germany
| -
|PlanET
|9
| -
| -
| -
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|
|}

=== Biorenewables Development Centre ===
{{Infobox provider-anaerobic digestion|Company=Biorenewables Development Centre|Country=UK|Image=Cropped-logo1.png|Contact=Deborah Rathbone|Webpage=https://www.biorenewables.org/|Technology name=anaerobic digestion|TRL=4|Feedstock=food waste, agricultural wastes, industrial wastes|Reactor=up to 30L}}

The Biorenewables Development Centre )BDC) has anaerobic digestion (AD) facilities that enables new/potential users of AD to characterise their feedstock to establish its suitability for production of high biomethane yields, and also help existing users of AD systems to test modifications or additions to their system. Our facilities comprise;

* Custom built low (3-5%) and high (~25%) solids contents systems: 30 L reaction volume; pH- and temperature-controlled stirred digester units with integral dewatering system to facilitate the continuous addition of high volumes of dilute feedstocks.
* 24 unit biomethane potential analysis (BMP) system
* Hach Lange BOD Trak II for biochemical oxygen demand (BOD) analysis
* Hach Lange DR3900 spectrophotometer with HT200 high temperature / high speed digestion unit for measurement of chemical oxygen demand (COD), organic acids, nitrogen, chloride etc
* A range of Hewlett Packard and SRI gas chromatography systems (TCD, FPD, FID and Methanizer detection systems) to measure gas composition
* Thermolyne muffle furnace
* Kern moisture balance
* Hach Lange TOC5 shaker
* Hach Lange Titralab AT1000 titration system
* Portable pH, DO and conductivity systems
* Robot Coupe Blixer 10 VV for sample homogenisation
* Gas detection / oxygen depletion detection system

=== Biogas Plus ===
{{Infobox provider-anaerobic digestion|Company=Biogas Plus|Webpage=https://www.biogasplus.nl|Country=The Netherlands|Reactor=Complete mix digester|Capacity=18.000 tons (input), 320.000 Nm3 green gas/year (output).|Feedstock=Animal Manure|Product=Green gas|TRL=9|Technology name=Compact Plus}}
Biogas Plus is a turnkey supplier of biogas installations. This biogas installation produces biogas through the fermentation of organic (residual) flows, such as manure, unpacked food, sewage treatment sludge or other products. The biogas is then upgraded to renewable gas (green gas / biomethane / RNG) or to green electricity and heat. Biogas Plus offers a variety of installation sizes able to meet the needs of a mid-size farm up to large-scale units (between 50.000 and 300.000 tons of input per year).

=== BioRenGaz ===
{{Infobox provider-anaerobic digestion|Company=BioRenGaz|Country=France|Webpage=https://www.biorengaz.com/|Contact=contact@biorengaz.com|Image=BioRenGaz_icone.png|TRL=7|Technology name=Bioreactor}}

BioRenGaz has developed a new patented anaerobic digestion technology that is 4 times more efficient and much more compact than conventional biogas plants thanks to vertical silo design. The anaerobic filter uses a recycled and 100% renewable packing material to replace costly and polluting plastic packing. This medium provides an ecological habitat for the bacteria and enhances their performance. The solution is adapted for the treatment of liquid effluents and the great advantage, unlike other technologies, is that it can also valorize pulpy effluents like biowaste pulp. The bioreactors have lower operational costs and increased energy production by keeping the micro-organisms on the packing material, which allows producing 10% more biogas. The system is modular, so bioreactors can be built from a small scale and easily be expanded as needed. The Solution aims for the optimization of the economic and environmental model of energy and agronomic recovery of biowaste.

=== Dranco ===
{{Infobox provider-anaerobic digestion|Company=DRANCO nv|Country=Belgium|Contact=Bruno Mattheeuws (bm@dranco.be)|Webpage=https://www.dranco.be|TRL=Successful Deployment|Technology name=DRANCO Dry anaerobic digestion|Capacity=>5000|Feedstock=biowaste, SSO, MSW, residual waste, ...|Reactor=2500-5000m³|Image=Logo dranco.png|Product=Digestate and/or high quality compost + biogas}}
DRANCO nv has developed innovative and patented designs for biogas plants, with a pretreatment, digester concept and post-treatment adapted to each type of feedstock. Find out about our 30+ years of experience and our 35 references!

=== PlanET Biogas Group GmbH ===
{{Infobox provider-anaerobic digestion|Company=PlanET Biogas Group GmbH|Webpage=https://www.planet-biogas.com|Country=Germany|Technology name=PlanET|TRL=9|Reactor=Complete mix digester (modular)|Feedstock=Animal manure, biogenic waste materials|Product=Green gas, heat & electricity}}
PlanET anaerobic digestion (AD) plants can convert almost all biogenic waste materials into energy, such as slaughterhouse waste, fish processing residuals, animal carcasses, expired food or off-specification batches used in food production as well as agricultural residues, fats and oils. PlanET Biogas’ portfolio covers the whole range of biogas technology and utilization: feeding technology, safety technology, energy concepts, hygienisation, and gas upgrading. PlanET Biogas offers its technology turn-key and provides all after-sale services including biological assistance as well as service and maintenance for all technical equipment. PlanET Biogas has completed 600 AD plants worldwide, from 40 kW liquid manure systems to 3 MW waste to energy plants.

== Open access pilot and demo facility providers ==
[[File:Pilots4U Database Logo 0.png|thumb]]
Here we make the link to the Europe-wide network & database of open access multipurpose pilot and demo infrastructures for the European bio-economy.

If you are looking for shared facilities that exist for the technology of anaerobic digestion, here is the link to the selection from the Pilots4U database : [https://biopilots4u.eu/database?field_technology_area_data_target_id=101&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database]

== Patents ==
Currently no patents have been identified.

== References ==
<references />

[[Category:Conversion]]
[[Category:Technologies]]

Hydrolysis

2023-02-06T14:50:11Z

Anna Alessi: /* Biorenewables Development Centre BDC */

{{Infobox technology|Name=Hydrolysis|Category=[[Pre-processing]] ([[Pre-processing#Chemical_processes_and_technologies|Chemical processes and technologies]])|Feedstock=Lignocellulosic biomass|Product=Sugars and organic acids}}
<onlyinclude>'''Hydrolysis''' (/haɪˈdrɒlɪsɪs/; from Ancient Greek ''hydro-'' 'water', and ''lysis'' 'to unbind') is a chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions that use water as the reagent.<ref>{{Cite web|year=2002|title=Hydrolysis|e-pub date=2002|date accessed=2021|url=https://en.wikipedia.org/wiki/Hydrolysis|Author=Wikipedia}}</ref> In lignocellulosic biomass, the cellulose and hemicellulose breaks down into individual sugars. Hemicellulose is easier to hydrolyse than cellulose.<ref>{{Cite journal|title=Dilute acid hydrolysis of lignocellulosic biomass|year=2010-01-15|author=P. Lenihan, A. Orozco, E. O’Neill, M.N.M. Ahmad, D.W. Rooney, G.M. Walker|journal=Chemical Engineering Journal|volume=156|issue=2|page=395–403|doi=10.1016/j.cej.2009.10.061}}</ref> The result of hydrolysing hemicellulose and cellulose are sugars (glucose, mannose, galactose, (C6) and xylose, arabinose (C5)) and organic acids (formic acid and acetic acid).<ref>{{Cite journal|title=Acid Hydrolysis of Lignocellulosic Biomass: Sugars and Furfurals Formation|year=2020-04-17|author=Katarzyna Świątek, Stephanie Gaag, Andreas Klier, Andrea Kruse, Jörg Sauer, David Steinbach|journal=Catalysts|volume=10|issue=4|page=437|doi=10.3390/catal10040437}}</ref> </onlyinclude>

== Feedstock ==

=== Origin and composition ===
Hydrolysis can be performed as a pretreatment on any biowaste with a high lignocellulose content. Lignocellulose is typically the nonedible part of a plant, composed of a complex of cellulose, hemi-cellulose and lignin. Suitable feedstocks include grasses, straw, leaves, stems, shells, manure, paper waste, and others. The ratio between cellulose, hemi-cellulose and lignin varies wildly depending on the specific feedstock.<ref name=":1" />

=== Structural features ===

==== Cellulose ====
''Explain structure of cellulose''

==== Hemicellulose ====
''Explain structure of hemi-cellulose''

==== Lignin ====
''Explain structure of Lignin''

== Process and technologies ==

=== Chemical hydrolysis===
Chemical pretreatments have been used extensively for removal of lignin surrounding cellulose and for destroying its crystalline structure. Even though chemical pretreatments are usually effective, they have disadvantages which should not be ignored [10]. These include use of specialized corrosion resistant equipment, need for extensive washing, and disposal of chemical wastes. Various chemical methods are discussed under several headings, namely, alkalis, acids, gases, oxidizing agents, cellulose solvents, extraction, and swelling agents.

==== Acid ====
'''Acid hydrolysis''' is a hydrolysis process in which a protic acid is used to catalyze the hydrolysis reaction. Acids are used mainly for hydrolysis of cellulose [10]. A strong acid, such as formic, hydrochloric, nitric, phosphoric, or sulphuric acid can be used in concentrated or diluted form. '''Concentrated acid''' (10-30 %) can penetrate the lignin structure and break down the cellulose and hemicellulose to individual sugars at low temperature and with high yield. Downsides are the high acid consumption and high corrosion potential. These downsides are circumvented with the use of '''diluted acid''' (2-5 %). However, in the latter case, higher temperature is required, which can lead to side product formation such as furfural and 5-hydroxymethyl-furfural.<ref name=":1">{{Cite book|author=Alessandra Verardi, Isabella De Bari, Emanuele Ricca and Vincenza Calabrò|year=2012|section_title=Hydrolysis of Lignocellulosic Biomass: Current Status of Processes and Technologies and Future Perspectives|editor=Marco Aurelio Pinheiro Lima and Alexandra Pardo Policastro Natalense|book_title=Bioethanol|publisher=IntechOpen}}</ref>

Acid hydrolysis can be further improved by the addition of salts, such as metal salts or suphite salts. Metals such as aluminium, calcium, copper, iron and zincnc can be used to increase the sugar yield [6]. Similar to [[Pulping and fractionation#Sulphite pulping|sulphite pulping]], sulphites can be added to aid in lignin removal.

===== Sulfuric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Hydrochloric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Phosphoric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

==== Alkali ====
'''Alkaline hydrolysis''' refers to hydrolysis reactions using hydroxide, commonly from sodium hydroxide or calcium hydroxide. The hydroxide breaks down the lignin bonds to make the cellulose more accessible. The reaction proceeds at lower temperature and pressure and residual alkali can be recycled. However, the pretreatment does result in irrecoverable salts in the product.<ref>{{Cite journal|title=Pretreatment of lignocellulosic sugarcane leaves and tops for bioethanol production|year=2020-01-01|journal=Lignocellulosic Biomass to Liquid Biofuels|page=301–324|doi=10.1016/B978-0-12-815936-1.00010-1|author=S. Niju, M. Swathika, M. Balajii|volume=}}</ref>

===== Sodium hydroxide =====
Dilute sodium hydroxide (NaOH) treatment of lignocellulosic material causes swelling, leading to an increase in internal surface area, decrease in the degree of polymerization, decrease in crystallinity, separation of structural linkages between lignin and carbohydrates, and disruption of the lignin structure [10].

''Elaborate more the reactions conditions and give some examples from literature.''

===== '''Ammonia''' =====
Liquid or gaseous ammonia acts as a strong swelling agent for cellulose [1].

''Elaborate more the reactions conditions and give some examples from literature.''

===== Ammonium sulfite =====
Ammonium sulfite is used mainly in a conventional pulping process.

''Elaborate more the reactions conditions and give some examples from literature.''

==== Solvent ====
Solvents can be added to improve the hydrolysis process. This is similar to [[Pulping#Dissolving pulp and organosolv|organosolv pulping]], but without the delignification as goal.<ref name=":2">{{Cite journal|title=Biomass pretreatment: Fundamentals toward application|year=2011-11|author=Valery B. Agbor, Nazim Cicek, Richard Sparling, Alex Berlin, David B. Levin|journal=Biotechnology Advances|volume=29|issue=6|page=675–685|doi=10.1016/j.biotechadv.2011.05.005}}</ref>

===== Organosolv (lignin hydrolysis) =====
Organosolv pretreatment is the process to extract lignin from lignocellulosic feedstocks with organic solvents or their aqueous solutions.

In an '''organosolv hydrolysis''' organic solvents are added to the process, usually performed at high temperatures (100-250 °C). This can be combined with a catalyst such as HCl or H2SO4.<ref name=":2" /> For example, in '''acid-acetone''' pre-treatment biowaste is treated with an acid such as phophoric acid and then mixed with pre-cooled acetone.<ref name=":0">{{Cite journal|title=A comprehensive review on pre-treatment strategy for lignocellulosic food industry waste: Challenges and opportunities|year=2016-01-01|journal=Bioresource Technology|volume=199|page=92–102|doi=10.1016/j.biortech.2015.07.106|author=Amit K. Jaiswal, Rajeev Ravindran}}</ref>

===== Ionic Liquids=====
Ionic liquids are '''solvents''' that can be used for biomass pretreatment, fractionation, and dissolution. During ionic liquid pretreatment, a cellulose-rich fraction can be generated through the degradation and removal of a large portion of lignin and hemicellulose <ref>{{Cite web|Author=Moyer, P., Kim, K., Abdoulmoumine, N. et al.|year=2018|title=Structural changes in lignocellulosic biomass during activation with ionic liquids comprising 3-methylimidazolium cations and carboxylate anions|e-pub date=27/09/2018|date accessed=06/12/2021|url=https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-018-1263-0}}</ref>

==== Subcritical water ====
Subcritical water hydrolysis (SWH), also called h''ydrothermal liquefaction'', ''hydrothermolysis'', or ''aquathe''rmolysis, has potential for breaking down the cellulose and hemicellulose biopolymers into simple sugars and small molecules. The technique uses water at high temperatures and pressures to keep it in a liquid form. SWH can reduce reaction time and thereby degradation product formation, generates less waste water and lower corrosion requirements.<ref>{{Cite journal|title=Subcritical water hydrolysis of sugarcane bagasse: An approach on solid residues characterization|year=2016-02-01|author=D. Lachos-Perez, F. Martinez-Jimenez, C. A. Rezende, G. Tompsett, M. Timko, T. Forster-Carneiro|journal=The Journal of Supercritical Fluids|volume=108|page=69–78|doi=10.1016/j.supflu.2015.10.019}}</ref>

=== Enzymatic hydrolysis ===
Enzymatic hydrolysis is a catalytic decomposition of a chemical compound by reaction with water, such as the conversion of lignocellulosic materials, by the addition of specific enzymes.

==== Cellulase enzymes ====
The hydrolysis of cellulose in native lignocellulosic material is slow and is primarily governed by structural features of the lignocellulosic biomass:

1. cellulose present in biomass possesses highly resistant crystalline structure;

2. lignin surrounding the cellulose forms a physical barrier;

3. The sites available for enzymatic attack are limited.

The cellulose present in lignocellulosic materials is composed of crystalline and amorphous components. The amorphous component is more susceptible to enzymatic attack than the crystalline component. The presence of lignin forms a physical barrier for enzymatic attack; therefore, treatments causing disruption of the lignin seal will increase the accessibility of cellulose to enzyme molecules and eventually its hydrolysis rate. The limitation of available sites for enzymatic attack stems from the fact that the average size of the capillaries in biomass is too small to allow the entry of large enzyme molecules; and thus, enzymatic attack is confined to the external surface [10].

Pretreatment, therefore, is an essential prerequisite to enhance the susceptibility of lignocellulosic materilas to enzyme action. An ideal pretreatment would accomplish reduction in lignin content, concommitant with a reduction in crystallinity, and an increase in surface area. The variety of pretreatments can be classified into physical, chemical, and biological depending on the mode of their action [10].

......

==== Hemicellulase enzymes ====
........

==== Ligninolytic enzymes ====
.... (See reference 11)

=== Biological hydrolysis ===
Lignin degradation can also occur through the action of lignin degrading enzymes secreted by microorganisms (e.g. fungi).

== Product==
Hydrolysis is generally performed on cellulose and hemi-cellulose, which results in different sugars: glucose, mannose, and galactose as C6 sugars, and xylose and arabinose asC5 sugars. Next to these, organic acids are often formed in formic acid and acetic acid.

=== Post-treatment ===
Currently no post-treatment has been identified.

== Technology providers ==
{| class="wikitable sortable mw-collapsible mw-collapsed"
|+'''Technology comparison'''
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Company name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Country
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology category
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| TRL
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Capacity [kg/h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Catalyst loading [wt %]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| pH
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Pressure [bar]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Reactor
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Residence time [h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Temperature [°C]
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Food waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Garden & park waste
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
!
!
|-
| [[Hydrolysis#Biorenewables Development Centre BDC|Biorenewables Development Centre BDC]]
| United Kingdom
|
|Pre-treatment vessel
|5
|
|
|
|12
|Stainless vessel grade
|
|< 180
|
|
|-
| [[Hydrolysis#Hysytech S.R.L.|Hysytech S.R.L.]]
| Italy
|
|Compost hydrolysis
|7
|1 m3/h
|
|
|1
|Continuous reactor, Cone bottom
|
|>60
|
|
|-
|[[Hydrolysis#Lule.C3.A5 University of Technology LTU|Luleå University of Technology LTU]]
|Sweden
|
|Organosolv pre-treatment
|6-7
|0,7 l/min (biomass)
|≤0.25 % sulfuric acid
|
|30
|Continuous organosolv reactor
|
|≤ 230 °C
|
|
|-
|[[Hydrolysis#Valmet%20Oyj|Valmet Oyj]]
|Finland
|
|BioTrac
|9
|800 tonne/day
|
|
|
|Horizontal tube reactor
|
|
|
|
|}

=== Biorenewables Development Centre ===
{{Infobox provider-hydrolysis|Company=Biorenewables Development Center|Country=United Kingdom|Image=Cropped-logo1.png|Webpage=http://www.biorenewables.org|Contact=Mark Gronnow|Technology name=Pre-treatment vessel|TRL=5|Temperature=up to 180|Processable volume=100|Agitator=variable}}

The Biorenewables Development Centre (BDC) has a range of pre-processing equipment capable of processing a variety of biomass materials. Our custom-made pre-treatment vessel is used for biomass pre-treatments and enzymatic hydrolysis. Our pre-treatmnet vessel is a 100 L stainless steel vessel grade 316L capable of operating at up to 12 bar and around 180 °C, thereby allowing acid, base, peroxide, enzyme, heat, pressure and fibre expansion (aka steam explosion) treatments to be carried out. A variable speed agitator allows for good mixing of the solid and liquid fractions. The vessel is jacketed and heated with Texotherm HT22 oil from an external HTF250e Tricool Thermal Heater. This vessel can be used for the pre-treatment of different types of biomass (e.g. wheat straw, wood and Miscanthus) and the fibre expansion vessel is also capable of doing explosion (i.e. rapid release of the pressure inside the vessel to open the structure of biomass).

=== Hysytech S.R.L. ===
{{Infobox provider-hydrolysis|Company=Hysytech Srl|Controlled parameters=pH and Temperature|Feedstock=Compost|Safety restrictions=None|Reactor material=Stainless steel|Reactor=Continuous reactor. Cone bottom.|Processable volume=400|Temperature=>60|Atmosphere=Environment|Country=Italy|Catalyst=Base|Capacity=1 m3/h|Agitator=None. Pump recirculation|TRL=7|Technology name=Compost hydrolysis|Webpage=www.hysytech.com|Contact=massimiliano.antonini@hysytech.com; Simone.solaro@hysytech.com; freddy.liendo@hysytech.com|Product=Hydrolyzed product}}

=== Luleå University of Technology LTU ===
{{Infobox provider-hydrolysis|Company=Luleå University of Technology|Country=Sweden|Contact=Tobias Wretborn tobias.wretborn@ltu.se|Image=DownloadLTU.png|Webpage=https://www.ltu.se/|Processable volume=0,7 l/min (biomass)|Controlled parameters=Pressure, Temperature, Time, Solvent concentration, Solvent to biomass ratio|Atmosphere=Saturated, at pressures up to 30 bar|Capacity=0,7 l/min (biomass)|Reactor material=EN 1.4301|Agitator=Hydraulic augers|Temperature=≤ 230 °C|Catalyst=≤0.25 % sulfuric acid|TRL=6-7|Technology name=Organosolv pre-treatment|Product=Cellulose rich pulp, Lignin and Hemicellulose rich process liquor|Feedstock=Lignocellulosic biomass|Reactor=Continuous organosolv reactor|Safety restrictions=not relevant|Other=not relevant}}
Department of Civil, Environmental and Natural Resources Engineering: Humanity faces enormous challenges in the areas of energy, environment, raw materials, water resources and security. By research and education in the areas of mining, civil and environmental engineering, we take responsibility for the development of a sustainable society. We are about 400 people of about 50 nationalities, of which 200 are doctoral students and just over 50 professors. You will find us in the T-pavilion and the C-house on the university campus in Luleå. You will find our Lab activities in the F-house and the C-house. Our research and education are characterized by a strong experimental and applied profile with several large and well-equipped laboratories. All activities are quality assured by our dedicated professors and lecturers in an exclusive and successful collaboration with industry and the public sector. 65% of our research is externally funded and we have well-developed international collaborations with universities in all continents.
=== Valmet Oyj ===
{{Infobox provider-hydrolysis|Company=Valmet Oyj|Webpage=https://www.valmet.com/|Country=Finland|Technology name=BioTrac|Technology category=Chemical processes and technologies|TRL=9|Capacity=biomass feed up to 800 tonne/day|Reactor=Horizontal tube reactor|Temperature=High|Catalyst=Acidic conditions|Feedstock=All lignocellulosic biomass, including wood and forestry residues, wheat straw, corn stover and bagasse}}

== Open access pilot and demo facility providers ==
[https://biopilots4u.eu/database?field_technology_area_data_target_id=107&field_technology_area_target_id%5B85%5D=85&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database]

== Patents ==
Currently no patents have been identified.

== References ==
<references />10. The Nature of Lignocellulosics and Their Pretreatments for Enzymatic Hydrolysis L. T. Fan, Young-Hyun Lee and M. M. Gharpuray Department of Chemical Engineering Kansas State University Manhattan, KS 66506/U.S.A.

11. Enzymatic hydrolysis of lignin by ligninolytic enzymes and analysis of the hydrolyzed lignin products Sitong Zhang, Jianlong Xiao, Gang Wang, Guang Chen
[[Category:Pre-processing]]
[[Category:Technologies]]

Hydrolysis

2023-02-06T14:45:26Z

Anna Alessi: /* Biorenewables Development Centre BDC */

{{Infobox technology|Name=Hydrolysis|Category=[[Pre-processing]] ([[Pre-processing#Chemical_processes_and_technologies|Chemical processes and technologies]])|Feedstock=Lignocellulosic biomass|Product=Sugars and organic acids}}
<onlyinclude>'''Hydrolysis''' (/haɪˈdrɒlɪsɪs/; from Ancient Greek ''hydro-'' 'water', and ''lysis'' 'to unbind') is a chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions that use water as the reagent.<ref>{{Cite web|year=2002|title=Hydrolysis|e-pub date=2002|date accessed=2021|url=https://en.wikipedia.org/wiki/Hydrolysis|Author=Wikipedia}}</ref> In lignocellulosic biomass, the cellulose and hemicellulose breaks down into individual sugars. Hemicellulose is easier to hydrolyse than cellulose.<ref>{{Cite journal|title=Dilute acid hydrolysis of lignocellulosic biomass|year=2010-01-15|author=P. Lenihan, A. Orozco, E. O’Neill, M.N.M. Ahmad, D.W. Rooney, G.M. Walker|journal=Chemical Engineering Journal|volume=156|issue=2|page=395–403|doi=10.1016/j.cej.2009.10.061}}</ref> The result of hydrolysing hemicellulose and cellulose are sugars (glucose, mannose, galactose, (C6) and xylose, arabinose (C5)) and organic acids (formic acid and acetic acid).<ref>{{Cite journal|title=Acid Hydrolysis of Lignocellulosic Biomass: Sugars and Furfurals Formation|year=2020-04-17|author=Katarzyna Świątek, Stephanie Gaag, Andreas Klier, Andrea Kruse, Jörg Sauer, David Steinbach|journal=Catalysts|volume=10|issue=4|page=437|doi=10.3390/catal10040437}}</ref> </onlyinclude>

== Feedstock ==

=== Origin and composition ===
Hydrolysis can be performed as a pretreatment on any biowaste with a high lignocellulose content. Lignocellulose is typically the nonedible part of a plant, composed of a complex of cellulose, hemi-cellulose and lignin. Suitable feedstocks include grasses, straw, leaves, stems, shells, manure, paper waste, and others. The ratio between cellulose, hemi-cellulose and lignin varies wildly depending on the specific feedstock.<ref name=":1" />

=== Structural features ===

==== Cellulose ====
''Explain structure of cellulose''

==== Hemicellulose ====
''Explain structure of hemi-cellulose''

==== Lignin ====
''Explain structure of Lignin''

== Process and technologies ==

=== Chemical hydrolysis===
Chemical pretreatments have been used extensively for removal of lignin surrounding cellulose and for destroying its crystalline structure. Even though chemical pretreatments are usually effective, they have disadvantages which should not be ignored [10]. These include use of specialized corrosion resistant equipment, need for extensive washing, and disposal of chemical wastes. Various chemical methods are discussed under several headings, namely, alkalis, acids, gases, oxidizing agents, cellulose solvents, extraction, and swelling agents.

==== Acid ====
'''Acid hydrolysis''' is a hydrolysis process in which a protic acid is used to catalyze the hydrolysis reaction. Acids are used mainly for hydrolysis of cellulose [10]. A strong acid, such as formic, hydrochloric, nitric, phosphoric, or sulphuric acid can be used in concentrated or diluted form. '''Concentrated acid''' (10-30 %) can penetrate the lignin structure and break down the cellulose and hemicellulose to individual sugars at low temperature and with high yield. Downsides are the high acid consumption and high corrosion potential. These downsides are circumvented with the use of '''diluted acid''' (2-5 %). However, in the latter case, higher temperature is required, which can lead to side product formation such as furfural and 5-hydroxymethyl-furfural.<ref name=":1">{{Cite book|author=Alessandra Verardi, Isabella De Bari, Emanuele Ricca and Vincenza Calabrò|year=2012|section_title=Hydrolysis of Lignocellulosic Biomass: Current Status of Processes and Technologies and Future Perspectives|editor=Marco Aurelio Pinheiro Lima and Alexandra Pardo Policastro Natalense|book_title=Bioethanol|publisher=IntechOpen}}</ref>

Acid hydrolysis can be further improved by the addition of salts, such as metal salts or suphite salts. Metals such as aluminium, calcium, copper, iron and zincnc can be used to increase the sugar yield [6]. Similar to [[Pulping and fractionation#Sulphite pulping|sulphite pulping]], sulphites can be added to aid in lignin removal.

===== Sulfuric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Hydrochloric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

===== Phosphoric acid =====
''Elaborate more the reactions conditions and give some examples from literature.''

==== Alkali ====
'''Alkaline hydrolysis''' refers to hydrolysis reactions using hydroxide, commonly from sodium hydroxide or calcium hydroxide. The hydroxide breaks down the lignin bonds to make the cellulose more accessible. The reaction proceeds at lower temperature and pressure and residual alkali can be recycled. However, the pretreatment does result in irrecoverable salts in the product.<ref>{{Cite journal|title=Pretreatment of lignocellulosic sugarcane leaves and tops for bioethanol production|year=2020-01-01|journal=Lignocellulosic Biomass to Liquid Biofuels|page=301–324|doi=10.1016/B978-0-12-815936-1.00010-1|author=S. Niju, M. Swathika, M. Balajii|volume=}}</ref>

===== Sodium hydroxide =====
Dilute sodium hydroxide (NaOH) treatment of lignocellulosic material causes swelling, leading to an increase in internal surface area, decrease in the degree of polymerization, decrease in crystallinity, separation of structural linkages between lignin and carbohydrates, and disruption of the lignin structure [10].

''Elaborate more the reactions conditions and give some examples from literature.''

===== '''Ammonia''' =====
Liquid or gaseous ammonia acts as a strong swelling agent for cellulose [1].

''Elaborate more the reactions conditions and give some examples from literature.''

===== Ammonium sulfite =====
Ammonium sulfite is used mainly in a conventional pulping process.

''Elaborate more the reactions conditions and give some examples from literature.''

==== Solvent ====
Solvents can be added to improve the hydrolysis process. This is similar to [[Pulping#Dissolving pulp and organosolv|organosolv pulping]], but without the delignification as goal.<ref name=":2">{{Cite journal|title=Biomass pretreatment: Fundamentals toward application|year=2011-11|author=Valery B. Agbor, Nazim Cicek, Richard Sparling, Alex Berlin, David B. Levin|journal=Biotechnology Advances|volume=29|issue=6|page=675–685|doi=10.1016/j.biotechadv.2011.05.005}}</ref>

===== Organosolv (lignin hydrolysis) =====
Organosolv pretreatment is the process to extract lignin from lignocellulosic feedstocks with organic solvents or their aqueous solutions.

In an '''organosolv hydrolysis''' organic solvents are added to the process, usually performed at high temperatures (100-250 °C). This can be combined with a catalyst such as HCl or H2SO4.<ref name=":2" /> For example, in '''acid-acetone''' pre-treatment biowaste is treated with an acid such as phophoric acid and then mixed with pre-cooled acetone.<ref name=":0">{{Cite journal|title=A comprehensive review on pre-treatment strategy for lignocellulosic food industry waste: Challenges and opportunities|year=2016-01-01|journal=Bioresource Technology|volume=199|page=92–102|doi=10.1016/j.biortech.2015.07.106|author=Amit K. Jaiswal, Rajeev Ravindran}}</ref>

===== Ionic Liquids=====
Ionic liquids are '''solvents''' that can be used for biomass pretreatment, fractionation, and dissolution. During ionic liquid pretreatment, a cellulose-rich fraction can be generated through the degradation and removal of a large portion of lignin and hemicellulose <ref>{{Cite web|Author=Moyer, P., Kim, K., Abdoulmoumine, N. et al.|year=2018|title=Structural changes in lignocellulosic biomass during activation with ionic liquids comprising 3-methylimidazolium cations and carboxylate anions|e-pub date=27/09/2018|date accessed=06/12/2021|url=https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-018-1263-0}}</ref>

==== Subcritical water ====
Subcritical water hydrolysis (SWH), also called h''ydrothermal liquefaction'', ''hydrothermolysis'', or ''aquathe''rmolysis, has potential for breaking down the cellulose and hemicellulose biopolymers into simple sugars and small molecules. The technique uses water at high temperatures and pressures to keep it in a liquid form. SWH can reduce reaction time and thereby degradation product formation, generates less waste water and lower corrosion requirements.<ref>{{Cite journal|title=Subcritical water hydrolysis of sugarcane bagasse: An approach on solid residues characterization|year=2016-02-01|author=D. Lachos-Perez, F. Martinez-Jimenez, C. A. Rezende, G. Tompsett, M. Timko, T. Forster-Carneiro|journal=The Journal of Supercritical Fluids|volume=108|page=69–78|doi=10.1016/j.supflu.2015.10.019}}</ref>

=== Enzymatic hydrolysis ===
Enzymatic hydrolysis is a catalytic decomposition of a chemical compound by reaction with water, such as the conversion of lignocellulosic materials, by the addition of specific enzymes.

==== Cellulase enzymes ====
The hydrolysis of cellulose in native lignocellulosic material is slow and is primarily governed by structural features of the lignocellulosic biomass:

1. cellulose present in biomass possesses highly resistant crystalline structure;

2. lignin surrounding the cellulose forms a physical barrier;

3. The sites available for enzymatic attack are limited.

The cellulose present in lignocellulosic materials is composed of crystalline and amorphous components. The amorphous component is more susceptible to enzymatic attack than the crystalline component. The presence of lignin forms a physical barrier for enzymatic attack; therefore, treatments causing disruption of the lignin seal will increase the accessibility of cellulose to enzyme molecules and eventually its hydrolysis rate. The limitation of available sites for enzymatic attack stems from the fact that the average size of the capillaries in biomass is too small to allow the entry of large enzyme molecules; and thus, enzymatic attack is confined to the external surface [10].

Pretreatment, therefore, is an essential prerequisite to enhance the susceptibility of lignocellulosic materilas to enzyme action. An ideal pretreatment would accomplish reduction in lignin content, concommitant with a reduction in crystallinity, and an increase in surface area. The variety of pretreatments can be classified into physical, chemical, and biological depending on the mode of their action [10].

......

==== Hemicellulase enzymes ====
........

==== Ligninolytic enzymes ====
.... (See reference 11)

=== Biological hydrolysis ===
Lignin degradation can also occur through the action of lignin degrading enzymes secreted by microorganisms (e.g. fungi).

== Product==
Hydrolysis is generally performed on cellulose and hemi-cellulose, which results in different sugars: glucose, mannose, and galactose as C6 sugars, and xylose and arabinose asC5 sugars. Next to these, organic acids are often formed in formic acid and acetic acid.

=== Post-treatment ===
Currently no post-treatment has been identified.

== Technology providers ==
{| class="wikitable sortable mw-collapsible mw-collapsed"
|+'''Technology comparison'''
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Company name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Country
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology category
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| TRL
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Capacity [kg/h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Catalyst loading [wt %]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| pH
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Pressure [bar]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Reactor
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Residence time [h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Temperature [°C]
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Food waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Garden & park waste
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
!
!
|-
| [[Hydrolysis#Biorenewables Development Centre BDC|Biorenewables Development Centre BDC]]
| United Kingdom
|
|
|
|
|
|
|
|
|
|
|
|
|-
| [[Hydrolysis#Hysytech S.R.L.|Hysytech S.R.L.]]
| Italy
|
|Compost hydrolysis
|7
|1 m3/h
|
|
|1
|Continuous reactor, Cone bottom
|
|>60
|
|
|-
|[[Hydrolysis#Lule.C3.A5 University of Technology LTU|Luleå University of Technology LTU]]
|Sweden
|
|Organosolv pre-treatment
|6-7
|0,7 l/min (biomass)
|≤0.25 % sulfuric acid
|
|30
|Continuous organosolv reactor
|
|≤ 230 °C
|
|
|-
|[[Hydrolysis#Valmet%20Oyj|Valmet Oyj]]
|Finland
|
|BioTrac
|9
|800 tonne/day
|
|
|
|Horizontal tube reactor
|
|
|
|
|}

=== Biorenewables Development Centre BDC ===
{{Infobox provider-hydrolysis|Company=Biorenewables Development Center|Country=United Kingdom|Image=Cropped-logo1.png|Webpage=http://www.biorenewables.org|Reactor material=not relevant|Contact=Mark Gronnow|Technology name=Pre-treatment vessel|TRL=5|Capacity=316|Atmosphere=|Temperature=up to 180|Processable volume=100|Agitator=variable}}

The Biorenewables Development Centre (BDC) has a range of pre-processing equipment capable of processing a variety of biomass materials. Our custom-made pre-treatment vessel is used for biomass pre-treatments and enzymatic hydrolysis. Our pre-treatmnet vessel is a 100 L stainless steel vessel grade 316L capable of operating at up to 12 bar and around 180 °C, thereby allowing acid, base, peroxide, enzyme, heat, pressure and fibre expansion (aka steam explosion) treatments to be carried out. A variable speed agitator allows for good mixing of the solid and liquid fractions. The vessel is jacketed and heated with Texotherm HT22 oil from an external HTF250e Tricool Thermal Heater. This vessel can be used for the pre-treatment of different types of biomass (e.g. wheat straw, wood and Miscanthus) and the fibre expansion vessel is also capable of doing explosion (i.e. rapid release of the pressure inside the vessel to open the structure of biomass).

=== Hysytech S.R.L. ===
{{Infobox provider-hydrolysis|Company=Hysytech Srl|Controlled parameters=pH and Temperature|Feedstock=Compost|Safety restrictions=None|Reactor material=Stainless steel|Reactor=Continuous reactor. Cone bottom.|Processable volume=400|Temperature=>60|Atmosphere=Environment|Country=Italy|Catalyst=Base|Capacity=1 m3/h|Agitator=None. Pump recirculation|TRL=7|Technology name=Compost hydrolysis|Webpage=www.hysytech.com|Contact=massimiliano.antonini@hysytech.com; Simone.solaro@hysytech.com; freddy.liendo@hysytech.com|Product=Hydrolyzed product}}

=== Luleå University of Technology LTU ===
{{Infobox provider-hydrolysis|Company=Luleå University of Technology|Country=Sweden|Contact=Tobias Wretborn tobias.wretborn@ltu.se|Image=DownloadLTU.png|Webpage=https://www.ltu.se/|Processable volume=0,7 l/min (biomass)|Controlled parameters=Pressure, Temperature, Time, Solvent concentration, Solvent to biomass ratio|Atmosphere=Saturated, at pressures up to 30 bar|Capacity=0,7 l/min (biomass)|Reactor material=EN 1.4301|Agitator=Hydraulic augers|Temperature=≤ 230 °C|Catalyst=≤0.25 % sulfuric acid|TRL=6-7|Technology name=Organosolv pre-treatment|Product=Cellulose rich pulp, Lignin and Hemicellulose rich process liquor|Feedstock=Lignocellulosic biomass|Reactor=Continuous organosolv reactor|Safety restrictions=not relevant|Other=not relevant}}
Department of Civil, Environmental and Natural Resources Engineering: Humanity faces enormous challenges in the areas of energy, environment, raw materials, water resources and security. By research and education in the areas of mining, civil and environmental engineering, we take responsibility for the development of a sustainable society. We are about 400 people of about 50 nationalities, of which 200 are doctoral students and just over 50 professors. You will find us in the T-pavilion and the C-house on the university campus in Luleå. You will find our Lab activities in the F-house and the C-house. Our research and education are characterized by a strong experimental and applied profile with several large and well-equipped laboratories. All activities are quality assured by our dedicated professors and lecturers in an exclusive and successful collaboration with industry and the public sector. 65% of our research is externally funded and we have well-developed international collaborations with universities in all continents.
=== Valmet Oyj ===
{{Infobox provider-hydrolysis|Company=Valmet Oyj|Webpage=https://www.valmet.com/|Country=Finland|Technology name=BioTrac|Technology category=Chemical processes and technologies|TRL=9|Capacity=biomass feed up to 800 tonne/day|Reactor=Horizontal tube reactor|Temperature=High|Catalyst=Acidic conditions|Feedstock=All lignocellulosic biomass, including wood and forestry residues, wheat straw, corn stover and bagasse}}

== Open access pilot and demo facility providers ==
[https://biopilots4u.eu/database?field_technology_area_data_target_id=107&field_technology_area_target_id%5B85%5D=85&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database]

== Patents ==
Currently no patents have been identified.

== References ==
<references />10. The Nature of Lignocellulosics and Their Pretreatments for Enzymatic Hydrolysis L. T. Fan, Young-Hyun Lee and M. M. Gharpuray Department of Chemical Engineering Kansas State University Manhattan, KS 66506/U.S.A.

11. Enzymatic hydrolysis of lignin by ligninolytic enzymes and analysis of the hydrolyzed lignin products Sitong Zhang, Jianlong Xiao, Gang Wang, Guang Chen
[[Category:Pre-processing]]
[[Category:Technologies]]

Microwave treatment

2023-02-06T14:38:42Z

Anna Alessi: /* Biorenewables Development Centre */

{{Infobox technology
| Feedstock = [[Food and kitchen waste]] (lignocellulosic materials), [[Garden and park waste]] (lignocellulosic materials)
| Product =Fermentable sugar
|Name=Microwave pre-treatment|Category=[[Pre-processing]] ([[Pre-processing#Physical_processes_and_technologies|Physical processes and technologies]]), [[Post-processing]] ([[Post-processing#Physical_processes_and_technologies|Physical processes and technologies]])}}
<onlyinclude>For '''microwave''' (MW) treatment electromagnetic radiation is used to induce thermal and non-thermal effects that drive physical, chemical or biological reactions<ref name=":0">{{Cite journal|author=Ethaib, S., Omar, R., Kamal, S. M. M., Biak, D. R. A.|year=2015|title=MICROWAVE-ASSISTED PRETREATMENT OF LIGNOCELLULOSICBIOMASS: A REVIEW|journal=Journal of Engineering Science and Technology|volume=January (2015)|page=97-109}}</ref>. As a rapid and effective heating source with both thermal and non-thermal effects, MW can directly interact with the material, thereby accelerating chemical, physical, and biologic reactions.<ref>{{Cite book|author=Jian Xu|year=2014|section_title=Microwave Pretreatment|editor=Ashok Pandey, Sangeeta Negi, Parmeswaran Binod, Christian Larroche|book_title=Pretreatment of Biomass: Processes and Technologies|publisher=Elsevier|place=Amsterdam}}</ref> Microwave treatment causes a rise in the temperature within a penetrated medium as a result of rapid changes of the electromagnetic field at high frequency.<ref>{{Cite book|author=Anthony R. Bird, Amparo Lopez-Rubio, Ashok K. Shrestha, Michael J. Gidley|year=2009|section_title=Resistant Starch in Vitro and in Vivo: Factors Determining Yield, Structure, and Physiological Relevance|editor=Stefan Kasapis, Ian T. Norton, Johan B. Ubbink|book_title=Modern Biopolymer Science|publisher=Elsevier|place=Amsterdam|ISBN=978-0-12-374195-0}}</ref> The technology is usually applied in food drying or to break down the structure of lignocellulosic biowaste leading to the release of different substances, such as fermentable sugars. </onlyinclude>

==Feedstock==
===Origin and composition===
Microwave irradiation has been successfully used in the pretreatment of several biowaste streams, including agricultural residues, woody biomass, grass, energy plants, and industrial residuals.<ref>{{Cite book|author=Ashok Pandey, Sangeeta Negi, Parameswaran Binod, Christian Larroche|year=2014|section_title=Chapter 9 - Microwave Pretreatment|book_title=Pretreatment of biomass : processes and technologies|publisher=Elsevier BV|place=Amsterdam|ISBN=978-0-12-800396-1}}</ref>
=== Pre-treatment ===

*[[Sizing]]
**[[Sizing#Chipping|Chipping]]
**[[Sizing#Grinding|Grinding]]

==Process and technologies==
The breakdown of lignocellulosic biomass into its monomers and oligomers is induced via molecular collision due to dielectric polarisation<ref name=":1">{{Cite journal|title=Microwave heating processing as alternative of pretreatment in second-generation biorefinery: An overview|year=2017-03|author=Alejandra Aguilar-Reynosa, Aloia Romaní, Rosa Ma. Rodríguez-Jasso, Cristóbal N. Aguilar, Gil Garrote, Héctor A. Ruiz|journal=Energy Conversion and Management|volume=136|page=50–65|doi=10.1016/j.enconman.2017.01.004}}</ref>. Compared to other thermal treatments, the technology brings several advantages, such as reduced plant footprint, higher throughput, higher reaction rates, as well as higher yield and purity<ref name=":0" />. However, a disadvantage is the unequal distribution of the applied microwave power through non-homogeneous material (such as differences in composition, geometry, or size) as well as local overheating through resonance (electromagnetic wave reflection and formation of standing waves) and low penetration for bulk materials <ref name=":1" />.

The process can also be combined with chemicals such as [[Hydrolysis#Alkali|alkaline]] (to remove lignin), [[Hydrolysis#Acid Acid|acid]] (to remove hemicellulose), ammonia, and [[Hydrolysis#Metal_salts|metal salts]]<ref name=":0" />.

==Product==
*Fermentable sugar (e.g. for bio-alcohol production)

=== Post-treatment ===

* [[Industrial fermentation]]
* [[Solid state fermentation]]

==Technology providers==
{| class="wikitable sortable mw-collapsible mw-collapsed"
|+'''Technology comparison'''
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Company name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Country
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology category
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology name
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| TRL
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Capacity [kg/h]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Temperature [°C]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Frequency [GHz]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Power [W]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Penetration depth [cm]
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Processable volume [L]
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Food waste
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Feedstock: Garden & park waste
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
!
|-
| [[Microwave treatment#Biorenewables%20Development%20Centre|Biorenewables Development Centre]]
|United Kingdom
| -
| -
| -
| -
| -
| -
| -
| -
| -
|
|
|-
| [[Microwave treatment#Biowave Technologies|Biowave Technologies]]
| Ireland
| -
| Microwave pre-treatment
| 7
|500-8000
| -
|0.915
|30000-300000
| -
|500-8000
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|-
|[[Microwave treatment#Endeavour%20Energia%20Srl|Endeavour Energia Srl]]
|Italy
| -
|Endeavour Microwave Gasification
|6
|100
|>1400
| -
|100000-200000
|
| -
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|-
|[[Microwave treatment#MEAM International|MEAM International]]
|Belgium
| -
|MEAM Dry S48 HR
| -
|5000
|70
|2.45
|48000
| -
| -
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center" |●
|
|}

=== Biorenewables Development Centre ===
{{Infobox provider-microwave treatment|Company=Biorenewables Development Centre|Image=Cropped-logo1.png|Country=United Kingdom|Webpage=http://www.biorenewables.org|Contact=Anna Alessi|Technology name=Microwave furnaces|TRL=up to 8|Capacity=30|Power=6|Temperature=up to 1000C|Feedstock=lignocellulose biomass|Processable volume=various|Product=biochar, oil}}

The Biorenewables Development Centre (BDC) has a long history of working with microwave technology for synthesis, extraction, hydrolysis and pyrolysis. Our microwave pyrolysis unit can pyrolyse a variety of biomass which can then be separated into bio-char and fractionated bio-oil using the integral product collection system. Our pyrolysis microwave unit is capable of continuous flow up to 30 kg/hour at variable power (6 kW) and has been custom built by SAIREM for the BDC. This machine is capable of continuous flow up to 30 kg/hour at variable power (6 kW) and has been custom built by SAIREM for the BDC. This unique patented technology was developed here at York and is particularly novel as it is a low temperature method (less than 200°C) and separates the bio-oil products into more useful groups. The second unit at the BDC is the Carbolite custom furnace - a continuous Inconel tube system with a designed temperature limit of 1000 °C. It allows the heating up of organic material in the absence of oxygen. This furnace has a 50 litre hopper and a heated section length of 2 metres with three programmable heated sections. Material is fed through the furnace via an auger system and can be ran in either continuous or batch mode. The throughput of the furnace is dependent on the material being processed, however there is a 60 litre collection bin and a 20 litre collection pot for any by-products being produced.

=== Biowave Technologies ===
{{Infobox provider-microwave treatment|Company=Biowave Technologies|Country=Ireland|Contact=info@biowave-tech.com|Webpage=www.biowave-tech.com|Technology name=Microwave pre-treatment|Frequency=0.915|Capacity=500-8000|Power=30,000-300,000|Feedstock=Dairy processing waste, FOG waste, waste activated sludge, agricultural residues, food waste|Product=Digestible feedstock for AD|Image=navygreenlogo.png|TRL=7|Processable volume=500-8000}}
Biowave Technologies transform organic waste streams into renewable energy resources.
=== Endeavour Energia Srl ===
{{Infobox provider-microwave treatment|Company=Endeavour Energia Srl|Country=Italy|Webpage=http://www.endeavoursrl.com/|Technology name=Endeavour Microwave Gasification|TRL=6|Capacity=100|Power=100 - 200 k|Temperature=>1400|Feedstock=Rice and wheat husks, anaerobic digestion digestate, animal litter, woody biomass.|Product=Syngas and biochar}}

Endeavor Srl. was born in 2015 as an innovative start-up with a clear project: to design and build a plant capable of transforming biomass and waste into electrical and thermal energy through an innovative and patented technology based on microwaves.

The Endeavour Microwave Gasification technology by Endeavour Energia S.r.l. can be used to upgrade waste and biomass feeds, such as rice and wheat husks, woody biomass, sludge from anaerobic digestion and litter from animal farms to electricity, heat, and biochar. According to Endeavour, the technology is characterized by the use of microwave-assisted high temperature gasification (>1400 °C) together with a simplified filtering system in a setup that does not generate waste in need of disposal.

=== MEAM International ===
{{Infobox provider-microwave treatment|Company=MEAM International|Country=Belgium|Webpage=https://meam-international.com/|Technology name=MEAM Dry S48 HR|Frequency=2.45|Power=48 k|Temperature=Max 70|Capacity=5000|Feedstock=Different industrial food and non-food applications.|Product=Drying, conditioning, heating.}}

MEAM was founded over 10 years ago by the electronic engineer specializing in high-power EM energy Carlo Groffils. Since then, MEAM has become an international player with offices in Belgium and the Netherlands and successfully delivered over 350 microwave projects to both large and small enterprises. MEAM's focus lies today on the food industry, as well as industrial microwave processing of wood, glass and plastics, and water and solvent-based paint, coating and drying in technical applications.

MEAM has developed an adapted continuous system, the MEAM DRY S48 HR, where the S stands for Sheet and HR for Heat Recovery, respectively. Depending on the process, it is possible to recover the heat from the cooling water or exhaust air to defrost or preheat the product.

== Open access pilot and demo facility providers ==
Currently no providers have been identified.

==Patents==
Currently no patents have been identified.

==References==
<references />

[[Category:Pre-processing]]
[[Category:Post-processing]]
[[Category:Technologies]]