Difference between revisions of "Pyrolysis"

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Pyrolysis (from greek ''pyr,'' "fire" and ''lysis,'' "loosing/unbind") is a thermochemical process which is able to convert organic compounds in presence of heat and absence of oxygen into valuable products which can be solid, liquid or gaseous. The chemical transformations of substances are generally accompanied by the breaking of chemical bonds which leads to the conversion of more complex molecules into simpler molecules which may also combine with each other to build up larger molecules again. The products of pyrolysis are usually not the actual building blocks of the decomposed substance, but are structurally modified (e.g. by cyclization and aromatisation or rearrangement).
{{Infobox technology
| Feedstock = [[Garden and park waste]] (wood, leaves)
| Product = Coal, pyrolysis oil, pyrolysis gas
|Name=Pyrolysis|Category=[[Conversion]] ([[Conversion#Thermochemical_processes_and_technologies|Thermochemical processes and technologies]])}}
<onlyinclude>'''Pyrolysis''' (from greek ''pyr,'' "fire" and ''lysis,'' "loosing/unbind") is a conversion technology that utilises a thermochemical process to convert organic compounds in presence of heat and absence of oxygen into valuable products which can be solid, liquid or gaseous. The chemical transformations of substances are generally accompanied by the breaking of chemical bonds which leads to the conversion of more complex molecules into simpler molecules which may also combine with each other to build up larger molecules again. The products of pyrolysis are usually not the actual building blocks of the decomposed substance, but are structurally modified (e.g. by cyclization and aromatisation or rearrangement).</onlyinclude>


== Feedstock ==
== Feedstock ==


=== Origin and composition ===
=== Origin and composition ===
Since all kind of biowaste contains hydrocarbonaceous material it can also be processed via pyrolysis. However, the composition of the feedstock has an impact on the pyrolysis process and therewith on the products which can be obtained. Usually wood or herbaceous are processed via pyrolysis which contain cellulose, hemicellulose, and lignin in different ratios<ref>{{Cite journal|author=Carpenter, D., Westover, T. L., Czernik, S. and Jablonski, W.|year=2014|title=Biomass feedstocks for renewable fuel production: a review of the impacts of feedstock and pretreatment on the yield and product distribution of fast pyrolysis bio-oils and vapors|journal=Green Chemistry|volume=16|issue=2|page=384-406|doi=10.1039/C3GC41631C}}</ref>.  
Since all kind of [[biowaste]] contains hydrocarbonaceous material it can also be processed via pyrolysis. However, the composition of the feedstock has an impact on the pyrolysis process and therewith on the products which can be obtained. Usually wood and herbaceous feedstocks are processed which are composed differently<ref name=":2">{{Cite journal|author=Carpenter, D., Westover, T. L., Czernik, S. and Jablonski, W.|year=2014|title=Biomass feedstocks for renewable fuel production: a review of the impacts of feedstock and pretreatment on the yield and product distribution of fast pyrolysis bio-oils and vapors|journal=Green Chemistry|volume=16|issue=2|page=384-406|doi=10.1039/C3GC41631C}}</ref> which qualifies [[garden and park waste]] as suitable feedstock.      
{| class="wikitable"
{| class="wikitable"
|+
|+
!
Typical composition of typical pyrolysis feedstocks<ref name=":2" />
!Feedstock:
!Corn stover
!Corn stover
!Switchgrass
!Switchgrass
Line 16: Line 21:
|Moisture
|Moisture
|8.0
|8.0
|
|9.8
|
|42.0
|-
|-
|Ash
|Ash
|6.9
|6.9
|
|8.1
|
|2.3
|-
|-
|Volatile matter
|Volatile matter
|69.7
|69.7
|
|69.1
|
|47.8
|-
|-
|Fixed carbon
|Fixed carbon
|15.4
|15.4
|
|12.9
|
|7.9
|-
|-
| colspan="4" |Elemental analysis wt [%]
| colspan="4" |Elemental analysis [%]
|-
|-
|Carbon
|Carbon
|49.7
|49.7
|
|50.7
|
|51.5
|-
|-
|Hydrogen
|Hydrogen
|5.91
|5.91
|
|6.32
|
|4.71
|-
|-
|Oxygen
|Oxygen
|42.6
|42.6
|
|41.0
|
|40.9
|-
|-
|Nitrogen
|Nitrogen
|0.97
|0.97
|
|0.83
|
|1.06
|-
|-
|Sulphur
|Sulphur
|0.11
|0.11
|
|0.21
|
|0.12
|-
|-
|Chlorine
|Chlorine
|0.28
|0.28
|
|0.22
|
|0.02
|-
|-
| colspan="4" |Structural organics
| colspan="4" |Structural organics wt [%]
|-
|-
|Cellulose
|Cellulose
|36.3
|36.3
|
|44.8
|
|38.3
|-
|-
|Hemicellulose
|Hemicellulose
|23.5
|23.5
|
|35.3
|
|33.4
|-
|-
|Lignin
|Lignin
|17.5
|17.5
|
|11.9
|
|25.2
|}
|}


=== Pre-treatment ===
=== Pre-treatment ===
The pre-treatment of the feedstock has an impact on the pyrolysis process, its efficiency, and the yield of certain products. The following pre-treatments may be considered <ref name=":0" />:
The pre-treatment of the feedstock has an impact on the pyrolysis process, its efficiency, and the yield of certain products. The following pre-treatments may be considered <ref name=":0" />:
*[[Sizing]] (e.g. chipping, grinding)
* [[Densification]] (e.g. pressure-densification)
* [[Steam explosion]]
* [[Drying]] (e.g. air drying, freeze-drying)
* [[Extraction]] (e.g. acid and alkali treatment for the removal of minerals)
* [[Torrefaction|Wet torrefaction]]
*[[Ammonia fibre expansion]]
* [[Composting]] (e.g. Decomposing via fungi)


* Physical pre-treatments
== Process and technologies ==
** Sizing (e.g. chipping, grinding)
The pyrolysis is an endothermal process requiring the input of energy in form of heat which can either be directly (direct pyrolysis) applied via hot gases or indirectly (indirect pyrolysis) via external heating of the reactor. Compared to [[gasification]], the process takes place in an atmosphere without oxygen or at least under a limitation of oxygen.
** Densification (e.g. pressure-densification)
* Chemical pre-treatment
** Acid and alkali pre-treatment (e.g for the removal of minerals)
** Hydrothermal pre-treatment (e.g. torrefaction)
** Steam explosion
** Ammonia fibre expansion
** Thermal pre-treatment (e.g. drying)
** Biochemical pre-treatment


== Process ==
In general, pyrolysis can be divided into different steps which include:
The pyrolysis is an endothermal process which requires the input of energy in form of heat which can either be directly (direct pyrolysis) applied via hot gases or indirectly (indirect pyrolysis) via external heating of the reactor. Compared to gasification, the process takes place in an atmosphere without oxygen or at least under a limitation of oxygen.
 
In general, pyrolysis can be divided into different steps which includes:


# Evaporation and vapourisation of water and other volatile molecules which is induced at temperatures > 100 °C
# Evaporation and vapourisation of water and other volatile molecules which is induced at temperatures > 100 °C
Line 107: Line 109:
# Reaction and recombination of the molecules, and triggering of chain reactions through free radicals
# Reaction and recombination of the molecules, and triggering of chain reactions through free radicals


The pyrolysis process and the formation of products can be controlled to a certain extend via different temperature ranges and reaction times as well as by utilising reactive gases, liquids, catalysts, alternative forms of heat application (e.g. via microwaves or plasma), and a variety of reactor designs.
The pyrolysis process and the formation of products can be controlled to a certain extend via different temperature ranges and reaction times as well as by utilising reactive gases, liquids, catalysts, alternative forms of heat application (e.g. via microwaves or plasma), and a variety of [[reactor designs]]. Depending on the residence time and temperature as well as different technical reaction environments the pyrolysis can be categorised under diffferent terms as follows.
 
=== Categorisation according residence time and temperature ===
 
* Fast pyrolysis
* Intermediate pyrolysis
* Slow pyrolysis (charring, torrefaction)
 
=== Categorisation according technical reaction environment ===
Depending on these factors the pyrolysis technology can be divided into different categories as follows:
 
* Catalytic cracking
** One-step process
** Two-step process
* Hydrocracking
* Thermal cracking
* Thermal depolymerisation


=== Reactions ===
=== Reactions ===
A range of different reactions occur during the process such as dehydration, depolymerisation, isomerisation, aromatisation, decarboxylation, and charring<ref name=":0">{{Cite journal|author=Hu, X. and Gholizadeh, M.|year=2019|title=Biomass pyrolysis: A review of the process development and challenges from initial researches up to the commercialisation stage|journal=Journal of Energy Chemistry|volume=39|issue=|page=109-143|doi=doi:https://doi.org/10.1016/j.jechem.2019.01.024}}</ref>.
A range of different reactions occur during the process such as [[dehydration]], [[depolymerisation]], [[isomerisation]], [[aromatisation]], [[decarboxylation]], and [[charring]]<ref name=":0">{{Cite journal|author=Hu, X. and Gholizadeh, M.|year=2019|title=Biomass pyrolysis: A review of the process development and challenges from initial researches up to the commercialisation stage|journal=Journal of Energy Chemistry|volume=39|issue=|page=109-143|doi=doi:https://doi.org/10.1016/j.jechem.2019.01.024}}</ref>.


== Product ==
== Product ==
A range of solid, liquid, and gaseous products can be obtained from the pyrolysis process including char, pyrolysis oil, and pyrolysis gas. Depending on the feedstock origin and composition as well as the pre-treatment and process the yield as well as the chemical and physical properties of the products can vary.
A range of solid, liquid, and gaseous products can be obtained from the pyrolysis process including [[char]], [[pyrolysis oil]], and [[pyrolysis gas]]. Depending on the feedstock origin and composition as well as the pre-treatment and process the yield as well as the chemical and physical properties of the products can vary.


=== Char ===
=== Char ===
[[File:Charcoal.jpg|thumb|Wood-based char]]
As mentioned the functional properties of char may vary which includes carbon content, functional groups, heating value, surface area, and pore-size distribution. The application possibilities are versatile, the char can be used as soil amendment for carbon sequestration, soil fertility improvement, and pollution remediation. Furthermore the char can be used for catalytic purposes, energy storage, or sorbent for pollutant removal from water or flue-gas.  
As mentioned the functional properties of char may vary which includes carbon content, functional groups, heating value, surface area, and pore-size distribution. The application possibilities are versatile, the char can be used as soil amendment for carbon sequestration, soil fertility improvement, and pollution remediation. Furthermore the char can be used for catalytic purposes, energy storage, or sorbent for pollutant removal from water or flue-gas.  


=== Pyrolysis oil ===
=== Pyrolysis oil ===
Produced pyrolysis oil is a multiphase emulsion composed of water and and hundrets of organic molecules such as acids, alcohols, ketones, furans, phenols, ethers, esters, sugars, aldehydes, alkenes, nitrogen- and oxygen- containing molecules. A longer storage or exposure to higher temperature increases the viscosity due to possible chemical reactions of the compounds in the oil which leads to the formation of larger molecules<ref name=":1">{{Cite journal|author=Czernik, S. and Bridgwater|year=2004|title=Overview of Applications of Biomass Fast Pyrolysis Oil|journal=Energy & Fuels|volume=18|issue=2|page=590-598|doi=10.1021/ef034067u}}</ref>. The presence of oligomeric species with a molecular weight >5000 decreases the stability of the oil<ref name=":0" />, furthermore the formation of aerosols from volatile substances accelerates the aging process in which the water content and phase separation increases. The application as fuel in standard equipment for petroleum fuels (e.g. boilers, engines, turbines) may be limited due to poor volatility, high viscosity, coking, and corrosiveness of the oil<ref name=":1" />. To overcome these problems the pyrolysis oil has to be upgraded in a post-treatment to be used as fuel and/or the equipment for the end-application has to be adapted.
[[File:Corn Stover Tar from Pyrolysis by Microwave Heating.jpg|thumb|upright|Pyrolysis oil from corn stover pyrolysis]]
Produced pyrolysis oil is a multiphase emulsion composed of water and hundreds of organic molecules such as acids, alcohols, ketones, furans, phenols, ethers, esters, sugars, aldehydes, alkenes, nitrogen- and oxygen- containing molecules. A longer storage or exposure to higher temperature increases the viscosity due to possible chemical reactions of the compounds in the oil which leads to the formation of larger molecules<ref name=":1">{{Cite journal|author=Czernik, S. and Bridgwater|year=2004|title=Overview of Applications of Biomass Fast Pyrolysis Oil|journal=Energy & Fuels|volume=18|issue=2|page=590-598|doi=10.1021/ef034067u}}</ref>. The presence of oligomeric species with a molecular weight >5000 decreases the stability of the oil<ref name=":0" />. Furthermore, the formation of aerosols from volatile substances accelerates the aging process in which the water content and phase separation increases. The application as fuel in standard equipment for petroleum fuels (e.g. boilers, engines, turbines) may be limited due to poor volatility, high viscosity, coking, and corrosiveness of the oil<ref name=":1" />. To overcome these problems, the pyrolysis oil has to be upgraded in a post-treatment to be used as fuel and/or the equipment for the end-application has to be adapted.


=== Pyrolysis gas ===
=== Pyrolysis gas ===
Line 126: Line 146:
=== Post-treatment ===
=== Post-treatment ===


* Fischer-Tropsch-Synthesis
* [[Fischer-Tropsch-Synthesis]]


== Technology providers ==
== 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}}}"| City
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Technology subcategory
! 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
! class="cd-text-darkgreen" style="vertical-align:{{{va|bottom}}}"| Reactor
! 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: Char
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Product: Oil
! class="cd-text-darkgreen" style="{{writing-mode|s2}};vertical-align:{{{va|bottom}}}"| Product: Syngas
|-
! style="height:1.8em;"|
!
!
!
!
!
!
!
!
!
!
!
!
!
!
|-
|[[Pyrolysis#BioBTX|BioBTX]]
|The Netherlands
|Groningen
|Catalytic Pyrolysis, two-step
|Integrated Cascading Catalytic Pyrolysis (ICCP) technology
|5-6
|10
|Zeolite
| -
|450-650
| 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"|●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center"|●
|-
|[[Pyrolysis#BTG_Bioliquids|BTG Bioliquids]]
|The Netherlands
|Hengelo
|Fast Pyrolysis
|BTG fast pyrolysis technology
|8-9
|5,000
| None
| Rotating Cone
|400-550
| 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"|●
|
|-
|[[Pyrolysis#Splainex Ecosystems|Splainex Ecosystems]]
|The Netherlands
|Rijswijk
|Pyrolysis
|Waste pyrolysis industrial plants
|7-9
|65,000
| -
| -
|400-700
| 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"|●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center"|●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center"|●
|-
|[[Pyrolysis#VTT Technical Research Centre of Finland|VTT Technical Research Centre of Finland]]
|Finland
|Espoo
|Pyrolysis
|Pyrolysis technology
|6
|154
| -
| -
| -
| 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"|●
| class="cd-background-lightgreen cd-text-darkgreen" style="text-align:center"|●
|
|-
|}


=== BioBTX (ICCP technology) ===
===BioBTX ===
 
{{Infobox provider-pyrolysis
=== Fortum (Combined Heat and Power plant, CHP; LignoCat?) ===
| Company = Bio-BTX B.V.
| Webpage = https://biobtx.com/
| Country = The Netherlands
| TRL = 5-6
| Technology name = Integrated Cascading Catalytic Pyrolysis (ICCP) technology
| Technology category = Catalytic Pyrolysis, two-step
| Feedstock = Biomass (liquid, solid), wood pulp lignin residues, used cooking oil
| Product = Benzene, toluene, xylene, aromatics, light gases
| Reactor = Fluidised sand bed, fixed bed
| Heating = Fluidised sand bed
| Atmosphere = Inert
| Pressure = 1-4
| Capacity = 10
| Temperature = 450-650
| Catalyst = Zeolite
| Other = Unknown
}}
BioBTX was founded in 2012 by KNN and Syncom in collaboration with the university of Groningen, Netherlands. The company is a technology provider developing chemical recycling technologies for different feedstocks including non-food bio- and plastics waste. In 2018 a pilot plant with the capability to process biomass and plastic waste was set up at the Zernike Advanced Processing (ZAP) Facility. The company is now focused on setting up their first commercial plant with a capacity of 20,000 to 30,000 tonnes. The investing phase B was recently completed, with the last investment phase in 2019 the financial requirements are fulfilled to complete the commercialisation activities to build the plant which is expected for 2023.


=== Fraunhofer UMSICHT (TCR-Process --> Susteen Technologies GmbH?) ===
The technology is based on an Integrated Cascading Catalytic Pyrolysis (ICCP) process, being able to produce aromatics including benzene, toluene, and xylene (BTX) as well as light olefins from low grade biomass and plastics waste. This technology utilises catalytic cracking in a two-step process at temperatures between 450- 850 °C. In the first step the feedstock material is vaporised via thermal cracking. The pyrolysis vapours are then directly passed into a second reactor in which they are converted into aromatics by utilising a zeolite catalyst which can be continuously regenerated. Finally, the products are separated from the gas via condensation. An ex situ approach of catalytic conversion has several advantages such as the protection of the catalyst from deactivation/degradation expanding its lifetime, a greater variety of feedstock, and a precise adjustment of process conditions (e.g. temperature, catalyst design, and Weight Hourly Space Velocity (WHSV) in each step for improved yields. In current pilot plant with 10 kg h-1 feed capacity for either waste plastics or biomass, final design details are established, which will be include in the running engineering activities for the commercial plant.


=== Green Fuel Nordic ===
=== BTG Bioliquids===
{{Infobox provider-pyrolysis
| Company = BTG Bioliquids
| Webpage = https://www.btg-bioliquids.com/
| Country = The Netherlands
| TRL = 8-9
| Technology name = BTG fast pyrolysis technology
| Technology category = Fast pyrolysis
| Feedstock = Woody biomass
| Product = Fast Pyrolysis Bio-Oil (FPBO), heat (steam), power (electricity)
| Reactor = Rotating Cone Reactor
| Heating = Fluidised sand bed
| Atmosphere = Inert
| Pressure = n.a.
| Capacity = 5,000
| Temperature = 400-550
| Catalyst = None
|Contact=mark.richters@btg-bioliquids.com|Image=Btg-bioliquids.png}}
[[File:EMPYRO.jpg|alt=EMPYRO factory|thumb|The EMPYRO pyrolysis factory in Hengelo, the Netherlands.]]
BTG Bioliquids, a spin-off company from BTG Biomass Technology Group, was founded in 2007 in Enschede, the Netherlands. BTG Bioliquids aims for commercial implementation of their fast pyrolysis technology, which focuses on converting biomass residues into Fast Pyrolysis Bio Oil (FPBO). Since 2015, the first successful production plant EMPYRO is in operation in Hengelo, the Netherlands, producing 24,000 tonnes pyrolysis oil per year. In 2018 EMPYRO was sold to Twence. In addition 2 FPBO-plants in Scandinavia are in commercial production at Green Fuel Nordic in Finland and Pyrocell in Sweden. Several other customer projects are under discussion in Europe and North America.


=== KIT (bioliq-Project) ===
=== Splainex Ecosystems ===
{{Infobox provider-pyrolysis|Company=Splainex Ecosystems|Country=The Netherlands|Webpage=www.splainex.com|Contact=www.splainex.com/pyrolysis-company-contact.html|Technology name=Waste pyrolysis industrial plants|TRL=7-9|Capacity=65,000|Atmosphere=Inert|Temperature=400-700|Feedstock=MSW, RDF, Sewage sludge, Wooden biomass|Product=Pyrolysis oil, pyrolysis gas, biochar, energy|Image=Splainex.jpg}}
In 2007 Splainex Ecosystems was founded originating from Splainex which was founded in 1994. The main focus of the company is the design and supply of pyrolysis plants, focussing on the pyrolysis unit equipment i.e. pyrolysis furnace, combustion chamber for energy recovery, char cooler. Quality equipment is supplied by their German partners. Offered services include project initiation/feasibility study, design and engineering, equipment fabrication and procurement, factory acceptance testing, packing and shipment, supply, on-site assistance with construction, commissioning, and start-up. Turn-key project delivery is also possible (mostly limited to Europe).


=== Preem (Biozin; RenFuel) ===
===VTT Technical Research Centre of Finland===
{{Infobox provider-pyrolysis|Company=VTT Technical Research Centre of Finland|Country=Finland|Webpage=www.vttresearch.com|Technology name=Pyrolysis technology|TRL=6|Capacity=154|Atmosphere=Inert|Feedstock=Biomass waste|Product=Pyrolysis oil, wax, char|Image=VTT-logo.png|Contact=www.vttresearch.com/en/about-us/contact-us}}
The VTT Technical Research Centre is a non-profit organisation owned and controlled by the state. The strategy is to support businesses and society to work on global challenges through research, innovation, and information. The research centre covers a wide range of topics such as biotechnology, circular economy, climate action, energy, plastics, and renewable and recyclable materials. VTT has a long-time experience in fast pyrolysis and realised one of VTT’s patent on biomass pyrolysis in 2006, on which a plant for bio oil production in Finland with a capacity of 10 tonnes per hour was established by Metso, UPM, and Fortum. A pilot scale with a capacity of 20 kg h<sup>-1</sup> as well as bench scale plants with a capacity of 1-2 kg h<sup>-1</sup> are available.


=== Pyrocell ===
== Open access pilot and demo facility providers ==
[https://biopilots4u.eu/database?field_technology_area_data_target_id=109&field_technology_area_target_id%5B95%5D=95&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database]


=== Statkraft (Silva Green Fuel) ===
==Patents==
Currently no patents have been identified.


=== VTT Technical Research Centre of Finland ===
==References==
 
== Patents ==
 
== References ==
Al Arni, S. 2018: Comparison of slow and fast pyrolysis for converting biomass into fuel. Renewable Energy, Vol. 124 197-201.  doi:<nowiki>https://doi.org/10.1016/j.renene.2017.04.060</nowiki>
Al Arni, S. 2018: Comparison of slow and fast pyrolysis for converting biomass into fuel. Renewable Energy, Vol. 124 197-201.  doi:<nowiki>https://doi.org/10.1016/j.renene.2017.04.060</nowiki>


Line 162: Line 319:


Zaman, C. Z., Pal, K., Yehye, W. A., Sagadevan, S., Shah, S. T., Adebisi, G. A., Marliana, E., Rafique, R. F. and Johan, R. B. 2017: Pyrolysis: A Sustainable Way to Generate Energy from Waste. IntechOpen
Zaman, C. Z., Pal, K., Yehye, W. A., Sagadevan, S., Shah, S. T., Adebisi, G. A., Marliana, E., Rafique, R. F. and Johan, R. B. 2017: Pyrolysis: A Sustainable Way to Generate Energy from Waste. IntechOpen
<references />
[[Category:Conversion]]
[[Category:Technologies]]

Latest revision as of 12:04, 1 August 2023

Technology
21-04-27 Tech4Biowaste rect-p.png
Technology details
Name: Pyrolysis
Category: Conversion (Thermochemical processes and technologies)
Feedstock: Garden and park waste (wood, leaves)
Product: Coal, pyrolysis oil, pyrolysis gas

Pyrolysis (from greek pyr, "fire" and lysis, "loosing/unbind") is a conversion technology that utilises a thermochemical process to convert organic compounds in presence of heat and absence of oxygen into valuable products which can be solid, liquid or gaseous. The chemical transformations of substances are generally accompanied by the breaking of chemical bonds which leads to the conversion of more complex molecules into simpler molecules which may also combine with each other to build up larger molecules again. The products of pyrolysis are usually not the actual building blocks of the decomposed substance, but are structurally modified (e.g. by cyclization and aromatisation or rearrangement).

Feedstock

Origin and composition

Since all kind of biowaste contains hydrocarbonaceous material it can also be processed via pyrolysis. However, the composition of the feedstock has an impact on the pyrolysis process and therewith on the products which can be obtained. Usually wood and herbaceous feedstocks are processed which are composed differently[1] which qualifies garden and park waste as suitable feedstock.

Typical composition of typical pyrolysis feedstocks[1]
Feedstock: Corn stover Switchgrass Wood
Proximate analysis wt [%]
Moisture 8.0 9.8 42.0
Ash 6.9 8.1 2.3
Volatile matter 69.7 69.1 47.8
Fixed carbon 15.4 12.9 7.9
Elemental analysis [%]
Carbon 49.7 50.7 51.5
Hydrogen 5.91 6.32 4.71
Oxygen 42.6 41.0 40.9
Nitrogen 0.97 0.83 1.06
Sulphur 0.11 0.21 0.12
Chlorine 0.28 0.22 0.02
Structural organics wt [%]
Cellulose 36.3 44.8 38.3
Hemicellulose 23.5 35.3 33.4
Lignin 17.5 11.9 25.2

Pre-treatment

The pre-treatment of the feedstock has an impact on the pyrolysis process, its efficiency, and the yield of certain products. The following pre-treatments may be considered [2]:

Process and technologies

The pyrolysis is an endothermal process requiring the input of energy in form of heat which can either be directly (direct pyrolysis) applied via hot gases or indirectly (indirect pyrolysis) via external heating of the reactor. Compared to gasification, the process takes place in an atmosphere without oxygen or at least under a limitation of oxygen.

In general, pyrolysis can be divided into different steps which include:

  1. Evaporation and vapourisation of water and other volatile molecules which is induced at temperatures > 100 °C
  2. Thermal excitation and dissociation of the molecules induced at temperatures between 100-600 °C, which also may involve the production of free radicals as intermediate stage
  3. Reaction and recombination of the molecules, and triggering of chain reactions through free radicals

The pyrolysis process and the formation of products can be controlled to a certain extend via different temperature ranges and reaction times as well as by utilising reactive gases, liquids, catalysts, alternative forms of heat application (e.g. via microwaves or plasma), and a variety of reactor designs. Depending on the residence time and temperature as well as different technical reaction environments the pyrolysis can be categorised under diffferent terms as follows.

Categorisation according residence time and temperature

  • Fast pyrolysis
  • Intermediate pyrolysis
  • Slow pyrolysis (charring, torrefaction)

Categorisation according technical reaction environment

Depending on these factors the pyrolysis technology can be divided into different categories as follows:

  • Catalytic cracking
    • One-step process
    • Two-step process
  • Hydrocracking
  • Thermal cracking
  • Thermal depolymerisation

Reactions

A range of different reactions occur during the process such as dehydration, depolymerisation, isomerisation, aromatisation, decarboxylation, and charring[2].

Product

A range of solid, liquid, and gaseous products can be obtained from the pyrolysis process including char, pyrolysis oil, and pyrolysis gas. Depending on the feedstock origin and composition as well as the pre-treatment and process the yield as well as the chemical and physical properties of the products can vary.

Char

Wood-based char

As mentioned the functional properties of char may vary which includes carbon content, functional groups, heating value, surface area, and pore-size distribution. The application possibilities are versatile, the char can be used as soil amendment for carbon sequestration, soil fertility improvement, and pollution remediation. Furthermore the char can be used for catalytic purposes, energy storage, or sorbent for pollutant removal from water or flue-gas.

Pyrolysis oil

Pyrolysis oil from corn stover pyrolysis

Produced pyrolysis oil is a multiphase emulsion composed of water and hundreds of organic molecules such as acids, alcohols, ketones, furans, phenols, ethers, esters, sugars, aldehydes, alkenes, nitrogen- and oxygen- containing molecules. A longer storage or exposure to higher temperature increases the viscosity due to possible chemical reactions of the compounds in the oil which leads to the formation of larger molecules[3]. The presence of oligomeric species with a molecular weight >5000 decreases the stability of the oil[2]. Furthermore, the formation of aerosols from volatile substances accelerates the aging process in which the water content and phase separation increases. The application as fuel in standard equipment for petroleum fuels (e.g. boilers, engines, turbines) may be limited due to poor volatility, high viscosity, coking, and corrosiveness of the oil[3]. To overcome these problems, the pyrolysis oil has to be upgraded in a post-treatment to be used as fuel and/or the equipment for the end-application has to be adapted.

Pyrolysis gas

Syngas can be obtained from the pyrolysis gas which is composed of different gases such as carbon dioxide, carbon monoxide, hydrogen, methane, ethane, ethylene, propane, suphur oxides, nitrogen oxides, and ammonia[2]. The different gases can be fractionated from each other in the post-treatment to utilise them for different applications such as the production of chemicals, cosmetics, food, polymers or the utilisation as fuel or technical gas.

Post-treatment

Technology providers

Technology comparison
Company name Country City Technology subcategory Technology name TRL Capacity [kg/h] Catalyst Reactor Temperature [°C] Feedstock: Food waste Feedstock: Garden & park waste Product: Char Product: Oil Product: Syngas
BioBTX The Netherlands Groningen Catalytic Pyrolysis, two-step Integrated Cascading Catalytic Pyrolysis (ICCP) technology 5-6 10 Zeolite - 450-650
BTG Bioliquids The Netherlands Hengelo Fast Pyrolysis BTG fast pyrolysis technology 8-9 5,000 None Rotating Cone 400-550
Splainex Ecosystems The Netherlands Rijswijk Pyrolysis Waste pyrolysis industrial plants 7-9 65,000 - - 400-700
VTT Technical Research Centre of Finland Finland Espoo Pyrolysis Pyrolysis technology 6 154 - - -

BioBTX

Pyrolysis provider
General information
Company: Bio-BTX B.V. 21-04-27 Tech4Biowaste rect-p.png
Country: The Netherlands
Contact:
Webpage: https://biobtx.com/
Technology and process details
Technology name: Integrated Cascading Catalytic Pyrolysis (ICCP) technology Technology category: Conversion (Thermochemical processes and technologies)
TRL: 5-6 Capacity: 10 kg·h-1
Atmosphere: Inert Catalyst: Zeolite
Heating: Fluidised sand bed Pressure: 1-4 bar
Reactor: Fluidised sand bed, fixed bed Temperature: 450-650 °C
Other: Unknown
Feedstock and product details
Feedstock: Biomass (liquid, solid), wood pulp lignin residues, used cooking oil Product: Benzene, toluene, xylene, aromatics, light gases

BioBTX was founded in 2012 by KNN and Syncom in collaboration with the university of Groningen, Netherlands. The company is a technology provider developing chemical recycling technologies for different feedstocks including non-food bio- and plastics waste. In 2018 a pilot plant with the capability to process biomass and plastic waste was set up at the Zernike Advanced Processing (ZAP) Facility. The company is now focused on setting up their first commercial plant with a capacity of 20,000 to 30,000 tonnes. The investing phase B was recently completed, with the last investment phase in 2019 the financial requirements are fulfilled to complete the commercialisation activities to build the plant which is expected for 2023.

The technology is based on an Integrated Cascading Catalytic Pyrolysis (ICCP) process, being able to produce aromatics including benzene, toluene, and xylene (BTX) as well as light olefins from low grade biomass and plastics waste. This technology utilises catalytic cracking in a two-step process at temperatures between 450- 850 °C. In the first step the feedstock material is vaporised via thermal cracking. The pyrolysis vapours are then directly passed into a second reactor in which they are converted into aromatics by utilising a zeolite catalyst which can be continuously regenerated. Finally, the products are separated from the gas via condensation. An ex situ approach of catalytic conversion has several advantages such as the protection of the catalyst from deactivation/degradation expanding its lifetime, a greater variety of feedstock, and a precise adjustment of process conditions (e.g. temperature, catalyst design, and Weight Hourly Space Velocity (WHSV) in each step for improved yields. In current pilot plant with 10 kg h-1 feed capacity for either waste plastics or biomass, final design details are established, which will be include in the running engineering activities for the commercial plant.

BTG Bioliquids

Pyrolysis provider
General information
Company: BTG Bioliquids Btg-bioliquids.png
Country: The Netherlands
Contact: mark.richters@btg-bioliquids.com
Webpage: https://www.btg-bioliquids.com/
Technology and process details
Technology name: BTG fast pyrolysis technology Technology category: Conversion (Thermochemical processes and technologies)
TRL: 8-9 Capacity: 5,000 kg·h-1
Atmosphere: Inert Catalyst: None
Heating: Fluidised sand bed Pressure: n.a. bar
Reactor: Rotating Cone Reactor Temperature: 400-550 °C
Other:
Feedstock and product details
Feedstock: Woody biomass Product: Fast Pyrolysis Bio-Oil (FPBO), heat (steam), power (electricity)
EMPYRO factory
The EMPYRO pyrolysis factory in Hengelo, the Netherlands.

BTG Bioliquids, a spin-off company from BTG Biomass Technology Group, was founded in 2007 in Enschede, the Netherlands. BTG Bioliquids aims for commercial implementation of their fast pyrolysis technology, which focuses on converting biomass residues into Fast Pyrolysis Bio Oil (FPBO). Since 2015, the first successful production plant EMPYRO is in operation in Hengelo, the Netherlands, producing 24,000 tonnes pyrolysis oil per year. In 2018 EMPYRO was sold to Twence. In addition 2 FPBO-plants in Scandinavia are in commercial production at Green Fuel Nordic in Finland and Pyrocell in Sweden. Several other customer projects are under discussion in Europe and North America.

Splainex Ecosystems

Pyrolysis provider
General information
Company: Splainex Ecosystems Splainex.jpg
Country: The Netherlands
Contact: www.splainex.com/pyrolysis-company-contact.html
Webpage: www.splainex.com
Technology and process details
Technology name: Waste pyrolysis industrial plants Technology category: Conversion (Thermochemical processes and technologies)
TRL: 7-9 Capacity: 65,000 kg·h-1
Atmosphere: Inert Catalyst:
Heating: Pressure: bar
Reactor: Temperature: 400-700 °C
Other:
Feedstock and product details
Feedstock: MSW, RDF, Sewage sludge, Wooden biomass Product: Pyrolysis oil, pyrolysis gas, biochar, energy

In 2007 Splainex Ecosystems was founded originating from Splainex which was founded in 1994. The main focus of the company is the design and supply of pyrolysis plants, focussing on the pyrolysis unit equipment i.e. pyrolysis furnace, combustion chamber for energy recovery, char cooler. Quality equipment is supplied by their German partners. Offered services include project initiation/feasibility study, design and engineering, equipment fabrication and procurement, factory acceptance testing, packing and shipment, supply, on-site assistance with construction, commissioning, and start-up. Turn-key project delivery is also possible (mostly limited to Europe).

VTT Technical Research Centre of Finland

Pyrolysis provider
General information
Company: VTT Technical Research Centre of Finland VTT-logo.png
Country: Finland
Contact: www.vttresearch.com/en/about-us/contact-us
Webpage: www.vttresearch.com
Technology and process details
Technology name: Pyrolysis technology Technology category: Conversion (Thermochemical processes and technologies)
TRL: 6 Capacity: 154 kg·h-1
Atmosphere: Inert Catalyst:
Heating: Pressure: bar
Reactor: Temperature: °C
Other:
Feedstock and product details
Feedstock: Biomass waste Product: Pyrolysis oil, wax, char

The VTT Technical Research Centre is a non-profit organisation owned and controlled by the state. The strategy is to support businesses and society to work on global challenges through research, innovation, and information. The research centre covers a wide range of topics such as biotechnology, circular economy, climate action, energy, plastics, and renewable and recyclable materials. VTT has a long-time experience in fast pyrolysis and realised one of VTT’s patent on biomass pyrolysis in 2006, on which a plant for bio oil production in Finland with a capacity of 10 tonnes per hour was established by Metso, UPM, and Fortum. A pilot scale with a capacity of 20 kg h-1 as well as bench scale plants with a capacity of 1-2 kg h-1 are available.

Open access pilot and demo facility providers

Pilots4U Database

Patents

Currently no patents have been identified.

References

Al Arni, S. 2018: Comparison of slow and fast pyrolysis for converting biomass into fuel. Renewable Energy, Vol. 124 197-201.  doi:https://doi.org/10.1016/j.renene.2017.04.060

Czajczyńska, D., Anguilano, L., Ghazal, H., Krzyżyńska, R., Reynolds, A. J., Spencer, N. and Jouhara, H. 2017: Potential of pyrolysis processes in the waste management sector. Thermal Science and Engineering Progress, Vol. 3 171-197.  doi:https://doi.org/10.1016/j.tsep.2017.06.003

Speight, J. 2019: Handbook of Industrial Hydrocarbon Processes. Gulf Professional Publishing, Oxford, United Kingdom.

Tan, H., Lee, C. T., Ong, P. Y., Wong, K. Y., Bong, C. P. C., Li, C. and Gao, Y. 2021: A Review On The Comparison Between Slow Pyrolysis And Fast Pyrolysis On The Quality Of Lignocellulosic And Lignin-Based Biochar. IOP Conference Series: Materials Science and Engineering, Vol. 1051  doi:10.1088/1757-899X/1051/1/012075

Waheed, Q. M. K., Nahil, M. A. and Williams, P. T. 2013: Pyrolysis of waste biomass: investigation of fast pyrolysis and slow pyrolysis process conditions on product yield and gas composition. Journal of the Energy Institute, Vol. 86 (4), 233-241.  doi:10.1179/1743967113Z.00000000067

Zaman, C. Z., Pal, K., Yehye, W. A., Sagadevan, S., Shah, S. T., Adebisi, G. A., Marliana, E., Rafique, R. F. and Johan, R. B. 2017: Pyrolysis: A Sustainable Way to Generate Energy from Waste. IntechOpen

  1. a b Carpenter, D., Westover, T. L., Czernik, S. and Jablonski, W., 2014: Biomass feedstocks for renewable fuel production: a review of the impacts of feedstock and pretreatment on the yield and product distribution of fast pyrolysis bio-oils and vapors. Green Chemistry, Vol. 16, (2), 384-406. doi: https://doi.org/10.1039/C3GC41631C
  2. a b c d Hu, X. and Gholizadeh, M., 2019: Biomass pyrolysis: A review of the process development and challenges from initial researches up to the commercialisation stage. Journal of Energy Chemistry, Vol. 39, 109-143. doi: https://doi.org/doi:https://doi.org/10.1016/j.jechem.2019.01.024
  3. a b Czernik, S. and Bridgwater, 2004: Overview of Applications of Biomass Fast Pyrolysis Oil. Energy & Fuels, Vol. 18, (2), 590-598. doi: https://doi.org/10.1021/ef034067u