Steam explosion
| Technology | |
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| Technology details | |
| Name: | Steam explosion |
| Category: | Pre-treatment |
| Feedstock: | lignocellulose, straws, wood |
| Product: | Dismantled lignocellulosic biomass |
Steam explosion is a is a physicochemical method to break the lignocellulose structure by using high-pressure steam to disrupt the bonding between polymeric components (lignin, cellulose) and decompression to break the lignocellulose structure. It can be used to pre-treat the lignocellulosic biomass to improve subsequent processes, such as enzymatic hydrolysis.
Feedstock
Origin and composition
Steam explosion is used to pre-treat lignocellulosic biomass such as wood, straw and lignocellulosic wastes for industrial processes. Normally, the material will enter the steam explosion process as chips, pellets or ground material.
Pre-treatment
Process and technologies
Lignocellulosic biomass such as wood exists of composite materials with high mechanical strength composed of cellulose fibres, lignin polymers as a matrix and hemicelluloses in a tightly packed cellular structure of fibres that form fibre bundles. Their natural function is to bear high mechanical loads, and to resist chemical and enzymatic degradation through microorganisms. Steam explosion breaks this structure down to enable these chemical and enzymatic conversions. It converts biomass in a steam atmosphere at elevated temperatures ranging from 140 to 240 °C. The steam pressure is rapidly reduced to atmospheric pressure, whereby a mechanical disruption of the biomass occurs. In steam explosion, the lignocellulosic biomass is treated with high-pressure hot steam for some time and then the vessel is rapidly depressurised to atmospheric pressure. With this explosive decompression and high temperature it causes degradation of hemicellulose, which is extracted as water-soluble fraction. The cellulose is largely preserved in its original form, and only slight depolymerisation occurs at mild reaction condition. The Lignin undergoes depolymerisation by cleavage of β–O–4 linkages, and condensation of the fragments occurs to form a more stable polymer.[1]
Steam explosion was introduced and patented as a biomass pre-treatment process in 1926 by Mason et al. (1926).[2]. The patent describes a steam explosion process for the pre-treatment of wood where wood chips are fed from a bin through a screw loading valve. The chips are then steam heated at a temperature of about 285°C and a pressure of 3.5 MPa for about 2 min. The pressure is increased rapidly to about 7 MPa (70 bar) for about 5 s, and the chips are then discharged and explode at atmospheric pressure into a pulp. The sudden pressure release defibrillates the cellulose bundles, and this result in a better accessibility of the cellulose for hydrolysis[3] or fermentation.[4][5][6]
Product
Steam explosion is a pre-treatment process that make biomass more suitable for following processes, such as enzymatic hydrolysis, acid hydrolysis[3] or fermentation. Depending on residence time and temperature, steam explosion can result in anything from small cracks in the wood structure, to total defibrillation of the wood fibers.[4][5][6]
Post-treatment
Technology providers
| Company name | Country | Technology category | Technology name | TRL | Capacity [kg/h] | Pressure [bar] | Temperature [°C] | Feedstock: Food waste | Feedstock: Garden & park waste |
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| Company 1 | [Country HQ location] | [Technology category (if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)] | [Technology name (the "branded name" or the usual naming from company side)] | [4-9] | [numeric value] | ● | ● | ||
| Company 2 | [Country HQ location] | [(if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)] | [Technology name (the "branded name" or the usual naming from company side)] | [4-9] | [numeric value] | ● | ● |
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| Technology name: | Technology category: | Pre-processing (Physical processes and technologies), Post-processing (Physical processes and technologies) | |
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Open access pilot and demo facility providers
Patents
Currently no patents have been identified.
References
- ↑ , : Steam Explosion - an overview | ScienceDirect Topics , Last access 2021-08-30. https://www.sciencedirect.com/topics/chemistry/steam-explosion
- ↑ W.H. Mason WH (1926): Process and apparatus for disintegration of wood and the like. US Patent: 1578609, 1926.
- ↑ a b David Steinbach, Andrea Kruse, Jörg Sauer, Jonas Storz (2020): Is Steam Explosion a Promising Pretreatment for Acid Hydrolysis of Lignocellulosic Biomass? Process 8, 1626;, p. 75–104. (pdf)
- ↑ a b M. Tanahashi (1990): Characterization and degradation mechanisms of wood components by steam explosion and utilization of exploded wood. Wood Research 77, 1990: p. 49-117. (pdf)
- ↑ a b Wolfgang Stelte: Steam explosion for biomass pre-treatment. Danish Technological Institute
- ↑ a b Kun Wang, Jinghuan Chen, Shao-Ni Sun, Run-Cang Sun: Steam Explosion. In: Pretreatment of Biomass. Elsevier, 2015, p. 75–104. (pdf)