Hydrolysis
| Technology | |
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| Technology details | |
| Name: | Hydrolysis |
| Category: | Pre-processing (Chemical processes and technologies) |
| Feedstock: | Lignocellulosic biomass |
| Product: | Sugars and organic acids |
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.[1] In lignocellulosic biomass, the cellulose and hemicellulose breaks down into individual sugars. Hemicellulose is easier to hydrolyse than cellulose.[2] 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).[3]
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.[4]
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.[4]
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 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.[5]
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 organosolv pulping, but without the delignification as goal.[6]
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.[6] For example, in acid-acetone pre-treatment biowaste is treated with an acid such as phophoric acid and then mixed with pre-cooled acetone.[7]
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 [8]
Subcritical water
Subcritical water hydrolysis (SWH), also called hydrothermal liquefaction, hydrothermolysis, or aquathermolysis, 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.[9]
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
| Company name | Country | Technology subcategory | Technology name | TRL | Capacity [kg/h] | Catalyst loading [wt %] | pH | Pressure [bar] | Reactor | Residence time [h] | Temperature [°C] | Feedstock: Food waste | Feedstock: Garden & park waste |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Biorenewables Development Centre | United Kingdom | Pre-treatment vessel | 5 | 12 | Stainless vessel grade | < 180 | |||||||
| Hysytech S.R.L. | Italy | Compost hydrolysis | 7 | 1 m3/h | 1 | Continuous reactor, Cone bottom | >60 | ||||||
| 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 | |||||
| Valmet Oyj | Finland | BioTrac | 9 | 800 tonne/day | Horizontal tube reactor |
Biorenewables Development Centre
| General information | |||
| Company: | Biorenewables Development Center | 
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| Country: | United Kingdom | ||
| Contact: | Anna Alessi | ||
| Webpage: | http://www.biorenewables.org | ||
| Technology and process details | |||
| Technology name: | Pre-treatment vessel | Technology category: | Pre-processing (Chemical processes and technologies) |
| TRL: | 5 | Capacity: | kg·h-1 |
| Agitator: | variable | Atmosphere: | |
| Catalyst: | Controlled parameters: | ||
| Temperature: | up to 180 °C | Catalyst: | |
| Processable volume: | 100 L | Reactor: | |
| Reactor material: | Safety restrictions: | ||
| Temperature: | up to 180 °C | Other: | |
| Feedstock and product details | |||
| Feedstock: | Product: | ||
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)
| General information | |||
| Company: | CENER BIO2C | 
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| Country: | Spain | ||
| Contact: | Goizeder Barberena, [email protected] | ||
| Webpage: | https://www.bio2c.es/pretreatment-unit/ | ||
| Technology and process details | |||
| Technology name: | BIO2C – Enzymatic Hydrolysis | Technology category: | Pre-processing (Chemical processes and technologies) |
| TRL: | 6-7 | Capacity: | Enzymes kg·h-1 |
| Agitator: | Coaxial Industrial mixer | Atmosphere: | Environment |
| Catalyst: | Enzymes | Controlled parameters: | Temperature, pressure, pH |
| Temperature: | 20-80ºC (Ambient temperature up to 130 ºC (sterilizable)) °C | Catalyst: | Enzymes |
| Processable volume: | 200L, 3000L L | Reactor: | High solids enzymatic hydrolysis stirred tank reactor. |
| Reactor material: | Stainless steel | Safety restrictions: | no atex, maximum working pressure 2 bar. |
| Temperature: | 20-80ºC (Ambient temperature up to 130 ºC (sterilizable)) °C | Other: | More info: https://www.bio2c.es/biochemical-unit/ |
| Feedstock and product details | |||
| Feedstock: | High flexibility in feedstocks: lignocellulosic feedstocks such herbaceous and woody, considering as well the OFMSW, agri-food waste. | 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.
| General information | |||
| Company: | Hysytech Srl |
| |
| Country: | Italy | ||
| Contact: | [email protected]; [email protected]; [email protected] | ||
| Webpage: | www.hysytech.com | ||
| Technology and process details | |||
| Technology name: | Compost hydrolysis | Technology category: | Pre-processing (Chemical processes and technologies) |
| TRL: | 7 | Capacity: | 1 m3/h kg·h-1 |
| Agitator: | None. Pump recirculation | Atmosphere: | Environment |
| Catalyst: | Base | Controlled parameters: | pH and Temperature |
| Temperature: | >60 °C | Catalyst: | Base |
| Processable volume: | 400 L | Reactor: | Continuous reactor. Cone bottom. |
| Reactor material: | Stainless steel | Safety restrictions: | None |
| Temperature: | >60 °C | Other: | |
| Feedstock and product details | |||
| Feedstock: | Compost | Product: | Hydrolyzed product |
Luleå University of Technology LTU
| General information | |||
| Company: | Luleå University of Technology | 
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| Country: | Sweden | ||
| Contact: | Tobias Wretborn [email protected] | ||
| Webpage: | https://www.ltu.se/ | ||
| Technology and process details | |||
| Technology name: | Organosolv pre-treatment | Technology category: | Pre-processing (Chemical processes and technologies) |
| TRL: | 6-7 | Capacity: | 0,7 l/min (biomass) kg·h-1 |
| Agitator: | Hydraulic augers | Atmosphere: | Saturated, at pressures up to 30 bar |
| Catalyst: | ≤0.25 % sulfuric acid | Controlled parameters: | Pressure, Temperature, Time, Solvent concentration, Solvent to biomass ratio |
| Temperature: | ≤ 230 °C °C | Catalyst: | ≤0.25 % sulfuric acid |
| Processable volume: | 0,7 l/min (biomass) L | Reactor: | Continuous organosolv reactor |
| Reactor material: | EN 1.4301 | Safety restrictions: | not relevant |
| Temperature: | ≤ 230 °C °C | Other: | not relevant |
| Feedstock and product details | |||
| Feedstock: | Lignocellulosic biomass | Product: | Cellulose rich pulp, Lignin and Hemicellulose rich process liquor |
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
| General information | |||
| Company: | Valmet Oyj |
| |
| Country: | Finland | ||
| Contact: | |||
| Webpage: | https://www.valmet.com/ | ||
| Technology and process details | |||
| Technology name: | BioTrac | Technology category: | Pre-processing (Chemical processes and technologies) |
| TRL: | 9 | Capacity: | biomass feed up to 800 tonne/day kg·h-1 |
| Agitator: | Atmosphere: | ||
| Catalyst: | Acidic conditions | Controlled parameters: | |
| Temperature: | High °C | Catalyst: | Acidic conditions |
| Processable volume: | L | Reactor: | Horizontal tube reactor |
| Reactor material: | Safety restrictions: | ||
| Temperature: | High °C | Other: | |
| Feedstock and product details | |||
| Feedstock: | All lignocellulosic biomass, including wood and forestry residues, wheat straw, corn stover and bagasse | Product: | |
Open access pilot and demo facility providers
Patents
Currently no patents have been identified.
References
- ↑ Wikipedia, 2002: Hydrolysis 2002, Last access 2021. https://en.wikipedia.org/wiki/Hydrolysis
- ↑ P. Lenihan, A. Orozco, E. O’Neill, M.N.M. Ahmad, D.W. Rooney, G.M. Walker, 2010-01-15: Dilute acid hydrolysis of lignocellulosic biomass. Chemical Engineering Journal, Vol. 156, (2), 395–403. doi: https://doi.org/10.1016/j.cej.2009.10.061
- ↑ Katarzyna Świątek, Stephanie Gaag, Andreas Klier, Andrea Kruse, Jörg Sauer, David Steinbach, 2020-04-17: Acid Hydrolysis of Lignocellulosic Biomass: Sugars and Furfurals Formation. Catalysts, Vol. 10, (4), 437. doi: https://doi.org/10.3390/catal10040437
- ↑ a b Alessandra Verardi, Isabella De Bari, Emanuele Ricca and Vincenza Calabrò, 2012: Hydrolysis of Lignocellulosic Biomass: Current Status of Processes and Technologies and Future Perspectives. Bioethanol. Marco Aurelio Pinheiro Lima and Alexandra Pardo Policastro Natalense (Ed.). IntechOpen, {{{place}}}.
- ↑ S. Niju, M. Swathika, M. Balajii, 2020-01-01: Pretreatment of lignocellulosic sugarcane leaves and tops for bioethanol production. Lignocellulosic Biomass to Liquid Biofuels, Vol. , 301–324. doi: https://doi.org/10.1016/B978-0-12-815936-1.00010-1
- ↑ a b Valery B. Agbor, Nazim Cicek, Richard Sparling, Alex Berlin, David B. Levin, 2011-11: Biomass pretreatment: Fundamentals toward application. Biotechnology Advances, Vol. 29, (6), 675–685. doi: https://doi.org/10.1016/j.biotechadv.2011.05.005
- ↑ Amit K. Jaiswal, Rajeev Ravindran, 2016-01-01: A comprehensive review on pre-treatment strategy for lignocellulosic food industry waste: Challenges and opportunities. Bioresource Technology, Vol. 199, 92–102. doi: https://doi.org/10.1016/j.biortech.2015.07.106
- ↑ Moyer, P., Kim, K., Abdoulmoumine, N. et al., 2018: Structural changes in lignocellulosic biomass during activation with ionic liquids comprising 3-methylimidazolium cations and carboxylate anions 27/09/2018, Last access 06/12/2021. https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-018-1263-0
- ↑ D. Lachos-Perez, F. Martinez-Jimenez, C. A. Rezende, G. Tompsett, M. Timko, T. Forster-Carneiro, 2016-02-01: Subcritical water hydrolysis of sugarcane bagasse: An approach on solid residues characterization. The Journal of Supercritical Fluids, Vol. 108, 69–78. doi: https://doi.org/10.1016/j.supflu.2015.10.019
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