Open access peer-reviewed chapter - ONLINE FIRST

Bioenergy Production

Written By

Alireza Shafizadeh and Payam Danesh

Submitted: January 4th, 2022 Reviewed: January 7th, 2022 Published: March 3rd, 2022

DOI: 10.5772/intechopen.102526

Biomass Edited by Mohamed Samer

From the Edited Volume

Biomass [Working Title]

Prof. Mohamed Samer

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In this chapter, an overview of bioenergy importance toward energy systems with low (zero or negative) greenhouse gas emissions and general conversion technologies to produce different types of bioenergy products from various biomass feedstock is presented. The bioenergy products from biomass cover all physical phases including solid (biochar), liquid (bio-oil and bio-crude oil), and gases phase (bio syngas) which make them an interesting field in terms of both academic types of research and industrial scale. A discussion on the available technologies for thermochemical, biochemical, and extraction processes is presented, which is followed by some important parameters on each separate process that cause the optimum production rate and desired products. In addition, in the final part, an overview of the technology readiness level for the processes is reported.


  • biomass
  • bioenergy
  • thermochemical conversion
  • biochemical conversion
  • technology readiness level

1. Introduction

Energy is an indispensable and prominent factor to accelerate economic and social development all over the world, undoubtedly. Therefore, due to the rise of the global population and incline to growth in both developed and developing countries, the energy request has been growing [1, 2, 3]. On one side, strong concerns over the depletion of fossil fuel reserve/resource and their accessibility in the next decades for long-term planning, and on another side, serious warns related to greenhouse gas emission due to fossil fuel consumption and destructive predictions of climate change consequences at the global level necessitate a huge scale transition toward new energy arrangements with reduced or even negative greenhouse gases [4, 5, 6]. In addition, The Paris Agreement on climate change calls on members to preserve the global temperature rise below 1.5 to 2 degrees Celsius (°C) above pre-industrial levels [7]. One of the most significant measures toward energy systems with low (zero or negative) greenhouse gas emissions to mitigate global temperature rise in the long-term and is the application of renewable energies and their share into global energy consumption instead of fossil fuel [8, 9, 10]. Biomass is clean renewable energy that accumulates and transfers sun energy in the form of chemical energy during the growth of plants and trees through the photosynthesis process [11]. Therefore, biomass has been recognized as one of the renewable energy sources, with carbon capture capability and carbon neutrality [12, 13, 14]. In this context as it is shown in Figure 1, biomass also demonstrates the capability of transformation of the accumulated energy into multiple general forms of final energy carries such as solid, liquid, and gaseous which are compatible for various sectors comprising heat, power, and transport fuel [15]. In order to convert biomass energy to carrier energy products, some approaches such as thermochemical, biochemical, and coupled hybrid bio-refinery platforms or processes have been developed to ease access to green energetic biofuels with high value-added and clean energy chemicals [16].

Figure 1.

General processes of bioenergy production from biomass feedstock.


2. Thermochemical conversion

Thermochemical conversion is defined as the degradation of organic matters due to heat exposition of biomass and chemical reactions. The process is mainly categorized in some processes named combustion, torrefaction, gasification, pyrolysis, and hydrothermal [17, 18]. In the thermochemical conversion of biomass, heat and catalysts are applied to transform biopolymers of biomass into biofuels and other valuable chemical components [19]. Based on the process the outputs mainly are biochar (carbon-rich solid residue,) liquid biofuel including bio-oil, bio-crude oil and tar (condensable vapors), and syngas (non-condensable gases) [20].

2.1 Combustion

Combustion is defined as high-temperature exothermic oxidation of biomass in the presence of oxygen and the presence of consecutive heterogeneous and homogeneous reactions which resulted in the production of heat as the main product. Combustion is divided into four stages: drying, pyrolysis (de-volatilization), volatiles combustion, and char combustion. As soon as biomass particles enter the burning environment, the particles moisture evaporate, on further heating, volatile gases and tars are released which follow by their combustion. The remaining char will essentially retain its original shape. The process outcomes mostly depend on the properties of the feedstock, particle size, temperature, and combustion atmosphere that can have char and ash (typically includes inorganic oxides and carbonates) as the solid byproducts of combustion [21, 22]. Carbon dioxide (CO2) and water vapor (H2O) are also produced during the complete combustion of biomass, however, it is not achieved under any conditions which cause the production of carbon monoxide (CO), methane (CH4), non-methane hydrocarbons (NMHCs), particulate matter (PM) and nitrogen and sulfur species mainly NOx and SOx during the incomplete combustion the biomass material [23]. The drawbacks are mainly controlled through modification of combustion processes via flue gas recirculation, boiler modification, and re-burning technology which often mitigate such emissions economically [24].

2.2 Hydrothermal conversion

The hydrothermal conversion process is a suitable technology especially for wet biomass into bio-fuel which is defined as a thermochemical transformation of biomass in high temperatures (100–700°C) and high pressures (5–40 MPa) in a liquid media or hot supercritical water [25]. In hydrothermal liquefaction (HTL) as an important hydrothermal process, raised temperatures (200–350°C) and high pressures (5–20 MPa) in the presence of solvent (sub−/super-critical water) applied to boost biomass decomposition and reformation to produce bio-crude (as the main output) bio-char, water-soluble organic polar fractions and gaseous [26, 27, 28]. During the HTL process, several complex mechanisms such as hydrolysis activate which degrade biomass macromolecules and then decompose them into smaller components to reactive fragments by bond cleavage and several reactions such as dehydration, dehydrogenation, deoxygenation, and decarboxylation while some complex chemicals such as bio-crude produce through depolymerization [29, 30, 31]. Derived bio-crude oil through HTL shows a higher heating value between 36 to 40 MJ/kg which is close to petroleum-derived oil characteristics [32, 33, 34]. HTL technology which is currently at the pilot/demonstration scale has several positive points in comparison to another thermochemical process including the ability to use high moisture content biomass inputs, lower operating temperature, higher throughput, and removal of oxygen from the bio-crude [35, 36]. In addition to biomass feedstock elemental composition, various operational parameters such as temperature, reaction time, pressure, presence of a catalyst (catalyst type and amount), solvent/biomass ratio, and reaction medium influence the process in terms of quantity and quality of produced bio-crude [37, 38, 39, 40]. HTL in comparison with other processes reveals various advantages including application feedstock with high moisture content without drying requirement, exploitation of the properties of superheated fluids to reduce mass transfer resistances, and penetration of the solvent to biomass structure to enable the fragmentation of biomass molecules due to high pressure which result to obtain high-quality bio-crude oil [41].

Hydrothermal Carbonization (HTC) is the second hydrothermal conversion which is performed in a temperature range of 180 to 350°C during which the biomass is submerged in water and heated under pressure (2 to 6 MPa) for 5 to 240 min while the main product of HTC is hydro-char [42]. Hydrothermal gasification (Supercritical water gasification) is a thermochemical conversion process in which, wet biomass was directly converted into combustible gases under 400 to 500°C (processed till 700°C) and 24 to 36 MPa pressure with/without catalyst aid. Further, supercritical water is (<374°C, 22.1 MPa pressure) is acting as a reactant and solvent that splits organic compounds. During gasification, decomposition of biomass causes dissolution of reactive species that promote the yield of gaseous products by impeding the biochar production at supercritical [39, 43]. The hydrothermal gasification technologies) have considerable economic, environmental, and technical advantages over other high-demand energy conversion technologies. These processes are compatible with wet feedstock (not suitable candidates for another thermochemical process). Also due to the reactions taking place at lower temperatures (less energy consumption) and the use of a wide range of feedstock processing [44]. Due to the unique dissolution properties of water during hydrothermal gasification, less coke and tars are produced while pressurized produced syngas is typically free from gaseous that do not usually require further processing and can lower compression costs [45].

2.3 Pyrolysis

Pyrolysis defines as thermal decomposition in the absence of oxygen to break biomass chemical bonds in high temperatures to produce biofuels [46]. Depending on process requirement and desired product the process temperatures vary between 280 to 1000°C [47, 48]. During the process, generally three-step mechanisms including de-hydrogenation, de-polymerization and fragmentation occur to transfer biomass to biofuel [49]. The percentage of main products including bio-oil and bio-char and bio-syngas as the byproduct differ depending on heating rate, solid residence time, and temperature as the main operational parameters in the process [50]. Lower pyrolysis temperatures and longer residence times (Slow pyrolysis) tend to produce more bio-char while high temperatures and longer residence times increase the production of gas. Moderate or high temperatures and short residence times (Fast and Flash pyrolysis) resulted in more bio-oil [51]. Several technologies and reactors with the semi-continuous or continuous process have been developed on a laboratory scale and considered as suitable reactors for commercialization of pyrolysis including Bubbling Fluidized Bed (BFB), Circulating Fluidized Bed (CFB), Circulating Spouted Bed (CSB), Rotary Cone (RC), Ablative reactor and Screw/auger reactor [52]. In addition, plasma pyrolysis reactor configuration, Vacuum pyrolysis, Microwave-assisted, and solar-assisted pyrolysis have been extensively investigated as the state-of-the-art technologies related to biomass pyrolysis which demonstrates their advantages over conventional electrical-heating-assisted biomass pyrolysis [53, 54].

The higher heating value (HHV) of the bio-oils normally ranges between 15 and 20 MJ/kg which is only 40–50% of the conventional petroleum fuels with HHV between 42 to 45 MJ/kg. The HHV of the bio-oils can be approximately calculated through some empirical equations formulated by elemental analysis of the bio-oil (CHNOS analysis plus ash content) as represented in (Eq. (1)) [49].


Since the liquid bio-fuel which contains oxygenated compounds such as acids, alcohols, phenols, ketones, and esters is commonly considered as poor quality, thus, it requires upgrading into a higher value-added product through promising methods such as catalytic steam reforming. The process of bio-oil quality upgrading and the water gas shift (WGS) reaction is presented in (Eq. (2)) and (Eq. (3)) respectively [55].


2.4 Gasification

In the condition in which production of biogas fuel is required, the gasification process under a reduced oxygen atmosphere applies to convert solid biomass to a gaseous fuel known as synthesis gas [56]. The biomass gasification process is conducted in four main stages including drying of the biomass particles followed by pyrolysis of the dried biomass particles(de-volatilization), in the next step partial oxidation of the pyrolysis gases and/or char occurred and finally char gasification happened (reduction). In contrast to pyrolysis, the feed is brought into contact with a gasifying agent (air) to ease the reaction between oxygen and biomass content in higher temperatures between 600°C and 1500°C. The produced gas contains various percentages of CO, H2, CH4, CO2, H2O, N2, and eleven other gases depending on the quality of the biomass used and the way gasification is conducted [57, 58]. Fixed bed, fluidized bed, entrained flow, rotary kiln reactor, and plasma reactor can be utilized based on the operational conditions in gasification [59]. Briefly, biomass feedstock type and composition, particle size, moisture and ash content (higher ash content cause ash agglomeration during the process especially in high temperature), operational temperature, pressure and residence time, gasifying media, equivalence ratio (actual air-to-biomass ratio), steam-to-biomass ratio (S/B) and finally catalyst type and amount are the most prominent factors during the gasification process [60].

According to the Figure 2 Biomass pass their steps of drying, pyrolysis, and partial oxidation before reach to the gasification point. Each stage is accrued in a specific range of temperature [61]. After the drying step, biomass is decomposed to solid char and pyrolysis which will be faced with the second decomposition stage and conversion into decomposes gases (non-condensable) and volatile hydrocarbons. Then, these products react with the oxidizing agent to produce syngas and smaller amounts of lower hydrocarbon gases (C1–C4) [62]. The global reaction inside the gasifier (except for unconverted solid carbon) can be described as (Eq. (4)) while for simplicity only the amount of hydrogen, carbon, nitrogen, oxygen, and sulfur of the biomass are considered in the model [58]:

Figure 2.

Gasification steps and the temperature zones.


One of the important issues during gasification is the removal of tar which is formed during the pyrolysis stage (as a transition step toward the gasification). Various tars components are released which can condense and form sticky deposits by quenching downstream when they contact cold points of the gasification system [63]. Tar roots severe damage to gas engines or turbines through fouling and coking in the system. Therefore, it is very important to reduce the tar content and particulate matter, in the syngas below the level of 100 mg/m3 and 50 mg/m3 respectively to apply for gas engine consumption [64]. Therefore, even though gasification is a relatively well-known technology, the share of gasification in overall energy demand is insignificant due to barriers concerning biomass harvesting and storage, biomass pre-treatment (drying, grinding, and densification), gas cleaning (physical, thermal or catalytic), process efficiency and syngas quality issues [65].


3. Biochemical conversion

3.1 Anaerobic digestion

In addition to thermochemical operation, bio-chemical processes such as anaerobic digestion (AD) and fermentation are promising technology as a renewable source of energy products [66, 67]. Regarding human health, environment, economy, and energy conservation issues, AD systems have attracted remarkable attention by the production of bio-methane gas (renewable energy source) through bio-chemical conversion of biodegradable wastes [68]. AD process has occurred in an insufficient O2 atmosphere which prepares suitable conditions for activation of the microorganism to degrade organic matter into biogas [69]. To convert the feedstock to bio-methane, a series of bi-metabolism steps including hydrolysis/acidogenesis, acetogenesis, and methanogenesis occurred in the AD systems reactors [70]. During the first stage, the high molecular weight complex insoluble organic matter is degraded into simple soluble molecules by the extracellular enzymes [69]. During the hydrolysis phase, the organic components of carbohydrate, protein, and lipid polymers are hydrolyzed into simple sugar, amino acid, and long-chain fatty acid respectively [71]. Meanwhile, monosaccharides are produced through hydrolysis of the insoluble compounds of cellulose and hemicellulose by enzymatic microorganisms (Streptococcus and Enterobacterium) [72]. However, at this step, rigid lignin structure which is resistant to the penetration of microorganisms requires delignification as a pretreatment process to undergo biodegradation [73]. In the next step acidogenic bacterizes such as Clostridium, Peptococcus Anaerobus, Lactobacillus, Psychrobacter, Anaerococcus, Bacteroides, Acetivibrio, Butyrivibrio, Halocella, and Actinomyces (highly active fermenter and the most abundant bacterizes in AD) applied to dissolve and bounded oxygen in the solution and carbon [74, 75]. At the final steps of the process, acetotrophic, hydrogenotrophic and methylotrophic pathways occurred which are the main route of methane production [76]. In the methanogenesis phase, acetic acid and hydrogen that formed in the acetogenesis phase are transformed to biomethane via methanogenic microorganisms while the pH in the system will increase to neutral values within the range of 6.8–8 [71]. The methanogenesis phase effectiveness is very reliant on the balanced relationship between bio-kinetics of microorganisms (Crenarchaeota, Euryarchaeota, etc.) with its growth environment (food supply and accessibility) [77, 78].

Working conditions in AD generally influence the formation of the produced biogas. The degradation process is affected by several factors including operation temperature, carbon to nitrogen (C: N) ratio, pH level, organic loading rate (OLR), Hydraulic retention time (HRT), and stirring [76]. Defining an optimum temperature that causes the stability of the enzymes and co-enzymes activity can have a significant influence on AD and bio-methane production while the efficient AD process is dependent on the optimum temperature [79, 80]. The optimum temperature for digestion process operation of anaerobic microorganisms could be range in psychrophilic (10–30°C), mesophilic (30–40°C), or thermophilic (50–60°C) conditions [81].

Alkalinity or acidity of the substrate is categorized by the important parameter of pH value. The stability of acidogenic activity and methanogenic bacteria is directly influenced by the changes in [82, 83]. Ideally, the optimum pH for acidogenesis and methanogenic stages place in a range from pH 5.5 to 6.5 and from 6.5 to 8.2, respectively [84]. Neutralization is essential in cases of excessively high or low pH during the anaerobic digestion feedstock especially before the plant is fed. The pH is chemically improved by adding the base, such as lime, to the reactor if negligible acidification happens during the AD process [85]. The next effective parameter in the AD process is the ratio of carbon to nitrogen in organic material [86]. A high C: N ratio indicated the low nitrogen sources that are needed to sustain the material supply for digestion. Meanwhile, the low C: N ratio signified the potential of NH4+ inhibition in the digestion process. Ideally, the optimum C: N ratio for the AD process is within the range of 20–35 [87]. The HRT which is defined as the retention period of the substrates inside the digester can vary based on the feedstock composition and digester temperature [88]. High HRT will result in improvement in biogas yields while the lower HTR is interested since decreasing cost of production and enhancement of process efficiency [89, 90]. The OLR also can affect The AD process negatively or positively [91]. Minor OLRs may cause malnutrition of microorganisms and adversely affects the AD while in contrast, a great ORL ratio may cause insufficient resources to support the development of microbial organisms [92, 93]. Temperature condition, characteristics of the substrates, and HRT of the AD operation impacts the OLR behavior and amount [76].

In terms of technological requirements, several types of reactors have been developed that generally can classify into wet or dry reactors based on their total solid contents [94]. In the design and operation of the anaerobic reactor, two parameters of reactor volume to daily flow and OLR have the most important value. The dry types (serve the feedstock with a solid concentration of more than 15%) itself could be categorized into three different types including horizontal plug-flow, vertical plug-flow, and non-flow (batch type) [95, 96]. In contrast, the wet digesters are defined to serve the feedstock having a total solid less than 15%value [97].

3.2 Fermentation

Fermentation is considered as another biochemical technology that can be applied to get energy from biomass. Fermentation defines as a process of central metabolism in which alcohol (for instance ethanol) or acid is produced by an organism through the conversion of carbohydrates, such as starch or sugar. Wines, beers, and ciders are traditionally carried out with fermentation process by using Saccharomyces cerevisiae strains, the most common and commercially available yeast [98, 99]. The utilization of feedstock such as wheat, corn, sugarcane, etc. for biofuel production (first generation biofuel) causes the problem of food security. The use of biomass feedstock (second generation) in bioethanol production solves this matter in many aspects [100]. Depending on fermentation conditions such as temperature, pH, aeration, and nutrient supplementation microorganisms are susceptible to lignocellulosic hydrolysate to produce bio ethanol [101]. Nevertheless, the production of biofuel through fermentation of promising sources (rice straw, wheat straw, corn straw, and sugarcane bagasse) is quite interesting but still meets some technical issues to release the fermentable sugars from lignocellulosic. The problem necessitates a pretreatment process including Physical (mechanical, extrusion, Irradiation), chemical (organosolv, ozonolysis, ionic liquid, acid, and alkali washing) physicochemical, and biological [102].

Several fermentation technologies such as batch and continues and fed-batch modes have been utilized. The complete subtract and highest conversion rate but lower volumetric production can be done through batch mode rather than continuous mode which led to high productivity (due to high dilution ratio and long duration process) and steady residual concentration [103]. Overly, batch fermentation could be applied for high viscous feedstock, while continuous fermentation methods can offer better plant capacity utilization [104]. During the batch and continuum operation, the addition of Indigenous Consortium Streptococcus sp. or enzyme glucoamylase has been reported that helps to fermentation process [105, 106].


4. Extraction

In addition to the thermochemical and biochemical process, the extraction method indeed is applied to oil from oil seeds or nuts materials such as hazelnut, almond nut, sesame seed, sunflower seed, or rapeseed. Traditionally, the oil can be extracted through cold pressing, hot pressing, or solvent extraction methods where the pressing is a mechanical method while solvent extraction is a chemical method [107, 108]. The pressing technique (solvent-free) is traditionally applied to extract edible oil from various sources such as nut or seed samples. Before the extraction sample preparation through various pretreatments on the sample is required before extraction in order to enhance the extraction efficiency [109]. The objectives of the pretreatment process are to destroy or soften the cellular structure of the sample and reduce the moisture content, which can increase the efficiency of the later extraction stage by destroying or softening the cellular structure of the sample and reduction of the seed moisture content [110]. The process is normally continued with solvent extraction (use solvent polar or non-polar) process due to the significant amount of oil remaining in the press cake, which is around 20–30%100. However new techniques such as microwave-assisted extraction [111], supercritical fluid extraction [112], ultrasound-assisted extraction can be applied in order to extract separate desired oil liquid from a solid–liquid sample [113].


5. Technology readiness level

It must be noticed that each mentioned process of bioenergy production is placed in a certain level of technical maturity as briefly demonstrated in the Figure 3 [114, 115, 116]. The maturity level of each technic is represented by a term which is called technical readiness level (TRL) and it is divided from lab scale (1–3), pilot-scale (4–6) to the highest level of maturity which is proven, tested, and qualified all parameters with a full commercial plant and industrialized scale (6–9) to produce products for public usage [114].

Figure 3.

General technical readiness level of each conversion process of biomass to bioenergy.



I would like to acknowledge and give my warmest thanks to my supporters at the University of Tehran who made this work possible.


Conflict of interest

The authors declare no conflict of interest.


  1. 1. Baz K, Cheng J, Xu D, Abbas K, Ali I, Ali H, et al. Asymmetric impact of fossil fuel and renewable energy consumption on economic growth: A nonlinear technique. Energy [Internet]. 2021;226:120357. Available from:
  2. 2. Barber J. Hydrogen derived from water as a sustainable solar fuel: Learning from biology. Sustainable Energy and Fuels [Internet]. 2018;2(5):927-935. DOI: 10.1039/C8SE00002F
  3. 3. Jeong J, Ko H. Bracing for Climate Impact: Renewables as a Climate Change Adaptation Strategy [Internet]. Abu Dhabi; 2021. pp. 1-104. Available from:
  4. 4. Capellán-Pérez I, Arto I, Polanco-Martínez JM, González-Eguino M, Neumann MB. Likelihood of climate change pathways under uncertainty on fossil fuel resource availability. Energy & Environmental Science Journal [Internet]. 2016;9(8):2482-2496. DOI: 10.1039/C6EE01008C
  5. 5. Shen N, Wang Y, Peng H, Hou Z. Renewable energy green innovation, fossil energy consumption, and air pollution—Spatial empirical analysis based on China. Sustainability. 2020;12. Article DOI: 10.3390/su12166397
  6. 6. Schwartz SE. Uncertainty in climate sensitivity: Causes, consequences, challenges. Energy & Environmental Science Journal [Internet]. 2008;1(4):430-453. DOI: 10.1039/B810350J
  7. 7. Bui M, Adjiman CS, Bardow A, Anthony EJ, Boston A, Brown S, et al. Carbon capture and storage (CCS): The way forward. Energy & Environmental Science Journal [Internet]. 2018;11(5):1062-1176. DOI: 10.1039/C7EE02342A
  8. 8. Schmidt J, Gruber K, Klingler M, Klöckl C, Ramirez Camargo L, Regner P, et al. A new perspective on global renewable energy systems: Why trade in energy carriers matters. Energy & Environmental Science Journal [Internet]. 2019;12(7):2022-2029. DOI: 10.1039/C9EE00223E
  9. 9. Davis M, Moronkeji A, Ahiduzzaman M, Kumar A. Assessment of renewable energy transition pathways for a fossil fuel-dependent electricity-producing jurisdiction. Energy for Sustainable Development [Internet]. 2020;59:243-261. Available from:
  10. 10. Atsu F, Adams S. Energy consumption, finance, and climate change: Does policy uncertainty matter? Journal of Economic Analysis & Policy [Internet]. 2021;70:490-501. Available from:
  11. 11. Demirbas A. Biofuels [Internet]. Angewandte Chemie International Edition. 2009;6(11):951-952. London: Springer London; 15-38 p. (Green Energy and Technology; vol. 13). Available from:
  12. 12. Liu X, Li N, Liu F, Mu H, Li L, Liu X. Optimal design on fossil-to-renewable energy transition of regional integrated energy systems under CO2 emission abatement control: A case study in Dalian, China. Energies. 2021;14. Article DOI: 10.3390/en14102879
  13. 13. Creutzig F, Breyer C, Hilaire J, Minx J, Peters GP, Socolow R. The mutual dependence of negative emission technologies and energy systems. Energy & Environmental Science Journal [Internet]. 2019;12(6):1805-1817. DOI: 10.1039/C8EE03682A
  14. 14. Zhao B, Wang H, Hu Y, Gao J, Zhao G, Ray MB, et al. Hydrothermal Co-liquefaction of lignite and lignocellulosic biomass with the addition of formic acid: Study on product distribution, characteristics, and synergistic effects. Industrial & Engineering Chemistry Research [Internet]. 2020;59(50):21663-21675. DOI: 10.1021/acs.iecr.0c04619
  15. 15. Osman AI, Mehta N, Elgarahy AM, Al-Hinai A, Al-Muhtaseb AH, Rooney DW. Conversion of biomass to biofuels and life cycle assessment: A review. Environmental Chemistry Letters [Internet]. 2021;19(6):4075-4118. DOI: 10.1007/s10311-021-01273-0
  16. 16. Kumar G, Dharmaraja J, Arvindnarayan S, Shoban S, Bakonyi P, Saratale GD, et al. A comprehensive review on thermochemical, biological, biochemical and hybrid conversion methods of bio-derived lignocellulosic molecules into renewable fuels. Fuel [Internet]. 2019;251:352-367. Available from:
  17. 17. Nazari L, Xu C (Charles), Ray MB. Advanced Technologies (Biological and Thermochemical) for Waste-to-Energy Conversion. Singapore: Springer; 2021. pp. 55-95. Available from:
  18. 18. Teh JS, Teoh YH, How HG, Sher F. Thermal analysis Technologies for Biomass Feedstocks: A state-of-the-art review. Processes [Internet]. 2021;9(9):1610. Available from:
  19. 19. Dhyani V, Bhaskar T. A comprehensive review on the pyrolysis of lignocellulosic biomass. Renew Energy [Internet]. 2018;129:695-716. Available from:
  20. 20. Daful AG, Chandraratne RM. Biochar production from biomass waste-derived material. In: Encyclopedia of Renewable and Sustainable Materials [Internet]. Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford, USA: Elsevier Inc.; 2020. pp. 370-378. Available from:
  21. 21. Adams P, Bridgwater T, Lea-Langton A, Ross A, Watson I. Biomass conversion technologies. In: Greenhouse Gases Balances of Bioenergy Systems [Internet]. Elsevier; 2018. pp. 107-139. Available from:
  22. 22. Mandø M. Direct combustion of biomass. In: Biomass Combustion Science, Technology and Engineering [Internet]. Sawston, Cambridge, UK: Woodhead Publishing Limited, Elsevier; 2013. pp. 61-83. Available from:
  23. 23. Demirbas A. Hazardous emissions from combustion of biomass. Energy Sources, Part A: Recovery, Utilization and Environmental Effects. 2007;30(2):170-178. Available from:
  24. 24. Oluwoye I, Altarawneh M, Gore J, Dlugogorski BZ. Products of incomplete combustion from biomass reburning. Fuel [Internet]. 2020;274:117805. Available from:
  25. 25. Tran K-Q. Fast hydrothermal liquefaction for production of chemicals and biofuels from wet biomass – The need to develop a plug-flow reactor. Bioresource Technology [Internet]. 2016;213:327-332. Available from:
  26. 26. Leng L, Zhang W, Leng S, Chen J, Yang L, Li H, et al. Bioenergy recovery from wastewater produced by hydrothermal processing biomass: Progress, challenges, and opportunities. Science of the Total Environment [Internet]. 2020;748:142383. Available from:
  27. 27. Arun J, Gopinath KP, SundarRajan P, Malolan R, Adithya S, Sai Jayaraman R, et al. Hydrothermal liquefaction of Scenedesmus obliquus using a novel catalyst derived from clam shells: Solid residue as catalyst for hydrogen production. Bioresource Technology [Internet]. 2020;310:123443. Available from:
  28. 28. Kumar G, Shobana S, Chen W-H, Bach Q-V, Kim S-H, Atabani AE, et al. A review of thermochemical conversion of microalgal biomass for biofuels: Chemistry and processes. Green Chemistry [Internet]. 2017;19(1):44-67. DOI: 10.1039/C6GC01937D
  29. 29. Gollakota ARK, Kishore N, Gu S. A review on hydrothermal liquefaction of biomass. Renewable & Sustainable Energy Reviews [Internet]. 2018;81:1378-1392. Available from:
  30. 30. Katakojwala R, Kopperi H, Kumar S, Venkata MS. Hydrothermal liquefaction of biogenic municipal solid waste under reduced H2 atmosphere in biorefinery format. Bioresource Technology [Internet]. 2020;310:123369. Available from:
  31. 31. Devi TE, Parthiban R. Hydrothermal liquefaction of Nostoc ellipsosporum biomass grown in municipal wastewater under optimized conditions for bio-oil production. Bioresource Technology [Internet]. 2020;316:123943. Available from:
  32. 32. Cheng F, Jarvis JM, Yu J, Jena U, Nirmalakhandan N, Schaub TM, et al. Bio-crude oil from hydrothermal liquefaction of wastewater microalgae in a pilot-scale continuous flow reactor. Bioresource Technology [Internet]. 2019;294:122184. Available from:
  33. 33. Khan N, Mohan S, Dinesha P. Regimes of hydrochar yield from hydrothermal degradation of various lignocellulosic biomass: A review. Journal of Cleaner Production [Internet]. 2021;288:125629. Available from:
  34. 34. Arun J, Gopinath KP, SundarRajan P, Malolan R, AjaySrinivaasan P. Hydrothermal liquefaction and pyrolysis of Amphiroa fragilissima biomass: Comparative study on oxygen content and storage stability parameters of bio-oil. Bioresource Technology Reports [Internet]. 2020;11:100465. Available from:
  35. 35. Kim SJ, Um BH. Effect of thermochemically fractionation before hydrothermal liquefaction of herbaceous biomass on biocrude characteristics. Renew Energy [Internet]. 2020;160:612-622. Available from:
  36. 36. Lozano EM, Pedersen TH, Rosendahl LA. Integration of hydrothermal liquefaction and carbon capture and storage for the production of advanced liquid biofuels with negative CO2 emissions. Applied Energy [Internet]. 2020;279:115753. Available from:
  37. 37. Tekin K, Karagöz S, Bektaş S. A review of hydrothermal biomass processing. Renewable & Sustainable Energy Reviews [Internet]. 2014;40:673-687. Available from:
  38. 38. Akhtar J, Amin NAS. A review on process conditions for optimum bio-oil yield in hydrothermal liquefaction of biomass. Renewable & Sustainable Energy Reviews [Internet]. 2011;15(3):1615-1624. Available from:
  39. 39. Mathimani T, Mallick N. A review on the hydrothermal processing of microalgal biomass to bio-oil - knowledge gaps and recent advances. Journal of Cleaner Production [Internet]. 2019;217:69-84. Available from:
  40. 40. Li Y, Zhu C, Jiang J, Yang Z, Feng W, Li L, et al. Catalytic hydrothermal liquefaction of Gracilaria corticata macroalgae: Effects of process parameter on bio-oil up-gradation. Bioresource Technology [Internet]. 2021;319:124163. Available from:
  41. 41. Kaur R, Biswas B, Kumar J, Jha MK, Bhaskar T. Catalytic hydrothermal liquefaction of castor residue to bio-oil: Effect of alkali catalysts and optimization study. Industrial Crops and Products [Internet]. 2020;149:112359. Available from:
  42. 42. Heidari M, Dutta A, Acharya B, Mahmud S. A review of the current knowledge and challenges of hydrothermal carbonization for biomass conversion. Journal of the Energy Institute [Internet]. 2019;92(6):1779-1799. Available from:
  43. 43. Rodriguez Correa C, Kruse A. Supercritical water gasification of biomass for hydrogen production – Review. The Journal of Supercritical Fluids [Internet]. 2018;133:573-590. Available from:
  44. 44. Elias Bamaca Saquic B, Irmak S, Wilkins M, Smith T. Effect of precursors on graphene supported platinum monometalic catalysts for hydrothermal gasification of biomass compounds to hydrogen. Fuel [Internet]. 2021;290:120079. Available from:
  45. 45. Okolie JA, Epelle EI, Nanda S, Castello D, Dalai AK, Kozinski JA. Modeling and process optimization of hydrothermal gasification for hydrogen production: A comprehensive review. The Journal of Supercritical Fluids [Internet]. 2021;173:105199. Available from:
  46. 46. Bridgwater AV. Review of fast pyrolysis of biomass and product upgrading. Biomass and Bioenergy [Internet]. 2012;38:68-94. Available from:
  47. 47. Fahmy TYA, Fahmy Y, Mobarak F, El-Sakhawy M, Abou-Zeid RE. Biomass pyrolysis: Past, present, and future. Environment, Development and Sustainability [Internet]. 2020;22(1):17-32. DOI: 10.1007/s10668-018-0200-5
  48. 48. Patel A, Agrawal B, Rawal BR. Pyrolysis of biomass for efficient extraction of biofuel. Energy Sources, Part A: Recovery, Utilization and Environmental Effects. 2020;42(13):1649-1661. DOI: 10.1080/15567036.2019.1604875
  49. 49. Kan T, Strezov V, Evans TJ. Lignocellulosic biomass pyrolysis: A review of product properties and effects of pyrolysis parameters. Renewable & Sustainable Energy Reviews [Internet]. 2016;57:1126-1140. Available from:
  50. 50. Perera SMHD, Wickramasinghe C, Samarasiri BKT, Narayana M. Modeling of thermochemical conversion of waste biomass – A comprehensive review. Biofuel Research Journal [Internet]. 2021;8(4):1481-1528. Available from:
  51. 51. Uddin MN, Techato K, Taweekun J, Mofijur M, Rasul MG, Mahlia TMI, et al. An overview of recent developments in biomass pyrolysis technologies. Energies [Internet]. 2018;11(11):3115. Available from:
  52. 52. Qureshi KM, Kay Lup AN, Khan S, Abnisa F, Wan Daud WMA. A technical review on semi-continuous and continuous pyrolysis process of biomass to bio-oil. Journal of Analytical and Applied Pyrolysis [Internet]. 2018;131:52-75. Available from:
  53. 53. Wang G, Dai Y, Yang H, Xiong Q, Wang K, Zhou J, et al. A review of recent advances in biomass pyrolysis. Energy & Fuels [Internet]. 2020;34(12):15557-15578. DOI: 10.1021/acs.energyfuels.0c03107
  54. 54. Raza M, Inayat A, Ahmed A, Jamil F, Ghenai C, Naqvi SR, et al. Progress of the Pyrolyzer reactors and advanced Technologies for Biomass Pyrolysis Processing. Sustainability [Internet]. 2021;13(19):11061. Available from:
  55. 55. Setiabudi HD, Aziz MAA, Abdullah S, Teh LP, Jusoh R. Hydrogen production from catalytic steam reforming of biomass pyrolysis oil or bio-oil derivatives: A review. International Journal of Hydrogen Energy [Internet]. 2020;45(36):18376-18397. Available from:
  56. 56. Cerinski D, Baleta J, Mikulčić H, Mikulandrić R, Wang J. Dynamic modelling of the biomass gasification process in a fixed bed reactor by using the artificial neural network. Cleaner Engineering and Technology [Internet]. 2020;1:100029. Available from:
  57. 57. Richardson Y, Drobek M, Julbe A, Blin J, Pinta F. Chapter 8 - biomass gasification to produce syngas. In: Pandey A, Bhaskar T, Stöcker M, Sukumaran RK, editors. Recent Advances in Thermo-Chemical Conversion of Biomass [Internet]. Boston: Elsevier; 2015. pp. 213-250. Available from:
  58. 58. Gambarotta A, Morini M, Zubani A. A non-stoichiometric equilibrium model for the simulation of the biomass gasification process. Applied Energy [Internet]. 2018;227:119-127. Available from:
  59. 59. Ren J, Cao J-P, Zhao X-Y, Yang F-L, Wei X-Y. Recent advances in syngas production from biomass catalytic gasification: A critical review on reactors, catalysts, catalytic mechanisms and mathematical models. Renewable & Sustainable Energy Reviews [Internet]. 2019;116:109426. Available from:
  60. 60. Sikarwar VS, Zhao M, Fennell PS, Shah N, Anthony EJ. Progress in biofuel production from gasification. Progress in Energy and Combustion Science [Internet]. 2017;61:189-248. Available from:
  61. 61. Hendriyana H. Effect of equivalence ratio on the Rice husk gasification performance using updraft gasifier with air suction mode. Jurnal Bahan Alam Terbarukan [Internet]. 2020;9(1):30-35. Available from:
  62. 62. Saleem F, Harris J, Zhang K, Harvey A. Non-thermal plasma as a promising route for the removal of tar from the product gas of biomass gasification – A critical review. Chemical Engineering Journa [Internet]. 2020;382:122761. Available from:
  63. 63. Valderrama Rios ML, González AM, Lora EES, Almazán del Olmo OA. Reduction of tar generated during biomass gasification: A review. Biomass and Bioenergy [Internet]. 2018;108:345-370. Available from:
  64. 64. Hwang JG, Choi MK, Choi DH, Choi HS. Quality improvement and tar reduction of syngas produced by bio-oil gasification. Energy [Internet]. 2021;236:121473. Available from:
  65. 65. Mikulandrić R, Böhning D, Böhme R, Helsen L, Beckmann M, Lončar D. Dynamic modelling of biomass gasification in a co-current fixed bed gasifier. Energy Conversion and Management [Internet]. 2016;125:264-276. Available from:
  66. 66. Hunter SM, Blanco E, Borrion A. Expanding the anaerobic digestion map: A review of intermediates in the digestion of food waste. Science of the Total Environment [Internet]. 2021;767:144265. Available from:
  67. 67. Batista AP, Gouveia L, Marques PASS. Fermentative hydrogen production from microalgal biomass by a single strain of bacterium Enterobacter aerogenes – Effect of operational conditions and fermentation kinetics. Renew Energy [Internet]. 2018;119:203-209. Available from:
  68. 68. Mao C, Feng Y, Wang X, Ren G. Review on research achievements of biogas from anaerobic digestion. Renewable & Sustainable Energy Reviews [Internet]. 2015;45:540-555. Available from:
  69. 69. Sytar O, Prasad MNV. Production of biodiesel feedstock from the trace element contaminated lands in Ukraine. In: Bioremediation and Bioeconomy [Internet]. Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford, USA: Elsevier Inc.; 2016. pp. 3-28. Available from:
  70. 70. Chiu SLH, Lo IMC. Reviewing the anaerobic digestion and co-digestion process of food waste from the perspectives on biogas production performance and environmental impacts. Environmental Science and Pollution Research [Internet]. 2016;23(24):24435-24450. Available from:
  71. 71. Strazzera G, Battista F, Garcia NH, Frison N, Bolzonella D. Volatile fatty acids production from food wastes for biorefinery platforms: A review. Journal of Environmental Management [Internet]. 2018;226:278-288. Available from:
  72. 72. Li W, Khalid H, Zhu Z, Zhang R, Liu G, Chen C, et al. Methane production through anaerobic digestion: Participation and digestion characteristics of cellulose, hemicellulose and lignin. Applied Energy [Internet]. 2018;226:1219-1228. Available from:
  73. 73. Koyama M, Yamamoto S, Ishikawa K, Ban S, Toda T. Inhibition of anaerobic digestion by dissolved lignin derived from alkaline pre-treatment of an aquatic macrophyte. Chemical Engineering Journa [Internet]. 2017;311:55-62. Available from:
  74. 74. Karthikeyan OP, Heimann K, Muthu SS, editors. Environmental footprints and eco-design of products and processes. In: Recycling of Solid Waste for Biofuels and Bio-Chemicals [Internet]. Singapore: Springer Singapore; 2016. Available from:
  75. 75. Ahammad SZ, Sreekrishnan TR. Energy from wastewater treatment. In: Bioremediation and Bioeconomy [Internet]. Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford, USA: Elsevier Inc.; 2016. pp. 523-536. Available from:
  76. 76. Zamri MFMA, Hasmady S, Akhiar A, Ideris F, Shamsuddin AH, Mofijur M, et al. A comprehensive review on anaerobic digestion of organic fraction of municipal solid waste. Renewable & Sustainable Energy Reviews [Internet]. 2021;137:110637. Available from:
  77. 77. Rada EC, editor. Biological Treatment of Solid Waste [Internet]. New York: Apple Academic Press; 2015. Available from:
  78. 78. Kigozi R, Aboyade A, Muzenda E. Biogas production using the organic fraction of municipal solid waste as feedstock. Int’l Journal of Research in Chemical, Metallurgical and Civil Engg. (IJRCMCE) 2014;1(1):108-114. ISSN: 2349-1442, EISSN: 2349-1450
  79. 79. Li D, Song L, Fang H, Shi Y, Li Y-Y, Liu R, et al. Effect of temperature on the anaerobic digestion of cardboard with waste yeast added: Dose-response kinetic assays, temperature coefficient and microbial co-metabolism. Journal of Cleaner Production [Internet]. 2020;275:122949. Available from:
  80. 80. Tabatabaei M, Aghbashlo M, Valijanian E, Kazemi Shariat Panahi H, Nizami A-S, Ghanavati H, et al. A comprehensive review on recent biological innovations to improve biogas production, part 1: Upstream strategies. Renew Energy [Internet]. 2020;146:1204-1220. Available from:
  81. 81. Toutian V, Barjenbruch M, Unger T, Loderer C, Remy C. Effect of temperature on biogas yield increase and formation of refractory COD during thermal hydrolysis of waste activated sludge. Water Resources [Internet]. 2020;171:115383. Available from:
  82. 82. Rajendran K, Mahapatra D, Venkatraman AV, Muthuswamy S, Pugazhendhi A. Advancing anaerobic digestion through two-stage processes: Current developments and future trends. Renewable & Sustainable Energy Reviews [Internet]. 2020;123:109746. Available from:
  83. 83. Zhang J, Kan X, Shen Y, Loh K-C, Wang C-H, Dai Y, et al. A hybrid biological and thermal waste-to-energy system with heat energy recovery and utilization for solid organic waste treatment. Energy [Internet]. 2018;152:214-222. Available from:
  84. 84. Zhang F, Zhang Y, Ding J, Dai K, van Loosdrecht MCM, Zeng RJ. Stable acetate production in extreme-thermophilic (70°C) mixed culture fermentation by selective enrichment of hydrogenotrophic methanogens. Scientific Reports [Internet]. 2015;4(1):5268. Available from:
  85. 85. Kouzi AI, Puranen M, Kontro MH. Evaluation of the factors limiting biogas production in full-scale processes and increasing the biogas production efficiency. Environmental Science and Pollution Research [Internet]. 2020;27(22):28155-28168. Available from:
  86. 86. Messineo A, Maniscalco MP, Volpe R. Biomethane recovery from olive mill residues through anaerobic digestion: A review of the state of the art technology. Science of the Total Environment [Internet]. 2020;703:135508. Available from:
  87. 87. Li D, Liu S, Mi L, Li Z, Yuan Y, Yan Z, et al. Effects of feedstock ratio and organic loading rate on the anaerobic mesophilic co-digestion of rice straw and cow manure. Bioresource Technology [Internet]. 2015;189:319-326. Available from:
  88. 88. Jain S, Jain S, Wolf IT, Lee J, Tong YW. A comprehensive review on operating parameters and different pretreatment methodologies for anaerobic digestion of municipal solid waste. Renewable & Sustainable Energy Reviews [Internet]. 2015;52:142-154. Available from:
  89. 89. Shi X-S, Dong J-J, Yu J-H, Yin H, Hu S-M, Huang S-X, et al. Effect of hydraulic retention time on anaerobic digestion of wheat straw in the Semicontinuous continuous stirred-tank reactors. BioMed Research International [Internet]. 2017;2017:1-6. Available from:
  90. 90. Aramrueang N, Rapport J, Zhang R. Effects of hydraulic retention time and organic loading rate on performance and stability of anaerobic digestion of Spirulina platensis. Biosystems Engineering [Internet]. 2016;147:174-182. Available from:
  91. 91. Guo J, Wang W, Liu X, Lian S, Zheng L. Effects of thermal pre-treatment on anaerobic co-digestion of municipal biowastes at high organic loading rate. Chemosphere [Internet]. 2014;101:66-70. Available from:
  92. 92. Zhang L, Loh K-C, Zhang J. Enhanced biogas production from anaerobic digestion of solid organic wastes: Current status and prospects. Bioresource Technology Reports [Internet]. 2019;5:280-296. Available from:
  93. 93. Dhanya BS, Mishra A, Chandel AK, Verma ML. Development of sustainable approaches for converting the organic waste to bioenergy. Science of the Total Environment [Internet]. 2020;723:138109. Available from:
  94. 94. Angelonidi E, Smith SR. A comparison of wet and dry anaerobic digestion processes for the treatment of municipal solid waste and food waste. Water and Environment Journal. 2015;29(4):549-557. Available from:
  95. 95. Van DP, Fujiwara T, Leu Tho B, Song Toan PP, Hoang MG. A review of anaerobic digestion systems for biodegradable waste: Configurations, operating parameters, and current trends. Environmental Engineering Research [Internet]. 2019;25(1):1-17. Available from:
  96. 96. Hinds GR, Lens PNL, Zhang Q, Ergas SJ. Microbial biomethane production from municipal solid waste using high solids anaerobic digestion. In: Microbial Fuels [Internet]. Boca Raton: CRC Press; 2018, 2017. pp. 153-188. Available from:
  97. 97. Rapport JL, Zhang R, Williams RB, Jenkins BM. Anaerobic digestion technologies for the treatment of municipal solid waste. International Journal of Environment and Waste Management [Internet]. 2012;9(1/2):100. Available from:
  98. 98. Maicas S. The role of yeasts in fermentation processes. Microorganisms [Internet]. 2020;8(8):1142. Available from:
  99. 99. Puligundla P, Smogrovicova D, Obulam VSR, Ko S. Very high gravity (VHG) ethanolic brewing and fermentation: A research update. Journal of Industrial Microbiology and Biotechnology [Internet]. 2011;38(9):1133-1144. Available from:
  100. 100. Devi A, Singh A, Bajar S, Pant D, Din ZU. Ethanol from lignocellulosic biomass: An in-depth analysis of pre-treatment methods, fermentation approaches and detoxification processes. Journal of Environmental Chemical Engineering [Internet]. 2021;9(5):105798. Available from:
  101. 101. Robak K, Balcerek M. Review of second-generation bioethanol production from residual biomass. Food Technology and Biotechnology [Internet]. 2018;56(2). Available from:
  102. 102. Pandiyan K, Singh A, Singh S, Saxena AK, Nain L. Technological interventions for utilization of crop residues and weedy biomass for second generation bio-ethanol production. Renew Energy [Internet]. 2019;132:723-741. Available from:
  103. 103. Ahmad A, Banat F, Taher H. A review on the lactic acid fermentation from low-cost renewable materials: Recent developments and challenges. Environmental Technology & Innovation [Internet]. 2020;20:101138. Available from:
  104. 104. Eş I, Mousavi Khaneghah A, Barba FJ, Saraiva JA, Sant’Ana AS, SMB H. Recent advancements in lactic acid production - a review. Food Research International [Internet]. 2018;107:763-770. Available from:
  105. 105. Peinemann JC, Demichelis F, Fiore S, Pleissner D. Techno-economic assessment of non-sterile batch and continuous production of lactic acid from food waste. Bioresource Technology [Internet]. 2019 Oct;289:121631 Available from:
  106. 106. Xu X, Zhang W, Gu X, Guo Z, Song J, Zhu D, et al. Stabilizing lactate production through repeated batch fermentation of food waste and waste activated sludge. Bioresource Technology [Internet]. 2020;300:122709. Available from:
  107. 107. Jahirul MI, Brown JR, Senadeera W, Ashwath N, Laing C, Leski-Taylor J, et al. Optimisation of bio-oil extraction process from beauty leaf (Calophyllum Inophyllum) oil seed as a second generation biodiesel source. Procedia Engineering [Internet]. 2013;56:619-624. Available from:
  108. 108. Yang S, Hallett I, Oh HE, Woolf AB, Wong M. Application of electrical impedance spectroscopy and rheology to monitor changes in olive (Olea europaea L.) pulp during cold-pressed oil extraction. Journal of Food Engineering [Internet]. 2019;245:96-103. Available from:
  109. 109. Hamm W, Hamilton RJ, Calliauw G, editors. Edible Oil Processing [Internet]. Chichester, UK: John Wiley & Sons, Ltd; 2013. Available from:
  110. 110. Ezeh O, Niranjan K, Gordon MH. Effect of enzyme pre-treatments on bioactive compounds in extracted Tiger nut oil and sugars in residual meals. Journal of the American Oil Chemists' Society [Internet]. 2016;93(11):1541-1549. Available from:
  111. 111. Gaber MAFM, Tujillo FJ, Mansour MP, Juliano P. Improving oil extraction from canola seeds by conventional and advanced methods. Food Engineering Reviews [Internet]. 2018;10(4):198-210. Available from:
  112. 112. da Silva RPFF, Rocha-Santos TAP, Duarte AC. Supercritical fluid extraction of bioactive compounds. TrAC Trends in Analytical Chemistry [Internet]. 2016;76:40-51 Available from:
  113. 113. Samaram S, Mirhosseini H, Tan CP, Ghazali HM. Ultrasound-assisted extraction and solvent extraction of papaya seed oil: Crystallization and thermal behavior, saturation degree, color and oxidative stability. Industrial Crops and Products [Internet]. 2014;52:702-708. Available from:
  114. 114. Shahbaz M, Al-Ansari T, Inayat A, Inayat M. Technical readiness level of biohydrogen production process and its value chain. In: Value-Chain of Biofuels [Internet]. Elsevier; 2022. pp. 335-355. Available from:
  115. 115. Stafford W, Lotter A, Brent A, Von MG. Biofuels technology: A look forward. WIDER Work Paper Series [Internet]. 2017. Available from:
  116. 116. Cerruti E, Di Gruttola F, Lauro G, Valentini TD, Fiaschi P, Sorrenti R, et al. Assessment of feedstocks and Technologies for Advanced Biofuel Production. E3S Web of Conferences [Internet]. 2020;197:05002. Available from:

Written By

Alireza Shafizadeh and Payam Danesh

Submitted: January 4th, 2022 Reviewed: January 7th, 2022 Published: March 3rd, 2022