Biomass Pretreatment Technologies Research Articles

Optimizing Biomass Pre-Treatment Technologies for BBJP Plants in Indonesia: A Multi-Criteria Decision Making Approach

The challenges of energy consumption and environmental sustainability are pronounced in the dynamic landscape of contemporary industries driven by Industry 4.0 technologies. Indonesia, heavily reliant on fossil fuels, charts a course toward a clean energy future with a National Energy Transition Roadmap for Net Zero Emission by 2060. This transition involves innovative strategies such as biomass co-firing and waste utilization in Solid Recovered Fuel (SRF) plants, known as Bahan Bakar Jumputan Padat (BBJP) plants. To optimize these BBJP plants, this study employs Multi-Criteria Decision Making (MCDM) methodologies, specifically the Analytical Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), to evaluate and select pre-treatment technologies. Criteria include capacity, conversion process, waste type, electricity consumption, operational ease, land requirement, and investment cost. Comparing bio-drying, thermal drying, and mechanical drying, AHP ensures consistent criterion weights, with TOPSIS ranking bio-drying as the most favorable, followed by thermal and mechanical drying. The study acknowledges global waste management challenges and introduces a mobile-modular containerized BBJP/SRF plant model, addressing installation, maintenance, scalability, and adaptability issues. While recognizing challenges, especially in pre-treatment processes, the research emphasizes the need for efficient and cost-effective solutions. Practical implications include enhanced decision-making in biomass drying, identification of technology advantages and disadvantages, and a commitment to address challenges for sustainable implementation. The study contributes to Indonesia's energy transition discourse, advocating the pivotal role of BBJP plants in balancing Industry 4.0 demands and environmental protection, providing insights for stakeholders and decision-makers in advancing sustainable waste-to-energy initiatives.

Multiscale investigation of the mechanism of biomass deconstruction in the dimethyl isosorbide/water Co-solvent pretreatment system

This study provides a fundamental understanding of the multiscale results on the biomass deconstruction mechanism by solvent DMI, contributing to the discovery of the green, efficient and sustainable lignocellulosic biomass pretreatment technologies.

Insights into the recent advances in the pretreatment of biomass for sustainable bioenergy and bio-products synthesis: Challenges and future directions

Recently, biomass has shown its viability as an alternative to fossil fuels. Due to the growing trend in greenhouse gas emissions generated by the continual burning of fossil fuel products, it will be advantageous for humanity to seek a more sustainable and renewable source of energy. Due to its availability, biomass has a promising approach as a feedstock for bioconversion processes that produce energy, fuels, and other chemicals. The carbon dioxide generated by burning biomass has no influence on atmospheric carbon dioxide since it is derived from a renewable source. Despite these benefits, its adoption in bioconversion and biorefinery processes has traditionally been hindered by its recalcitrant nature, as indicated by its intrinsic characteristics. Prior to any conversion process, biomass must be pretreated to enhance product recovery. To satisfy the rising need for renewable and sustainable energy sources, the present conversion efficiency must be improved and the biorefinery concept must transition from using just one biomass component (cellulose) to utilizing the complete biomass component. This study examines numerous pretreatment procedures used prior to any conversion process, the challenges faced, and the future of biomass pretreatment technologies. Physical, hydrothermal, chemical, oxidation, biological, and hybrid pretreatment techniques are evaluated. The review indicates that the ideal approach to biomass pretreatment must be able to deal with the recalcitrant nature of biomass, enhance the crystallinity of cellulose, and provide the greatest recovery of biofuels, bio-char, sugars, and other industrially relevant bioproducts. The data offered in this study will equip readers with the knowledge necessary to effectively identify solutions to pretreatment problems and energy generation from pretreated biomass.

Quantitative comparison of the delignification performance of lignocellulosic biomass pretreatment technologies for enzymatic saccharification.

Pretreatments for delignification are required for the enzymatic saccharification of lignocellulosic biomasses. However, in the current literature, various pretreatment approaches have been applied for the same kinds of biomass. To find the optimum pretreatments for biomaterials containing various lignin contents, in this study, a quantitative comparison was carried out on the delignification performance of 15 categories of pretreatments. In total, 1729 sets of biomass, cellulose, hemicellulose, and lignin recovery data were collected from 214 relevant studies. Box plots and Cate-Nelson-like graphs were applied for analyses. The results showed that alkali, oxidation, organic solvent, and multistep pretreatments generally were better at removing lignin and recovering cellulose. Moreover, among these four categories, alkali pretreatments had the best performance, increasing the saccharification efficiency by approximately five-fold. Considering both delignification performance and saccharification improvement, alkali pretreatments are currently considered to be the optimum pretreatment methods for enzymatic saccharification.

Prediction of the Behavior of Sunflower Husk Ash after Its Processing by Various Torrefaction Methods

Biomass can be considered an alternative to coal in the production of heat and electricity. Many types of biomass are waste from agriculture and the food industry. This waste is cheap, readily available, and replenished annually. However, most agricultural and food industry wastes (sugar cane pulp, olive and sunflower oil production wastes, straw, etc.) have ash with a low melting point. This leads to a rapid growth of ash deposits on the heating surfaces of boilers; as a result, the actual efficiency of boilers in which waste from agriculture and the food industry is burned is 45–50%. Known biomass pre-treatment technologies that allow for the fuel characteristics of biowaste. For example, leaching of biowaste in water at a temperature of 80–240 °C makes it possible to drastically reduce the content of alkali metal compounds in the ash, the presence of which reduces the melting point of the ash. However, this biomass pre-treatment technology is complex and requires additional costs for drying the treated biomass. We proposed to use torrefaction for pre-treatment of biomass, which makes it possible to increase the heat of combustion of biomass, increase the hydrophobicity of biomass, and reduce the cost of grinding it. However, we are not aware of studies that have studied the effect of torrefaction on the chemical composition of ash from the point of view of solving the problem of preventing the formation of agglomerates and reducing the growth rate of ash deposits on the convective heating surfaces of boilers. In this paper, the characteristics of sunflower husk subjected to torrefaction in an environment of superheated steam at a temperature of 300 °C and in an environment of gaseous products at a temperature of 250 °C are studied. All experiments were conducted using fluidized bed technology. The resulting biochar has a calorific value of 14.8–23% higher than the initial husk. To assess the behavior of sunflower husk ash, predictive coefficients were calculated. Torrefaction of sunflower husks does not exclude the possibility of slagging of the furnace but reduces the likelihood of slagging by 2.31–7.27 times. According to calculations, the torrefaction of sunflower husks reduces the likelihood of ash deposits on the convective heating surfaces of the boiler by 2.1–12.2 times. According to its fuel characteristics, the husk, after torrefaction in an environment of superheated steam, approaches wood waste, i.e., can be burned separately without additives or mixtures with other fuels with refractory ash.

Optimisation of Logistic Model Using Geographic Information Systems: A Case Study of Biomass-based Combined Heat & Power Generation in China

Biofuel large-scale application was constrained due to cost control. In order to reduce biofuel production cost and increase profitability, long-term strategy (strategic) and medium-term strategy (tactical) combined logistic model were assessed in this study. Geographic information system has been integrated into logistic model to minimize the effect of uncertainty on logistic modelling accuracy, with aims of transferring uncertainty problem to be certain. Combined heat and power generation plant as a case study present in logistic model, which provide a method in plant location and capacity selection criteria; logistic model design; and interaction between logistic model and local conditions. The logistic plan with compression as a pre-treatment technology has the optimal profitability performance, their properties affect the selection of the transport route, especially optimal for a lower availability of agricultural residues. With increased availability, torrefaction turns to more efficiency biomass pre-treatment technology due to storage cost significant reduction. With geographic information system transportation route assistance, logistic model transportation cost and CO2 emission has a 0.02% and 0.01% reduction.

Prediction and evaluation of fuel properties of hydrochar from waste solid biomass: Machine learning algorithm based on proposed PSO–NN model

Hydrothermal carbonization is an effective and environmentally friendly biomass pretreatment technology, which converts high moisture biomass into homogeneous, carbon–rich, and high calorific value solid hydrochar. This study aimed to predict the fuel properties of the hydrochar based on hydrothermal conditions and biomass characteristics by machine learning (ML) models. Artificial neural network (ANN) combined with particle swarm optimization (PSO) algorithm was proposed and developed based on 296 data points collected from abundant previous studies, and the prediction capability is analyzed with ordinary ANN model. The results showed that particle swarm optimization–neural network (PSO–NN) model with optimal hyper–parameters can reduce iteration time, and improve the stability and accuracy of ANN model. Fuels properties of hydrochar were predicted by PSO–NN model with R2 greater than 0.85 and the convergence speed is increased by 26.8%. Feature importance and correlation were explored by the integration of PSO–NN model and model explainer based on SHAP methodology. The result showed that the carbon content in raw biomass was the significant feature impacting mass yield, and the mass yield of hydrochar mainly depended on elemental composition of feedstock. The HTC temperature of water is the most important factor affecting HHV of the hydrochar, so raising hydrothermal temperature is the best way to improve the HHV. N content was considered as the most important parameter for the N/C molar ratio among all the evaluated features. The O content of the raw biomass had obvious influence on the ASH content of hydrochar, and the influence of operating conditions for ash content changes only accounted for 14.3%, which indicated that the removing efficiency of ash from biomass was low only by changing the operating conditions. Both DHD and DCD of hydrochars were most affected by temperature, and the ash content played a significant role in the prediction of the DHD. Furthermore, we found that most of ash remained in feedstock negatively affected DHD of the hydrochar but had a positive effect on DCD. The PSO–NN model can be used for pre–experiment condition design, which is convenient for researchers to obtain ideal hydrothermal products.

Recent Advances in Biomass Pretreatment Technologies for Biohydrogen Production

Hydrogen is an economical source of clean energy that has been utilized by industry for decades. In recent years, demand for hydrogen has risen significantly. Hydrogen sources include water electrolysis, hydrocarbon steam reforming, and fossil fuels, which emit hazardous greenhouse gases and therefore have a negative impact on global warming. The increasing worldwide population has created much pressure on natural fuels, with a growing gap between demand for renewable energy and its insufficient supply. As a result, the environment has suffered from alarming increases in pollution levels. Biohydrogen is a sustainable energy form and a preferable substitute for fossil fuel. Anaerobic fermentation, photo fermentation, microbial and enzymatic photolysis or combinations of such techniques are new approaches for producing biohydrogen. For cost-effective biohydrogen production, the substrate should be cheap and renewable. Substrates including algal biomass, agriculture residue, and wastewaters are readily available. Moreover, substrates rich in starch and cellulose such as plant stalks or agricultural waste, or food industry waste such as cheese whey are reported to support dark- and photo-fermentation. However, their direct utilization as a substrate is not recommended due to their complex nature. Therefore, they must be pretreated before use to release fermentable sugars. Various pretreatment technologies have been established and are still being developed. This article focuses on pretreatment techniques for biohydrogen production and discusses their efficiency and suitability, including hybrid-treatment technology.

Realizing Sustainable Biomass Utilization Through Circular Economy Concepts

Owing to carbon neutrality, biomass is a popular renewable energy source in the global context. In Sri Lanka, a significant portion of primary energy supply in industrial and domestic sectors comes from biomass sources but a sustainable biomass supply chain is yet to be realized. Researchers at the Department of Chemical and Process Engineering are working towards the realization of circular bioeconomy with novel concepts of thermochemical biomass pretreatment technologies.

Analysis of Plant Biomass Pretreatment Technology for Fuel Production

Facing the double challenges of energy shortage and environmental pollution, development and utilization of biomass energy is of great urgency. In this review paper, the current situation and types of biomass energy are reviewed and discussed based on the world energy crisis and its environmental problems. As a typical renewable green liquid energy, bio-ethanol, made from plants with rich reserves, could be applied to the field of traffic transportation. Due to the complex structure, variety, and stable nature of plant biomass, cost-effective pretreatment technology has become an urgent demand in the bio-energy field of current world. At present, various pretreatment methods for enzymatic saccharification of plant biomass have different defects. Therefore, the research on pretreatment technology needs to comprehensively consider the heterogeneity of chemical composition and structural characteristics of raw material and the pertinence of pretreatment methods.

Supercritical Fluids: A Promising Technique for Biomass Pretreatment and Fractionation.

Lignocellulosic biomasses are primarily composed of cellulose, hemicelluloses and lignin and these biopolymers are bonded together in a heterogeneous matrix that is highly recalcitrant to chemical or biological conversion processes. Thus, an efficient pretreatment technique must be selected and applied to this type of biomass in order to facilitate its utilization in biorefineries. Classical pretreatment methods tend to operate under severe conditions, leading to sugar losses by dehydration and to the release of inhibitory compounds such as furfural (2-furaldehyde), 5-hydroxy-2-methylfurfural (5-HMF), and organic acids. By contrast, supercritical fluids can pretreat lignocellulosic materials under relatively mild pretreatment conditions, resulting in high sugar yields, low production of fermentation inhibitors and high susceptibilities to enzymatic hydrolysis while reducing the consumption of chemicals, including solvents, reagents, and catalysts. This work presents a review of biomass pretreatment technologies, aiming to deliver a state-of-art compilation of methods and results with emphasis on supercritical processes.

Study on applicability of pretreatment technology for low-grade biomass

Study on applicability of pretreatment technology for low-grade biomass

Influence of torrefaction pretreatment on the pyrolysis characteristics of seaweed biomass

Torrefaction is a promising pretreatment technology for biomass and its pyrolysis products upgrading. The aim of this study was to investigate the effect of torrefaction on the pyrolysis of seaweed biomass. TG, Py-GC/MS and fixed-bed experiments were used at a series of typical torrefaction temperatures (225 °C, 250 °C, 275 °C and 300 °C) and pyrolysis temperatures (450 °C, 500 °C, and 550 °C). The results showed that increasing of torrefaction temperature led to gradual reduction in moisture content and volatile content due to the precipitation of water and volatile functional groups (OH, NH, CO, C=O, etc.), which resulted in increase of solid products of torrefied seaweed. In addition, the liquid yield showed a promotion at first and then decreased. It also indicated that thermal stability of seaweed became stronger after the pretreatment leading to the initial pyrolysis temperature shifting toward the high temperature section. Meanwhile, the maximum pyrolysis weight loss rate and the total weight loss got a reduction. Moreover, the optimal conditions for maximum bio-oil production were obtained when the temperature of torrefaction was 250 °C at the pyrolysis temperature of 500 °C. Furthermore, the bio-oil under such conditions gave the highest relative content of aromatic hydrocarbons.

Effect of the torrefaction on the emission of PM10 from combustion of rice husk and its blends with a lignite

Torrefaction is a competitive biomass pretreatment technology. However, its impacts on particulate matter (PM) formation during biomass combustion and co-combustion with coal have little been investigated. This work provides new data on the formation of PM10 (particulate matter with aerodynamic diameters less than or equal to 10 µm) from combustion of raw (RH), torrefied rice husk (TRH) and their blends with a lignite (SZ). All combustion experiments were carried out on a drop-tube furnace at 1300 °C and in air. The combustion-generated PM10 was collected by a Dekati low pressure impactor and classified into 14 size fractions for further quantification and characterization. The results indicate that, compared with the RH, the TRH-derived PM10+ (particle size above 10 µm) contains more alkalis, leading to a decrease in the production of PM1 (particle size below 1 µm). During co-combustion, fuel interactions promote the transformation of alkali chlorides to aluminosilicates. A considerable amount of water-soluble Ca and P in PM1 transforms to PM1–10 (particle size between 1–10 µm). As a result, the production of PM1 (on an ash basis) decreases while that of PM1–10 increases. Co-combustion of coal with torrefied rice husk is found to generate less PM1 but more PM1–10 than that with raw rice husk.

Lignocellulosic Biomass Pretreatment for Biorefinery: A Review

Lignocellulosic biomass consists of cellulose, hemicellulose, and lignin, which have the potential to produce the so-called green chemicals. Many processes are available at different scales (e.g. labs, pilots, demos, commercials), utilizing lignocellulosic biomass as the raw material. Due to its complicated chemical structures, lignocellulosic biomass must be pretreated before it can be processed further. Simultaneous separation of cellulose, hemicellulose, and lignin from the biomass is an important step to maximize the full potential of the biomass. In this review, several well-known biomass pretreatment technologies are evaluated. These are low pH process (e.g. dilute acid, steam explosion, hot water liquid, and concentrated acid), high pH (e.g. NaOH, lime, NH3), organosolv, ozonolysis, CO2 explosion, and ionic liquids. The objective of this review is to understand how effective the pretreatment process for separating cellulose, hemicellulose, and lignin. Based on this review, organosolv is the only pretreatment process that is capable of separating cellulose, C5 sugars (from hemicellulose), and lignin, simultaneously. This process is currently at pilot scales of 30 – 100 ton per day of biomass feedstock.

Comparative Characterization of a Torrefied Wood Pellet under Steam and Nitrogen Atmospheres

Torrefaction is a pretreatment technology for biomass to enhance its fuel quality for thermal conversion. Torrefied biomass has many advantages for handling and storage including high energy density and hydrophobicity. It also improves the grindability, which is beneficial for cofiring with pulverized coal in a power plant. This study aims to investigate the optimum operating conditions for a biomass torrefaction process using steam as a purge gas. Wood pellets were torrefied using steam heated to between 230 and 300 °C in a lab-scale packed-bed reactor. The characteristics of the torrefied wood pellets (TWPs) were compared to those produced under nitrogen. The results showed that when the temperature increased from 230 to 300 °C, the TWP yield using steam decreased from 82 to 46 wt %, but the carbon content and heating value increased from 54 to 75 wt % and 21.14 to 28.85 MJ/kg, respectively. On the other hand, the TWPs using nitrogen had a slightly larger mass yield but with a lower carbon content and h...

Choice of Pretreatment Technology for Sustainable Production of Bioethanol from Lignocellulosic Biomass: Bottle Necks and Recommendations

Sustainable and renewable resources are inevitable factors for biofuel production to meet the energy and transportation fuel demand of a nation. The urge in meeting the energy demand can be achieved by intensified research on agricultural and waste biomass utilization. In recent days, advanced agricultural practice throughout the world generates surplus biomass residues and this can be utilized through aggressive pretreatment technology for bioethanol production. Bioethanol production from food crops was having some ethical issues on cost and availability of potential sources. It has been anticipated that the lignocellulosic biomass to bioethanol transformation process contains several challenges and bottlenecks. Selection of an appropriate of pretreatment technology for individual lignocellulosic biomass decides the economic feasibility of biofuel production process. Scientists from different countries were working on the development of biofuel production in sustainable manner, but the technology abides only at a demonstration level due to lack of process intensification. Recent advancements in processing and conversion of biomass dealt with integration of conventional pretreatment principles to vanquish the bottleneck issues faced in development of sustainable biofuel production technology. This paper reviews the development of intensified pretreatment technologies with their current status and advancements. Several key processes and recommendations for cost-effective and eco-friendly pretreatment technologies were also discussed in details.

Dimethyl Sulfoxide Assisted Ionic Liquid Pretreatment of Switchgrass for Isoprenol Production

The production cost and viscosity of certain ionic liquids (ILs) are among the major factors preventing the establishment of economically viable IL-based biomass pretreatment technologies. Recently, mixtures of an IL with an organic solvent have been proposed for cellulose processing and biomass pretreatment. Dimethyl sulfoxide (DMSO) is an inexpensive organic solvent that is industrially produced from lignin, a byproduct of the pulping process. We carry out a mechanistic study of DMSO-assisted IL pretreatment of switchgrass. The physical structures of biomass samples are studied by X-ray diffraction (XRD), N2 adsorption analysis, and small angle neutron scattering (SANS). Both dry and aqueous suspensions of biomass samples are measured by SANS which provides unique information on biomass pretreatment. A mixture of 42 wt % [C2C1Im][OAc] and 58 wt % DMSO is proposed as the optimal pretreatment solution, and the recycling and reuse of the mixture of solvents are also studied. The fermentability of the hydrolysates generated after pretreatment is evaluated using an E. coli strain engineered to produce isoprenol. This study suggests an avenue for developing more efficient and cost-effective IL-based processes for the production of lignocellulosic biofuels and bioproducts.

Process design and economics of a flexible ethanol-butanol plant annexed to a eucalyptus kraft pulp mill

This work proposes a strategy, from a process design standpoint, for pulp companies to enter the Brazilian ethanol market. The flexible plant converts eucalyptus-derived glucose to either ethanol or butanol (according to market conditions) and xylose only to butanol production. Depending on the biomass pretreatment technology, Monte Carlo simulations showed that the Net Present Value (NPV) of the flexible plant increases by 20–28% in relation to an ethanol-dedicated plant. Whereas the lower costs of the steam explosion technology turns the investment more attractive (NPV = 184 MMUSD; IRR = 29%), the organosolv technology provides better flexibility to the plant. This work also shows that excessive power consumption is a hurdle in the development of flash fermentation technology chosen for the flexible plant. These results indicate that conventional batch fermentation is preferable if the enzymatic hydrolysis step operates with solids loading up to 20 wt%.

Integrated 1st and 2nd generation sugarcane bio-refinery for jet fuel production in Brazil: Techno-economic and greenhouse gas emissions assessment

Abstract This study presents a techno-economic analysis and an environmental assessment, of the whole production chain (biomass production, sugar extraction, biomass pretreatment, sugars fermentation, and products recovery and purification), of a fully autarkic sugarcane-based biorefinery for biojet fuel production. All scenarios considered correspond to 1st/2nd generation integrated biorefineries ( i.e. simultaneous use of sugarcane juice stream and lignocellulosic fractions) with a production scale of 208 kton (biojet fuel) yr −1 . In this paper, we compared multiple options for the most relevant processing steps of the biorefinery: eight biomass pretreatment technologies ( i.e. dilute acid, dilute acid + alkaline treatment, steam explosion, steam explosion + alkaline treatment, organosolv, alkaline wet oxidation, liquid hot water and liquid hot water + alkaline treatment); two biojet fuel production routes from sugars ( i.e. ethanol to jet and direct fermentation); one biojet fuel production route from biomass ( i.e. fast pyrolysis); two biojet fuel production routes from lignin obtained after biomass pretreatment ( i.e. fast pyrolysis and gasification Fischer- Tropsch); and one alternative use for lignin ( i.e. co-generation). From the combination of these key features, 81 scenarios are selected and compared. Furthermore, three potential technological improvements were analysed for selected scenarios: i) recovery of acetic acid and furfural (for cases with bagasse pretreatment); ii ) production of succinic acid from a fraction of concentrated juice; iii) increase of operation time (from 200 to 320 days yr −1 ) by using sweet sorghum as cumulative feedstock. The different scenarios are compared first based on the minimum jet fuel selling price (MJSP) and then based on their environmental performance ( i.e. greenhouse gas (GHG) emissions and non-renewable energy use (NREU)). Among the scenarios considering biomass pretreatment, the lower MJSP are obtained when 1G/2G sugars are upgraded via ethanol fermentation (ETJ) ( i.e. SO 2 steam explosion: 3409 US $.ton −1 , and wet oxidation: 3230 US $.ton −1 ). Additional technological improvements may help to further reduce the MJSP either marginally (2%, by using 1G sugars for succinic acid production) or significantly (30%, by increasing the operation time). Thus, the lowest MJSP here calculated is 1725 US $.ton −1 (with 1G sugars to biojet fuel via ethanol, and bagasse to biojet fuel via fast pyrolysis). Finally, for all scenarios considered, the GHG emissions and NREU were found to be lower than 42.5 kg CO 2 eq.GJ −1 and 700 MJ GJ −1 respectively (except for scenarios with fast pyrolysis of bagasse where those figures were further reduced by 50% and 80% respectively). Although, the MJSP calculated for all scenarios are higher than those of the fossil jet fuel reference, the significant potential for environmental impacts reduction (in terms of GHG emissions and primary energy use) are encouraging for further research in costs reduction and technology development.