Records with Keyword: Biomass
Showing records 1 to 25 of 394. [First] Page: 1 2 3 4 5 Last
Enhancing PHAs Production Sustainability: Biorefinery Design through Carbon Source Diversity
Fernando D. Ramos, Matías H. Ramos, Vanina Estrada, M. Soledad Diaz
July 9, 2024 (v1)
Keywords: Biomass, Environment, Modelling, Optimization, Process Design
In this work, we propose a Mixed Integer Nonlinear Programming (MINLP) model to determine the optimal sustainable design of a poly(hydroxyalkanoate)s (PHAs) production plant configuration and its heat exchanger network (HEN). The superstructure-based optimization model considers different carbon sources as raw material: glycerol (crude and purified), corn starch, cassava starch, sugarcane sucrose and sugarcane molasses. The PHA extraction section includes four alternatives: the use of enzymes, solvent, surfactant-NaOCl or surfactant-chelate. Model constraints include detailed capital cost for equipment, mass and energy balances, product specifications and operating bounds on process units. To assess the feasibility of the PHA plant, we considered the Sustainability Net Present Value (SNPV) as the objective function, a multi-criteria sustainability metric that considers economic, environmental and social pillars. The Net Present Value (NPV) was also calculated. SNPV metric provides usef... [more]
Nature-inspired Bio-Mineral Refinery for Simultaneous Biofuel Feedstock production and CO2 mineralization
Pavan Kumar Naraharisetti
July 9, 2024 (v1)
Subject: Environment
Inspired by Nature, we propose that synergies between biorefinery and mineral refinery can be exploited so that at least a part of the carbon is captured before being released to the atmosphere. In doing so, carbon is captured not only from CO2 but also from biomass and developing more such processes may be the cornerstone for controlling CO2 emissions. A comparison of circular economy in traditional biorefineries and bio-mineral refineries is done by using general chemical formulas and it is shown that the bio-mineral refinery captures carbon. In this work, we have shown that Serpentine may be used to partially neutralise biomass pyrolysis oil. The extracted oil may be used as feedstock to produce downstream chemicals and further studies are required to produce the same.
Integrated Ex-Ante Life Cycle Assessment and Techno-Economic Analysis of Biomass Conversion Technologies Featuring Evolving Environmental Policies
Dat T. Huynh, Marianthi Ierapetritou
July 9, 2024 (v1)
Biorefineries can reduce carbon dioxide emissions while serving the global chemical demand market. Governments are also using carbon pricing policies, such as carbon taxes, cap-and-trade models, and carbon caps, as a strategy to reduce emissions. The use of biomass feedstocks in conjunction with carbon capture usage and storage technologies are mitigation strategies for global warming. Businesses can invest in these technologies to accommodate the adoption of these policies. Rapid action is necessary to halt global warming, which results in aggressive policies. In this work, a multi-period process design and planning problem is developed for the design and capacity expansion of biorefineries. The three carbon pricing policies are integrated into the model and parameters are selected according to the aggressive scenario denoted by the Paris Agreement. The results show that the cap-and-trade policy achieves a higher net present value evaluation over the carbon tax model across all pareto... [more]
Biofuels with Carbon Capture and Storage in the United States Transportation Sector
Caleb H. Geissler, Christos T. Maravelias
July 9, 2024 (v1)
There is a need to drastically reduce greenhouse gas emissions. While significant progress has been made in electrifying transport, heavy duty transportation and aviation are not likely to be capable of electrification in the near term, spurring significant research into biofuels. When coupled with carbon capture and storage, biofuels can achieve net-negative greenhouse gas emissions via many different conversion technologies such as fermentation, pyrolysis, or gasification to produce ethanol, gasoline, diesel, or jet fuel. However, each pathway has a different efficiency, capital and operating costs, and potential for carbon capture, making the optimal pathway dependent on policy and spatial factors. We use the Integrated Markal-EFOM System model applied to the USA, adding a rich suite of biofuel and carbon capture technologies, region-specific CO2 transportation and injection costs, and government incentives from the Inflation Reduction Act. We find that under current government ince... [more]
Surface Chemistry of Cherry Stone-Derived Activated Carbon Prepared by H3PO4 Activation
Jose M. González-Domínguez, Carmen Fernández-González, María Alexandre-Franco, Vicente Gómez-Serrano
June 24, 2024 (v1)
Keywords: activated carbon, Biomass, chemical activation, phosphoric acid, surface chemistry
The preparation of activated carbons (ACs) from cherry stones and chemical activation with H3PO4 can be controlled by the experimental variables during the impregnation step in order to obtain a tailored porous structure of the as-prepared ACs. This control not only extends to the ACs’ texture and porosity development, but also to the chemical nature of their surface. The spectroscopic and elemental characterization of different series of ACs is presented in this study. The spectroscopic band features and assignments strongly depend on the H3PO4 concentration and/or the semi-carbonization treatments applied to the feedstock before impregnation, which ultimately influence different characteristics such as the AC hydrophilicity. Different surface chemistries arise from the different tailored impregnation solutions, showing a practical outcome for future applications of the as-prepared ACs.
Variability in Physical Properties of Logging and Sawmill Residues for Making Wood Pellets
Jun Sian Lee, Hamid Rezaei, Omid Gholami Banadkoki, Fahimeh Yazdan Panah, Shahab Sokhansanj
June 21, 2024 (v1)
Subject: Materials
Keywords: ash, Biomass, density, moisture, particle sizes, pellets
Wood pellets are a versatile ingredient to produce bioenergy and bioproducts. Wood pellet manufacturing in Canada started as a way of using the excess sawdust from sawmilling operations. With the recent dwindling availability of sawdust and the growth in demand for wood pellets, the industry uses more non-sawdust woody biomass as feedstock. In this study, woody biomass materials received from nine wood pellet plants in British Columbia (BC) and Alberta were analyzed for their properties, especially those used for fractionating feedstock to make pellets. Half of the feedstock received at the plants was non-sawdust. Moisture contents varied from 10 to 60% wet basis, with the hog having an average of 50%. Ash contents ranged from 0.3 to 4% dry basis and were highest in the hog fraction. Bulk density varied from 50 to 450 kg/m3, with shavings having the lowest bulk density. Particle density ranged from 359 kg/m3 for infeed mix to 513 kg/m3 for sawdust. In total, 25% of particles received w... [more]
Exergoeconomic Evaluation of a Cogeneration System Driven by a Natural Gas and Biomass Co-Firing Gas Turbine Combined with a Steam Rankine Cycle, Organic Rankine Cycle, and Absorption Chiller
Ji Liu, Jie Ren, Yujia Zhang, Weilong Huang, Chen Xu, Lu Liu
June 21, 2024 (v1)
Keywords: Biomass, cogeneration, dual fuel gas turbine, exergoeconomic analysis, multi-objective optimization, Natural Gas
Considering energy conversion efficiency, pollution emissions, and economic benefits, combining biomass with fossil fuels in power generation facilities is a viable approach to address prevailing energy deficits and environmental challenges. This research aimed to investigate the thermodynamic and exergoeconomic performance of a novel power and cooling cogeneration system based on a natural gas−biomass dual fuel gas turbine (DFGT). In this system, a steam Rankine cycle (SRC), a single-effect absorption chiller (SEAC), and an organic Rankine cycle (ORC) are employed as bottoming cycles for the waste heat cascade utilization of the DFGT. The effects of main operating parameters on the performance criteria are examined, and multi-objective optimization is accomplished with a genetic algorithm using exergy efficiency and the sum unit cost of the product (SUCP) as the objective functions. The results demonstrate the higher energy utilization efficiency of the proposed system with the therma... [more]
Bioenergy and Biopesticides Production in Serbia—Could Invasive Alien Species Contribute to Sustainability?
Magdalena Pušić, Mirjana Ljubojević, Dejan Prvulović, Radenka Kolarov, Milan Tomić, Mirko Simikić, Srđan Vejnović, Tijana Narandžić
June 10, 2024 (v1)
Subject: Environment
Keywords: Biofuels, biogas, Biomass, biopesticides, biowaste, circular economy, invasive alien species, nature-based solutions, sustainable development goals, urban greenery
The critical role of energy in contemporary life and the environmental challenges associated with its production imply the need for research and exploration of its novel resources. The present review paper emphasizes the continuous exploitation of non-renewable energy sources, suggesting the transition toward renewable energy sources, termed ‘green energy’, as a crucial step for sustainable development. The research methodology involves a comprehensive review of articles, statistical data analysis, and examination of databases. The main focus is biomass, a valuable resource for bioenergy and biopesticide production, highlighting not only its traditional diverse sources, such as agricultural waste and industrial residues, but also non-edible invasive alien plant species. This study explores the utilization of invasive alien species in circular economy practices, considering their role in bioenergy and biopesticide production. The potential conflict between bioproduct acquisition and foo... [more]
Challenges and Perspectives of the Conversion of Lignin Waste to High-Value Chemicals by Pyrolysis
Zhouqing Tan, Yuanyuan Li, Feifei Chen, Jiashu Liu, Jianxiong Zhong, Li Guo, Ran Zhang, Rong Chen
June 7, 2024 (v1)
Keywords: bio-oil, Biomass, catalyst, lignin, pyrolysis, tobacco stem waste
The pyrolysis process is a thermochemical conversion reaction that encompasses an intricate array of simultaneous and competitive reactions occurring in oxygen-depleted conditions. The final products of biomass pyrolysis are bio-oil, biochar, and some gases, with their proportions determined by the pyrolysis reaction conditions and technological pathways. Typically, low-temperature slow pyrolysis (reaction temperature below 500 °C) primarily yields biochar, while high-temperature fast pyrolysis (reaction temperature 700−1100 °C) mainly produces combustible gases. In the case of medium-temperature rapid pyrolysis (reaction temperature around 500−650 °C), conducted at very high heating rates and short vapor residence times (usually less than 1 s), the maximum liquid yield can reach up to 85 wt% (on a wet basis) or achieve 70 wt% (on a dry basis), with bio-oil being the predominant product. By employing the pyrolysis technique, valuable utilization of tobacco stem waste enriched with lign... [more]
Investigating Salt Precipitation in Continuous Supercritical Water Gasification of Biomass
Julian Dutzi, Nikolaos Boukis, Jörg Sauer
June 5, 2024 (v1)
Keywords: Biomass, gasification, process design, supercritical water
The formation of solid deposits in the process of supercritical water gasification (SCWG) is one of the main problems hindering the commercial application of the process. Seven experiments were conducted with the grass Reed Canary Grass with different preheating temperatures, but all ended early due to the formation of solid deposits (maximum operation of 3.8 h). The position of solid deposits in the lab plant changed with the variation in the temperature profile. Since the formation of solid deposits consisting of salts, coke, and corrosion products is a severe issue that needs to be resolved in order to enable long-time operation, inner temperature measurements were conducted to determine the temperature range that corresponds with the zone of solid formation. The temperature range was found to be 400 to 440 °C. Wherever this temperature was first reached solid deposits occurred in the system that led to blockage of the flow. Additional to the influence of the temperature, the influe... [more]
Investigation on Synergism and Its Influence Parameters between Coal and Biomass during Co-Gasification Based on Aspen Plus
Jinbo Chen, Peng Jiang, Yipei Chen, Shuai Liu
June 5, 2024 (v1)
Keywords: Aspen Plus, Biomass, co-gasification, Coal, influence parameters, synergistic effect
The co-gasification of coal and biomass offers numerous benefits, including improved gasification efficiency, reduced pollution emissions, and the utilization of renewable resources. However, there is a lack of comprehensive research on the synergistic effects of, and influence parameters on, coal−biomass co-gasification. This study employs Aspen Plus simulations to investigate the co-gasification behavior of coal and corn straw, focusing on the synergistic effects and the impact of various operating conditions. A synergistic coefficient is defined to quantify the interactions between the feedstocks. Sensitivity analyses explore the effects of gasification temperature (800−1300 °C), coal rank (lignite, bituminous, anthracite), biomass mass fraction (0−50%), oxygen-to-carbon ratio, and steam-to-carbon ratio on the synergistic coefficients of effective syngas content (CO + H2), specific oxygen consumption, specific fuel consumption, and cold gas efficiency. The results reveal an optimal... [more]
CFDs Modeling and Simulation of Wheat Straw Pellet Combustion in a 10 kW Fixed-Bed Downdraft Reactor
Bidhan Nath, Guangnan Chen, Les Bowtell, Raid Ahmed Mahmood
June 5, 2024 (v1)
Keywords: Biomass, Computational Fluid Dynamics, downdraft reactor, Simulation, wheat straw pellets
This research paper presents a comprehensive study on the combustion of wheat straw pellets in a 10 kW fixed-bed reactor through a Computational Fluid Dynamics (CFDs) simulation and experimental validation. The developed 2D CFDs model in ANSYS meshing simulates the combustion process in ANSYS Fluent software 2021 R2. The investigation evaluates key parameters such as equivalence ratio, heating value, and temperature distribution within the reactor to enhance gas production efficiency. The simulated results, including combustion temperature and produced gases (CO2, CO, CH4), demonstrate a significant agreement with experimental combustion data. The impact of the equivalence ratio on the conversion efficiency and lower heating value (LHV) is systematically explored, revealing that an equivalence ratio of 0.35 is optimal for maximum gas production efficiency. The resulting producer gas composition at this optimum condition includes CO (~27.67%), CH4 (~3.29%), CO2 (~11.09%), H2 (~11.09%),... [more]
Transitioning towards Net-Zero Emissions in Chemical and Process Industries: A Holistic Perspective
Peter Glavič, Zorka Novak Pintarič, Helena Levičnik, Vesna Dragojlović, Miloš Bogataj
January 12, 2024 (v1)
Subject: Environment
Keywords: Biomass, cement, chemicals, climate, emissions, Energy, metals, net zero, process industries, waste
Given the urgency to combat climate change and ensure environmental sustainability, this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction, efficient energy use, and sustainable practices. What is new, however, is that it focuses on cutting-edge technologies such as biomass utilization, biotechnology applications, and waste management strategies that are key drivers of this transition. In particular, the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular, the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors, pointing the way to cleaner and greener operations. In addition, the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the... [more]
Effects of High-Intensity Ultrasound Pretreatment on the Exopolysaccharide Concentration and Biomass Increase in Cheese Whey Kefir
Ismael A. Encinas-Vazquez, Esther Carrillo-Pérez, Abraham R. Mártin-García, Carmen L. Del-Toro-Sánchez, Enrique Márquez-Ríos, Luis J. Bastarrachea, José C. Rodríguez-Figueroa
August 2, 2023 (v1)
Keywords: Biomass, cheese whey, exopolysaccharide, high-intensity ultrasound, kefir beverage, kefir grains
Cheese whey (CW) is the liquid by-product of cheese and yogurt making. This potential pollutant has high-quality nutrients exploitable through fermentation processes. Using high-intensity ultrasound on dairy products has shown several technological advantages for bioprocesses. Therefore, this study aimed to investigate the effect of high-intensity ultrasound (HIUS) on kefir grains biomass increase and specific metabolites in CW kefir. Fresh CW was ultrasonicated at 9.0 ± 2.7 and 18.0 ± 3.0 W/cm2 for 30 and 180 s, inoculated with kefir grains, and fermented for 40 h. Total exopolysaccharide production, kefir grains biomass increase, titratable acidity, pH, and soluble solids were analyzed every 8 h. CW pretreated with 18.0 ± 3.0 W/cm2 for 180 s and fermented for 16 h had significantly higher (p < 0.05) total exopolysaccharide concentration than the control: 212.7 ± 0.0 and 186.6 ± 0.0 mg/L, respectively. Ultrasonicated CW at 18 W/cm2 for 30 and 180 s at 24 h fermentation time had sig... [more]
Optimizing Pressure Prediction Models for Pneumatic Conveying of Biomass: A Comprehensive Approach to Minimize Trial Tests and Enhance Accuracy
Hossein Rajabnia, Ognjen Orozovic, Kenneth Charles Williams, Aleksej Lavrinec, Dusan Ilic, Mark Glynne Jones, George Klinzing
July 7, 2023 (v1)
Subject: Materials
Keywords: Biomass, dense phase, plug flow, pneumatic conveying
This study investigates pneumatic conveying of four different biomass materials, namely cottonseeds, wood pellets, wood chips, and wheat straw. The performance of a previously proposed model for predicting pressure drop is evaluated using biomass materials. Results indicate that the model can predict pressure with an error range of 30 percent. To minimize the number of trial tests required, an optimization algorithm is proposed. The findings show that with a combination of three trial tests, there is a 60 percent probability of selecting the right subset for accurately predicting pressure drop for the entire range of tests. Further investigation of different training subsets suggests that increasing the number of tests from 3 to 7 can improve the probability from 60% to 90%. Moreover, thorough analysis of all three-element subsets in the entire series of tests reveals that when considering air mass flow rate as the input, having air mass flow rates that are not only closer in value but... [more]
Investigating the Relationship between the Time Constant Ratio and Plug-Flow Behaviour in the Pneumatic Conveyance of Biomass Material
Hossein Rajabnia, Ognjen Orozovic, Kenneth Williams, Aleksej Lavrinec, Dusan Ilic, Mark Jones, George Klinzing
July 7, 2023 (v1)
Subject: Materials
Keywords: aeration, Biomass, deaeration, dense phase, fluidisation, plug flow, pneumatic conveying, time constant
This study introduces a novel methodology to evaluate the behaviour of biomass material by examining the ratio of aeration and deaeration time constants. To this end, a series of tests were conducted on four different materials, namely, cottonseed, wood chips, wood pellets, and wheat straw, in order to investigate their aeration and deaeration behaviours. The study derives the aeration and deaeration pressure drop equations, and discusses the corresponding time constant expression. Subsequently, the four materials were conveyed in 12 m long batch-fed and continuous pneumatic conveying pipelines to examine their behaviour in longer pipelines. The results indicate that the aeration and deaeration time constants increased with an increase in air superficial velocity. However, the ratio of the aeration and deaeration time constants was identified as a unique number, where a value close to 1 indicates a higher likelihood of plug flow. On the basis of the results, cottonseed, with the lowest... [more]
Renewable Energy Potential and CO2 Performance of Main Biomasses Used in Brazil
Elem Patricia Rocha Alves, Orlando Salcedo-Puerto, Jesús Nuncira, Samuel Emebu, Clara Mendoza-Martinez
May 24, 2023 (v1)
Keywords: Biofuels, Biomass, Carbon Dioxide, Renewable and Sustainable Energy, thermochemical conversion
This review investigates the effects of the Brazilian agriculture production and forestry sector on carbon dioxide (CO2) emissions. Residual biomasses produced mainly in the agro-industrial and forestry sector as well as fast-growing plants were studied. Possibilities to minimize source-related emissions by sequestering part of carbon in soil and by producing biomass as a substitute for fossil fuel were extensively investigated. The lack of consistency among literature reports on residual biomass makes it difficult to compare CO2 emission reductions between studies and sectors. Data on chemical composition, heating value, proximate and ultimate analysis of the biomasses were collected. Then, the carbon sequestration potential of the biomasses as well as their usability in renewable energy practices were studied. Over 779.6 million tons of agricultural residues were generated in Brazil between 2021 and 2022. This implies a 12.1 million PJ energy potential, while 4.95 million tons of for... [more]
Comparison Study on the Water-to-Biomass Ratio in Hydrothermal Carbonization of Fresh Seaweed
Sepideh Soroush, Frederik Ronsse, Jihae Park, Philippe M. Heynderickx
April 28, 2023 (v1)
Subject: Materials
Keywords: Biomass, hydrochar, moisture content, waste seaweed, water to biomass ratio
Upgrading wet biomass to char via hydrothermal carbonization is a promising method to produce valuable resources for adsorption of organic impurities. In this work, a fresh green seaweed, Ulva pertusa, was investigated to demonstrate the effects of pre-drying and pre-washing on the process and the hydrochar production. Surface moisture and bound moisture were found to affect this process. Hydrochar produced from fresh seaweed with additional water showed similar adsorption capacity to fresh seaweed without additional water and 38% higher than hydrochar from soaked dry seaweed. This was supported by FTIR spectra analysis, which showed that these hydrochars produced from fresh seaweed without additional water have the highest proportion of carboxyl functional groups.
Experimental Study of Model Refuse-Derived Fuel Pellets Swelling during Heating and Combustion
Igor Donskoy, Denis Svishchev
April 28, 2023 (v1)
Keywords: Biomass, bloat, ignition, polyethylene, single particle, visualization
Composites of sawdust and crushed polyethylene were obtained by pressing at 5−10 atm. The resulting pellets with a size of about 10−20 mm were then burned in airflow in a muffle furnace at a temperature of 800 °C. The combustion process was recorded, and obtained video data were analyzed. The data obtained made it possible to estimate the change in particle size at different stages of combustion. An increase in linear dimensions during conversion was achieved of up to 2 times. Particle swelling led to a decrease in mechanical strength and destruction of particles before complete burnout.
Availability of Biomass and Potential of Nanotechnologies for Bioenergy Production in Jordan
Ala’a K. Al-Bawwat, Antonio Cano, Mohamed R. Gomaa, Francisco Jurado
April 28, 2023 (v1)
Keywords: biodiesel, bioenergy, Biofuels, biogas, Biomass, nanotechnology
Jordan’s energy situation is in a critical state of dependency, with the country relying heavily on imports to satisfy its ever-increasing energy requirements. Renewable energy is a more competitive and consistent source of energy that can supply a large proportion of a country’s energy demand. It is environmentally friendly and minimizes atmospheric pollutant emissions. Thus, bioenergy has the potential to be a crucial alternative energy source in Jordan. Biomass is the principal source of bioenergy; it accounts for approximately 13% of the primary energy demand and is anticipated to supply half of the total primary energy demand by 2050. Nanotechnology has emerged as an important scientific research area with numerous applications, including biofuels. This review summarizes the application of nanoparticles to improve the properties and processes of biofuels. It presents the availability and viability of nanotechnology-supported bioenergy production in Jordan. Jordan generates up to 5... [more]
Research on Model Predictive Control of a 130 t/h Biomass Circulating Fluidized Bed Boiler Combustion System Based on Subspace Identification
Heng Wei, Shanjian Liu, Jianjie He, Yinjiao Liu, Guanshuai Zhang
April 28, 2023 (v1)
Keywords: Biomass, circulating fluidized bed, combustion system, dynamic simulations, Model Predictive Control, subspace identification
The structure of large biomass circulating fluidized bed (BCFB) boilers is complex, and control schemes for coal-fired boilers cannot be simply applied to biomass boilers. Multivariable coupling and operational disturbances are also common issues. In this study, a state space model of a 130 t/h BCFB boiler was established under different operating conditions. Using the 100% operating point as an example, a model predictive controller was designed and tested under output disturbance and input disturbance conditions. The results show that the predictive control system designed in this study has a fast response speed and good stability.
Sequential Hydrothermal HCl Pretreatment and Enzymatic Hydrolysis of Saccharina japonica Biomass
Eun-Young Park, Jung-Kyu Park
April 27, 2023 (v1)
Keywords: Biomass, enzymatic hydrolysis, hydrothermal acid pretreatment, reducing sugar yield, sequential hydrolysis
This study investigated the production of fermentable sugars from carbohydrate-rich macroalgae Saccharina japonica using sequential hydrolysis (hydrothermal acid pretreatment and enzymatic hydrolysis) to determine the maximum reducing sugar yield (RSy). The sequential hydrolysis was predicted by three independent variables (temperature, time, and HCl concentration) using response surface methodology (RSM). Enzymatic hydrolysis (8.17% v/wbiomass Celluclast® 1.5 L, 26.4 h, 42.6 °C) was performed after hydrothermal acid pretreatment under predicted conditions (143.6 °C, 22 min, and 0.108 N HCl concentration). Using this experimental procedure, the yields of hydrothermal acid pretreatment, enzymatic hydrolysis, and sequential hydrolysis were 115.6 ± 0.4 mg/g, 117.7 ± 0.3 mg/g, and 183.5 ± 0.6 mg/g, respectively. Our results suggested that sequential hydrolysis of hydrothermal acid pretreatment and enzymatic hydrolysis was more efficient than their single treatment.
Impact of Pretreatment on Hydrothermally Carbonized Spruce
Anna Partridge, Ekaterina Sermyagina, Esa Vakkilainen
April 26, 2023 (v1)
Keywords: Biomass, energy densification, hydrothermal carbonization, lignin
Upgrading biomass waste streams can improve economics in wood industries by adding value to the process. This work considers use of a hydrothermal carbonization (HTC) process for the residual feedstock after lignin and hemicelluloses extraction. Batch experiments were performed at 200−240 °C temperatures and three hours residence time with an 8:1 biomass to water ratio for two feedstocks: Raw spruce and spruce after lignin extraction. The proximate analysis and heating value showed similar results for both feedstocks, indicating that the thermochemical conversion is not impacted by the removal of lignin and hemicelluloses; the pretreatment processing slightly increases the heating value of the treated feedstock, but the HTC conversion process produces a consistent upgrading trend for both the treated and untreated feedstocks. The energy yield was 9.7 percentage points higher for the treated wood on average across the range temperatures due to the higher mass yield in the treated experi... [more]
Solid Fraction of Digestate from Biogas Plant as a Material for Pellets Production
Wojciech Czekała
April 24, 2023 (v1)
Subject: Materials
Keywords: Biofuels, Biomass, circular economy, Renewable and Sustainable Energy, solid biofuels, waste to energy
One of the anaerobic digestion process products in an agricultural biogas plant is digestate (digested pulp). Large quantities of digestate generated in the process of biogas production all over the world require proper management. Fertilization is the main management of this substrate, so it is essential to look for new alternatives. The work aims to determine and discuss the possibilities of using digestate solid fraction (DSF) for pellets as biofuel production. Pellets from DSF alone and pellets with sawdust, grain straw additives were analyzed. The lower heating value (LHV) based on the dry matter for all analyzed pellets ranged from 19,164 kJ∙kg−1 to 19,879 kJ∙kg−1. The ash content was similar for all four samples and ranged from 3.62% to 5.23%. This value is relatively high, which is related to the degree of fermentation in the anaerobic digestion process. The results showed that the DSF substrate after the anaerobic digestion process still has energy potential. Analyzing those r... [more]
A Review of Hydrothermal Liquefaction of Biomass for Biofuels Production with a Special Focus on the Effect of Process Parameters, Co-Solvents, and Extraction Solvents
Ankit Mathanker, Snehlata Das, Deepak Pudasainee, Monir Khan, Amit Kumar, Rajender Gupta
April 24, 2023 (v1)
Keywords: bio-crude, bio-oil, Biofuels, Biomass, char, hydrothermal liquefaction, hydrothermal processing, lignocellulosic biomass
Hydrothermal liquefaction is one of the common thermochemical conversion methods adapted to convert high-water content biomass feedstocks to biofuels and many other valuable industrial chemicals. The hydrothermal process is broadly classified into carbonization, liquefaction, and gasification with hydrothermal liquefaction conducted in the intermediate temperature range of 250−374 °C and pressure of 4−25 MPa. Due to the ease of adaptability, there has been considerable research into the process on using various types of biomass feedstocks. Over the years, various solvents and co-solvents have been used as mediums of conversion, to promote easy decomposition of the lignocellulosic components in biomass. The product separation process, to obtain the final products, typically involves multiple extraction and evaporation steps, which greatly depend on the type of extractive solvents and process parameters. In general, the main aim of the hydrothermal process is to produce a primary product... [more]
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