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Bioenergy Research
Journal Prestige (SJR): 1.151  Citation Impact (citeScore): 3 Number of Followers: 3  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1939-1242 - ISSN (Online) 1939-1234 Published by Springer-Verlag  [2468 journals]
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- Efficient Production of Fermentable Sugars from Common Reed Biomass
Through Hydrothermal and Citric Acid Pretreatment Processes-
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Abstract: Abstract Production of fermentable sugars from renewable lignocellulosic biomass could provide a sustainable substrate for biofuel production by microbial fermentation. However, the inherent structure of lignocellulose largely hinders enzymatic saccharification efficiency to obtain sugars, thus the development of efficient pretreatment methods to reduce biomass recalcitrance is an important issue. In this study, the effects of two typical processes including hydrothermal (HTP) and citric acid pretreatments (CAP) on the enzymatic hydrolysis yield of reed biomass were investigated. The results indicate that, when performing HTP at 180 °C for 120 min to deconstruct reed, the pretreated biomass led to a higher glucose yield of 87.1% after 72 h enzymatic hydrolysis with cellulase (10 FPU/g substrate). Furthermore, under the pretreatment conditions with 6% (w/v) citric acid, 150 °C, and 60 min, the glucose yield of pretreated reed was 63.4% after hydrolysis with cellulase (10 FPU/g substrate). In this case, adding Tween 80 (100 mg/g substrate) significantly facilitated the enzymatic saccharification activity resulting in the glucose yield of CA-pretreated reed to 84.2%. Compared with the untreated reed, the glucose yield of pretreated residues after HTP and CAP was largely improved by 4.97–5.18 folds which was mainly due to the enhanced crystallinity (50.0–53.2% vs. 45.9%). The total fermentable sugars of 34.7–34.8 g can be produced from 100 g of raw reed biomass based on the proposed HTP and CAP processes. The mechanism of enhanced enzymatic hydrolysis after pretreatments was elucidated through physicochemical characterization techniques. In summary, the proposed pretreatments show high potential application for biorefinery from renewable, abundant reed biomass.
PubDate: 2024-08-08
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- Waste Palm Leaves-Based Hydrochar Support Catalytic Esterification of Palm
Fatty Acid Distillate-
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Abstract: Heterogeneous acid catalysis provides a sustainable and cost-effective replacement to homogeneous catalysts, as it is easily accessible and reusable. In this research, biodiesel was synthesized from palm fatty acid distillate (PFAD) by way of esterification utilizing a heterogeneous acid catalyst composed of CuO/WPLAHC-S, which was derived from waste palm leaves-based hydrochar. The catalyst was characterized using TGA, XRD, FESEM, EDX, BET, FT-IR, Raman, and acid density. The synthesized catalyst was found to have remarkable stability during the thermal test. The BET surface area, pore volume, and pore width of the synthesized catalyst were measured at 118.47 m2/g, 0.05 cm3/g, and 8.15 nm, respectively. The significant acidity density (18.57 mmol/g) facilitated the simultaneous esterification process. The investigation found that the copper-doped activated hydrochar, treated with sulfuric acid, exhibited excellent catalytic activity. A high yield of 98.34% fatty acid methyl ester (FAME) was achieved under mild conditions with the use of a catalyst concentration of 2 wt.%, a methanol-to-PFAD molar ratio of 15:1, and a reaction temperature of 80 °C for a duration of 3 h. For statistical analysis, one-way ANOVA was applied to verify the experimental data set for PFAD esterification optimization parameters by predetermining a 95% confidence interval. All of the esterification parameters met the expectation of a p-value less than 0.05 indicating its significant impact on FAME production. The catalyst exhibited excellent performance by maintaining a FAME yield of over 90% after four reaction cycles without requiring reactivation. The study demonstrates the efficacy of CuO/WPLAHC-S as a promising acid catalyst derived from waste palm leaves-based hydrochar for biodiesel production from PFAD. Graphical
PubDate: 2024-08-02
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- Improvising Biodiesel Production from Scenedesmus dimorphus via Nutrient
Starvation and Optimized Pretreatment Process-
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Abstract: Microalgae show great potential as a biodiesel feedstock, primarily attributed to their rapid growth rates and higher lipid content. Biomass pretreatment is a critical step in biodiesel production, as it is essential for providing unsaturated and saturated fatty acids to produce fatty acid methyl ester (FAME). The present study investigates the effect of two-stage cultivation of nutrient starvation and ultrasonic-assisted solvent extraction technique from Scenedesmus dimorphus on lipid content and productivity. Preliminary studies facilitated the identification of an appropriate range to which the variables must be optimized. Scenedesmus dimorphus was obtained from the National Repository for Microalgae and Cyanobacteria [NRMC-F]. The medium optimization resulted in a higher lipid content (38.45%) in the M4N medium under starved conditions. The generated model (R2 = 0.998) forecasted the lipid content of 0.317 g/L after 87.19 min of sonication under the sonication power (65.77 W) with a molar ratio [chloroform:methanol] (1.3:1), which was experimentally validated. Under optimized conditions, the efficiency of extraction has been improved from 64.6 to 72.5% with a maximum biodiesel yield of 25.4 wt.%. In summary, this research successfully identified the optimal growth medium and pretreatment conditions, ultimately maximizing the production of biodiesel. Graphical
PubDate: 2024-07-19
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- Optimal Bio-Oil Production Using Triplochiton scleroxylon Sawdust Through
Microwave-Assisted Pyrolysis-
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Abstract: Abstract This study aims to optimize bio-oil production through microwave pyrolysis of Triplochiton scleroxylon sawdust (Ayous). After a physicochemical characterization of the sawdust, response surface methodology via centered composite design was used to investigate the influence of pyrolysis factors on bio-oil yield and determine the optimal pyrolysis conditions. The studied pyrolysis factors were microwave power (W), irradiation time (min), and biochar (%) as wave absorber. Finally, the bio-oil produced under optimal conditions was characterized by GC–MS. It emerges from this study that Ayous biomass has physicochemical properties that can be valorized for bio-oil production, with a high volatile matter content (63.2 ± 2%) and low ash content (2.8 ± 0.3%). The optimization study of bio-oil yield shows that all factors have significant effects with a statistical significance level of 5% (p < 0.05) on the measured parameters. The optimal bio-oil yield of 44.82% is obtained at optimal conditions: microwave power of 576 W, irradiation time of 28 min, and a biochar (wave absorber) input of 3.18%. The bio-oil produced under optimal conditions has a pH of 4.6 ± 0.7 and a water content of 25 ± 1.2%. Compound identification of this bio-oil by GC–MS identified families of compounds including alkanes (13.90%), esters (5.88%), alcohols (1.10%), and high molecular weight phenolic compounds (58%). The produced bio-oil can be used as biofuel or in industrial applications. Nevertheless, further processing steps are needed to lower the water content and acidity of the oil.
PubDate: 2024-07-18
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- Innovative Approach to Characterize Cheese Whey Anaerobic Digestion Using
Combined Mechanistic and Machine Learning Models-
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Abstract: Whey, a cheese production byproduct, can be anaerobically digested to reduce pollution and generate energy. Yet, stability is challenging due to organic content sensitivity and influent fluctuations. The present work attempts to implement the mechanistic model and machine learning (ML) models (support vector regression (SVR) and artificial neural networks (ANNs)) together to predict the concentration dataset of substrate 1 (S1) (i.e., carbohydrates and proteins), substrate 2 (S2) (i.e., glucids and amino acids), VFA, and methane (CH4) as a function of input independent variables, namely time and organic loading rate (OLR). The R2 values for S1, S2, VFA, and CH4 obtained through the mechanistic model remained as 0.953, 0.918, 0.84, and 0.976, respectively; for ANN models, 0.982, 0.928, 0.958, and 0.99; and for SVR models, 0.984, 0.939, 0.938, and 0.999, respectively. ML models have been discovered to be among the most precise and versatile compared to the mechanistic model. Moreover, other performance metrics, such as RMSE (0.022–2.177), MRE (0.007–0.100), and AARE (0.008–0.104) for ANN and RMSE (0.083–1.961), MRE (0.021–0.091), and AARE (0.037–0.089) for SVR, are obtained, indicating good prediction performances for both ML models. SVR and ANN models excel, aligning concentration curves to the optimum line when input parameters are adjusted, unlike the subpar traditional-based mechanistic model. Therefore, ML methods offer a tool to predict anaerobic digestion more effectively, enhancing design and operations. Graphical
PubDate: 2024-07-16
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- Design, Development, and Optimization of Sustainable Pyrolyzer for Biochar
Production from Agricultural Crop Residue-
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Abstract: Abstract This article presents an energy-efficient biochar kiln that produces biochar from agricultural crop residues. The kiln is designed to be easy to operate and has minimal requirements for special operations. It works by heating biomass in a combustion chamber using recirculated pyrogas. The study optimized the process parameters and economics of producing biochar from wheat straw using Response Surface Methodology (RSM) based on Central Composite Design (CCD). The sustainable pyrolyzer had a thermal efficiency of 43.69%, with steady-state operation at 517.68 ± 98.18 °C. It produced an average of 54.57 ± 1.86 kg of biochar per batch, using 36.96 ± 3.66 kg of subabul (Leucaena leucocephala) as fuel and 179.61 ± 2.87 kg of wheat straw as feedstock. Subabul is chosen as a fuel due to its rapid growth, high calorific value, low moisture content, efficient combustion, and minimal smoke emission. The thermogravimetric index (TGI) and calorific value of WSB were 7.14 and 25.91 ± 0.74 MJ/kg, respectively. The benefit–cost ratio and payback period were 2.27 ± 0.16 and 4.92 ± 0.44 months, respectively.
PubDate: 2024-07-15
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- Study on the Co-pyrolysis Behavior of Copper Slag and Pine Sawdust and the
Adsorption of Chromium-
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Abstract: Abstract The co-pyrolysis behavior of pine sawdust (PS) biochar doped with copper slag (CS) and the adsorption performance of the prepared CS catalyzed composite adsorbent is studied. Thermogravimetric, SEM, and BET are used to analyze the co-pyrolysis characteristics and the adsorption performance of PS and its mixed samples with different ratios of PS and CS. The co-pyrolysis of CS and PS effectively improves the pyrolysis characteristics. Compared with PS pyrolysis alone, with little change in activation energy, the reaction order changed from 1.5 to 0.5. When the mixing ratio PS:CS = 3:1, the pyrolysis release characteristics were the highest; the most favorable for the pyrolysis reaction. The H3PO4, KOH, and ZnCl2 used to modify PS biochar improved its adsorption capacity. The results show that the modified PS biochar has a larger specific surface area and provides more adsorption sites, effectively improving the adsorption effect. The adsorption capacity of the PS biochar is inversely proportional to the concentration of the Cr(VI) solution. Under the conditions of modified PS at 1:1 based on H3PO4, KOH, and ZnCl2, the concentration of the Cr(VI) solution is 20 mg, and the adsorption effect is best in an acidic environment with pH = 1. The high value-added utilization of metallurgical solid waste and agricultural waste was realized, namely the governance concept of “treating danger with waste.”
PubDate: 2024-07-14
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- Comparative Assessment of the Environmental and Economic Performance of
Two Straw Utilization Pathways in China-
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Abstract: Abstract Straw management is extremely challenging, and irrational treatment can cause environmental pollution and affect the development of a circular economy in agriculture. The high-value utilization of agricultural straw as an important pathway to promote circular economy and achieve carbon neutrality goals has attracted much attention. Herein, the environmental and economic performance of the main straw-based fuel (straw-to-biochar, ethanol, and biogas) and material (straw-to-board and paper) utilization scenarios in China were compared from a life cycle perspective. This study is based on data from the eFootprint platform and the China Life Cycle Database. The results show that straw production for fuel has a better environmental performance than the production of materials option for water use, acidification potential, eutrophication potential, and respiratory inorganics. Utilizing straw to produce fuels or materials can reduce greenhouse gas emissions by 155–1296 kg CO2 eq. and decrease primary energy consumption by 8949–31270 MJ. Straw-to-board has the worst energy conservation and emission reduction performance but has the best economic performance with an LCC value of − 46.38 USD. The scenario with the shortest payback time is straw-to-ethanol, which take only 2 years. Sensitivity analysis reveals that the product has the most significant impact on the environmental and economic performance. The study analyzed the environmental impacts and economic benefits of these straw utilization pathways to provide solutions for sustainable straw management.
PubDate: 2024-07-11
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- Comparative Study of High-Temperature Anaerobic Digestion of Municipal
Sludge Under Acid/Alkali and Low-Temperature Hydrothermal Synergistic
Pretreatment-
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Abstract: The efficiency of anaerobic digestion of sludge can be significantly improved through a combination of acid or alkali hydrolysis with low-temperature hydrothermal (LTH) pretreatment. The impact of various agents in conjunction with LTH treatment on sludge properties and high-temperature anaerobic digestion (HTAD) systems was comprehensively examined in this study. Comparative analyses reveal that NaOH-LTH pretreatment surpasses HCl-LTH pretreatment in enhancing sludge organic matter solubilization and enhancing HTAD system. Contrary to expectations, the use of acetic acid (HAc) pretreatment does not further enhance organic matter solubilization in sludge. Instead, it inhibits gas production efficiency and diminishes the removal efficiency of total chemical oxygen demand (TCOD) during HTAD. Among the pretreatments, NaOH (pH 11, 24 h)-LTH (90 °C, 30 min) co-treatment emerges as the optimal condition. This configuration results in a 12.5-fold increase in sludge soluble chemical oxygen demand (SCOD) compared to untreated samples, a 34.1% improvement in methane yield in the HTAD system, and a remarkable TCOD removal efficiency of 36.8%. Notably, this combined pretreatment induces significant alterations in the microbial community structure of the sludge HTAD system. Following NaOH-LTH pretreatment, the total relative abundance of methanogenic archaea increases from 80.2 to 92.3% compared to untreated systems. Graphical
PubDate: 2024-07-06
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- Biodiesel Production from Spent Coffee Grounds by Using Ethanolic
Extraction and Supercritical Transesterification-
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Abstract: This work presents a way to use ethanol and spent coffee grounds (SCG) as feedstocks for biodiesel production to solve ethanol overproduction in Thailand and biodiesel feedstock shortage problems together. Waste coffee oil (SCGO) was ethanolic extracted from SCG; then, ethanol-SCGO mixture was transesterified in supercritical condition without ethanol removal. The ethanolic extraction curves of SCG at a temperature range of 50–70 °C were constructed. Transesterification experiments were studied in a batch reactor and a continuous reactor at various temperatures (275–350 °C) and reaction time (5–40 min) under 15.0 MPa. The molar ratio of ethanol-oil mixture was set at 30:1. The highest ester content of 88.37 ± 3.00 wt% was found in biodiesel obtained at a temperature of 275 °C and a reaction time of 40 min in a batch reactor. Furthermore, excess temperature (< 300 °C) and reaction time (< 20 min) induced thermal degradation and promoted the loss of ethyl linoleate. For continuous reactor, the maximum ester content of 83.38 ± 5.86 wt% was observed at 325 °C and 29.4 min of residence time. Unlike in batch reactors, thermal degradation of ethyl linoleate was not observed in a continuous reactor. The results showed that ethanolic extraction and supercritical transesterification are alternative ways to produce biodiesel from SCG without removing extractant and using catalyst. From a prospective point of view, techno-economic analysis (TEA) and life-cycle assessment (LCA) of invented process should be conducted to ensure profitability and environmental benefits, respectively. Graphical
PubDate: 2024-07-05
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- Ecosystem Carbon and Nutrient Balances in Short-Rotation Hybrid Aspen
Coppice Under Different Thinning Methods-
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Abstract: Coppice plantations have gained a high interest for biofuel production and carbon uptake in short rotation cycles. There is a limited knowledge how such intensive coppice management affects soil fertility and nutrients supply to maintain carbon sink. We studied ecosystem carbon and nutrients balance and allocation during a 5-year period in hybrid aspen coppice under different thinning methods in hemiboreal Estonia. The benchmark value for the changes was defined before the coppice emerged after the clear-cut of the previously planted hybrid aspen plantation. The studied systematical thinning treatments were as follows: corridor thinning with removal of 67% of the trees (CT), cross-corridor thinning with removal of 89% of the trees (CCT), and unthinned (UT) coppice. The UT and CT treatments resulted in a positive carbon balance at the ecosystem level. In all treatments, a decrease of soil acidity, organic C, total N, K, Mg and Mn contents, and an increase of soil Cu and B contents were observed in the 0–20-cm deep layer. The concentrations of leaf N, P, and K were higher in UT than in the two thinning treatments, indicating that the aspens had not entirely recovered from the changed root to shoot ratio 2 years after thinning, whereas the leaf mass fraction of medium- and small-sized trees had already increased. Bioenergy harvest from the UT site in a 5-year rotation would cause 5–18% removal of NPK from the total ecosystem pool. Overall, hybrid aspen coppice showed positive ecosystem carbon balance after the first 5-year period; however, further monitoring of soil properties is needed as we found decrease of soil organic C and nutrients concentrations in short term. Graphical
PubDate: 2024-06-29
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- Anaerobic Co-digestion of Expired Dairy Products and Synthetic Domestic
Wastewater: Effect on Methane Potential in Batch Reactors-
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Abstract: Substantial amounts of expired dairy products (EDP) are generated due to their high perishability. These wastes are rich in organic matter, and their landfill disposal negatively impacts the environment. An alternative to reducing and recovering this waste would be to use it as a substrate in anaerobic digestion (AD) to produce biogas. This study investigated methane (CH4) production using different concentrations of EDP co-digested with synthetic domestic wastewater (SDW). Five anaerobic batch reactors (1000 mL) were assembled with different concentrations of EDP in SDW (500 mL working volume), namely (1) 0%, (2) 5.0%, (3) 7.5%, (4) 10.0%, and (5) 15.0% (v/v). COD removals were 81%, 84%, 80%, 89%, and 14% for assays 1 to 5, respectively. The cumulative CH4 productions were (mL/L) 717, 3354, 5327, 6584, and 1156 for assays 1 to 5, respectively. Assay 5 (15% EDP) was inhibited by volatile fatty acid (VFA) accumulation. However, assays 2, 3, and 4 (with 5.0–10.0% EDP) showed high CH4 yields (mLCH4/gVSadd) of 319, 333, and 317, respectively, demonstrating the feasibility of anaerobic co-digestion of EDP with SDW. In assays 3 and 4, a similar archaeal community structure was observed, dominated by the genera Methanosaeta, Methanolinea, Methanoregula, and Methanobacterium. In assay 2, the archaeal community demonstrated lower dominance due to insufficient substrate adaptation. This study confirms the viability of using EDP in AD systems to generate CH4, suggesting future sustainable applications for this residue. Graphical
PubDate: 2024-06-22
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- Advancements in Valorization of Food Waste Resources by Microalgae for
Sustainable Biorefinery Production-
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Abstract: Abstract The increasing global population has led to a significant accumulation of food waste. It is important to focus on reducing food waste instead of disposal methods like landfilling and incineration, which have severe environmental impacts. Upcycling food waste has emerged as an effective strategy for repurposing discarded food into higher-value products. However, concerns about food safety and public acceptance of products directly produced from food waste persist. Consequently, there is growing interest in utilizing food waste rich in moisture and biodegradable organic compounds as a potential medium for cultivating microalgae. This review article examines the utilization of food waste as a culture medium for microalgae cultivation and the methods for treating food waste to enhance its nutrient content. Additionally, it discusses the influence of nutrients such as carbon, nitrogen, and phosphorus on microalgae growth and external factors such as pH and light intensity. The article also addresses the innovation of the food supply chain from environmental, social, and economic perspective, along with food safety and public acceptability concerns. Furthermore, it explores the legislative issues surrounding products derived from food waste and the end use of microalgae biomass produced from food waste. Overall, this review provides insight into the potential of microalgae cultivation using food waste, serving as a platform towards the realization of a circular bioeconomy.
PubDate: 2024-06-20
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- Economical and Facile Synthesis of Monolignols
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Abstract: Abstract Monolignols are efficiently synthesized from the corresponding cheap and readily available cinnamic acids through a borohydride reduction of the derived mixed carbonic anhydrides. Judicious choices of the reaction conditions allow for removal of the byproducts by aqueous workup and give the products cleanly in high yields.
PubDate: 2024-06-19
DOI: 10.1007/s12155-024-10779-8
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- Production of Ethanol from Green Coconut Fiber by Integrating Cloud Point
Extraction and Simultaneous Saccharification and Fermentation-
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Abstract: Abstract The fermentation of whole slurry favors the increase in ethanol titers and minimizes water consumption. However, inhibitors accumulate in the liquid fraction pretreatment, reducing fermentation performance. In order to find a way out, the present study proposed an integration between cloud point extraction (CPE) and ethanol production using fiber of green coconut (GCF) as substrate. Triton X-114 was used to detoxify the liquid fraction from acid pretreatment, and optimal operating conditions were obtained by mathematical modeling. The effects of the residual surfactant from the dilute phase of CPE were analyzed in cellulase adsorption tests, enzymatic hydrolysis, and fermentation of acid-pretreated GCF. CPE promoted high removal of furans (86.23–100%) and phenolic compounds (22.79–75.15%), while the sugars migrated to the dilute phase. A neural network model coupled with a genetic algorithm obtained an optimal condition of 2.38% Triton X-114, temperature of 42 °C, pH of 4.3, and 0.55% sodium chloride. The incubation with the CPE dilute phase increased the residual activity from 25.1 to 50.1% and increased the cellulosic conversion from 32.28 to 41.15%. CPE-saccharification and simultaneous fermentation integration boosted the ethanol production to 12.40 g/L, while the untreated whole slurry reached only 6.29 g/L. Because of these results, the CPE emerges as a promising alternative to favor the full use of sugars from lignocellulosic biomass.
PubDate: 2024-06-17
DOI: 10.1007/s12155-024-10776-x
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- Single-Pass, Single-Stream Harvest of Corn Grain and Stover: a Comparison
of Two Harvest Methods-
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Abstract: Abstract The single-pass, split-stream harvest of corn grain and stover has been extensively studied. Challenges for these systems include the logistics and economics of handling separate grain and stover streams. Single-pass, single-stream processes have been explored using a self-propelled forage harvester to collect whole-plant corn as a biomass feedstock. However, due to the processing done by the self-propelled forage harvester, a significant portion of the grain fraction is damaged during harvest limiting its marketability. To evaluate an alternative system, a combine harvester was modified with a rear blower to collect corn stover, facilitating the collection of the grain and stover fractions into the same wagon, creating an aggregate, whole-plant corn material. Utilizing this system, a plot study was conducted to compare it to a self-propelled forage harvester. Parameters studied for system performance were yield, grain damage, and geometric mean particle size. While the combine system reduced grain damage (p < 0.001) by 18 percentage points compared to the self-propelled forage harvester and had a similar whole plant particle size (p = 0.11), it collected 1.86 Mg DM ha−1 less biomass (p < 0.001). The combine harvester with a stover collection system provides a method to collect whole-plant corn as a biomass feedstock that maintains a large portion of the grain integrity but decreases dry matter yield.
PubDate: 2024-06-13
DOI: 10.1007/s12155-024-10775-y
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- Effects of Different Parameters and Co-digestion Options on Anaerobic
Digestion of Parboiled Rice Mill Wastewater: a Review-
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Abstract: Abstract A growing paddy crop produces large quantities of parboiled rice mill wastewater (PRMWW), which contains several organic and inorganic compounds and nutrients (nitrogen and phosphate). Discharges of the rice industry’s wastewater pose a substantial threat to aquatic bodies and the surrounding environment, so an eco-friendly treatment plan is necessary. Parboiling stands out among grain-processing methods due to its numerous nutritional and physical advantages. Fewer literatures have only mentioned about the severity of the organic rich liquid effluents generated after parboiling process. Generating renewable energy from anaerobic digestion (AD) is one of the most environmentally friendly technologies to address the growing energy demands. This study is intended to give a systematic and critical review of the parboiling process, solid and liquid fractions of wastes generated, and various treatment options, with special emphasis on scope of application of AD for treating PRMWW along with energy recovery. The study explains various glitches in the AD processes of PRMWW for biogas generation and also recommends co-digesting PBMWW with other carbonaceous organic substrates for improved digestibility, and to reduce the inhibitions caused by lack of alkalinity, acid accumulation, and pH imbalance. To this end, this literature review seeks to provide a broad overview of knowledge to laypeople, entrepreneurs, and researchers.
PubDate: 2024-06-01
DOI: 10.1007/s12155-022-10522-1
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- Energy and Element Fate of Hydrochar from Hydrothermal Carbonization of
Dairy Manure Digestate-
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Abstract: Abstract Hydrothermal carbonization (HTC) of dairy manure digestate (DMD) was explored in this study. Response surface methodology was used to investigate the influence of temperature, time, and DMD pH on hydrochar properties. Hydrochar obtained in the study exhibited higher heating value (HHV) in the range of 17.5–20.6 MJ kg−1, with energy and hydrochar yields 45.8–72.4% and 57.6–80.1%, respectively. It was demonstrated that temperature was the most significant factor. At higher temperature, the HHV of hydrochar was higher while both energy and hydrochar yields were lower. In particular, hydrochar obtained at temperature ≥ 260 °C had HHV ≥ 20.0 MJ kg−1, which was close to that of lignite and implied its potential as fuel. To gain insights about the fate of various elements during HTC and facilitate overall evaluation of hydrochar, a wide range of elements (30 in total, including macro- and micro-nutrients, as well as heavy metals) was analyzed. Hydrochar had carbon to nitrogen (C/N) ratio between 10 and 12, which was in the suitable range for nutrient availability as soil amendment. Half of the elements remained in the hydrochar, while most of Na, K, and half of S leached into process water, especially at temperature ≥ 260 °C, thus combusting hydrochar can potentially alleviate the slagging and fouling problems associated with direct combustion of dried DMD. The study provided insights for further rational utilization of DMD hydrochar, and integration of HTC into existing on-farm anaerobic digestion was a promising option for reduction disposal of DMD.
PubDate: 2024-06-01
DOI: 10.1007/s12155-022-10470-w
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- A Systematic Review on Photocatalytic Biohydrogen Production from Waste
Biomass-
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Abstract: Hydrogen, a form of energy that is both clean and renewable, is now being researched and developed as a potential source of alternative energy. There are many different kinds of microbial systems that have the potential to be utilised in the manufacturing of biohydrogen. Thermophiles are found as potential producers of hydrogen, at a high rate, in adverse operating conditions. Temperature, pH, and concentration of substrates play a crucial role in affecting the metabolism of these microorganisms. Sustainable production of hydrogen is feasible when organic waste is employed as a potential feedstock. The overall yield of hydrogen production procedures demands improvements, to turn them into commercial applications. The integration of two-stage processes may contribute to an overall increase in energy output. As examples of second-stage processes, biomethanation, microbial electrolysis cells, photo-fermentation, and microbial fuel cells have been the subject of extensive research. This article provides an overview of the photocatalytic method for producing biohydrogen, including its fundamentals and underlying mechanisms, as well as other biological methods of hydrogen production. This process exhibits reduced energy consumption and demonstrates environmental friendliness by potentially utilising waste material as a substrate. Graphical
PubDate: 2024-06-01
DOI: 10.1007/s12155-023-10704-5
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- Assessment of Feedstock Quality of Poplars (Populus L.) Using Selected
Pellet-Quality Parameters-
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Abstract: Abstract Wood pellet is an important biomass-based source of cleaner and renewable energy with a growing global demand. Populus spp. (poplars) are fast-growing trees with high productivity potential in the southeastern US. Selected pellet-quality parameters were examined as a proxy for assessing if the feedstock quality of poplar stem wood was affected by stand location (Coastal, Piedmont, Mountains of North Carolina, clone “140”), stand age (five vs. seven years, clone-“140”), clones (“140”, “176”, “230”, “185”, “356”) and stem sections (clone-“356”) by examining sulfur, ash, volatile-matter, fixed-carbon, gross caloric, carbon, hydrogen, and nitrogen contents of moisture-free samples. Location-study samples significantly varied (p≤0.027) in ash (0.6–0.9 wt%), and gross caloric (19.75–19.89 MJ/kg) contents and study clones significantly differed (p≤0.0271) in ash (means: 0.75–0.97 wt%), volatile-matter (means: 80.5–82.7 wt%), fixed-carbon (means: 16.5–18.7 wt%) and hydrogen (means: 4.19–4.78 wt%) contents. The only other significant variations were hydrogen (mean: 4.19–4.67 wt%) content with stand age (p≤0.009) and gross caloric values (19.5–19.9 MJ/kg) among stem sections (p = 0.0003). This study showed that poplars have stem-wood quality suitable for pellet production and most of the studied feedstock samples had ash, nitrogen, sulfur, and caloric (at 10% moisture content) contents that would meet the ENplus pellet-quality standards. Results from this study can be used for facilitating decisions about managing poplar stands for sustainable pellet feedstock production in the southeastern US, including selecting optimum rotation length, pellet-suitable clones, and sites.
PubDate: 2024-06-01
DOI: 10.1007/s12155-023-10711-6
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