Agricultural Straw Research Articles

A negative-carbon planning method for agricultural rural industrial park integrated energy system considering biomass energy and modern agricultural facilities

Biomass energy, recognized as a “zero-carbon” energy, has gradually become a crucial approach to promoting the low-carbon transformation of agricultural rural industrial parks (ARIP). Meanwhile, modern agricultural facilities (MAF) can play a significant role in adjusting agricultural load. Therefore, this paper proposes a negative-carbon planning method for the ARIP integrated energy system (IES). Firstly, carbon activities occurring during the operation of ARIP are sorted out and modeled based on the life cycle assessment (LCA) method, especially modeling the “zero-carbon” and “negative-carbon” benefits of biomass energy. At the same time, the models of both agricultural irrigation systems and straw bundling direct combustion heating are constructed in the ARIP planning. Then, a negative-carbon planning model for ARIP IES is established with the goal of minimizing the annualized total cost, where carbon emission reduction is integrated into the optimization objectives through carbon trading. On this basis, a two-stage distributionally robust optimization (DRO) planning model is constructed, where a box-like set and comprehensive norm constraints are used to model the seasonal differences of agricultural industry loads and the uncertainty of probability distribution in photovoltaic (PV) scenarios. Especially, a box set with adjustable uncertainty coefficients is introduced to simulate fluctuations of output in PV scenario. Finally, the CPLEX solver is used to solve the planning model. verify the effectiveness of the proposed planning method in enhancing the economic and environmental effects of ARIP. Results indicate that the proposed planning model can reduce the total cost by 49.584 × 104 $. Besides, the annual carbon emissions can be reduced from 37533.98 t CO2-eq to −15834.5 t CO2-eq. Especially, the carbon sequestration effect of biochar is the key link in achieving “negative carbon” in ARIP.

Application of straw-derived biochar: a sustainable approach to improve soil quality and crop yield and reduce N2O emissions in paddy soil.

The burning of agricultural straw is a pressing environmental issue, and identifying effective strategies for the rational utilization of straw resources is decisive for achieving sustainable development. Owing to its high carbon content and exceptional stability, straw biochar produced via pyrolysis has emerged as a key focus in multidisciplinary research. However, the efficacy of biochar in mitigating nitrous oxide (N2O) emissions from paddy soils is not consistent. A 2-year field experiment was conducted and investigated the impact of biochar derived from two feedstocks (rice straw and wheat straw, pyrolyzed at 450°C) on N2O emissions, global warming potential (GWP), greenhouse gas intensity (GHGI), nitrogen use efficiency (NUE), crop yield, and soil quality. The static chamber technique was used for collecting N2O gas samples, and concentrations were analyzed through gas chromatography methods. The treatment combinations included BR0 (control), BR1 (NPK at the recommended dose, 120:60:40kgha-1), BR2 (wheat straw biochar, 5 t ha-1), and BR3 (rice straw biochar, 5 t ha-1). The results exhibited that cumulative N2O emissions from BR2 and BR3 treatments decreased by 10.55% and 13.75% respectively, compared to BR1. Lower GWP and GHGI were observed under both biochar treatments compared with BR1. The highest rice grain yield (3.48Mgha-1) and NUE (76.72%) were recorded from BR3, which also exhibitedthe lowest yield-scaled N2O emission. We observed positive correlations between soil nitrate, ammonia and water-filled pore spaces, while NUE showed negative correlations with N2O emissions. Significant (p < 0.05) improvements in soil quality were also detected in both the biochar treated plots, indicated by increased soil pH, water holding capacity, porosity, and nutrient contents. Overall, the results suggest that applying biochar at a rate of 5 t ha-1 in paddy soil is a viable nutrient management strategy with the potential to reduce reliance on inorganic fertilizers, mitigate N2O emissions, and contribute to sustainable food production.

Thermal Catalytic Production of Potassium Humate Fertilizer from Tobacco Straw and Its Performance in Wheat Hydroponics

Production of artificial humic acid (AHA) from waste biomass will contribute to environmental protection and agricultural productivity. However, there is still a lack of a faster, more efficient and eco-friendly way for sustainable production. In this study, potassium humate was prepared from agricultural waste tobacco straw by thermal catalysis using environmentally friendly Fe2O3 as a catalyst. The yield of potassium humate was successfully increased to 68.77 %. In the present study, using characterization methods such as TG-DTG and UV, it was found that the potassium humate prepared from tobacco straw had lower aromaticity, smaller molecular weight, as well as better solubility and better quality. In addition, the effect of potassium humate fertilizer on wheat biomass was also investigated in this experiment by wheat hydroponics. The results showed that the germination rate of wheat increased by 17 % and the fresh and dry weights increased by 6.94 % and 19.31 %, respectively, with the addition of potassium humate prepared with iron catalyst. This study provides a green and simple technology for the resourceful utilization of tobacco straw to produce high value-added potassium humate, and enriches the source of raw materials for potassium humate, expanding its application in the field of crop growth.

Biobased Construction from Agricultural Crops: Paper 1 - A State of Play of Commercial Solutions in Europe

In response to environmental concerns and the global warming issue in particular there is a growing drive to decarbonise the building sector and transition it to more circular practices. Biobased construction materials, products and systems are an important low carbon and circular strategy as they can enable low to negative carbon construction and have strong circularity advantages notably being able to enter the bio cycle, using renewable, low to zero toxic resources and provide a range of other performance benefits, including moisture and vapour regulation. This novel research presents a unique state of play on the commercial application of biobased construction from selected agricultural crops, straw, miscanthus and hemp, focused on the European context. A desk-based review of known biobased material producers and manufacturers is undertaken, supplemented with semi structured interviews and site visits, to provide a comprehensive overview of the sector and detailed account of the types of biobased materials, products and systems that are being applied in buildings across Europe and beyond. The findings show that a diversity of agricultural crops are being utilised at different process, manufacture and construction technology levels, providing a range of tested and certified materials and products for application in mainly timber frame construction, but also some masonry solutions, and a growing number of modular systems. These operate in a diversity of supply chains and are being applied in a wide range of building types, both domestic and non-domestic, including multi story and complex buildings.

Preparation and characterization of biochar/polypropylene composites from recycled waste plastics and agricultural waste-reed straw

To alleviate the increasingly serious plastic pollution problem, developing biomass-plastic composite materials has become a research hotspot. In this study, waste polypropylene (PP) and reed biochar (RC) are used as raw materials to prepare biochar/polypropylene composites (BPCs), and γ-aminopropyl triethoxysilane (KH550) is used as an interfacial modifier to improve the interficical compatibility between RC and PP. Benefiting from the coupling effect of KH550, the obtained KH550-modified reed charcoal/polypropylene (K-RC/PP) composites exhibit enhanced tensile and bending strengths compared to the RC/PP. When 2.4 wt% of KH550 is applied, the tensile and flexural strengths of K-RC/PP reach 22.77 MPa and 49.6 MPa, respectively. Moreover, the interfacial modification simultaneously improves the thermal stability and hydrophobicity of the composites, which not only significantly reduces the fire risks but also improves the durability of the material. This work provides a feasible solution for developing biochar/plastic composites with excellent mechanical performances and high fire safety.

Co-pyrolysis of wheat straw with polyester-based polyurethane for nitrogenous compounds: Pyrolysis kinetic properties and synergistic effects

To re-utilize agricultural waste straw and waste plastic, the co-pyrolysis process of wheat straw (WS) and high-nitrogen polymer polyester-based polyurethane (PU) and the synergistic effects were studied. The results showed that PU facilitated pyrolysis to occur at lower temperatures. The effective apparent activation energies (Eα) of different samples were calculated at different conversion rates with three methods (Kissinger, KAS and Starink). It was found that PU decreased the Eα values and enthalpy change of WS and increased the reactivity. Both ΔG and ΔS results indicate that a heating rate of 5 ℃/min is more favorable for co-pyrolysis. PU greatly promoted the production of pyrolysis oil. Co-pyrolysis oil doped with 75 % PU gave the highest yield of 77 wt%. Co-pyrolysis effectively suppressed the production of acids, aldehydes, and phenols in pyrolysis oils. It increased the levels of alcohols and ketones, improving the pyrolysis oil's stability and calorific value. α, β-unsaturated aldehydes produced by WS during pyrolysis reacted with hydrazine derivatives produced by PU pyrolysis to produce pyrazole compounds after dehydration. In the co-pyrolysis of 50 % doped PU, the reaction of methyl and methylene produced by WS with amines (-NH2) produced by the pyrolysis of PU promotes the production of trimethylamine. The yield of amines in the nitrogenous compounds reached a maximum at this time. PU increased the yield of nitrogenous compounds and their variety. It favored the output of high-value chemicals. FT-IR analyses of pyrolytic charcoal showed that the addition of PU promoted the cleavage of WS and the dehydration and decarboxylation reactions of C-O and C-O-C. Finally, synergistic effects and nitrogen conversion mechanisms in the co-pyrolysis process are proposed. This work provided a theoretical basis for the resource utilization of WS waste and PU waste.

Assessment of bioenergy plant locations using a GIS-MCDA approach based on spatio-temporal stability maps of agricultural and livestock byproducts: A case study

Addressing the global challenge of energy sustainability and global directives on farming emissions, the United Nations, the European Union, and China have led with strict targets for clean energy, renewable share growth, and carbon neutrality, highlighting a commitment to collective sustainability. This work is situated within the ambit of the Sustainable Development Goals (SDGs), advocating for a transition towards renewable energy sources. With substantial and accessible bioenergy resources, notably in Hubei Province, China, biogas technology has emerged as an emission-cutting solution. This research, focused on the Jianghan Plain, employs an integrated approach combining spatial analyses with machine learning tools to evaluate crop yield stability over two decades, with the aim of maximising the biogas yield from agricultural byproducts, i.e., crop straw and livestock manure. Using Multi-Criteria Decision Analysis (MCDA), which is informed by grey-based DEMATEL, 9 constraints and 13 environmental, social, and economic criteria were assessed to identify optimal sites for biogas facilities. The findings underscore the significant bioenergy potential of agricultural byproducts from the plain of 6.3 × 1012 kJ/year at an 11.4 kJ/m2 density. Stability analyses revealed consistent biomass availability, with rice in Gongan and Shayang and wheat in Jiangling being the primary contributors. Through the MCDA, 45–66 optimal biogas plants were identified across 4 critical counties (Zhongxiang, Shangyang, Jingshan, and Yichen), balancing the energy supply and demand under various stable scenarios. Furthermore, this study demonstrated the criticality of moderate biomass stability for stakeholder consensus and identified areas of high stability essential for energy demand fulfilment. Theoretically, this study offers a practical model for bioenergy resource exploitation that aligns with global sustainability and carbon neutrality goals to address the urgent need for renewable energy solutions amidst the global energy crisis. Practically, this study sets a precedent for policy and planning in environmental, agricultural, and renewable sectors, signifying a step forwards in achieving environmental sustainability and an energy-efficient future.

Biochar enhanced anaerobic co-digestion of poultry litter and wheat straw: Performance, microbial analysis, and multiple factors’ interaction

Amendment of anaerobic co-digestion (Co-AD) of poultry litter (PL) and agricultural straw using biochar has rarely been practiced. This study conducted two sequential experiments to evaluate the effect of adding alkaline biochar on improving the batch Co-AD of PL and wheat straw. The feasibility experiment identified the advantages of adding biochar by the improved observed cumulative methane yield (CMYo, mL CH4/g VSsubstrate) of 9.7%; the increased removal rates of the substrate total solids (TSsubstrate) and volatile solids (VSsubstrate) of 15.2% and 14.2%, respectively; the enhanced abundance of both hydrolytic bacteria and methanogens, including hydrogegenotrophic Methanobacterium and, especially, the acetolactic Methanosaeta; and the 37.3% higher abundance of the methanogenic pathways, compared to the control. The interaction experiment showed that biochar dosage (BD) interacted with the initial substrate carbon-to-nitrogen ratio (C/N) and total solids level (TS). The developed mathematical models for CMYo and VSsubstrate removal by response surface methodology were significant, which predicted the optimal conditions being initial substrate C/N ratio 29.93 and TS 6.98%, and BD 9.98% substrate. The optimized CMYo and VSsubstrate removal were 17.7% and 22.1% higher, respectively, than those of the Control. These results support the utilization of biochar in improving the Co-AD of agricultural wastes.

Optimizing Biomass Supply Chains to Power Plants under Ecological and Social Restrictions: Case Study from Poland

The growing demand for social and regulatory forest ecosystem services can significantly modify the availability and cost of biomass for energy purposes. This article presents a model for optimizing biomass supply chains using a linear programming framework integrated with a geographic information system (GIS). Based on a given type of biomass resource, its calorific value, price, distance from the power plant, and transportation costs, the model identifies the optimal source of biomass, allowing it to cover the demand for the required total energy value with the lowest possible costs. The case study includes the Połaniec power plant in southeastern Poland and potential sources of forest biomass and agricultural straw within 100 km of the plant. The impact of constraints on the availability and cost of biomass was analyzed in the following scenarios: (1) all forest and agriculture biomass is available, (2) forest area in Natura 2000 network is excluded, and (3) firewood and forests with dominated ecological and social function are excluded. Unit costs of biomass varied depending on biomass availability and energy demands. The lowest unit costs of biomass (3.19 EUR/MJ) were for energy demand at the level of 1 TJ yearly for all kinds of biomass and the highest (4.91 EUR/MJ) for ecological and social constraints and energy demand 4 TJ. As energy demand increased, unit costs increased, and the ability to meet this demand with just one type of biomass decreased. The energy biomass sector can utilize the model to benefit both biomass producers and their final buyers.

Effect of Lentinus sajor-caju on the chemical composition and antioxidant activity of highland barley straw under solid-state fermentation.

The efficient utilization of straw resources as animal feed has gained considerable attention. The objective of this study was to evaluate whether Lentinus sajor-caju treatment alters the chemical composition and antioxidant activity of highland barley straw and enhances its functional value as a ruminant feed. The chemical composition, antioxidant capacity, and metabolomic profile of highland barley straw were determined after 21 days of solid-state fermentation with L. sajor-caju at 25°C. The differential metabolites between fermented and unfermented highland barley straw were identified by LC-MS and the relationship between the identified metabolites and antioxidant capacity was elucidated. The results showed that, compared with untreated highland barley straw, the crude protein and ether extract contents were higher (51.55 and 76.43%, respectively) in highland barley straw after 21 days of incubation with L. sajor-caju, whereas the hemicellulose, cellulose, and acid detergent lignin contents were lower (2.48, 25.08, and 45%, respectively). The total antioxidant capacity was significantly higher in L. sajor-caju-treated than in untreated highland barley straw. In total, 600 differential metabolites (301 upregulated and 299 downregulated) were identified between L. sajor-caju-fermented and unfermented highland barley straw. Correlation analysis results showed that Fe2+ scavenging and total phenolic content were strongly correlated with total antioxidant capacity. Meanwhile, the differential flavonoid metabolites between fermented and unfermented highland barley straw were primarily associated with antioxidant activity, with kaempferol 3-xylosylglucoside, isoginkgetin, and rhoifolin being the most representative. Thus, this study demonstrates that L. sajor-caju could enhance the functional value of highland barley straw, showing the potential of L. sajor-caju for improving the utilization of agricultural straws in ruminants.

Mechanical and vegetative performance of ecological concrete with nutrient aggregates

Enhancing its performance and maximizing the utilization of solid waste are pressing matters that require attention to guarantee the sustainable development of ecological concrete. This study focuses on the development of a nutrient-rich aggregate ecological concrete that demonstrates favorable plant growth performance through the utilization of recycled engineering muck and agricultural waste straw biochar. First, a unsintered nutrient aggregate is formulated through the combination of engineering muck, agricultural waste straw biochar, compound fertilizer powder, and super absorbent polymer with magnesium phosphate cement (MPC) and a hydrophilic polyurethane solution (HPS). Subsequently, by employing the prepared unsintered nutrient aggregates to partially substitute natural aggregates, a novel ecological concrete containing nutrient aggregates is generated. The study examines the impact of the composition of nutrient aggregates and porosity on the mechanical properties, water retention capacity, fertilization performance, and ecological attributes of concrete. The findings indicated that a combination of 17.06% MPC and 5.38% HPS proved to be the most effective curing method for nutrient aggregates at a liquid-solid ratio of 0.34. The water retention, fertility, and ecological performance of ecological concrete with nutrient aggregates improve with higher nutrient aggregate content, albeit at the expense of reduced mechanical performance. Under equivalent nutrient aggregate content, low porosity ecological concrete demonstrates higher fertility performance compared to high porosity ecological concrete, whereas the water retention performance shows the opposite trend. Furthermore, the patterns observed in phosphorus leaching concentration and conductivity suggest that the ecological concrete with nutrient aggregates exhibits a self-release characteristic of nutrients. The study can offer technical assistance for the efficient utilization of solid waste, thus advancing the sustainable growth of the ecological concrete industry.

Synthesis of biomass‐derived ethyl levulinate from steam‐exploded corn straw

AbstractEthyl levulinate (EL) production from steam‐exploded corn straw (SCS) in a cascade of reaction using a Brønsted (B) acid and a Lewis (L) acid in ethanol was studied. The entangled structure of corn straw could be obviously damaged through steam explosion when the pressure was 1.5 MPa holding 10 min. The content of cellulose can be increased from 35.9% to 46.8%, and the contents of hemicellulose and lignin were changed from 16.7% to 8.8% and 22.6% to 27.5%, respectively. EL yield was significantly increased from 10.7 to 24.6 wt% under optimal reaction conditions (L/B = 1/20 [mol/mol], 205°C, 90 min, 1.8 g of SCS, 60 mL of ethanol). According to kinetic models, the activation energies for the main and side reactions were 56.8 and 110.5 kJ mol−1, respectively. It suggested that SCS was more easily to be converted to EL rather than other by‐products. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gaps (HOMO‐LUMO gaps) of cellobiose over the mixed acids in ethanol were significantly reduced with frontier molecular orbital (FMO) theory. This work provides an effective strategy for EL production from agricultural waste straws.

A wastes-based hierarchically structured cellulose membrane: Adsorption performance and adsorption mechanism

It was imperative to expeditiously investigate novel avenues for the valorization of agricultural waste biomass crop straws. The straws represented promising substrates to design eco-friendly adsorbents for the effective treatment of complex dyeing wastewater owing to their widespread availability, low cost, easy production, and environmental friendliness. Despite the advantages, developing adsorbents with versatile uses, antibacterial properties, and strong mechanical qualities remained a challenge. Herein, a sustainable waste treatment strategy is put forward by developing multifunctional adsorbents derived from agricultural waste. The adsorbents are designed to synchronously adsorb the typical contaminants such as organic molecule (methylene blue, MB) and heavy metal ions (cadmium ion, Cd2+) in dyeing wastewater. Through the assembly of cellulose fibers, multiscale cellulose membrane (MCM) substrates with enhanced two-dimensional (2D) structure were simply fabricated from biomass crop straws. Coating functional copper phosphate (CP) nanoflakes on the MCM substrate effectively constructed the hierarchical structure to achieve the synchronous adsorption. The synergistic effects of electrostatic attraction, hydrogen bonding and coordination greatly prompted the adsorption process. Furthermore, the multifunctional adsorbents were imparted with satisfactory antibacterial properties, thereby expected to solve the problem of membrane fouling in wastewater. Hierarchically structured copper phosphate @ cellulose antibacterial adsorbents (CP@MCM) exhibit huge application potential in the resource utilization of agricultural waste and effective treatments for dyeing wastewater.

Application of waste rice straw as fibre or filler in asphalt mixtures: materials characterisation and performance evaluation

ABSTRACT This study investigated the application of agricultural waste rice straw as fibre or filler in asphalt mixtures. Initially, the physical, chemical, mineralogical and morphological characterisation of rice straw products were analysed. Subsequently, the performance of stone matrix asphalt (SMA) mixtures containing rice straw fibre was evaluated in terms of rutting, crack resistance and moisture susceptibility, compared to cellulose fibre. Additionally, the properties of asphalt concrete (AC) mixtures incorporating rice straw filler to replace conventional mineral filler partially were examined. The findings revealed that rice straw products exhibited similar characteristics to cellulose fibre or mineral filler, indicating their suitability for use in asphalt mixtures. The appropriate addition of rice straw fibre or filler demonstrated enhancement in the high-temperature performance, low-temperature crack resistance and moisture stability of asphalt mixtures. Through experimental tests, the optimum content of rice straw fibre in SMA-13 mixtures was determined to be 0.4%, while for the rice straw filler in AC-13 mixtures, it was 20%. The mechanisms of rice straw fibre and filler added in asphalt mixtures to strengthen their road performance were binder adsorption and reinforcement effect through scanning electron microscope (SEM) images. Furthermore, rice straw filler also contributed to void filling within asphalt mixtures.

Simultaneous removal of U(VI) and tetracycline from aqueous solution by biochar-supported nano-hydroxyapatite: New insights into the role of biochar and interactions between pollutants

U(VI) and tetracycline (TC) in hospital wastewater pose serious threats to human health and the environment. In this study, agricultural corn straw residue was utilized as a precursor for biochar, and biochar-supported nano-hydroxyapatite (nHAP) adsorbents (CSPCs) were synthesized at various ratios. These CSPCs were employed for the removal of U(VI) and TC in both one-component and two-component systems. In the one-component system, the adsorption capacity of the material was related to the ratio of nHAP to biomass, and the maximum adsorption capacities of CSPC-1 (nHAP/biomass = 1/1) for U(VI) and TC were 724.63 mg g−1 and 15.06 mg g−1, respectively. The XPS and XRD results confirmed that biochar promoted the dissolution and precipitation of U(VI) by nHAP, which stabilized the adsorption of U(VI) by CSPC-1. In the two-component system, the complexation strength of U(VI) and TC had a significant effect on the adsorption of both. At pH < 3.0, U(VI) inhibited the adsorption of TC, whereas TC enhanced the adsorption of U(VI). However, at pH > 4.0, the adsorption of U(VI) and TC were mutually reinforcing. At pH = 5.0, TC inhibited the adsorption of U(VI) only when the concentration of TC was significantly greater than that of U(VI). Combined with the systematic analysis of the FTIR, XPS and Raman spectroscopic results, these results suggest that these phenomena can be attributed to the complexation-bridging interactions between U(VI) and TC and their competition for adsorption sites.

Spatial autocorrelation and driving factors of carbon emission density of crop production in China.

Mitigating carbon emissions from crop production is essential for addressing global warming. At a macro-level, existing studies have often relied on the calculation of carbon emission intensity of crop production to understand comparable carbon effects between regions. However, this approach obscures the differences in crop planting scale and natural attributes across regions, leaving room for improvement in the methods and scope of analysis. To extend the existing research, we proposed an idea for calculating the carbon emission density of crop production based on planting area. Additionally, we developed an analytical framework for driving factors of carbon emission density of crop production from a spatial interaction perspective. The provincial carbon emission density of crop production in mainland China between 2000 and 2020 was calculated, and spatial econometric models were utilized to investigate the spatial autocorrelation and driving factors. The results indicate that the national average carbon emission density of crop production was 1.462 t/hm2 annually. Over 21years, the carbon emission density of agricultural materials, rice cultivation, soil management, and straw burning evolved from 0.384 to 0.470 t/hm2, 0.409 to 0.367 t/hm2, 0.171 to 0.169 t/hm2, and 0.317 to 0.448 t/hm2, respectively. The global Moran's index indicated a positive spatial autocorrelation of carbon emission density of crop production and the subdivided carbon sources among provinces. Regarding direct effects, an increase in the proportion of paddy fields in cropland composition and irrigation efficiency would significantly promote the carbon emission density, while factors such as cropland area, multiple cropping, agricultural personnel numbers, departmental proportion, and disaster degree would decrease the local carbon emission density. Certain factors, such as cropland area and agricultural disasters, had a spatial spillover effect on carbon emission density between provinces. The study suggests harnessing key drivers and spatial spillover effects to achieve regional low-carbon crop production.

ShF5H1 overexpression increases syringyl lignin and improves saccharification in sugarcane leaves

ABSTRACT The agricultural sugarcane residues, bagasse and straws, can be used for second-generation ethanol (2GE) production by the cellulose conversion into glucose (saccharification). However, the lignin content negatively impacts the saccharification process. This polymer is mainly composed of guaiacyl (G), hydroxyphenyl (H), and syringyl (S) units, the latter formed in the ferulate 5-hydroxylase (F5H) branch of the lignin biosynthesis pathway. We have generated transgenic lines overexpressing ShF5H1 under the control of the C4H (cinnamate 4-hydroxylase) rice promoter, which led to a significant increase of up to 160% in the S/G ratio and 63% in the saccharification efficiency in leaves. Nevertheless, the content of lignin was unchanged in this organ. In culms, neither the S/G ratio nor sucrose accumulation was altered, suggesting that ShF5H1 overexpression would not affect first-generation ethanol production. Interestingly, the bagasse showed a significantly higher fiber content. Our results indicate that the tissue-specific manipulation of the biosynthetic branch leading to S unit formation is industrially advantageous and has established a foundation for further studies aiming at refining lignin modifications. Thus, the ShF5H1 overexpression in sugarcane emerges as an efficient strategy to improve 2GE production from straw.

Valorization of Agricultural Rice Straw as a Sustainable Feedstock for Rigid Polyurethane/Polyisocyanurate Foam Production.

Agricultural rice straw (RS), often discarded as waste in farmlands, represents a vast and underutilized resource. This study explores the valorization of RS as a potential feedstock for rigid polyurethane/polyisocyanurate foam (RPUF) production. The process begins with the liquefaction of RS to create an RS-based polyol, which is then used in a modified foam formulation to prepare RPUFs. The resulting RPUF samples were comprehensively characterized according to their physical, mechanical, and thermal properties. The results demonstrated that up to 50% by weight of petroleum-based polyol can be substituted with RS-based polyol to produce a highly functional RPUF. The obtained foams exhibited a notably low apparent density of 18-24 kg/m3, exceptional thermal conductivity ranging from 0.031-0.041 W/m-K, and a high compressive strength exceeding 250 kPa. This study underlines the potential of the undervalued agricultural RS as a green alternative to petroleum-based feedstocks to produce a high-value RPUF. Additionally, the findings contribute to the sustainable utilization of abundant agricultural waste while offering an eco-friendly option for various applications, including construction materials and insulation.

Amidoxime-functionalized corn straw for efficient Cr(VI) adsorption from water: Waste utilization, affinity character and DFT simulation

To endow the added value of agricultural waste straw resources, we introduced amidoxime groups onto corn straw to fabricate amidoxime-functionalized corn straw sorbents (AO-CS) capable of efficiently adsorbing Cr(VI). The presence of surface-anchored functional moieties significantly accelerated the adsorption rate, achieving equilibrium in just 10 min. The Langmuir isotherm model and experimental data agreed well, with the maximum adsorption capacity reaching 199.7 mg/g at pH = 2.0, 303 K. Experiments with various temperatures were used to obtain the thermodynamic parameters (ΔG, ΔH, and ΔS). The Cr(VI) adsorption mechanism on AO-CS was found to involve electrostatic attraction, hydrogen bonding, redox reactions, and complexation, as confirmed by DFT calculations, FT-IR, and XPS analysis results. Under conditions of coexisting anions (Cl-, NO3-, SO42-, and PO43-), AO-CS exhibited a high selectivity for Cr(VI) due to the establishment of a more stable complex between amidoxime groups and Cr2O72-. Moreover, AO-CS could be easily regenerated using EDTA, with only a slight decrease in adsorption capacity even after four cycles. In conclusion, these cost-effective sorbents with rapid adsorption toward Cr(VI) held great promise for practical applications in wastewater treatment.

Briquetting as a source pretreatment strategy to improve energy recovery from the anaerobic digestion of agricultural straw: Experimental and economic evaluation

The sustainability of biogas production from straws is limited by the collection, transportation, storage, and pretreatment of feedstocks. To address these constraints, this study investigated briquetting as a pretreatment strategy for rice straw (RS) to increase bioenergy generation. The results indicated that briquetted RS yielded 205.4 mL/g VS of methane, which was 11.7% higher compared to that produced by the untreated RS. The economic analysis revealed that the briquetting process had positive effects with a payback time of 3.4 y and an internal rate of return of 23.4%. It also reduced feedstock transportation and storage costs by 42.6%. Adding a NaOH treatment to the briquetting process increased methane production by 26.4% compared to untreated RS. However, the integration of briquetting with NaOH treatment might be an unprofitable method for processing RS. This became apparent when examining the production cost, which stood at 1.13 $/kg biomethane with an internal rate of return of 16.2%, representing an 8.7% increase and a 7.2% decrease, respectively, compared to the mono briquetting method. These results revealed that briquetting as a source pretreatment strategy can improve the productivity of straw biogas plants, thereby advancing the industry towards cleaner production.