Cotton Stalk Research Articles

PREPARATION OF THERMOCHEMICALLY ACTIVATED CARBON ADSORBENTS BASED ON COTTON STEM AND COTTON SHELL AND THEIR IR SPECTROSCOPY ANALYSIS

This article discusses the practical importance of adsorbents today, areas of application, and methods of obtaining activated carbon adsorbents based on local raw materials. Preparation of adsorbents activated by the method of thermochemical activation based on cotton stalks and cotton bolls, functional groups in the obtained adsorbents were analyzed by IR spectroscopy.

Systematical analysis and application of distributed activation energy model (DAEM) with Weibull distribution for pyrolysis kinetics of lignocellulosic biomass

The distributed activation energy model (DAEM) is a comprehensive and accurate kinetic model for describing the thermal decomposition kinetics of complex materials. The Gaussian distribution is commonly used for representing the activation energy distribution, however, it is symmetric and cannot reflect the reactivity asymmetry involved in complex chemical kinetics. The Weibull distribution offers an alternative to represent the distribution of activation energies. This study performed a systematical investigation of the DAEM with Weibull distribution, focusing particularly on its asymmetric characteristics. Additionally, the DAEM with Weibull distribution was applied to analyze the pyrolysis kinetics of rice straw and cotton stalk. The theoretical analysis results showed that the DAEM with Weibull distribution could provide abundant flexibility to elucidate the asymmetric reactivity of complex chemical kinetics. The pyrolysis processes of rice straw and cotton stalk could be deconvoluted into several sub-processes, which could be accurately described by the DAEMs with Weibull distribution. The obtained Weibull distributions of activation energies for those deconvoluted sub-processes validated their asymmetric reactivities. It is expected that the results could help in exploring the kinetic mechanisms of lignocellulosic biomass pyrolysis and facilitate the application of the DAEM with Weibull distribution in analyzing complex chemical kinetics.

Thermal Behaviour, Chemical Composition and Morphological analysis ofCotton Stalk for Efficient Biochar Production

The escalating concern over air pollution from crop stubble burning necessitates responsible biomass disposal or utilisation. In this study, characterisation of cotton stalk was carried out to assess its feasibility for biochar production. The proximate analysis revealed that cotton stalk had moisture content of 8.65%, bulk density of 215.8 kg m-3, volatile matter of 71.65%, and fixed carbon content of 16.03%. The ultimate analysis showed that cotton stalks were predominantly composed of carbon (64.88%), hydrogen (6.58%) , and oxygen (2.55%), with a low (0.66%) nitrogen content . Thermo-gravimetric analysis (TGA) highlighted the pyrolysis process, identifying a peak temperature of approximately 500°C and distinct stages of thermal degradation: moisture loss up to 150°C, hemicellulose decomposition between 200°C and 300°C, cellulose decomposition from 300°C to 400°C, and lignin decomposition from 400°C to 500°C. X-ray diffraction (XRD) analysis confirmed the presence of crystalline cellulose with a diffraction peak at 2θ = 22.5°, indicating significant structural stability during pyrolysis for biochar production. Fourier-transform infrared (FTIR) spectroscopy revealed characteristic peaks associated with cellulose and lignin, underscoring the retention of essential structural components in biochar during biomass conversion. These analyses demonstrated the potential of cotton stalks as a viable feedstock for biochar production, providing a sustainable method for agricultural waste management and soil health improvement.

Effect of bone char catalyst on the pyrolysis behavior and crystal structure of cotton stalks

This study investigated the characteristics of bone char (BC) in the in situ catalytic pyrolysis of cotton stalk (CS) using a fixed-bed pyrolysis system at 600 °C. The results revealed that BC contained abundant pore structures and polar active sites, which prolonged the residence time of gases and provided numerous reaction sites for the secondary reaction of pyrolysis products. At a CS-to-BC mass ratio of 1:2 (CB-1:2), the reaction rate was accelerated. As the BC proportion increased, the crystallinity of the char decreased, while the specific surface area increased. At CB-1:2, both the crystallite size and crystallinity of BC improved. The oxygen-containing functional groups in BC, such as CO32−, PO43−, −COOH, and −OH, effectively increased the adsorption active sites. Additionally, Ca2+ in BC promoted dehydrogenation, deoxidation, fused cyclization, and decarboxylation of carboxylic acids, leading to increased production of H2, CO, and CO2. Moreover, Ca2+ facilitated the homolytic reactions of lignin, generating hydrogen free radicals. These radicals reacted with methoxy radicals formed during lignin decomposition to produce methane.

Mechanical and environmental performance assessment of cotton stalk composites with natural adhesives for sustainable construction materials

Mechanical and environmental performance assessment of cotton stalk composites with natural adhesives for sustainable construction materials

Unlocking biomass valorization: Machine Learning insights for Reductive Catalytic Fractionation of cotton stalks

Lignocellulosic biomass valorization has become an intensive area of research due to the importance of renewable nature and availability of biomass. However, biomass fractionation and depolymerization produce numerous datasets, that are difficult to visualise and interpret for the scale-up of the process. Therefore, machine learning algorithms, which can discover hidden patterns in data are applied to these datasets. Reductive Catalytic Fractionation (RCF) of lignocellulosic biomass is an emerging methodology to valorize biomass completely and effectively. Herein, the present work includes the Correlation Analysis and the Principal Component Analysis (PCA) of product distribution obtained from RCF of cotton stalks. Interactions between process variables and delignification (DL), sugar retention (SR), total phenolic monomers (PM), and individual phenolic monomers yield were evaluated. Correlations among DL, SR, and PM yields were also evaluated at different reaction conditions through PCA, which were explained using the reaction mechanism and molecular chemistry of lignin.

Insights into the role of A/B-site substitution in chemical looping gasification of cotton stalk for enhanced syngas production over La-Co-O based perovskite oxygen carriers

Biomass chemical looping gasification (BCLG) is an emerging technology for efficient and clean utilization of cotton stalk (CS) to produce high-quality syngas. Among various oxygen carriers, perovskite oxides are holding an ever-increasing position in BCLG due to their unique structural properties and compositional flexibilities. However, research on perovskite-type oxygen carriers mostly focused on Fe-based oxides, and there is little in-depth investigation of Co-based perovskite and the role of A/B site substitution in the BCLG process. Herein, the LaCoO3 perovskite is selected as the basic oxygen carrier, and Sr, Fe are further doped on the A/B-site to form LaCo1-xFexO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) and La1-ySryCoO3 (y = 0, 0.2, 0.4, 0.6, 0.8) series. Effects of perovskite type, gasification temperature, steam volume fraction and oxygen carrier mass fraction of the BCLG performance are investigated. Results indicate that La0.6Sr0.4CoO3 and LaCo0.2Fe0.8O3 exhibit enhanced syngas production with the maximum of 1.304 m3/kg and 1.188 m3/kg, respectively, and outstanding cyclic stability at optimal reaction conditions. Further characterizations including H2-TPR, XPS and EPR analysis reveal that Sr substitution facilitate the formation of oxygen vacancies and adsorbed oxygen species, while Fe doping leads to the increasing concentration of oxygen vacancies and surface lattice oxygen species. Combined with the experimental and characterization results, it is deduced that the oxygen vacancies which promote the adsorption of reactants and accelerate the migration of bulk lattice oxygen, play the key role in the enhanced BCLG performance.

Characterization of Ash from Tropical Biomass Gasification for Soil Fertilization

This study aims to determine the characteristics of bottom ash from the gasification of four agricultural biomasses namely corn stalks and cobs, cotton stalks, and wood residues, for potential use as agricultural fertilizer. The methodological approach consisted in carrying out gasification trials for each of these biomasses under identical operating conditions on a pilot-scale gasifier. The fly ash was collected at the end of the tests from the reactor bottom and cyclone bottom for analysis. Analysis showed that the ash from the reactor bottom contained higher levels of mineral elements, including Ca, P, K, and Mg in comparison to the cyclone bottom ash. However, the latter exhibited a higher content of Zn. Trace metallic elements (TMEs) were present in relatively low proportions. Ash from the gasification of cotton stalks had the highest Ca, Mg, K, and P content. The TME content was relatively above the required threshold, but it remained below the threshold in the ash from corn stalks. This suggests that cotton stalk ash is more suitable for use in agriculture as a soil fertilizer.

Reductive catalytic fractionation of cotton stalks: catalytic strategy for tuning the selectivity of phenolic monomers

Reductive catalytic fractionation of cotton stalks: catalytic strategy for tuning the selectivity of phenolic monomers

Examining the efficacy of biological filters in the removal of agricultural pesticides and nutrient elements from agricultural drainage water

The high water consumption in agriculture has led to an obvious water crisis in this sector, and the use of unconventional water sources, especially agricultural drains, is considered necessary. For this purpose, the present study was carried out to evaluate the efficiency of biological filters with different types of substrates for treating agricultural wastewater in Khuzestan province, located in the south of Iran, to use receptive resources and reuse them in agriculture. Next, the efficiency of four types of biological filters for treating agricultural drainage water with different retention times was evaluated. Sawdust, cotton stalks, wheat straw, stubble, and rice husk were used as filters. Qualitative factors included agricultural pesticides (Atrazine, Randup, Paraquat, and 2, 4-D) and nutrients (nitrate, nitrogen, phosphate, and phosphorus). By examining the trend of increasing the retention time and the corresponding removal percentage, it was observed that the retention time has a direct relationship with the amount of removal efficiency of nutrients and agricultural toxins. As the residence time increases, the average amount of nutrient compounds in different filters decreases, and their removal percentage increases. The highest removal percentage of nitrate, total nitrogen, phosphate, and total phosphorus was 74.03, 71.66, 57.97, and 61.85% in the sawdust filter and was assigned to 10 days. The highest percentage of removal of Atrazine, Tofudi, Paraquat, and Roundup toxins with a removal efficiency of 91.73, 84.27, 89.81, and 88.46% was also observed in the treatment of sawdust for 10 days. The sawdust filter showed a good performance in removing the parameters of agricultural toxins and nutrient compounds in a retention time of 10 days compared to other filters and retention times. As a general result, the sawdust filter can be cited as a reliable substrate with acceptable efficiency compared to other filters.

Yield, Nutrient Availability and Soil Properties of Pearl Millet as Influenced by Enriched Phosphocompost

Aims: Soil Properties, Yield and Nutrient Availability for Pearl Millet as Influenced by Enriched Phosphocompost Study Design: Randomized Block Design Place of Study: Bajra Research Scheme, College of Agriculture, Dhule. Methodology: There were 10 treatments viz. T1- Control, T2- 100 % Recommended Dose of Fertilizer (RDF), T3- 100% RDF + 2.5 t Bajra straw phosphocompost ha-1, T4- 100% RDF+ 2.5 t Cotton stalks phosphocompost ha-1, T5- 100% RDF + 2.5 t FYM ha-1, T6- 100% RDF + 5 t FYM ha-1, T7- 75% RDF + 2.5 t Bajra straw phosphocompost ha-1, T8- 75% RDF + 2.5 t Cotton stalks phosphocompost ha-1, T9- 75 % RDF + 2.5 t FYM ha-1, T10- 75% RDF + 5 t FYM ha-1. Results: The results indicated that yield, nutrient uptake and soil properties viz. organic carbon, cation exchange capacity, soil available N, P, K and micronutrients were found highest in treatments T4- 100 % RDF+ 2.5 t Cotton stalks phosphocompost ha-1 and treatment T3- 100% RDF+ 2.5 t bajra straw phosphocompost ha-1 and lowest in treatment T1- Control. Conclusion: Based on the experimental findings application of 100 % RDF+ 2.5 t Cotton stalks phosphocompost ha-1 and 100% RDF+ 2.5 t bajra straw phosphocompost ha-1 were beneficial in terms of yield parameter, plant nutrient uptake and soil chemical properties on pearl millet.

Utilization of cotton stalk waste for sustainable isopropanol production via hydrolysis and coculture fermentation

The present investigation focused on isopropanol production from lignocellulosic cotton stalk biomass (CSB) using conventional pretreatment, enzymatic hydrolysis and fermentation methods. In comparison to alkaline (NaOH) pretreatment, dilute sulphuric acid (H2SO4) pretreatment showed higher cellulose exposure (448.5 mg/g). Further, ultrasono assisted acid and alkali pretreatment was performed for maximum exposure of cellulose and it was found 616.9 and 586.15 mg/g respectively. Chemical pretreated CSB was additionally exposed to independent enzymatic hydrolysis using commercial enzymes (Celluclast and Viscozymes) following Response Surface Methodology (RSM), which revealed a maximal production of glucose and xylose yield (544.6 mg/g and 41.8 mg/g). Pretreated and enzymatic hydrolyzed cotton stalk biomass at various conditions were analysed using SEM, FTIR, and XRD to determine the structural and functional changes. Further, a co-culture strategy was employed on pretreated and hydrolyzed CSB using two fermented yeast strains (Saccharomyces cerevisiae and Pichia pastoris) for isopropanol production. HR-MS analysis revealed that the maximum concentration of isopropanol (126.228 mM) was produced in 2:1 proportionate ratio of two fermented yeasts with 20 g/L of substrate loadings at 72 h of incubation time. These results indicate that the production of isopropanol (7.46 g/L) from CSB with different parametric conditions is an encouraging step and can be exploited further for various industrial applications.

Economic and Environmental Analyses of an Integrated Power and Hydrogen Production Systems Based on Solar Thermal Energy

This study introduces a novel hybrid solar–biomass cogeneration power plant that efficiently produces heat, electricity, carbon dioxide, and hydrogen using concentrated solar power and syngas from cotton stalk biomass. Detailed exergy-based thermodynamic, economic, and environmental analyses demonstrate that the optimized system achieves an exergy efficiency of 48.67% and an exergoeconomic factor of 80.65% and produces 51.5 MW of electricity, 23.3 MW of heat, and 8334.4 kg/h of hydrogen from 87,156.4 kg/h of biomass. The study explores four scenarios for green hydrogen production pathways, including chemical looping reforming and supercritical water gasification, highlighting significant improvements in levelized costs and the environmental impact compared with other solar-based hybrid systems. Systems 2 and 3 exhibit superior performance, with levelized costs of electricity (LCOE) of 49.2 USD/MWh and 55.4 USD/MWh and levelized costs of hydrogen (LCOH) of between 10.7 and 19.5 USD/MWh. The exergoenvironmental impact factor ranges from 66.2% to 73.9%, with an environmental impact rate of 5.4–7.1 Pts/MWh. Despite high irreversibility challenges, the integration of solar energy significantly enhances the system’s exergoeconomic and exergoenvironmental performance, making it a promising alternative as fossil fuel reserves decline. To improve competitiveness, addressing process efficiency and cost reduction in solar concentrators and receivers is crucial.

Parametric Analysis and Numerical Optimization of Root-Cutting Shovel of Cotton Stalk Harvester Using Discrete Element Method

Aiming at solving the problems of the high cost of manual pulling, the low reliability of existing pulling devices, and the high breaking rates and high leakage rates in the process of cotton stalk reuse after removal from the field in the Xinjiang cotton area, a soil-loosening and root-cutting cotton stalk pulling and gathering machine was researched and designed; a root-cutting force model was established; the key parameters of the V-shaped root-cutting knife were calculated and optimized; and the ranges of the slide cutting angle, the cutting-edge angle, and the soil entry angle were determined. A shoveling process simulation of the V-shaped root-cutting knife and the root–soil complex was constructed, and the working mechanism of the V-shaped root-cutting knife was clarified. In order to verify the reliability and operation performance of the V-shaped root-cutting knife, the slide cutting angle, the cutting-edge angle, and the soil entry angle were used as the test factors, and a response surface test with three factors and three levels was carried out with the root-breaking force and the mean value of the cutting resistance as the test indices. The test results were analyzed by variance analysis, and the significant factors influencing the root-breaking force in descending order were the slide cutting angle, cutting-edge angle, and soil entry angle. The degrees of influence on the mean value of the cutting resistance were ordered as follows: slide cutting angle, soil entry angle, and cutting-edge angle. In order to make the V-shaped root-cutting knife achieve the optimal working state, the parameters of the test indices were optimized, and the optimal design parameters of the V-shaped root-cutting knife were set as follows: the slide cutting angle was 48.3°, the cutting-edge angle was 43.4°, and the soil entry angle was 26.2°. The field uprooting test showed that the average pass rate of root breakage was 94.8% and the average pull-out rate of cotton stalks was 93.2%. This study provides theoretical guidance for the development of a root-breaking mechanism for cotton straw harvesters.

Study on the properties and components of solid-liquid products by co-pyrolysis of sludge and cotton stalk

The effects of sludge content and pyrolysis temperature on the pyrolysis process and product properties were studied through the co-pyrolysis of sludge and cotton stalk. Multi-objective fuzzy hierarchical analysis was used to analyze the multiphase properties of pyrolysis products, and describe the internal relationship between pyrolysis conditions and product properties. It has been proved using kinetic calculation that the mass ratio of sludge and cotton stalk is higher than 1:2 required the lower pyrolysis activation energy. According to the comparison between experimental and theoretical results, the addition of sludge is beneficial to increase the bio-oil yield. In terms of product performance, the addition of sludge and increase of pyrolysis temperature both can improve the specific surface area, pore volume of biochar and the pH value of bio-oil, reduce the total acid content, increase the total phenol content and optimize calorific value of bio-oil. The specific surface area of biochar, calorific value of bio-oil, total phenol content and pH were evaluated by multi-objective decision analysis method, the optimum process condition of sludge: cotton stalk = 2:1 at 600 ℃. Under the conditions, the specific surface area of biochar is 57.40 m2/g, the pH of the bio-oil is 8.06, the total acid content is 5.94 mg/g, the calorific value is 27.18 KJ/g and the total phenol content is 47.32 mg/g, respectively. Compared to the pyrolysis product of cotton stalks, the specific surface area is increased almost 20 times, the calorific value is increased by 13 %, the total acid content is decreased by 95 %, and the total phenol content is similar. This study proposed a preparation process of bio-oil with high performance, and provided a theoretical basis for the subsequent co-pyrolysis research.

Establishment and Research of Cotton Stalk Moisture Content–Discrete Element Parameter Model Based on Multiple Verification

Establishment and Research of Cotton Stalk Moisture Content–Discrete Element Parameter Model Based on Multiple Verification

Superhydrophobic cellulose-nanofiber aerogels from waste cotton stalks for superior oil–water and emulsion separation

Cellulose aerogel, a sustainable material characterized by low density and high porosity, demonstrates promising potential for addressing oil spill incidents. In this study, waste cotton stalk biomass was processed using formic acid and hydrogen peroxide to extract cellulose, resulting in the successful creation of a cost-effective aerogel. This material exhibits notable attributes: low density (21.1 mg cm−3), high porosity (91.5%), significant hydrophobicity (water contact angle of 147°), exceptional adsorption capacity (47.61 g g−1), and robust cycling performance (maintaining 94% adsorption capacity after 15 cycles). Moreover, the CNF/CS biomass aerogel boasts high mechanical strength and exceptional oil–water and emulsion separation properties. These characteristics position this aerogel as a promising solution for mitigating various sudden oil spill incidents, indicating its potential for widespread application.

Co-pyrolysis of pretreated cotton stalk and low-density polyethylene: Evolved products and pyrolysis mechanism analysis

The preparation of bio-oil from cotton stalks and agricultural residue films using co-pyrolysis technology can achieve resource recovery and energy conversion, which has important research value and significance. In this study, cotton stalks were subjected to different chemical pretreatments using NaOH, HCl, and H2O solutions to understand their structural changes and pyrolysis characteristics. In addition, the lower H/C ratio of cotton stalks resulted in higher oxygen content in the pyrolysis oil, which limited its efficient and clean utilization. Therefore, the characteristics and pyrolysis kinetics of the pyrolysis products of pretreated cotton stalks and LDPE (low-density polyethylene) were studied. The results showed that the ash content of alkali pretreatment cotton stalks decreased by 1.24 %, and the dense structure of cotton stalks significantly relaxed. NaOH pretreatment effectively removed hemicellulose sugars and cracked them. During the co-pyrolysis process, when the ratio of NaOH-CS/LDPE was 50/50, the synergistic effect was more pronounced, and the oil yield increased by 2 % compared to the theoretical value. The oxygen content of CO and CO2 in the pyrolysis gas was higher than the theoretical value, at 10.4 % and 14.1 % respectively. The synergistic effect of bio-oil on hydrocarbons was the most significant, reaching 18.9 %. More hydrogen and less oxygen migrated into the co-pyrolysis oil, resulting in an increase in hydrocarbons and a decrease in oxygen-containing compounds, and improving the quality of bio-oil. Results from electron paramagnetic resonance (EPR) indicated that adding LDPE might raise the quantity of stable free radicals. The evolution mechanism of functional groups of NaOH-CS and LDPE co-pyrolysis behavior was analyzed by Fourier in-situ infrared spectrometry (FTIR), and it was found that C–O–C, C=O, and O–H decreased due to dehydroxylation, decarboxylation, decarbonylation, and demethoxy reactions with the increase of temperature, indicating that there was a synergistic effect between NaOH-CS and LDPE co-pyrolysis. The pyrolysis kinetics of NaOH-CS, LDPE and their blends were determined by the model-free method. The introduction of LDPE can reduce the activation energy of NaOH -CS pyrolysis alone, and the 3D diffusion (D3) model is suitable for their blends.

Rapid humification of cotton stalk catalyzed by coal fly ash and its excellent cadmium passivation performance.

Due to industrialization, soil heavy metal pollution is a growing concern, with humic substances (HS) playing a pivotal role in soil passivation. To address the long duration of the compost humification problem, coal fly ash (CFA) in situ catalyzes the rapid pyrolysis of the cotton stalk (CS) to produce HS to address Cd passivation. Results indicate that the highest yield of humic acid (HA) (8.42%) and fulvic acid (FA) (1.36%) is obtained when the CS to CFA mass ratio is 1:0.5, at 275 ℃ for 120min. Further study reveals that CFA catalysis CS humification, through the creation of alkaline pyrolysis conditions, Fe2O3 can stimulate the protein and the decomposition of hemicellulose in CS, and then, through the Maillard and Sugar-amine condensation reaction synthesis HA and FA. Applying HS-CS&CFA in Cd-contaminated soil demonstrates a 26.69% reduction in exchangeable Cd within 30days by chemical complexation. Excellent maize growth effects and environmental benefits of HS products are the prerequisites for subsequent engineering applications. Similar industrial solid wastes, such as steel slag and red mud, rich in Fe2O3, can be explored to identify their catalytic humification effect. It could provide a novel and effective way for industrial solid wastes to be recycled for biomass humification and widely applied in remediating Cd-contaminated agricultural soil.

Eco-friendly lignin nanoparticles as antioxidant and antimicrobial material for enhanced textile production

Natural polymers are bioactive compounds that are used in the treatment of several disorders. Natural lignin, an amorphous polymer, offers significant potential for use as a building block in the production of bio-renovation materials. This study used an alkaline solvent technique to extract lignin from two Egyptian cotton cultivar byproducts, Giza 86 and 90. We then created nano-lignin to recycle cotton stalks into an environmentally beneficial product. The characterization of L86, L90, LNP86, and LNP90 was carried out using particle size, zeta potential, FT-IR, and TEM. Antioxidant activity using the DPPH assay and antimicrobial activity were determined for lignin and nano-lignin. Seven pathogenic bacteria (Bacillus cereus, Staphylococcus aureus, Staphylococcus sciuri, Salmonella typhi, Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa) and five mycotoxigenic fungi (Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger, Fusarium proliferatum and Penicillium verrucosum) were used for antimicrobial activity. The results showed high antioxidant efficiency for LNP90, with an IC50 of 10.38 µg/mL. The antimicrobial activity showed positive growth inhibition for all studied microorganisms, with significant differences in nano-lignin compared to ordinary lignin. lignin and nano-lignin were effectively applied to treated textiles for medical purposes. The study concluded that single-use medical textiles with anti-microbial and anti-oxidant properties, made from lignin and nano-lignin, could benefit patients intolerant to antibiotics.