Bioenergy Recovery from Cotton Stalk

Cotton stalk (CS) plant residue left in the field following harvest must be buried or burned to prevent it from serving as an overwintering site for insects such as the pink bollworm (PBW). This pest incurs economic costs and detrimental environmental effects. However, CS contains lignin and carbohydrates, like cellulose and hemicelluloses, which can be converted into a variety of usable forms of energy. Thermochemical or biochemical processes are considered technologically advantageous solutions. This chapter reviews potential energy generation from cotton stalks through combustion, hydrothermal carbonization, pyrolysis, fermentation, and anaerobic digestion technologies, focusing on the most relevant technologies and on the properties of the different products. The chapter is concluded with some comments on the future potential of these processes

A case study of Al-Karak, Jordan

Funding Information: This work was supported by the Portuguese Foundation for Science and Technology – FCT (under PhD scholarship of Yasmine Ayed [UI/BD/150894/2021]. The authors would like to thank the Institute of Chemical and Energy Engineering, University of Natural Resources and Life Sciences for providing the HOMER licence. Funding Information: This work was supported by the Portuguese Foundation for Science and Technology – FCT (under PhD scholarship of Yasmine Ayed [ UI/BD/150894/2021 ]. The authors would like to thank the Institute of Chemical and Energy Engineering, University of Natural Resources and Life Sciences for providing the HOMER licence. Publisher Copyright: © 2023 The AuthorsThe aim of this research is to examine the techno-economic viability of both off-grid and on-grid hybrid renewable energy systems for Jordan's Al-Karak governorate. Hybrid Optimization of Multiple Energy Resources (HOMER) Pro software was used in this article to evaluate the carry feasibility to maximize the renewable energy (RE) integration in hybrid energy systems based on different configurations, grid-connected and stand-alone systems of the wind turbine, biogas plant, photovoltaic (PV) panels, flywheel, and batteries while minimizing the net present cost, the Levelized cost of energy and CO2 emissions mitigation. The results showed that the PV/Wind system, connected to the grid with batteries for storage is the optimal configuration for sustainable Al-Karak governorate electrification whilst achieving environmental benefits and guaranteeing reliable and continuous energy access with the lowest net present cost and the Levelized cost, 298,359 USD$and 0.024 USD$/kWh respectively, and high RE share, 71.8% of electricity is generated from wind and 28.2% is purchased from the grid and emits 220 tons of CO2 per year, 53% less than a grid alone system. Such a system would provide advantages in terms of energy independence and improved environmental quality.publishersversionpublishe

Pyrolysis of cotton stalks and utilization of pyrolysis char for sustainable soil enhancement and carbon storage

Worldwide, a large amount of biomass accumulates in the form of ligno-cellulosic agricultural by-products that can neither be efficiently used as animal feed nor as feedstock for anaerobic digestion. A clean and energy-efficient utilization in combustion plants is counter-indicated by high contents of elements like Cl, K and Na that decrease the ash-melting-point and lead to fouling and corrosion. Although this biomass is, therefore, not suitable for conventional combustion plants, a pyrolysis process can be applied that works at lower temperatures of 500-600°C. Please click on the file below for full content of the abstract

Cotton Fiber and Carbon Materials Filters for Efficient Wastewater Purification

Carbon materials and cotton fibers (CFs) are eco-friendly and cost-effective solutions for water purification. However, enhancing the filtration efficiency of these materials remains challenging. In this study, the capacity of heat-treated sorbents (CFs and low-temperature graphite intercalation compounds (LT-GICs)) to improve the efficiency of wastewater purification from heavy metals and petroleum compounds, was investigated. The properties of the thermally modified CFs were studied in order to obtain a material which is highly efficient in purifying wastewater from heavy metal ions (HMIs). The duration of sorption equilibrium and the optimal ratio of heat-treated cotton fibers (HTCFs) and wastewater were determined. The adsorption capacities of CFs for iodine and methylene blue were determined before and after the heat treatment. Experimental results indicated that thermal treatment of CFs resulted in increased numbers of micropores and mesopores, indicating a high sorption capacity for petroleum products (PPs) in wastewater (A = 11.5 g/g) with an efficiency score of 90%. Furthermore, LT-GIC/CF composite filters were optimized for efficient purification. The results indicated that a filter with a composition of 1 g LT-GIC + 3 g CF had the highest sorption capacity for HMIs (28.7 mg/g) and PPs (80.6%) due to its looser surface structure. The X-ray phase analysis of the sintered composite filters showed the presence of carbon in the amorphous phase, which had a similar structure to the activated carbon from black coal. In summary, the high sorption capacities and simple preparation processes of LT-GIC/CF composites make them potential candidates for wastewater purification

Batch pyrolysis of cotton stalks for evaluation of biochar energy potential

The thermal cracking of cotton stalks (CS) via pyrolysis was performed using a laboratory scale batch pyrolysis reactor. The effects of the final pyrolysis temperature varying from 300 to 800°C on the pyrolysis products distribution has been investigated. The maximum biochar yield of 46.5% was obtained at 400°C. As the pyrolysis process temperature increased, the solid char product yield decreased. The lowest biochar yield of 28% was obtained at 800°C. The largest higher heating value (HHV, 25.845 MJ kg-1) was obtained at 600°C. All biochar samples produced between 500 and 700°C had an energy densification ratio of 1.41, indicating a higher mass-energy density than the initial feedstock. A larger share of syngas and bio-oil were produced at higher temperatures, as estimated. Preferential selection of a char based on the energy yield would lead to a selection of the 400°C product, while selection based on the energy densification ratio would be for a product obtained between 500 to 700°C

Performance Evaluation of a Hybrid Grid-Connected Photovoltaic Biogas-Generator Power System

In recent decades, works have been published on the Hybrid Renewable Energy System (HRES) to provide available, feasible, and efficient renewable energy systems. Several studies have looked at the efficiency of the systems in terms of sustainability through performance parameters. This study aims at estimating the optimum HRES based on biomass and photovoltaic (PV) using the case study of 94 residential buildings with an electricity demand of 84.5 kWp. The influence of key parameters (global solar irradiation, component efficiencies, fuel consumption, economic convenience) and their impact on the performance and cost of the system is investigated. The optimum system is evaluated by the simulation software HOMER Pro. A single year of hourly data is used to analyze the component performance and the overall system performance. In this work, a mathematical model based on the IEC 61724 standard is used to incorporate numerous performance indicators that are critical for estimating the performance of a hybrid system. Evaluating results comprise of three performance basic indicators, namely, energy efficiency, system sizing, and economic parameters

Performance Evaluation of a Hybrid Grid-Connected Photovoltaic Biogas-Generator Power System

In recent decades, works have been published on the Hybrid Renewable Energy System (HRES) to provide available, feasible, and efficient renewable energy systems. Several studies have looked at the efficiency of the systems in terms of sustainability through performance parameters. This study aims at estimating the optimum HRES based on biomass and photovoltaic (PV) using the case study of 94 residential buildings with an electricity demand of 84.5 kWp. The influence of key parameters (global solar irradiation, component efficiencies, fuel consumption, economic convenience) and their impact on the performance and cost of the system is investigated. The optimum system is evaluated by the simulation software HOMER Pro. A single year of hourly data is used to analyze the component performance and the overall system performance. In this work, a mathematical model based on the IEC 61724 standard is used to incorporate numerous performance indicators that are critical for estimating the performance of a hybrid system. Evaluating results comprise of three performance basic indicators, namely, energy efficiency, system sizing, and economic parameters

Development of Full-Cycle Utilization of Chlorella sorokiniana Microalgae Biomass for Environmental and Food Purposes

The application of microalgae biomass of Chlorella sorokiniana as environmentally friendly biosorbents for removing potentially toxic elements (PTE) from water and as a source of biofuel has been thoroughly studied. In this paper, we investigate its physicochemical properties infrared spectroscopy (IR spectra), microstructure, adsorption properties); we have managed to isolate the lipid complex, which amounted to 20% of dry biomass. Studies of the lipid complex showed that 80.02% of lipids are unsaturated fatty acids (C18:1, C18:2, C18:3). Additionally, we have investigated the efficiency of using the residual biomass obtained after lipid extraction for water purification from rare-earth metals (REM) and PTE. To increase the sorption properties of residual biomass, its thermal modification was carried out and sorption materials based on heat-treated residual biomass and chitosan were created. The physicochemical and mechanical properties of the obtained sorption materials were studied. The total sorption capacity was 31.9 mg/g for REM and 349.7 mg/g for PTE. Moreover, we propose a new method for the disposal of spent sorbents as additional fuel. Spent sorbents can be considered to be biofuel in terms of energy content (20.7 MJ*kg−1). The results of this study provide the basis for increased use of microalgae

Modified solar cells with antireflection coatings

Designing a solar cell that can harvest energy with a high level of efficiency is an important research topic. For improving the performance of solar cells, this paper introduces four proposed structures for solar cells and examines their efficiencies for potential production with low cost and high efficiency. In each model, the absorbent material is Borofloat glass and the antireflection coatings used are SiNx and sol-gel -based materials. The four proposed solar cell structures are as follows: (i) a three-layer solar cell in which a sol-gel film is used to match the refractive index between the glass substrate and air cladding; (ii) a four-layer solar cell in which a sol-gel film is used to match the refractive index between SiNx laid on top of a glass substrate and air cladding; (iii) a four-layer structure in which a sol-gel film topped with air cladding is used as a match between the glass and SiNx; and (iv) a four-layer solar cell in which two layers of SiNx are stacked between the glass and the air. A transfer-matrix method is used to solve for the total transmission and total reflection for all structures, and the effects of the film thicknesses and incidence angles are considered in each case. An analysis is carried out using Maple 17, and the results show that using a sol-gel material between glass and air gives almost zero reflection for a wide range of wavelengths, meaning that this can be used as a perfect absorbent and can therefore be recommended for high-efficiency solar cells. Using two layers of SiNx between the air and glass gives almost zero reflection at 600 nm, making this approach an outstanding candidate for solar cells with a maximum absorption of around 600 nm. The other two structures have lower values of transmission, meaning that they are good candidates for low-efficiency solar cells. However, further techno-economic studies of the proposed structures should be carried out, and that solar cell manufacturers should consider these structures