Environmental Progress & Sustainable Energy最新文献

Lignocellulosic waste biomass (LWB) is a rich source of valuable bioresources. Its generation is rapidly increasing globally, due to the expansion of agricultural activities and the growth of food processing industries. Owing to its complex structure, effective pre-treatment is essential to unlock its potential. Developing cost-effective and energy-efficient pre-treatment methods is crucial to make biomass-derived products competitive in the market and to support the bio-economy. This comprehensive review compiles recent advancements in various pre-treatment techniques, analyzing their advantages and limitations to guide future research focused on process optimization and energy efficiency. The review also explores the economic potential of biomass derivatives obtained after the pre-treatment, helping the scientific community to assess cost-recovery strategies. Key cellulose and hemicellulose-derived compounds include polyhydroxyalkanoates, sorbitol, ethanol, hydroxy methyl furfural, ethylene, citric acid, lactic acid, succinic acid, glutamic acid, gluconic acid, butanol, acetone, furfuryl alcohol, 2-methyl tetrahydrofuran, tetrahydrofuran, tetra hydro furfuryl alcohol, maleic anhydride, and 1,5-pentanediol—with market prices ranging between US$ 0.06/kg and US$ 10/kg. In contrast, lignin-derived products, such as lignosulfonates and organosolv lignin, have comparatively lower market values, ranging from US$ 0.1/kg to US$ 0.6/kg. These insights can serve as a foundation for developing innovative pre-treatment strategies that balance the efficiency, sustainability and economic viability.

Aerosol absorption and scattering notably influence the atmospheric radiative balance. Significant uncertainties persist regarding the impact of aerosol models on aerosol radiative forcing (ARF) under distinct atmospheric conditions. The effects of various aerosol models on ARF under clear and haze conditions are analyzed utilizing MODIS data, combined with observations from Beijing, and the 6S (Second Simulation of the Satellite Signal in the Solar Spectrum) for simulations. Results showed that ARF at the surface (ARF-SFC) and top of the atmosphere (ARF-TOA) registered negative values on clear and hazy days. On hazy days, the desert model demonstrated enhanced cooling at TOA, while the urban model showed intensified surface cooling. Hazy conditions amplified ARF-TOA by 57%, 54%, and 61% for desert, urban, and continental models respectively, relative to clear days, with corresponding ARF-SFC increases of 57%, 54%, and 56%. Aerosol radiative forcing efficiency at TOA generally exhibited greater values in winter than in summer. Black carbon (BC) radiative forcing simulations using the three-component method showed positive values at TOA and negative values at the surface. During hazy days, BC intensified upper-atmosphere heating and surface cooling effects. This research will lay the scientific foundation for reducing uncertainty in ARF estimates and developing effective environmental strategies.

This study investigates the use of cellulose extracted from cocoa shell waste as an additive in cellulose acetate (CA)-based membranes to enhance membrane properties while minimizing extraction-related waste. Both organic and inorganic extraction solvents were evaluated to determine their impact on porosity, hydrophilicity, mechanical strength, and salt rejection efficiency. Characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), contact angle measurements, porosity assessments, and tensile strength testing, were employed. The results showed that the functional groups of the CA membrane remained unchanged with cellulose addition. Membranes containing cellulose extracted with citric acid exhibited higher porosity (500–650 nm) compared to unmodified membranes (300–400 nm) and improved hydrophilicity, with contact angles of 59°–63°. Salt rejection varied with extraction solvents, with hydrochloric acid-extracted cellulose achieving 11.13% rejection and 232.73 L·m⁻²·h⁻¹ flux, while citric acid-extracted cellulose resulted in 8% rejection and 140 L·m⁻²·h⁻¹ flux. Additionally, citric acid-treated membranes demonstrated superior tensile strength. These findings suggest that cocoa shell-derived cellulose can enhance CA-based membranes, contributing to sustainable membrane technology and supporting green processing and circular economy initiatives.

The purpose of this study is to investigate the outcomes of fueling a diesel engine with biodiesel and recirculating the exhaust gases (EGR). The MRSO 30%'s destroyed energy and unaccounted losses fell by 6.72% and 2.33%, respectively, when compared to petroleum diesel. Diesel reduced the destroyed availability of MRSO 10%, 20%, and 30% by 66.67%, 66.93%, and 67.51%, respectively. In comparison to diesel, the exhaust gas availability and unexplained loss were decreased by 48.18% and 17.14%, respectively. The improvement in the trend towards diesel and MRSO 0%EGR was demonstrated by the availability of fuel with input energy of MRSO 10%, MRSO 20%, and MRSO 30%. Shaft availability and engine cooling water were improved for MRSO 30% with diesel under the same operating conditions by 32.41% and 5.84%, respectively. When compared to diesel for maximum load, the second law efficiency of MRSO 0%, MRSO 10%, MRSO 20%, and MRSO 30% was improved by 12%, 23.64%, 17.36%, and 6.32%, respectively. With high loads, the usage of EGR often results in an increase in BSCO, and BSHC emissions. It was discovered that the usage of 10% EGR was sufficient to reliably reduce BSCO, BSHC, and NO_x emissions at low and moderate loads.

The Demand for sustainable and effective removal of dye has driven the recent research into the synthesis of innovative material with maximum adsorption capabilities. This research focuses on the development of an innovative crosslinked guar gum/polyvinyl alcohol (PVA) blend for the enhanced removal of methyl red dye. The obtained blend was further characterized with techniques: Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), EDX, XRD, and TGA, which showed the blend formation (functional group), surface morphology, elemental analysis, crystalline nature, and thermal analysis, respectively. Furthermore, to check the mechanical strength of the blend, the swelling study was performed, which shows swelling in deionized water for 105 min, with the swelling ratio of 115.6 g/g, maximum swelling of 276.84–284.16 g/g at neutral pH studied at a range of pH 6–7. In electrolyte solutions, the swelling ratio of the blend decreased with increasing salt concentration. The adsorption of dye onto the prepared blend was optimized at pH 6, contact time 60 min, adsorbent dose of 0.0025 g, and temperature of 25°C. Under these conditions, the maximum adsorption capacity was 82.18 mg/L (80%) achieved. There was a decrease in adsorption with increasing temperature; at 25°C, it was 13.85 mg/L, while at 55°C, it was 11.79 mg/L, indicating an exothermic process. To check the efficiency of the blend, the adsorption data was simulated by applying different adsorption models, which shows Isotherm data closely followed the Langmuir isotherm with R² value of 0.99, and kinetic data best fitted by pseudo-second-order model having R² equal to 0.98. Langmuir isotherm indicated the monolayer adsorption, and the kinetic model showed chemisorption has taken place on the blend. The thermodynamic parameters were calculated, and the data revealed that the process of this adsorption was exothermic and spontaneous. The gel content of the blend was found to be 42%, which shows the crosslinking density of the blend. Regeneration trials showed that the adsorbent could successfully retain methyl red even after four cycles. Synthesized blends can remove dyes from wastewater in sustainable and effective ways. This study examines the unique features of this composite blend, including its better performance, eco-friendliness, efficiency, innovation above traditional blends, and its structural makeup and fabrication method.

The present investigation is performed outdoors to explore the thermal performance (η_th) of a rectangular pyramid roughened solar air heater. The experiment was conducted on the roof of the Mechanical Department, MANIT Bhopal (latitude 23.25°, longitude 77.43°) during February–June 2023 between 10:00 AM and 3:00 PM at a test rig kept flat on the ground using six different mass flow rates (ṁ) while keeping one mass flow rate fixed for the entire day. The presence of rectangular pyramid roughness induces disturbances and enhances the mixing of primary and secondary flows. Consequently, this leads to a greater improvement in η_th. The roughness parameters varied and investigated are the relative roughness height (e/D_h) varied from 0.033 to 0.054, the relative roughness pitch (p/e) varied from 8 to 20, and two novel geometrical parameters, the relative base length to width ratio (b_L/b_W) and the roughness height to base length ratio (e/b_L) are introduced and varied as 1.25–2 and 0.35–0.63, respectively. The Reynolds number (Re) is varied in the range of 3350–13,350. η_th is evaluated in terms of the collector heat removal factor (f_hrf) and the collector efficiency factor (f_cef). A maximum η_th of 79.8% has been reported at e/D_h = 0.047, p/e = 16, e/b_L = 0.58, b_L/b_W = 1.5, and at ṁ = 0.0476 kg/s. F_hrf and F_cef are maximum at p/e = 16, e/D_h = 0.047, b_L/b_W = 2, and e/b_L = 0.63. Maximum and minimum F_hrf were found to be 0.79 and 0.65, respectively Maximum and minimum F_cef were found to be 0.87 and 0.68, respectively as 0.87 and 0.68 corresponding to the optimum parameters.

The recycling and utilization of industrial solid waste exhibited significant combined environmental and economic advantages. As an industrial solid waste generated during the production of calcium carbide, the disposal of purified ash residue has long been a challenging issue in the context of solid waste resource utilization. In the present work, a novel approach was proposed to directly synthesize dispersed layered magnesium hydroxide [Mg(OH)₂] and needle-shaped aragonite from purified ash residue using wet chemical precipitation coupled with carbonation methods. This study investigated the influence of ammonia concentration and the ammonia/Mg²⁺ molar ratio on the yields and crystal forms of Mg(OH)₂, as well as the effect of ammonium bicarbonate concentration and additives on the crystal forms of aragonite. The synthesized samples were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The obtained results revealed that the synthesized Mg(OH)₂ exhibited a higher degree of exposed (001) crystal planes, and the I₀₀₁/I₁₀₁ results can reach 1.44. The morphology of obtained Mg(OH)₂ was lamellar with dispersed particle distribution, and the size of particles was 1–2 μm length or width and about 10 nm thickness. In addition, the synthesized aragonite has shown the shape of needles with the length–diameter ratio of 8–15. The formation and regulation of dispersed layered Mg(OH)₂ and needle-like aragonite products were closely related to the proportion and interaction between calcium and magnesium ions in the solution.

This research investigates the use of waste plastic fuel in compression ignition (CI) engines, focusing on two main objectives: producing pyrolysis plastic oil from waste plastic and reducing dependence on conventional CI engine fuels. The pyrolysis process involves heating low-density polyethylene (LDPE) in a reactor at temperatures between 300°C and 500°C to generate plastic oil. Engine performance was evaluated using various blends of this oil, including 10%, 20%, and 30% mixtures with diesel. Additionally, 30 ppm of aluminum oxide (Al₂O₃) nanoparticles were mixed with 10% and 30% pyrolyzed waste plastic oil (WPO) to enhance fuel properties and engine performance. The study analyzed the impact of nanoparticles on engine efficiency and emissions, revealing that adding 30 ppm Al₂O₃ to all WPO blends improved overall performance compared to conventional diesel. Notably, the WPO 30 + 30 ppm Al₂O₃ blend significantly reduced emissions, with a 37.45% decrease in carbon monoxide (CO), a 22.5 ppm reduction in unburned hydrocarbons (HC), and a 33.23% reduction in smoke opacity. However, nitrogen oxide (NO_x) emissions increased by 487 ppm compared to diesel.

This paper proposes a new simulation method for gas dispersion. Based on that method, the orthogonal analysis was conducted for different gas leakage conditions. The plume rise model was improved and the optimal application range of the modified Gaussian plume model was clarified. Results demonstrate the FDS can well reconstruct the atmospheric environment in full-scale experiments. The effect of the atmospheric stability on the NMSE is higher than that of the initial density and the gas type. The modified Gaussian plume model has different forecasting ability under different atmospheric stability conditions. Currently, the best practice is to use the modified model under B and D stability conditions. The prediction accuracy of the modified model under other stability conditions still needs to be improved in the future.

Epoxidized vegetable oils have emerged as a promising renewable feedstock to produce dihydroxystearic acid (DHSA), a high-value hydroxyl fatty acid used in industrial applications such as cosmetics, lubricants, and biodegradable polymers. This review provides a comprehensive overview of the epoxidation process, oxirane ring formation, and subsequent hydrolysis to DHSA, emphasizing the role of peracid oxidation as a key reaction pathway. Various factors affecting epoxidation efficiency and DHSA yield, including reaction conditions, catalyst selection, and are critically analyzed. The hydrolysis mechanism of oxirane rings leading to DHSA formation is discussed alongside. This process aligns with the rising demand for sustainable alternatives to petrochemical resources, offering advantages such as biodegradability and versatility in industrial applications like lubricants and polymers.