Environmental Progress & Sustainable Energy最新文献

Pakistan is facing a major challenge in the domestic gas and energy sector, and its demand is continuously growing. It is imperative to produce more energy in the form of gaseous resources and electricity to reduce this energy crisis in the future. The current work is related to studying various factors that play a critical role in enhancing the process and production of biogas. The effect of codigestion, substrate size, temperature, pH, and catalyst addition are important parameters. Three batch processes are conducted for 21 days under mesophilic conditions, which is easier to achieve as compared with the thermophilic one. Codigestion of cow manure combined with food, poultry waste, and sewerage water showed some promising results compared with a single substrate (cow dung). This results in the production of biogas of about 120 L. The particle size is then reduced to 5 mm, which leads to an increase in the available surface area for microbial attack and hence increases and enhances further the process and production of biogas. However, the addition of 250 g of silica gel increases production by up to 17%. The better value for the pH range for this batch was found in the range of 6.5–7.8. The codigestion would help in cost-effective and more efficient waste treatment. The digestate in all the batch processes comes out enriched in nitrogen that is used as an organic fertilizer.

Assessment of alternate fuel is categorized on thermophysical aspects and performance—emission derived due to its combustion. Data derived from such analysis is short as the energy expenditure to available chemical exergy of fuel is rarely studied. The study of energy derived from fuel energy gives a detailed picture of fuel efficiency and broadens the field of fuel search criteria. The current article aims to find the thermodynamic effects in terms of energy and exergy utilization of neem biodiesel blends and nickel oxide nano additive dosed neem biodiesel blends. Neem biodiesel was transesterified using standard procedures and analyzed using gas chromatography and mass spectroscopy. Later, neem biodiesel was blended with diesel in three volumetric proportions, that is, NB25, NB50, NB75, and pure Neem Oil Methyl ester was investigated as an engine fuel, and later synthesized nickel oxide nano additives of 25 mg/L was added to all the above fuels and further studied for energy, exergy utilization on a TV-1 VCR engine test rig under varying engine CR. Nickel oxide additives were manufactured using homogenous addition method and were thoroughly studied for formation and presence of constituents using XRD, FE-SEM, and EDS methods. The usage of nano additives does prove reduction in exergy destruction and entropy generation for NB25 base blend with 25 mg/L NiO leading to a reduction of 8.2% and 9.7% when compared to base blends. Also, the emission found for hydrocarbon, and carbon monoxide for all base fuel blends reduced by an average of 16.8% and 7.35%.

Anti-reflection coatings have potential usage in photovoltaic solar cells, sensors, and display devices to reduce reflectance, glare and enhance light transmission. ARC was developed to increase more efficiency of solar cell cover glasses, by depositing SnO₂/TEOS/MTMS coating using the sol–gel spin coating technique. The coating showed a maximum transmittance of 92.70% at 399 nm wavelength with an average refractive index of 1.42. The transmittance of the antireflective film was increased by 2.29% than the bare glass substrate. The surface morphology of the coatings was investigated using FESEM analysis. The mechanical stability of the coating was evaluated using ASTM standard D 3363–05 pencil scratch test, and it demonstrated good performance against 3H hardness pencil. The efficiency of solar cells has been increased by 1.56% after depositing with single layer SnO₂/TEOS/MTMS film. Moreover, the coating maintains the solar cell's performance even during dust exposure, because of its self-cleaning ability with water contact angle of 94°. Thus, the Anti-reflection coating can be applied to enhance the efficiency of photovoltaic system.

The Organic Rankine Cycle (ORC) serves as a pivotal technology for energy conversion, harnessing high-temperature organic liquids sourced from heat reservoirs to propel turbines and generate electricity. This process not only facilitates the conversion of heat into mechanical energy but also significantly mitigates environmental impacts. ORC stands out as the preferred technology for enhancing energy efficiency and leveraging low-temperature resources optimally. With the advent of artificial intelligence, particularly fuzzy logic, these systems have witnessed integration, providing a robust solution to address uncertainties. Unlike traditional logic, which offers binary outcomes, fuzzy logic offers a more adaptable approach by accommodating uncertainty, thus enabling modeling of complex real-world situations. In this study, utilizing the fuzzy logic method, we estimated the energy and exergy efficiency of the ORC, resulting in an impressive 90% estimation accuracy.

The downstream processing of biocrudes obtained from direct biomass pyrolysis poses significant challenges due to stability issues, necessitating costly upgrading for further coprocessing with refinery feeds. This study examines the impact of torrefaction pretreatment on pyrolysis product distribution and biocrude composition using sawdust (SD) and groundnut shell (GS) feeds. Torrefaction was conducted at varying temperatures (200, 250 and 300°C) for 30 min under different reactor conditions. Increasing the severity of torrefaction resulted in decreased biocrude yields with reduced water content and gas formation, particularly evident with GS. A torrefaction temperature of 250°C and 30 min of pretreatment yielded higher phenolics and hydrocarbons. This increase in phenolics can be attributed to lignin enrichment during torrefaction, which, in the presence of a catalyst, undergoes deoxygenation leading to hydrocarbon formation. The influence of feed particle size, whether in powder or pellet form, on biocrude yield and composition was found to be minimal. Catalytic pyrolysis of SD using molecular sieve catalysts yielded the highest hydrocarbon (42%) and aromatic content (44%) at catalyst to biomass ratios of 1:1 and 2:3. The combination of torrefaction and pyrolysis was shown to enhance the quality of biocrude by increasing its hydrocarbon content, but at the expense of lower liquid yields. Experimental observations were supported by statistical analysis tools such as principal component analysis, which assessed pyrolysis product yields and composition.

In order to promote syngas yield and reduce carbon emission, Ni loaded ZrO₂ (Ni/ZrO₂) catalysts were prepared for the co-pyrolysis of cypress sawdust and green algae in a two stage fixed bed reactor. The syngas yield, syngas component, and carbon emission were investigated. The results showed that Ni/ZrO₂ catalyst could obviously increase the combustible gas component in syngas. H₂ content was increased from 7.5% (single component) and 8.12% (co-pyrolysis) to 16.56% (catalytic pyrolysis). CO content was also increased from 19.62% (single component) and 19.46% (co-pyrolysis) to 25.94% (catalytic pyrolysis). However the catalyst had a little effect on the syngas yield compared with single component pyrolysis and co-pyrolysis. The pyrolysis temperature could make great influence on the carbon emission. The carbon emission reduction was increased from 33.32 to 234.25 g CO₂ and from 105.94 to 369.23 g CO₂, respectively for green algae and cypress sawdust.

The outer prickly shells of the Ricinus communis (castor plant) have intrigued researchers interested in the synthesis of carbon black (CB) nanoparticles because of their excellent biocompatibility, low toxicity, and widespread availability. Both chemical and physical synthesis methods, such as pyrolysis and ball milling, are employed to obtain the fine-sized CB nanoparticles. The ball milling process is done for 5 h to reduce the size of the biochar from the pyrolysis process. The as-synthesized CB nanoparticles are characterized using Fourier transform infrared spectroscopy, x-ray diffraction, and field emission scanning electron microscopy analysis. The energy dispersive spectrum also confirmed that the nanoparticles are highly composed of carbon and oxygen. CB nanoparticles made from green materials are added to a low-concentrated biodiesel blend of waste fried edible oil at a rate of 100 ppm. The experiment was performed in a single-cylinder diesel engine under varying compression ratios (CRs) (16:1–18:1), loads (0–16 kg), and exhaust gas recirculation (EGR) rates (0%, 15%, and 25%). The results revealed that the existence of carbon in nanoparticles increased the mean gas temperature, and the mass fraction burned was also slightly higher than diesel. Raising both CR (16:1–17:1 and 16:1–18:1) and EGR (25%) boosted the cylinder pressure of CBB30 (1.844% and 10.391%, respectively). In contrast, it lowered the net heat release rate (7.88% and 14.56%, respectively). Similar to this, smoke emissions decreased by 6.38% and 15.02%, respectively, at the same CR and EGR parameters. On the other hand, brake thermal efficiency slumped by 7.22% and 10.13% concurrently.

This study aims to design a new multi-stage photoreactor with immobilized ZnO and assess its performance in reducing textile wastewater toxicity using solar energy. The electric conductivity measurement is retained as a detection method to obtain the residence time distribution (RTD) function. The RTD is then used to characterize the hydrodynamic behavior of the photoreactor and to evaluate its deviation from the distribution curves of ideal reactors. Solar experiments are conducted to demonstrate the performance of this multistage reactor towards the degradation of a textile azo dye namely Solophenyl Red 3BL (SR 3BL). The influence of the flow rate and the SR 3BL initial concentration (C_O) are considered. The variation of the flow rate slightly influences the SR 3BL photodegradation efficiency and it is inversely proportional to its concentration. The study of the reuse of the immobilized catalyst shows that the degradation efficiency of 98% is reached even after multiple photocatalytic cycles. The figure of merit collector area per order was in the range of 35 to 110 $��m^2�/�m^3�\text{order}�$. This result provides useful information for scaling up and estimating energy efficiency of the reactor.

Increased chromium usage in industrial applications as chromium III and chromium VI, include metal plating, steel alloys, leather processing, medical applications, and chromium dyeing operations, has resulted in water pollution by Cr (VI) ions, which being toxic and carcinogenic has developed into significant environmental and health problems. The purpose of this research is to remove Cr (VI) ions from synthetic wastewater utilising modified sawdust as an inexpensive adsorbent. Two modified sawdust samples were produced, one using sodium hydroxide and one using sulfuric acid. The experimentation, based on several batch systems, has been undertaken at 25–65°C with 0.5–1.5 g/L sawdust dosage. These conditions were applied to remove Cr (VI) ions at concentrations of 1–6 ppm at pH values from 3 to 10. The results have shown that adsorption onto sawdust followed an intraparticle diffusion mechanism with various rate parameters from 0.65 to 5.24 mg g⁻¹ min, for treated and untreated sawdust. The distribution coefficient $��\left(k_c\right)�$, enthalpy $��\left(�\Delta �H�\right)�$, thermodynamic standard free energy $��\left(�\Delta �G�\right)�$, and entropy $��\left(�\Delta �S�\right)�$ were determined from a number of temperature studies. Kinetic studies showed that the pseudo-second order model gave the optimum correlation to the experimental results. The Freundlich and Langmuir isotherms were applied to analyse the experimental equilibrium results. The optimised conditions for the adsorption process were obtained using the D-optimal design method, and the maximum removal percentage of 100%, was determined at pH = 3, T = 25°C, adsorbent dosage = 1.5 g/L, and an initial Cr (VI) concentration = 5.72 ppm.