Nowadays, generating energy is discussed as a paramount option in waste management, because the share of energy from waste is increasing annually. The ever-increasing need for energy and limitations of using fossil resources, and also the increase in environmental pollution from consuming these resources have made the use of renewable energies of especial importance. In this research, we first studied renewable energies, followed by technologies related to the biogas system. Biogas systems have been referred to by landfill and discussed comprehensively in this scheme for utilization. For this purpose, the input source of this system is considered as the volume of garbage in the city of Germi as the study area. In the next step, the amount of garbage produced in this city was extracted and the Landfill software was used for methane production potential assessment from this system and the Homer software was used for economic analysis and reliability evaluation. The most important results are payback period, which is about 10 years, and the amount of electricity produced per year, which is 11658.265 MWh.

This article investigates and presents the upshots observed in the brook of hybrid composites especially, the current investigation focuses on the impact of fiber composition, sequence, and stacking pattern on composite mechanical Features. Five varied stacking sequences of hybrid composites encompassing laminates are used to create four classes of fiber with jute/bamboo/glass by utilizing a conscientious hand lay‐up process with glass fiber‐laced mats as their peripheral layer. For examination, fiber sequences are arranged in the combination of GJBJG, GBJBG, GJGJG, and GBGBG, where G, J, and B refer to glass fiber, jute fiber, and bamboo fiber, respectively. The position of fiber in the core layer is kept in a perpendicular direction with respect to adjacent piles which might be jute or bamboo fiber and the best position of fiber is considered due to the stacking order. Stress and strain were linear in the load versus deflection curves, and all of the samples failed quickly, it is observed that the sample containing a higher or considerable number of bamboo fiber layers exhibited increased strain and toughness. In comparison to other samples, embolism of glass fiber as the main and covering layer expressed a higher impact on the mechanical properties of the composites is observed in this investigation. The shattered sample morphology demonstrated that the matrix and reinforcements were compatible.

Despite having detrimental impacts on the environment and human health, used engine oil is not properly disposed of in Ghana. However, used engine oil can be a valuable resource when recycled. This study investigates the recovery of base oils from used engine oils collected in one Ghanaian municipality. The used engine oils are re‐refined either through acid‐clay treatment or solvent extraction. Pour point, density, viscosity index, and total acid number of used engine oil and re‐refined oils were measured in order to evaluate the two re‐refining processes used and assess whether it is appropriate to reuse the re‐refined oils as base oils. The pour point, total acid number, and viscosity index of the re‐refined oils were significantly different from those of the used engine oils. The density of the re‐refined oils varied little from that of the used engine oils (by 0.83% to 6.65%). These changes indicate the separation of some components, primarily impurities, from used engine oil as a result of re‐refining. Compared to solvent extraction, acid‐clay treatment was found to be less selective. When nitric acid or sulphuric acid was used, acid‐clay treatment often produced group I and II base oils, whereas hydrochloric acid typically produced group III base oils. Also, the solvent extraction process frequently yielded oils with very high viscosity indices comparable to group III base oils. It is recommended that the type of base oil preferred for the production of new lubricants should be taken into account when deciding on a specific method for re‐refining used engine oil.

Thermal safety during the synthesis of a Grignard reagent under different dosing rates was evaluated in this work. A reaction calorimeter (SIMULAR) was used to investigate the heat release under isothermal experiment in the range of 0.5–2.0 g⋅min −1 dosing rates. The thermal decomposition of the Grignard reagent was analyzed using accelerating rate calorimetry (ARC). Furthermore, the risk assessment of thermal runaway was analyzed using a risk matrix and a Stoessel criticality diagram. The results indicate that decreasing the dosing rate can decrease the risk level of synthesizing the Grignard reagent from class 3 to class 1. However, the risk level was class 3 at different dosing rates when the induction period was considered. In the case of cooling failure, the most hazardous moment was the induction period, followed by the dosing period. These findings provide further evidence that the dose rate of 0.5 g⋅min −1 was safer to produce Grignard reagents.

This research investigates the optimum operating conditions related to the adsorption of nitrogen gas from ambient air on zeolite Li‐LSX to produce oxygen gas by the pressure‐vacuum swing adsorption process. Experiments were performed using a column (4 cm inside diameter and 17 cm length) packed with different heights of packing ( h ) of zeolite (9, 12, and 16 cm) from 0.4 to 0.8 mm diameter pellets. At each packing height, different flow rates ( f ) (2, 4, 6, 8, and 10 L·min −1 ) for different input pressures ( p ) (0.5, 1, 1.5, 2, and 2.5 bar) were used to detect their effects on the purity of produced oxygen as percentage volume of the outlet air stream. The results showed that the purity of produced oxygen increased with increasing packing height, pressure, and flowrate to a specific limit. The maximum purity obtained was 73.15% at 16 cm packing height, 2.5 bar input pressure, and 6 L·min −1 inlet flowrate, and the productivity was equal to 18 mmol·(Kg·s) −1 at these conditions. A response surface methodology was used to determine the most influential variables and their interactions. The results confirmed the strong effects of the input pressure, the packing height, and to a lesser extent, the flowrate. A quadratic model was predicted based on the experimental result and assessed statistically. The impacts of quadratic terms in the model were in the order: of p ∗ p > p ∗ h > p ∗ f . The model was applied to predict the operating conditions of 95% purity of oxygen.

Water and wastewater treatment are very important for obtaining clean and sanitary water as well as protecting the environment from toxic pollutants. Not only enriched with cellulose and carbon but the abundant resources of bamboo also make it suitable to be utilized as an adsorbent. With the right processing technologies and improvements, the potential of bamboo is unlimited. This study review provides knowledge on the use of bamboo‐based adsorbents for the removal of contaminants and pollutants in wastewater in the form of activated carbon, biochar, and aerogel. This review highlighted bamboo utilization and its relevance as an adsorbent for wastewater treatment. The technologies for the processing and improvement of bamboo as well as the performance of the bamboo‐based adsorbents are also discussed in this study. The adsorption capacity of bamboo has shown improvement with modification and good adsorption capacity achieved with some of the adsorbent being able to be recycled and reused.

Water pollution has become a major issue in many countries, including Malaysia. Malaysia is one of the countries that suffers from this detrimental influence on water resource sustainability. Adsorption has been discovered to be a cost‐effective and efficient method of removing contaminants such as pigments, dyes, and metal impurities. Many biomass‐based adsorbent materials have been successfully used for the removal of dyes from aqueous solutions. In this study, the potential use of coconut dregs as the new biosorbent for the removal of Methylene Blue (MB) (basic dye) and Brilliant Red Remazol (BRR) (acidic dye) was investigated. The effects of adsorption time, adsorbent dosage, pH, and initial dye concentration on coconut dregs adsorption for MB and BRR dye were investigated using 2‐Level Factorial Design of Design‐Expert 7.1.5. The results indicated that the amount of dye adsorbed on the coconut dregs increased with increasing dye concentration, adsorbent dosage, and adsorption time. However, both MB and BRR dyes favor different pH for the adsorption process. The adsorption capacity of MB dye increased with increasing pH, while the adsorption capacity of BRR dye increased with decreasing pH. Removal of MB was optimum at pH 11, contact time of 240 min, a dosage of 0.25 g adsorbent, and an initial dye concentration of 50 mg/L. Meanwhile, for BRR dye, the optimum condition was pH 2, contact time of 180 min, the dosage of 0.25 g adsorbent, and an initial dye concentration of 50 mg/L. The equilibrium data for both dyes fitted very well with the Langmuir Isotherm equation giving a maximum monolayer adsorption capacity as high as 5.7208 mg/g and 3.7636 mg/g for Methylene Blue Dye and Brilliant Red Remazol dye, respectively. This study shows that coconut dregs can be one of the potential and low‐cost biosorbents for the treatment of industrial dyes soon.

Catalysts play an important role in the preparation of biodiesel. It is of great significance to study catalysts with high efficiency, low cost, and easy preparation. Compared with the homogeneous catalyst system, the heterogeneous catalyst is easy to separate and has a better catalytic effect. In heterogeneous catalysts, supports and preparation methods have important effects on the dispersion of active centers and the overall performance of catalysts. However, the supports of existing solid catalysts have defects in porosity, structural uniformity, stability, and specific surface area, and the preparation methods cannot stabilize covalent bonds or ionic bonds to bind catalytic sites. Considering the activity, preparation method, and cost of the catalyst, biomass-based catalyst is the best choice, but the specific surface area of the biomass-based catalyst is relatively low, the distribution of active centers is uneven, and it is easy to lose. Therefore, the hybrid carrier of biomass-based catalyst and other materials can not only improve the specific surface area but also make the distribution of active centers uniform and the catalytic activity better. Based on this, we summarized the application of chitosan hybrid material catalysts in biodiesel. The preparation, advantages and disadvantages, reaction conditions, and so on of chitosan-based catalysts were mainly concerned. At the same time, exploring the effects of different types of chitosan-based catalysts on the preparation of biodiesel and exploring the process technology with high efficiency and low consumption is the focus of this paper.

In this research, the fabrication of drug delivery systems based on oxidized multiwall carbon nanotubes (O-MWCNTs) was studied. Herein, TiO2 and Au were conjugated with O-MWCNTs to prepare efficient nanocarriers for dexamethasone (dex). The samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In addition, dex loading was studied using adsorption isotherms including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich. The results show that dex adsorption agreed well with the Freundlich isotherm. Increasing the TiO2 to O-MWCNT ratio from (1 : 4) to (1 : 2) can improve the adsorption capacity from 290 mg ⋅ g − 1 to 320 320 mg ⋅ g − 1 . The increasing Au amount increases the adsorption capacity from 437.78 mg ⋅ g − 1 (SA1) to maximum 476.19 mg ⋅ g − 1 (SA6). The maximum equilibrium binding energy A T 1.67 L ⋅ mg − 1 was obtained for SA2, and SA7 shows high binding strength between dex and the nanoadsorbent. Carbon nanotubes (CNTs) show good affinity with high loading capabilities for dexamethasone adsorption. The synthesized TiO2-O-MWCNTs:1/2 with the maximum removal percent (80%) was proposed as an appropriate nanocarrier for dexamethasone. Pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion models were investigated for all synthesized drug nanocarriers. According to regression coefficients, experimental data are in good agreement with the pseudo-second order model for all adsorbents except O-MWCNT/CTAB. Experimental results revealed that the Elovich model could account for the O-MWCNT/CTAB adsorbent.

This paper deals with modeling hydrogen contents of bio-oil (H-BO) as a function of pyrolysis conditions and biomass compositions of feedstock. The support vector machine algorithm optimized by the grey wolf optimization method has been used in modeling this end. Comprehensive data for this purpose were aggregated from previous sources and reports. The results of various analyses showed that this algorithm has a high ability to predict actual results. The calculated values of R2, MRE (%), MSE, and RMSE were obtained as 0.973, 1.98, 0.0568, and 0.241, respectively. According to the results of various analyses, the high performance of this model in predicting the output values was proved. Also, by comparing this model with the previously proposed models in terms of accuracy, it was observed that this model had a better performance. This algorithm can be a good alternative to costly and time-consuming laboratory data.