Bioenergy has emerged to be among the primary choices for the short- and medium-term replacement of fossil fuels and the reduction in greenhouse gas (GHG) emissions. The most practical method for transforming biomass into biofuel is thermochemical conversion, which may be broken down into combustion, torrefaction, pyrolysis, hydrothermal liquefaction, and gasification. In this study, producing biofuels using a biomass pyrolysis process was investigated. This study explored the pyrolysis process and operating conditions to optimize the process parameters to maximize the desired product yields and quality. The pyrolysis process produces three main products, which are bio-oil, bio-char, and gas. There are three classifications for the pyrolysis method, with each of them producing a majority of a certain product. First, slow pyrolysis is conducted in the temperature range of 300–950 °C and residence time of 330–550 s. It produces around a 30% oil yield and 35% char yield, and thus, the majority yield of slow pyrolysis is char. Second, fast pyrolysis produces around 50% oil, 20% char, and 30% gas yields with a temperature range of 850–1250 °C and a residence time of 0.5–10 s. The average yield of flash pyrolysis was found to be 75% bio-oil, 12% bio-char, and 15% gas, which is conducted within less than 1 s. It was reported that the pyrolysis of biomass was simulated using ASPEN Plus, where the effects of several parameters, such as the temperature, heating rate, and residence time, on the product yield and composition were investigated. Pyrolysis was performed under different conditions ranging from 400 to 600 °C. The effects of different catalysts on the pyrolysis process were studied. It was found that the addition of a catalyst could increase the yield of bio-oil and improve the quality of the product. The optimal operating condition for the pyrolysis process was determined to be a temperature of 500 °C, which resulted in a higher bio-oil yield. It was found that the biofuel yield was enhanced by selecting appropriate raw materials, such as rice husk, along with the pyrolysis temperature (e.g., 450 °C) and particle size (350–800 µm), and using a low residence time and pressure.

Climate change is the leading severe problem in the twenty-first century, which is associated with greenhouse gas emissions, carbon dioxide that is the foremost cause of global warming and super greenhouse effect. In this concern, to avoid hazardous problems, the steady stream of CO₂ effluents existing in the atmosphere must be transformed to beneficial products for being used as an abundant chemical feedstock. Implementing a new green strategy, which is known for the catalytic hydrogenation of CO₂ into alternative fuels and valuable chemicals, will be a long-lasting solution to alleviate CO₂ emissions. In this paper, a process simulation showing the synthesis of dimethyl ether (DME) from CO₂ hydrogenation (CO₂ produced from EL-Sewedy cement industry) is performed using Aspen HYSYS V10 to attain a complete distinctive design for all equipment for producing a capacity of 475,000 tons per year, while energy integration is performed using Energy Analyzer Simulation software. In the main model, catalytic dehydration is done in a single-pass reactor, and then separation in multi-column product separations. Other configurations were tested by developing three simulation models with different reactors, a double pipe reactor and membrane reactor were with the aim of modification for higher energy efficiency and lower operating and capital costs. Moreover, an economic and environmental study was obtained for the basic & the integrated case, which showed that the total annual/capital costs based on the “base case” are estimated to be 90 million USD without heat integration while the optimum and integrated costs are found to be 100 Million USD. Finally, process optimization and integration were obtained to reduce the utilized energy of the hot & cold utilities by 90% and 60%, respectively.

Polymers play a crucial role in various industries due to their versatility, affordability, and lightweight characteristics. However, their extensive production and limited biodegradability have become significant environmental challenges. Traditional plastics, often destined for landfills, persist for centuries or contribute to pollution through incineration. The growing environmental concerns surrounding plastic waste have driven the development of biodegradable polymers. These polymers, derived from renewable resources such as starch, cellulose, and vegetable oils, or synthetic bio-based monomers like lactic acid, are designed to degrade naturally through microbial action or photodegradation. The degradation process of these polymers results in harmless byproduct, such as water which supports environmental sustainability. This study provides a detailed examination of the degradation mechanisms of both synthetic and bio-based polymers, identifying key factors that influence polymer degradation in various applications. The study highlighted the significant role of bacteria and fungi in the biodegradation of polymers in freshwater environments, with optimal pH values for landfill degradation ranging between 5.8 and 8.5. The impact of blending biodegradable and non-biodegradable polymers on the overall biodegradation process was thoroughly explored. The findings contributed to a deeper understanding of polymer degradation, offering valuable insights into enhancing the biodegradability of polymers for a more sustainable future.

Climate change is one of the most critical problems facing humanity. One of the most important reasons is greenhouse gas (GHG) emissions, particularly carbon dioxide. In Egypt, the cement sector is the heaviest emitting industry, accounting for 12% of the total CO2 emissions. This study aims to capture and utilise CO2 for methanol synthesis. The importance of methanol has been growing steadily in recent years, as it has many applications, including automotive fuel, wastewater treatment, fuel cells, and as a feedstock for many chemicals, including dimethyl ether (DME), formaldehyde, acetic acid, and olefins. The market size of methanol is expected to reach 38.98 MM in the next five years. However, the method used for 95% of the world’s methanol production is through the catalytic hydrogenation of synthesis gas obtained from natural gas steam reforming. This conventional method is not viable, hence the need for a greener, yet economic, process for methanol production. This study presents the approach to designing a methanol plant with a 2 MT/year production capacity. The used methanol is synthesised through the catalytic hydrogenation of carbon dioxide, captured from a cement plant in Egypt. The process is simulated using Aspen HYSYS software V10 to monitor its performance. After designing the unit operations and estimating its costs, the designed methanol plant was found to be viable and profitable. The economic aspect is described to highlight the specific value of capital investment for the given basic design, which is 237714540 USD while the operating cost is 68,894,000,000 USD.