Recent advances in the solar thermochemical splitting of carbon dioxide into synthetic fuels

Recent years have seen a sharp rise in CO2 emissions into the atmosphere, which has contributed to the issue of global warming. In response to this several technologies have been developed to convert CO2 into fuel. It is discovered that the employment of a solar-driven thermochemical process (S-DTCP) that transforms CO2 into fuels can increase the efficiency of the production of sustainable fuels. The process involves the reduction of metal oxide (MO) and oxidizing it with CO2 in a two-step process using concentrated solar power (CSP) at higher and lower temperatures, respectively. This study summarizes current advancements in CO2 conversion methods based on MO thermochemical cycles (ThCy), including their operating parameters, types of cycles, and working principles. It was revealed that the efficiency of the solar conversion of CO2 to fuel is not only influenced by the composition of the MO, but also by its morphology as well as the available surface area for solid/gas reactions and the diffusion length. The conversion mechanism is governed by surface reaction, which is influenced by these two parameters (diffusion length and specific surface area). Solar energy contributes to the reduction and oxidation steps by promoting reaction kinetics and heat and mass transport in the material. The information on recent advances in metal oxide-based carbon dioxide conversion into fuels will be beneficial to both the industrial and academic sectors of the economy.Scopu

Optimizing Seaweed (<i>Ascophyllum nodosum</i>) Thermal Pyrolysis for Environmental Sustainability: A Response Surface Methodology Approach and Analysis of Bio-Oil Properties

This study focuses on optimizing the thermal pyrolysis process to maximize pyrolysis oil yield using marine biomass or seaweed. The process, conducted in a batch reactor, was optimized using response surface methodology and Box–Behnken design. Variables like temperature, residence time, and stirring speed were adjusted to maximize bio-oil yield. The optimal conditions yielded 42.94% bio-oil at 463.13 °C, with a residence time of 65.75 min and stirring speed of 9.74 rpm. The analysis showed that temperature is the most critical factor for maximizing yield. The bio-oil produced contains 11 functional groups, primarily phenol, aromatics, and alcohol. Its high viscosity and water content make it unsuitable for engines but suitable for other applications like boilers and chemical additives. It is recommended to explore the potential of refining the bio-oil to reduce its viscosity and water content, making it more suitable for broader applications, including in engine fuels. Further research could also investigate the environmental impact and economic feasibility of scaling up this process

Estimation of Sustainable Bioenergy Production from Olive Mill Solid Waste

The disposal of olive wastes and their wastewater is a major problem worldwide. An important recycling chain can be formed through biogas production and energy conversion from olive waste. This study developed an efficient and effective sustainable model for biogas production using anaerobic digestion conditions with the co-digestion of pretreated olive waste. The sample used was hard olive pomace, which was dried in an oven before being crushed to fine particles with a mortar and pestle. The sample was analyzed by a CE-440 Elemental Analyzer, and Fourier Transform Infrared Spectrophotometer (FTIR) analysis was performed using Shimadzu IRTracer-100. Through the analysis, a substantial amount of electrical energy of 769 kWh/t was found to be generated per ton of olive pomace due to the high volatile solid (VS) percentage of organic waste material incorporated during the calculation. Reduced land area for landfilling olive waste was calculated to be 108 m2 per year, whereas the potential to reduce landfill leachate production was evaluated to be 0.32 m3 per year