In recent years, the depletion of fossil fuel resources and the increase in greenhouse gas emissions have underscored the necessity of developing sustainable technologies to mitigate environmental impacts. The primary objective of this research is to propose a solution for the efficient utilization of industrial waste gases and the reduction of CO₂ emissions by converting them into value-added products. A key approach is converting CO₂ into syngas and light olefins to cut carbon emissions and enhance renewable resource use. Overall, this study presents an effective strategy for transforming CO₂, a greenhouse gas, into value-added products, which can contribute to reducing the environmental footprint of industries and fostering the development of sustainable technologies. In this research, light olefins, were selected as the main products. Additionally, methane and light paraffins were considered as byproducts of the process. Initially, an integrated system comprising RWGS and Fischer-Tropsch reactors was simulated using Aspen Hysys V11 software. In the first stage, the RWGS reactor was utilized for syngas production, and its process was simulated. Then, the output composition of this reactor was used as feedstock for the Fischer-Tropsch reactor to produce light olefins. To eva‎luate the process performance, six different scenarios were simulated with the aim of optimizing the operating conditions, and the results were reported. In this study, a comprehensive analysis and optimization of key process parameters including feed molar ratio, temperature, and pressure of the RWGS and Fischer-Tropsch reactors were conducted for all scenarios. The goal was to enhance operational conditions, increase olefin production, and minimize undesirable byproducts. A comparison of different scenarios indicates that increasing the temperature from 600°C to 1000°C and optimizing the H₂/CO₂ feed ratio significantly improve CO yield, reduce methane formation, and enhance light olefin production. However, increasing the pressure from 1 bar to 22 bar leads to a decrease in CO production and an increase in methane as a byproduct. Finally, for the optimized scenarios, an economic eva‎luation was performed based on criteria such as initial capital investment, operating costs, and annual revenue. The third scenario, in which the RWGS reactor operates at 950°C and 22 bar while additional hydrogen is injected into the Fischer-Tropsch reactor, was identified as the optimal economic option. This scenario achieved a CO₂ conversion rate of 72%, the highest net present value, and an internal rate of return of 42%, with the shortest payback period of 2.59 years among the eva‎luated scenarios. These results highlight the economic superiority of the third scenario compared to other alternatives, primarily due to higher annual revenue and reduced capital and operational costs. Therefore, it is recommended that this scenario be further examined for large-scale industrial applications. Additionally, by implementing energy optimization for this scenario, energy consumption was reduced from 920 million kJ per hour to 720 million kJ per hour.

محسن محمدي

محمد هادي جزيني , صفورا كريمي