CO₂ Capture and Reduction

Abstract

Capturing and utilizing the emissions of CO₂ has become a method to reduce the occurring emissions from industrial flue gases. One of the methodologies to capture and use the CO₂ is through the CO₂ capture and reduction (CCR) process. This process uses a bi-functional catalyst to capture CO₂ from diluted gas streams and subsequently reduce it to CO in the presence of H₂. The obtained product (syngas) can be further used as feedstock in for example the Fischer-Tropsch process. To implement a novel technology in industry, the
technology itself should be economical feasible.

To determine the feasibility of the process a technoeconomical analysis is executed. The analysis uses process parameters obtained by evaluating the catalytic activity of the bifunctional catalysts. Two catalytic
systems have been evaluated: Cu-K/𝛾-Al₂O₃ and FeCrCuK/PMG20. Effect on the synthesis conditions of Cu-K/𝛾-Al₂O₃ were also investigated. Cu-K/𝛾-Al₂O₃
without additional drying steps during the synthesis shows a higher CO₂ capacity and a faster CO production rate compared to the other catalysts. Furthermore, to
estimate the H₂ requirement in an industrialized process the consumption of H2 during the process has been quantified.

To ensure a continuous process operation, a two reactor process has been proposed in the techno-economical analysis. The sizing and subsequent cost of the process equipment has been determined by utilizing the obtained process parameters. Besides the capital costs, the operating costs were also estimated to determine the profitability of the process. After the monetary benefit of selling the syngas was determined, it could be stated that the process is profitable under certain conditions. The process is profitable if the used H₂ source has a buying price below $1.8 per kilogram. If sales of allowances is possible, the buying price of H₂ needs to be below $2.4 to ensure a profitable process.