Carbon dioxide capture and conversion to fuels

This research explores an innovative approach to carbon dioxide capture and utilisation as an effective solution to the problem of carbon dioxide emissions.

In a global surge in carbon emissions and the shift towards a circular economy, we are exploring strategies to capture carbon dioxide in a manner that reduces the environmental impact and promotes sustainability within industrial processes.

One highly feasible strategy involves a combination of ammonia-based carbon dioxide (CO2) capture and its use for methanol production. However, traditional methods often entail substantial energy demands and limited hydrogen utilisation.

To address these problems, we introduce an innovative strategy aimed at providing a sustainable solution that not only reduces the environmental impact of CO2 capture but also improves the use of conventional technologies.

Our enhanced design

We propose utilising ammonia-based CO2 capture with double tower absorption and solvent split, coupled with wet hydrogen for large-scale methanol production. This process is then refined through a multi-criteria assessment, considering key factors such as CO2 capture rate, NH3 loss rate, CO2 conversion rate and energy efficiency. The energy efficiency encompasses two critical components: reboiler duty and condenser duty. We then employ exergy analysis to streamline the process, leading to the creation of a highly efficient integrated system.

To achieve this integrated system, we initially simulate the C-ACCMP process using Aspen Plus software to determine the CO2 capture rate, CO2 conversion rate, heat duty and other essential parameters. We then summarise various enhancement strategies for CO2 capture and methanol production, including double tower absorption, solvent splitting, and a switch to an alternative hydrogen source. Then, we delve into the improved ammonia-based CO2 capture and methanol production (I-ACCP) process and optimise its parameters. Finally, we identify and optimise equipment with significant exergy loss within the I-ACCMP process to minimise wastage.

 

An illustrated overview of carbon capture, utilization, and storage processes
An illustrated overview of carbon capture, utilization, and storage processes.

References

Yang, N, Kang, F, Zhang, K, Zhou, Y, Lin, WF.  A strategy for CO2 capture and utilization towards methanol production at industrial scale: An integrated highly efficient process based on multi-criteria assessment, Energy Conversion and Management, 293, 117516. DOI: 10.1016/j.enconman.2023.117516.