Assessment of carbon capture, utilization and storage for gasendal

Abstract

In order to meet the goals set in the Paris Agreement and the stringent CO2 emission level targets set in Sweden, there is an urgent need to increase the amount of CO2 utilization and storage.

This thesis presents a techno-economic analysis of CO2 liquefaction and the synthesis of electro-methanol (e-MeOH) as a CO2 utilization pathway for captured CO2 from Gasendal, a biogas upgrading plant. The processes are implemented and simulated in Aspen Plus to extract important parameters and calculate capital and operational costs as key performance indicators.

The results show that liquefaction costs 34 €/tonCO2 for Gasendal, which is approximately 80% higher than shown in other studies. However, when increasing the plant size to 1M tonCO2/year, the cost decreases to 10 €/tonCO2. In terms of heat recovery potential, the plant could only provide heat to district heating, but the amount is too small considering no close pipelines.

On the other hand, e-methanol synthesis costs amounted to 1387 €/tonMeOH, with about 91% of expenses attributed to alkaline water electrolysis for hydrogen generation. Given that electrolysis costs pose a limitation and do not decrease with the scale of the plant in this study, the overall cost of e-methanol synthesis remains unaffected by the plant’s capacity. Regarding heat recovery, the process is able to supply 98% of its heating demand and reduce the natural gas consumption in the existing process at Gasendal by around 43%.