Mineralisation - Carbon Capture and Sequestration by Mineralisation (CCSM) Stage 2b Techno-Economic Assessment (TEA) Report

Abstract:

This report describes the high level techno-economic assessment of an ammonia based process for the mineralisation of CO₂. The overall process requirement is to remove 80% of the CO₂ content in the flue gas arising from a 300 MW coal based power plant. The design basis was latterly further modified with the aim of reducing the plant energy usage and equipment sizes. The heat and mass balance using this revised basis is described here, along with the overall energy requirements andestimated capital cost. The impact of the modified design basis is also given. The ammonia based mineralisation process that this group has developed is uneconomic due to its energy requirements and high capital cost.

Much of the process equipment is large and multi-streamed and the process will be complex to operate. The capital cost is equivalent to that of the Shell designedprocess, but as a result of the ammonium sulphate decomposition stage, ammonium sulphate recovery, and the recovery and recycling of excess reagents from the precipitation stage, the plant has high variable costs of operation and is unable to capture the carbon dioxide generated by the power station without significant additional energy usage. This energy usage equates to a carbon dioxide production rate which exceeds the amount that the recovery plant is designed to capture. At this stage of development of the process, therefore, it is less favourable than the Shell designed process that it has been compared to. There are a number of further technology development options that can be explored.It is believed that these are likely to raise the plant capital cost, but have the potential to significantly reduce its operating costs and increase its carbon capture potential.

Author(s):

Jeffery, I., Humphries, G., Hillier, G., Li, Y. and Paulson, T.