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

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.

本报告针对用于二氧化碳（CO₂）矿化的氨基工艺开展了高层次技术经济评估。该工艺的整体目标为脱除300兆瓦燃煤电厂烟气中80%的二氧化碳组分。后续对设计基准进行了进一步优化，旨在降低装置能耗与设备规模。本报告阐述了基于该优化后设计基准的热质平衡计算结果，同时涵盖了整体能耗需求与预估基建成本，并分析了优化后设计基准带来的影响。
本团队开发的氨基二氧化碳矿化工艺因能耗较高、基建成本高昂，尚不具备经济性。该工艺多数设备体量庞大且采用多流道设计，运行复杂度较高。其基建成本与壳牌（Shell）开发的工艺相当，但由于增设了硫酸铵分解段、硫酸铵回收段，以及沉淀段过量试剂的回收与循环回用工序，该装置的可变运行成本居高不下；且若不投入大量额外能耗，便无法捕集电厂产生的全部二氧化碳。该额外能耗对应的二氧化碳生成量，超出了该捕集装置的设计捕集规模。因此在当前工艺开发阶段，该方案相较于对标壳牌的工艺方案并无优势。
目前尚有多项技术优化路径可供探索，预计这些路径虽会提升装置基建成本，但有望大幅降低运行成本并提升碳捕集能力。