Adsorption Materials and Processes for Carbon Capture from Gas-Fired Power Plants - AMPGas

2008年的《气候变化法案》设定了一个具有法律约束力的目标，即到2050年将二氧化碳排放量减少80%。为了应对这一挑战，英国气候变化委员会（CCC）定期发布碳预算，并就英国需要减少排放的方式提出建议。在2010年第四次碳预算中，有一个到2030年电力部门脱碳的明确计划，通过投资30-40吉瓦的低碳产能，价值约1000亿英镑。到2030年，这将使发电的平均排放量降至50克二氧化碳/千瓦时左右，到2020年包括4个CCS示范工厂。CCC承认英国燃气发电厂的关键作用：目前46%的发电量和35%的排放量来自天然气。报告还指出，CCS改造是现有CCGT电厂的一个有吸引力的选择，表明目前系统上的20GW电厂将适合在本世纪20年代进行改造，再加上未来十年增加的任何电厂（10- 15gw）。到21世纪30年代，CCGT电厂可能会贡献25%的发电量。大约2/3的CCS成本在捕集过程中，这是最大的节约机会所在。因此，政府正在支持研究开发改进和低成本的工艺和设备，该提案直接符合这一目标，以支持英国经济，并帮助英国在未来10到20年内在这一新兴技术方面处于领先地位。根据气候变化委员会的建议，本提案的重点是改造现有CCGT电厂的捕集技术。我们建议开发下一代增强型捕获技术，特别是通过新型先进吸附剂和使用旋转轮吸附剂的快速循环热再生优化来减小工厂规模。研究挑战——燃气发电厂燃烧后捕集的主要挑战是由于烟气中的二氧化碳浓度较低，按体积计约为4%。这意味着，传统的胺过程将有一个大的能量惩罚和高浓度的氧气的存在导致高胺失活率。新型吸附剂和吸附工艺有可能提高分离过程的效率。考虑到烟气中CO2分压非常低，新型吸附剂的选择与燃煤电厂的等效方法有很大不同。吸附剂必须具有非常高的选择性，才能在稀混合物中获得良好的捕获能力。因此，这些材料必须基于非常强的物理吸附或化学吸附，并且必须通过热循环再生。这就提出了一项工程挑战，即开发一种能够实现几分钟的快速热波动的工艺，这比传统的热波动吸附（TSA）固定床工艺快一个数量级。我们计划了一项雄心勃勃的工作计划，将解决燃气发电厂碳捕获的材料和工艺开发问题。

The 2008 Climate Change Act sets a legally binding target of 80% CO2 emissions reductions by 2050. To meet this challenge the UK Climate Change Committee (CCC) issues regular carbon budgets with recommendations on the way in which the UK needs to reduce its emissions. In its 2010 4th carbon budget, there is a clear plan for power sector decarbonation to 2030, by investing in 30-40 GW of low carbon capacity with a value of the order of £100 billion. This would drive average emissions from generation down to around 50gCO2/kWh by 2030 and includes 4 CCS demonstration plants by 2020. The CCC recognises the key role for the UK of gas fired power plants: 46% of current electricity generation and 35% of emissions are from gas. It also identifies CCS retrofit as an attractive option for existing CCGT plants, indicating that 20GW of plant currently on the system would be suitable for retrofit in the 2020s, together with any plant added over the next decade (10-15 GW). CCGT plants are likely to contribute 25% of electricity generation in the 2030s. Roughly 2/3 of CCS costs lie in the capture process and it is here that the greatest opportunities for savings lie. Therefore, the Government is supporting research to develop improved and lower cost processes and equipment and this proposal is directly aligned with this aim in order to support the UK economy and help the UK take the lead in this emerging technology over the next 10 to 20 years.In line with the CCC recommendations the focus of this proposal is on capture technology for retrofit to existing CCGT plants. We propose to develop next generation enhanced capture technology and in particular reduce plant size through novel advanced adsorbents and the optimisation of fast cycle thermal regeneration using rotary wheel adsorbers.Research challenge - The key challenge in post combustion capture from gas fired power plants is due to the low CO2 concentration in the flue gas, approximately 4% by volume. This means that conventional amine processes will have a large energy penalty and the presence of high concentration of oxygen leads to high amine deactivation rates. Novel adsorbents and adsorption processes have the potential to improve the efficiency of the separation process. Given the very low CO2 partial pressure in the flue gas, the selection of novel adsorbents is very different from the equivalent approach to coal fired power plants. The adsorbents will have to have a very high selectivity to achieve good capture capacity with dilute mixtures. As a result these materials will have to be based either on very strong physisorption or chemisorption and the regeneration will have to be by thermal cycling. This poses the engineering challenge of developing a process that will achieve rapid thermal swings of the order of a few minutes, which is over an order of magnitude faster than traditional Thermal Swing Adsorption (TSA) fixed bed processes. We plan an ambitious programme of work that will address both materials and process development for carbon capture from gas fired power plants.