Selective Exhaust Gas Recirculation for Carbon Capture with Gas Turbines: Integration, Intensification, Scale-up and Optimisation.

英国的发电量仍有80%左右依赖化石燃料，由此产生的碳强度--每单位发电量排放到大气中的碳量--比为避免危险的气候变化而建议的水平高出十倍。目前，一半的电力来自天然气，预计未来十年还会增加，因为新的燃气发电将与可再生能源一起投入使用，以取代建于20世纪60年代的效率低下的旧燃煤电厂。自2007年以来，英国已经批准了超过20千兆瓦的天然气装机容量，相当于目前发电装机容量的四分之一。与英国到2030年建议的发电量水平相比，有增无减的(无碳捕获)燃气发电厂每单位电力产生的碳量是6到7倍。它们必须配备碳捕获和储存装置，以提供可靠的低碳能源，以填补僵化的核能和间歇性风力发电与波动的电力需求之间的空白。天然气CCS研发是一个重要的新兴领域，特别是为了解决页岩气储量中迅速增加的额外碳的问题，许多概念和基本的科学原理仍在“发明”中。英国正在进行基础设施投资和能源政策决策，这将受益于对相关天然气CCS技术的更好信息，使学术研究人员的独立基础研究成为高度优先事项。作为撰写本文时英国CCS商业化计划的一部分，英国正在领导天然气CCS的部署，对彼得黑德发电站进行改造。将于本世纪20年代和30年代推出的第二批和第三批天然气CCS项目仍然面临关键的工程挑战。如果排气中的二氧化碳(CO2)浓度远高于现代燃气轮机系统中常见的3-4%的值，CCS与燃气轮机的有效和经济的集成将得到加强，发电成本将大大降低。一个创新的解决方案是有选择地将燃烧后二氧化碳捕获过程上游的CO2从燃气轮机排气通过发动机进口回流，从而极大地提高CO2浓度，从而减轻CCS工厂的负担。主要结果将是一个更具成本效益的工厂，视觉影响显著减少。为了实现这一概念，必须克服3个主要挑战，这些挑战构成了拟议工作的基础：1.工厂设计和优化。根据制造商的建议和研究数据，将考虑通过发动机的废气再循环量的一系列方案。这将包括项目其他部分的结果，如发动机性能测试。GT-CCS集成。实验测试将展示发动机和CCS过程如何工作，当两者必须以共生方式工作时。这将包括测量燃气轮机燃烧器在运行条件下的性能，发动机测试，以及在CCS柱上进行实验，以确定其对这种再循环废气的有效性。规模扩大和集约化。根据在前面步骤中收集的研究数据，该项目随后将公布关于这一概念的可行性的研究结果，包括应用这些数据为未来的燃气轮机-CCS工厂制定设计规则。将这一想法进一步应用，该项目将评估如果这些电厂被认为在经济上可行的话对英国能源结构的影响。该项目有很强的实践基础，使用了来自3所英国著名大学的各种最先进的研究设施。这些将包括高压和高温条件下燃烧行为的测量，使用回收废气的燃气轮机机组的性能测试，以及CCS塔性能的基础研究。

UK electricity generation still relies around 80% on fossil fuels, with a resulting carbon intensity - the amount of carbon emitted to the atmosphere per unit of electricity generated - ten times higher than the level recommended to avoid dangerous climate change. Half of that electricity currently comes for natural gas and is expected to increase in the next decade as new gas-fired generation is commissioned to replace, along with renewables, old inefficient coal plants built in the 1960s. Over 20GW of gas capacity has been permitted since 2007, equivalent to a quarter of the current installed capacity for electricity generation.Unabated (no carbon capture) gas plants produce six to seven the amount of carbon per unit of electricity compared to the levels recommended for UK electricity generation by 2030. They must be fitted with Carbon Capture and Storage to provide reliable low-carbon energy to fill-in gaps between inflexible nuclear and intermittent wind power generation and a fluctuating electricity demand.Gas CCS R&D is an important emerging field, particularly to address the issue of rapidly increasing additional carbon in shale gas reserves, and many of the concepts and underlying scientific principles are still being 'invented'. Ongoing UK infrastructure investments and energy policy decisions are being made which would benefit from better information on relevant gas CCS technologies, making independent, fundamental studies by academic researchers a high priority. The UK is leading Gas CCS deployment with the retrofit of Peterhead power station, as part of the UK CCS Commercialisation programme at the time of writing. Key engineering challenges remain for the second and third tranche of gas CCS projects to be rolled out in the 2020s and 2030s. Efficient and cost-effective integration of CCS with gas turbines would be enhanced and costs of electricity generation greatly reduced if the carbon dioxide (CO2) concentration in the exhaust were much higher than the typical 3-4% value seen in modern Gas Turbine systems.An innovative solution is to selectively recirculate CO2, upstream of the post-combustion CO2 capture process, from the Gas Turbine exhaust back through the inlet of the engine, thereby greatly increasing CO2 concentration and subsequently reducing the burden on the CCS plant. The main result would be a more cost-effective plant with a significantly reduced visual impact. In order to achieve this concept, 3 main challenges must be overcome, which form the basis of the proposed work:1. Plant Design and Optimisation. Based on advice from manufacturers and research data, a series of scenarios will be considered for the amount of exhaust recirculation through the engine. This will include results from other parts of the project, such as the engine performance tests.2. GT-CCS Integration. Experimental testing will show how engines and CCS processes function when the two must work in a symbiotic fashion. This will include the measurement of gas turbine burner performance under operational conditions, engine testing, plus experiments on CCS columns to determine their effectiveness with this recirculated exhaust gas.3. Scale-up and Intensification. Based on the research data gathered in the previous steps, the project will then publish findings on the viability of this concept, including application of this data to set design rules for future GT-CCS plants. Applying this idea further the project will estimate the impact on the UK's energy mix if these plants were considered economically viable.This project has a strong practical basis, employing a variety of state-of-the-art research facilities from 3 well-established UK Universities. These will include measurement of combustion behaviour under high pressure and temperature conditions, performance testing of GT engine sets with recycled exhaust and fundamental studies of the behaviour of CCS columns.