In the context of the process intensification of Post-combustion Carbon Capture (PCC), Selective Exhaust Gas Recirculation (SEGR) in Natural Gas-fired Combined Cycle (NGCC) plants, a concept where CO₂ is selectively recycled to increase concentration and reduce flow rates of the flue gas, is analysed. SEGR operated either in parallel or in series with a downstream PCC system increases CO₂ concentration beyond 14 vol% and maintains oxygen levels in the combustor to approximately 19 vol%, well above the 16 vol% limit reported for non-selective Exhaust Gas Recirculation (EGR). Process modelling shows that the current class of gas turbine engines can operate without a significant deviation in the compressor and in the turbine performance. Compressor inlet temperature and CO₂ concentration in the working fluid are the two critical parameters affecting the gas turbine net power output and efficiency. A higher turbine exhaust temperature allows the generation of additional steam in the HRSG. This results in an increase in net power output of approximately 42 MW (5.2%) and 18 MW (2.3%), and in net thermal efficiency of 0.55%point and 0.83%point, for the investigated configurations with SEGR in parallel and SEGR in series, respectively. With 30 wt% aqueous monoethanolamine scrubbing technology, SEGR leads to operation and cost benefits. SEGR in parallel with 70% recirculation, 97% selective CO₂ transfer efficiency and 96% PCC efficiency results in a reduction of 46% in packing volume and 5% in specific reboiler duty, compared to air-based combustion CCGT with PCC, and of 10% in packing volume and 2% in specific reboiler duty, compared to 35% EGR. SEGR in series operating at 95% selective CO₂ transfer efficiency and 32% PCC efficiency results in a reduction of 64% in packing volume and 7% in specific reboiler duty, compared to air-based CCGT with PCC, and of 40% in packing volume and 4% in specific reboiler duty, compared to 35% EGR. On selecting a technology for SEGR applications, CO₂ selectivity, pressure drop and heat transfer flow rate are the operating parameters with a larger effect on the power plant performance with SEGR. It is important to minimise oxygen leakages from the air into the flue gas, minimise heat transfer that would otherwise increase CO₂-enriched air temperature at compressor inlet, and minimise pressure drop, e.g. a 1 kPa pressure drop results in gas turbine derating of 2 MW (0.7%).

在天然气联合循环电厂（NGCC）的燃烧后碳捕集（PCC），选择性废气再循环（SEGR）的过程强化的背景下，CO ₂被选择性地再循环以增加浓度和减少流量的概念分析烟气的速率。与下游PCC系统并联或串联操作的SEGR可将CO ₂浓度增加到14 vol％以上，并将燃烧器中的氧气水平维持在约19 vol％，远高于非选择性废气再循环的16 vol％限值（ EGR）。过程建模表明，当前类别的燃气涡轮发动机可以在压缩机和涡轮性能无明显偏差的情况下运行。压缩机入口温度和CO ₂工作流体中的浓度是影响燃气轮机净功率输出和效率的两个关键参数。较高的涡轮机排气温度允许在HRSG中产生额外的蒸汽。对于并联的SEGR和SEGR的研究配置，这导致净输出功率分别增加了约42 MW（5.2％）和18 MW（2.3％），以及净热效率分别为0.55％和0.83％。系列，分别。凭借30 wt％的单乙醇胺水溶液洗涤技术，SEGR可带来运行和成本优势。SEGR与70％的再循环，97％的选择性CO ₂并行与带PCC的空气燃烧CCGT相比，转移效率和96％的PCC效率导致填料体积减少46％，比重沸腾器负荷减少5％，填料体积减少10％，比重沸腾器负荷减少2％，相比于35％的EGR。与带有PCC的空气CCGT相比，串联的SEGR在95％的选择性CO ₂转移效率和32％的PCC效率下运行，与采用PCC的空气CCGT相比，其包装体积减少了64％，比重沸腾器负荷减少了7％，而包装则减少了40％体积和4％的特定再沸器负荷（相比之下，EGR为35％）。在为SEGR应用选择技术时，CO ₂选择性，压降和传热流量是使用SEGR对发电厂性能产生较大影响的运行参数。重要的是最小化从空气中泄漏到烟道气中的氧气，最小化传热，否则传热会增加压缩机入口处富含CO _2的空气温度，并且最小化压降，例如1 kPa压降会导致燃气轮机降额2 MW（0.7％）。