CCS Ready Assessment Of NGCC-CHP Plant——CCS Ready Assessment And Energy Consumption Analysis Of Gaojing Power Plant

Recently, with the development of human industrial activity, atmospheric CO2level increases every year. Response to global warming, CO2emissions reduction is imperative.At present, among the various methods of reducing CO2emissions, CO2capture and storage technology (CCS) has the highest viability. CCS technology can capture CO2from the emission sources, and then permanently seal it under the ground. However, the implementation of CCS technology still faces significant technical, legal, policy problems, also the economic barriers of large-scale implementation. It needs time to solve these problems. Therefore, the concept of CCS Ready appears.As a clean energy, natural gas power is relative environmental friendly. Natural gas power plant has a higher energy efficiency. But there is still a lot of CO2discharged from flue gas generated in the gas steam combined cycle unit. Therefore, for the long-term consideration, NGCC-CHP plant also needs to reduce CO2emissions by CCS technology. When the regulatory measures of mandatory reduction and economic incentives appear, CCS Ready plants can much easier to be transformed to CCS power plants, reducing the cost of implementing CCS technology.This paper mainly introduces the following contents:(1)This paper introduces the basic situation of natural gas power plant, and introduces CCS and CCS Ready’s definitions, researching status and the international standard and regulations of CCS Ready. Taking Gaojing NGCC-CHP power plant as an example, calculated under the90%CO2capture plant scale with the CO2capture capacity of445.2t/h. According to the actual situation of power plant and its capture capacity, refering to international academic research references and past experiences, comparing many CO2capture technology for power plant, Gaojing NGCC-CHP ultimately chooses the post combustion capture with MEA CO2absorption method.(2)This article uses Aspen Plus to simulate capture process. Calculate and simulate that there is a total of18sets of capture equipments in Gaojing Power Plant, wherein the washing tower diameter is7m, and height is24m; the absorption tower diameter is10m, and height is27m; regeneration tower diameter is6m, and height is21m.(3) Using Aspen Plus to simulate capture process, it results the power,energy and material consumption of Gaojing CO2capture system. By adjusting the parameters, the software can optimize the process further. It simulated that the energy consumption of1tons of CO2-capture is3.53GJ/tCO2, the total power consumption of the capture system is74MW/h, consumption of circulating cooling water for the capture system is114m3/tCO2. Adjusting the concentration of absorbent, lean liquid load, the regeneration tower pressure, and therich liquid temperature of regeneration tower entrance, it finally concludes the best capture condition,which is the MEA absorber optimum concentration is30%, lean liquid load is0.25mol CO2/mol MEA, the regeneration tower pressure is2bar, the regeneration tower entrance temperature is90℃.(4)This article discusses the methods of integrating plant’s steam cycle with CO2absorption system. Comparing three kinds of external heating systems for offering the reboiler’s energy, it finally chooses to use power plant steam cycle for regeneration energy supplyment. Selectthe end of the medium and low pressure part, where steam is330℃and0.36MPa, as the regeneration towerreboiler’s heat source. According to the energy consumption of CO2capture, it calculated that the amount of steam ofall plant three units is598.94t/h.(5)This article analysesthe necessary requirements and obstacles of GaoJing NGCC-CHP Plant’s CCS Ready,especially in capture ready. At present, in Gaojing NGCC-CHP Plant,the system of flue gas desulphurization and denitration, cooling water and fire control have reached the capture ready’s requirements. It still need to reserve the space of capture device and transformation space, also the transformation of steam turbine and auxiliary system, add the capture sewage treatment system, electrical facilities, water pipeline architecture analysis of monitoring point and do a good job in CCS power plant safe operation plan. It estimated that Gaojing Power Plant need a total area of about90020m2, which CO2capture equipment area is87320m2, amd the sewage treatment plant, drug warehouses, repair shop, parking, loading zone covers an area of2700m2. Plane sketch is also shown.Besides, the article introduces the requirements of plant’s transport ready and storage ready. (6) This article makes the choice of the transformation scheme of the Steam turbine. Respectively, comparing the advantages and disadvantages of throttled LP turbine, floating LP/IP turbine pressure,and clutched LP turbine, finally choose the floating LP/IP turbine pressure way as steam turbine reconstruction scheme of Gaojing NGCC CHP plant.(7) This article analysesthe effections ofplant’s power generation efficiency before and after adding CO2capture equipments in the conditions of ISO. The results of one unit is that after adding the CO2capture device, the power generation efficiency loss about15.4%, of which the reboiler energy loss reached45.24MW, power loss9.97%and the capture device power consumption to achieve24.7MW, power loss5.4%.(8) At last, this article sums up the gap of Gaojing Power Plant being CCS Ready, from the policy, capital cost, and Gaojing Power plant’s actual situation. And the future developments of CCS Ready in China are discussed.