Process Analysis And Optimization Of IGCC System Based On Air-blown Gasification

With the progress of society and the development of industry,the demand for energy is also increasing.In our country,coal is the pillar energy in the energy structure,especially the most important in power generation.Among many clean coal utilization technologies,integrated gasification combined cycle(IGCC)is recognized as the most promising coal-based power generation technology.Although IGCC has obvious advantages in terms of power generation efficiency and energy saving and emission reduction,at the same time,traditional IGCC mainly uses oxygen as the medium,but the air separator required to prepare oxygen consumes a lot of factory electricity,which will lead to power generation.The problem of low efficiency and high cost.In response to this problem,some researchers have proposed the use of air as the gasification medium,but there are few related studies and insufficient systems.Based on the related research,this article further studies the IGCC based on air-blown gasification from the system level.the study.Based on the existing IGCC process plan and the Aspen Plus simulation platform,this paper builds an IGCC based on air-blown gasification system process flow model,verifies the feasibility of air as a gasification medium,and determines it by referring to design experience values,heat balance calculations and software simulations Some technical parameters in the process flow;based on this model,study the key operating parameters in the system,such as gasification pressure,air preheating temperature,gasto-coal ratio,etc.,for syngas temperature,effective gas distribution and other gasifier operating indicators,and System power consumption distribution,power generation efficiency and other IGCC system overall performance indicators,the operating parameters of the IGCC based on air-blown gasification system are selected as gas-tocoal ratio 3.4,air preheating temperature 450℃,gasification pressure 3MPa,under this working condition,The efficiency of the IGCC based on air-blown gasification system is3.17 percentage points higher than that of the oxygen gasification IGCC system,and the exergy efficiency is 3.09 percentage points higher.On the basis of the above research,optimize the process flow of IGCC based on airblown gasification,study the feasibility of gas turbine integration,high pressure reheat gas turbine,high temperature gas desulfurization and other advanced process flow and its impact on the thermal performance of the system.The results show The IGCC based on air-blown gasification system with gas turbine integrated has no advantage in efficiency.The process flow of high-pressure reheat gas turbine and high-temperature gas desulfurization can significantly improve system efficiency.For high-pressure reheat system,the reheat pressure is 1.2MPa and the maximum pressure is 14.4 The system efficiency can reach 50.28% at MPa.For high-temperature gas desulfurization systems,the system efficiency can reach 50.14% at a desulfurization temperature of 650℃.If both processes are used at the same time,the IGCC based on air-blown gasification system efficiency can reach 52.80%.