Performance analysis of biomass gasification coupled with ultra-supercritical power generation system

• The energy and exergy efficiencies are the largest when air/biomass ratio is 1.6. • The coupled system has better energy and exergy efficiencies. • Its’ energy efficiency is 2.70% higher than ultra-supercritical coal-fired system. • Its’ exergy efficiency is 1.81% higher than ultra-supercritical coal-fired system. • The coupled system has many advantages in terms of environmental performance. In order to alleviate the impact of coal combustion on the environment, a scheme of biomass gasification in coal-fired ultra-supercritical power plant is proposed and simulated with Aspen plus. Simulation results show that the energy and exergy efficiencies of the coupled system have an increasing-decreasing tendency with the increase of the air/biomass ratio, reaching the maximum value when the air/biomass ratio is 1.6. The energy and exergy efficiencies of the coupled system decrease continuously with the increase of the excess air ratio. The coupled system has the highest energy and exergy efficiencies of 46.89% and 43.13%, which are 2.70% and 1.81% higher than those of an ultra-supercritical coal-fired system, respectively. Meanwhile, the coupled system has low CO 2 , SO 2 , and NO x emissions and thus many advantages in terms of environmental performance. .