Techno-Economic Analysis of a Hybrid System with Carbon Capture for Simultaneous Power Generation and Coal-to-Hydrogen Conversion

Abstract

Under the growing pressure of decarbonization across industrial sectors, power plants face great challenges in reducing carbon emissions. To improve energy efficiency and reduce the carbon emissions of thermal power plants, a hybrid system with carbon capture for simultaneous power generation and coal-to-hydrogen is proposed, which features comprehensive consideration of the energy demands of power plants and coal-to-hydrogen units. In the proposed system, the reduction of energy demand is realized by heat exchanger network synthesis (HENs) of the internal streams, and a carbon capture unit is then integrated for further reduction of carbon emissions. The techno-economic feasibility of the integrated system is analyzed and discussed by using energy consumption, economics, and emission reduction as major performance indexes. The results show that energy integration saves 108.2 MW of heat, while nearly 90% of carbon emissions are reduced for the system. When comparing the total energy consumption of the subsystems and a stand-alone carbon capture unit, the consumption for cooling and heating utilities in the integrated system is reduced by 8.81 and 9.11%, respectively. In addition, the total overnight cost and the annual operation cost using the proposed integrated system are reduced by 8.51 and 22.69%, respectively, and the cost of hydrogen production decreases by 5.99%. The economics of the integrated system is significantly affected by the market prices of coal and hydrogen. The integrated system has significant advantages in reducing energy consumption and carbon emissions with higher economic performance, which can provide guidance for the low-carbon transition of coal-fired power plants.