Thermodynamics study of a solar hybrid allam cycle integrated with methane reforming

Abstract

Development of solar hybrid system to reduce the fossil fuel consumption is being aggressively researched currently. To advance the utilization of solar energy as well as achieve the zero emission for fossil-based power generation, a novel solar hybrid system integrating methane steam reforming with a direct-fired supercritical carbon dioxide power cycle (Allam cycle) was proposed and analyzed. In the proposed system, the concentrated solar energy is used to drive the methane steam reforming to be converted into the stable chemical energy in the syngas; then, the produced syngas is combusted with high-purity oxygen to drive the Allam cycle with intensive heat recuperation and near-zero emission. Detailed thermodynamic models were developed and the overall system performance were determined by process simulation. Thermodynamic analysis results showed that, through introducing the solar energy by methane reforming reaction, the fuel consumption is reduced by 11.0% at designate point with the system net efficiency of 42.7%; from the perspective of the solar utilization, the system can operate flexibly in response to solar variation by syngas storage, and the daily performance showed that the fuel saving ratio can reach 5í10% with the net solar-to-electricity efficiency above 20%.