Thermodynamic Analysis of a Novel Process With Integrated CO2 Capture for the Production of Electric Power and Hydrogen

Abstract

This paper presents a detailed description and thermodynamic analysis of a novel process generating electric energy and hydrogen, i. e. two important energy products for the future. Coal and high-temperature heat are used as input energy to the process. The process is a true “zero emission process” because (a) no NOX is formed during coal combustion with sulfuric acid, and (b) the combustion products SO2 and CO2 are removed as compressed liquids from the overall process. The commercial process simulator Aspen Plus was used for the thermodynamic modeling of this process. Detailed results of the simulation are presented. The overall process is characterized by very high energetic and exergetic efficiencies in comparison with other energy conversion systems in which electric power or hydrogen are generated using the same energy inputs. The influence of important process parameters, e.g. the concentration of the sulfuric acid solution on the overall efficiency is discussed. The evaluation of the thermodynamic performance of the process, which is based on a detailed exergetic analysis, represents the first step in a comprehensive evaluation of this concept to be conducted in the future.