Scenario analysis of implementing a power-to-gas and biomass gasification system in an integrated steel plant: A techno-economic and environmental study

Abstract

Since the European Union's target a domestic greenhouse gas emission reduction of 80% till 2050, as compared to the value of 1990 (European Commission, 2011), there has been an increasing interest in greening large industrial processes. Thus, gas greening and alternative emission reduction processes are gaining importance. In this study, a gas greening system for an integrated steel plant, producing synthetic natural gas serving as a substitute for the fossil fuel-based gas, was investigated. The analysed system consisted of a Power-to-Gas unit combined with a biomass gasification plant, where carbon rich steel gases were used as a CO2 source for methanation. To analyse the system, three extreme value scenarios and three constrained scenarios were defined and evaluated. The biomass gasification plant, set to a maximum nominal power of 105 MWth, was the main limiting factor for the constrained scenarios. The assessment included a basic mass and energy balance, techno-economic analysis, sensitivity analysis, and CO2 potential impact analysis. It was found that the main cost influencing factor throughout all six scenarios was the energy supply cost (electricity and biomass).