Techno-Economic Assessment of a Combined Heat and Power Plant Integrated with Carbon Dioxide Removal Technology: A Case Study for Central Poland

Abstract

The objective of this study is to assess the techno-economic potential of the proposed novel energy system, which allows for negative emissions of carbon dioxide (CO2). The analyzed system comprises four main subsystems: a biomass-fired combined heat and power plant integrated with a CO2 capture and compression unit, a CO2 transport pipeline, a CO2-enhanced geothermal system, and a supercritical CO2 Brayton power cycle. For the purpose of the comprehensive techno-economic assessment, the results for the reference biomass-fired combined heat and power plant without CO2 capture are also presented. Based on the proposed framework for energy and economic assessment, the energy efficiencies, the specific primary energy consumption of CO2 avoidance, the cost of CO2 avoidance, and negative CO2 emissions are evaluated based on the results of process simulations. In addition, an overview of the relevant elements of the whole system is provided, taking into account technological progress and technology readiness levels. The specific primary energy consumption per unit of CO2 avoided in the analyzed system is equal to 2.17 MJLHV/kg CO2 for biomass only (and 6.22 MJLHV/kg CO2 when geothermal energy is included) and 3.41 MJLHV/kg CO2 excluding the CO2 utilization in the enhanced geothermal system. Regarding the economic performance of the analyzed system, the levelized cost of electricity and heat are almost two times higher than those of the reference system (239.0 to 127.5 EUR/MWh and 9.4 to 5.0 EUR/GJ), which leads to negative values of the Net Present Value in all analyzed scenarios. The CO2 avoided cost and CO2 negative cost in the business as usual economic scenario are equal to 63.0 and 48.2 EUR/t CO2, respectively, and drop to 27.3 and 20 EUR/t CO2 in the technological development scenario. The analysis proves the economic feasibility of the proposed CO2 utilization and storage option in the enhanced geothermal system integrated with the sCO2 cycle when the cost of CO2 transport and storage is above 10 EUR/t CO2 (at a transport distance of 50 km). The technology readiness level of the proposed technology was assessed as TRL4 (technological development), mainly due to the early stage of the CO2-enhanced geothermal systems development.