Evaluation of energy vectors poly-generation schemes based on solid fuel gasification processes with Carbon Capture and Storage (CCS)

Energy issue is very important and actual for the modern world giving the double significance of the problem: security of energy supply, environmental protection and climate change prevention by reducing the greenhouse gas emissions (mainly carbon dioxide). This paper investigates the innovative ways for transforming the coal in addition with renewable energy sources (biomass), through gasification into different energy vectors (power, hydrogen, heat etc.) simultaneous with carbon dioxide capture and storage (CCS). Lately, solid fuel gasification is extensively evaluated being one of the energy conversion technologies having the highest potential to capture CO₂ with low penalties in efficiency and cost. Also, gasification, compared with other technologies, has very good potential to generate by thermo-chemical conversion various energy vectors apart from power (e.g. hydrogen, substitute natural gas, liquid fuels etc.). The innovative energy conversion processes investigated in the paper were modeled and simulated using commercial process flow modeling software (ChemCAD) for technical evaluation of poly-generation processes (focused on poly-generation processes of power, hydrogen and heat) based on gasification with carbon capture and storage. The case studies investigated in the paper will produce a flexible ratio between power and hydrogen (in the range of about 400 MW electricity and 0 - 200 MW hydrogen) with more than 90 % carbon capture rate (design assumptions). A particular accent is put in the paper on thermal and power integration of plant sub-systems, flexibility analysis of the energy conversion process (ability to change plant generated energy vectors over time), carbon dioxide capture and storage and discussing the quality specifications for hydrogen and carbon dioxide considering the potential use of hydrogen in the transport sector (fuel cells) and for carbon dioxide storage in geological formation or using for Enhanced Oil Recovery (EOR).