Abstract
Biomass utilisation for energy production is very important in modern society. At EU level, by 2030, 27 % of the energy requirements are expected to be covered by renewable energy sources, biomass being one of the most important sources. Also, for the same period, the greenhouse gas emissions are expected to be reduced by at least 40 % below the 1990 level. In this context, carbon capture and storage (CCS) technologies are equally important for transition to low carbon economy. Chemical looping technique is a particular promising carbon capture option for reducing CO2 capture energy and cost penalties.
This paper evaluates, from techno-economic and environmental perspective, the hydrogen and power co- generation based on biomass direct chemical looping systems with total decarbonisation of the fuel. As illustrative example, an ilmenite-based chemical looping system was assessed to generate about 500 MW net electricity with a flexible hydrogen output in the range of 0 to 100 MWth (based on hydrogen LHV). The capacity of evaluated plant concept to produce flexible hydrogen output is an important aspect for integration in modern energy conversion systems in which flexible operation scenario is of great importance due to greater integration of high time-irregular renewable energy sources (e.g. solar, wind). The carbon capture rate of evaluated concepts is almost total (>99 %). In addition, considering biomass (e.g. sawdust, agricultural wastes etc.) processing, the investigated power plant concepts have negative fossil CO2 emissions. The performances are assessed for a number of case studies (including some benchmark cases) through process flow simulations. The simulation results are used to assess the main techno-economic and environmental indicators, e.g. energy efficiency, ancillary consumption, carbon capture energy and cost penalty, specific CO2 emissions, capital and operation costs, cost of electricity, implication of hydrogen co-production on techno-economic and environmental performances etc.
