Abstract
Development of energy efficient ways to convert biomass and wastes to energy is of paramount importance in modern society. The development and large scale deployment of energy and cost effective carbon capture and storage (CCS) technologies are equally important for transition to low carbon economy. This paper investigates the potential use of biomass (sawdust and agricultural wastes) and solid wastes (e.g. municipal wastes, meat and bone meal etc.) in a co-gasification process with coal to co-generate hydrogen and electricity with carbon capture. The paper underlines one of the main advantages of gasification technology, namely the possibility to process lower grade fuels (lower grade coals, biomass, solid wastes etc.), which are more widely available and cheaper than the high grade coals normally used in combustion-based power plants, this fact contributing to the improvement of energy security supply.
Based on a proposed plant concept that generates 400 – 425 MW net electricity with a flexible output of 0– 200 MWth hydrogen and a carbon capture rate of at least 90 %, the paper presents in details coal and biomass / solid waste blending for optimizing plant performance, mass and energy integration aspects, hydrogen and power co-generation and overall energy efficiency. Energy vectors poly-generation capability of gasification plants and a critical comparison of coal and biomass co-gasification with correspondent co-combustion are also discussed. The key technical performance indicators are calculated for a number of case studies through process flow simulations. The mass and energy balances resulted from simulation are then used to assess the main techno-economic and environmental indicators of the evaluated cases, like plant energy efficiency, ancillary power consumption, carbon capture energy and cost penalty, specific CO2 emissions, capital costs, specific capital investment per kW, operation and maintenance (O&M) costs, cost of electricity, CO2 removal and avoidance costs, cash flow analysis.
