Technical, Economic and Environmental Assessment of Energy Generation using Bioenergy with Carbon Capture, Utilisation and Storage.

Bioenergy with Carbon Capture and Storage is a promising negative emissions technology to mitigate climate change across different sectors. This thesis explores the application potential of this technology in energy generation by evaluating the technical, economic and environmental performance to present detailed information for the literature. This will help stakeholders including researchers, policymakers and the public make informed choices on the best route to decarbonisation. In power generation, the performance of different types of biomass, coupled with different CO2 abatement technologies, has been evaluated. The performance of each case has been thoroughly assessed against technical, economic and environmental parameters, then benchmarked against natural gas in power generation. An analysis to determine the effect on carbon pricing as an economic tool has been explored as well as a sensitivity analysis to identify the most significant factors influencing the production of electricity. In fuel generation, the production of Fischer-Tropsch fuels, synthetic natural gas and oxymethylene ethers via biomass gasification without carbon capture and storage and with carbon capture and storage has been assessed. After modelling and simulation in Aspen Plus to determine the mass and energy balances, an economic model has been developed in Microsoft Excel to estimate the capital costs, operating costs, levelised costs of energy and minimum selling prices; and the greenhouse gas emission factors have been estimated to investigate the environmental effect. Then, fuel generation via electrochemical conversion and CO2 utilisation has been considered. The electrofuel production routes have focused on storing renewable energy in fuels. The gasification step has been replaced with an electrolyser to produce H2 in addition to the CO2 captured from different sources to produce the same fuels. The environmental assessment compared different CO2 sources on the mitigation potential of each electrofuel production route. In conclusion, energy generation via bioenergy with CCS cannot currently compete with energy generation using fossil fuels mainly due to the higher levelised costs of energy but with the use of carbon pricing in the range of £48/tCO2 and £146/tCO2, such that these plants are rewarded for each tonne of CO2 removed and the fossil-fuel plants are penalised, fossil-fuel energy generation could be phased out faster to achieve decarbonisation. Also, these routes show promising mitigation potential with the ability to remove up to 1.52 Mt of CO2 per year from the atmosphere. With electrofuel production, there is more work to be done to attain feasibility and this is mainly due to the cost of electricity which is the major expense in the economics; also, CO2 storage needs to be coupled with CO2 utilisation to increase the chances of achieving negative emissions.