Techno-economic evaluation of biomass fired or co-fired power plants with post combustion CO2 capture

Abstract

The use of biomass in power generation is a key option to reduce greenhouse gas emissions. Specifically, the co-firing of biomass with coal could be regarded as a common feature of any new build power plant if a sustainable supply of biomass fuel is readily accessible. Currently, there is an on-going discussion on what could be the pros and cons of incorporating CO2 capture and storage (CCS) to any type of biomass-fired power plant. The discussion has primarily centred on how to consider the CO2 emitted from biomass-fired power plants, if it is counted as “ CO2 neutral” and if stored, whether it could be considered as a “negative” CO2 emission. One of the main questions addressed in this study was “What should be the CO2 emission cost that would make CCS an attractive option to be incorporated into a biomass fired power plant assuming that the stored CO2 from a biomass fired power plant could generate an additional revenue as CO2 credit”. The study, carried out by Foster Wheeler for the IEA Greenhouse Gas R&D Programme (IEA GHG), aimed to address these questions, and investigated and evaluated the different options and techno-economic performance of a biomassfired power plant or a coal power plant co-fired with biomass, based on current state-of the art boiler and steam generation equipment incorporating post-combustion CO2 capture based on MEA solvent. Specifically, the study evaluated the following cases comparing the performance and techno-economics of the power plants with and without CO2 capture. • Case 1: nominal 500 MWe (net) co-firing of biomass and coal in pulverised fuel (PF) power plant. • Case 2: nominal 500 MWe (net) co-firing of biomass and coal in CFB power plant. • Case 3: nominal 250 MWe (net) circulating fluidized bed standalone biomass power plant. • Case 4: nominal 75 MWe (net) bubbling fluidized bed standalone biomass power plant. To evaluate the potential impact of any incentives from the “Green Certificate” or the “ETS Mechanism”, four different scenarios for all cases were assumed, which are briefly described below. [1] Scenario 01–The calculation of the Levelised Cost of Electricity does not include any revenues from the Green Certificate nor from ETS mechanism. [2] Scenario 02–The calculation of the Levelised Cost of Electricity only allows the revenues from the Green Certificate. For the reference case, the Green Certificate is given a price of 50 € /MWh. [3] Scenario 03–The calculation of the Levelised Cost of Electricity only allows the revenues from the ETS mechanism. For the reference case, the Green Certificate is given a price of 14 € /t CO2. [4] Scenario 04–The calculation of the Levelised Cost of Electricity considers the revenues from both the Green Certificate and ETS mechanism. This study presents the following results: • Performance of the power plants. • Techno-economic assessment of the power plant assuming no incentives from the “Green Certificate” or the “ETS Mechanism”. • Sensitivity of the economics to the inclusion of the “Green Certificate” and “ETS Mechanism” incentives