The impact of CO 2 capture in the power and heat sector on the emission of SO 2, NO x, particulate matter, volatile organic compounds and NH 3 in the European Union

Abstract

This study quantifies the trade-offs and synergies between climate and air quality policy objectives for the European power and heat (P&H) sector. An overview is presented of the expected performance data of CO 2 capture systems implemented at P&H plants, and the expected emission of key air pollutants, being: SO 2, NO X, NH 3, volatile organic compounds (VOCs) and particulate matter (PM). The CO 2 capture systems investigated include: post-combustion, oxyfuel combustion and pre-combustion capture. For all capture systems it was found that SO 2, NO x and PM emissions are expected to be reduced or remain equal per unit of primary energy input compared to power plants without CO 2 capture. Increase in primary energy input as a result of the energy penalty for CO 2 capture may for some technologies and substances result in a net increase of emissions per kWh output. The emission of ammonia may increase by a factor of up to 45 per unit of primary energy input for post-combustion technologies. No data are available about the emission of VOCs from CO 2 capture technologies. A simple model was developed and applied to analyse the impact of CO 2 capture in the European P&H sector on the emission level of key air pollutants in 2030. Four scenarios were developed: one without CO 2 capture and three with one dominantly implemented CO 2 capture system, varying between: post-combustion, oxyfuel combustion and pre-combustion. The results showed a reduction in GHG emissions for the scenarios with CO 2 capture compared to the baseline scenario between 12% and 20% in the EU 27 region in 2030. NO x emissions were 15% higher in the P&H sector in a scenario with predominantly post-combustion and lower when oxyfuel combustion (−16%) or pre-combustion (−20%) were implemented on a large scale. Large scale implementation of the post-combustion technology in 2030 may also result in significantly higher, i.e. increase by a factor of 28, NH 3 emissions compared to scenarios with other CO 2 capture options or without capture. SO 2 emissions were very low for all scenarios that include large scale implementation of CO 2 capture in 2030, i.e. a reduction varying between 27% and 41%. Particulate Matter emissions were found to be lower in the scenarios with CO 2 capture. The scenario with implementation of the oxyfuel technology showed the lowest PM emissions followed by the scenario with a significant share allocated to pre-combustion, respectively −59% and −31%. The scenario with post-combustion capture resulted in PM emissions varying between 35% reduction and 26% increase.