Life cycle GHG emissions and water consumption for a hypothetical 400 MW coal-fired power plant in Western Australia: Impacts of carbon capture and a comparison of two prevailing carbon capture technologies

Habib, Ramy (2017) Life cycle GHG emissions and water consumption for a hypothetical 400 MW coal-fired power plant in Western Australia: Impacts of carbon capture and a comparison of two prevailing carbon capture technologies. Masters by Coursework thesis, Murdoch University.

Abstract

Carbon capture technology is expected to play a significant role in Australia to meet its long-term commitment for reducing greenhouse gas (GHG) emissions, so it is important to evaluate its impact by conducting an environmental life cycle assessment to evaluate the total GHG emissions and total lifecycle water consumption.

In this study, a hypothetical 400MW sub-critical coal-fired power plant in Western Australia without carbon capture is considered as the base case. The total life cycle GHG emissions and life cycle water consumption are compared with two prevailing carbon capture technologies (e.g. oxy-fuel combustion and post-combustion carbon capture).

The results show that both carbon capture technologies will reduce the total GHG emissions but will result in an increase of the total life cycle water consumption during the power plant operation and coal mining as a result of the energy penalty imposed by the use of carbon capture technology and the additional water requirement of the carbon capture system (e.g. direct contact cooler in case of post-combustion carbon capture). The study, also, shows that oxy-fuel combustion with carbon capture is more efficient in carbon abatement with less water requirement compared to post-combustion carbon capture.

A sensitivity analysis is conducted to investigate the effect of using different combustion technologies for the base case and the effect of reducing the percentage of carbon captured on the total GHG emissions and water consumption for all scenarios.

This trade-off between GHG abatement and water consumption as a result of using carbon capture technology will require the use of an environmental indicator that assess the water requirement for different low-carbon technologies against the base case. The Water-Carbon Abated Ratio indicator (WCAR) is proposed as a single indicator that measures the amount of water consumed or saved for each kilogram of carbon abated.

The study shows that oxy-fuel combustion is more efficient in reducing GHG emissions with lower impact on water consumption compared to post-combustion carbon capture (e.g. oxy-fuel combustion has higher WCAR values compared to post-combustion carbon capture).

Item Type:	Thesis (Masters by Coursework)
Murdoch Affiliation(s):	School of Engineering and Information Technology
Supervisor(s):	Gao, Xiangpeng
URI:	http://researchrepository.murdoch.edu.au/id/eprint/40483

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