An LCA study of an electricity coal supply chain

Abstract

Purpose: The aim of this paper is to provide methods to find the emission source and estimate the amount of waste gas emissions in the electricity coal supply chain, establish the model of the environmental impact (burden) in the electricity coal supply chain, detect the critical factor which causes significant environmental impact, and then identify the key control direction and reduce amount of environmental pollution in the electricity coal supply chain.

Design/methodology/approach: In this context, life cycle inventory and life cycle assessment of China’s electricity coal were established in three difference stages: coal mining, coal transportation, and coal burning. Then the outcomes were analyzed with the aim to reduce waste gases emissions’ environmental impact in the electricity coal supply chain from the perspective of sensitivity analysis.

Findings: The results and conclusion are as follow: (1) In terms of total waste gas emissions in electricity coal supply chain, CO₂ is emitted in the greatest quantity, accounting for 98-99 wt% of the total waste gas emissions. The vast majority of the CO₂, greater than 93%, is emitted from the power plant when the coal is combusted. (2) Other than CO₂, the main waste gas is CH₄, SO₂ and so on. CH₄ is mainly emitted from Coal Bed Methane (CBM), so the option is to consider capturing some of the CH4 from underground mines for an alternative use. SO₂ is mainly emitted from power plant when the coal is combusted. (3) The environmental burden of coal burning subsystem is greatest, followed by the coal mining subsystem, and finally the coal transportation subsystem. Improving the coal-burning efficiency of coal-fired power plant in electricity coal supply chain is the most effective way to reduce the environmental impact of waste gas emissions. (4) Of the three subsystems examined (coal mining, coal transportation, and coal burning), transportation requires the fewest resources and has the lowest waste gas emissions. However, the energy consumption for this subsystem is significant (excluding the mine mouth case), and transportation distance is found to have a substantial effect on the oil consumption and non-coal energy consumption. (5) In electricity coal supply chain, the biggest environmental impact of waste gas emissions is GWP, followed by EP, AP, POCP and ODP, and regional impact is greater than the global impact.

Practical implications: The model and methodology established in this paper could be used for environmental impact assessment of waste gas emissions in electricity coal supply chain and sensitivity analysis in China, and it could supply reference and example for similar researches. The data information on life cycle inventory, impact assessment and sensitivity analysis could supply theory and data reference for waste gas emissions control in electricity coal supply chain.

Originality/value: To the best of our knowledge, this is the first time to study the environmental influence of electricity coal supply chain by employing a LCA approach from life cycle of electricity coal.