Environmental life cycle assessment of methanol and electricity co-production system based on coal gasification technology

• Published in: The Science of the total environment 2017-01, Vol.574, p.1571-1579
• Main Authors: liwiska, Anna, Burchart-Korol, Dorota, Smoliski, Adam
• Format: Article
• Language: English
• Subjects: Allocation; Coal gasification; Life cycle assessment; Methanol; System expansion
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2016.08.188

This paper presents a life cycle assessment (LCA) of greenhouse gas emissions generated through methanol and electricity co-production system based on coal gasification technology. The analysis focuses on polygeneration technologies from which two products are produced, and thus, issues related to an allocation procedure for LCA are addressed in this paper. In the LCA, two methods were used: a ‘system expansion’ method based on two approaches, the ‘avoided burdens approach’ and ‘direct system enlargement’ methods and an ‘allocation’ method involving proportional partitioning based on physical relationships in a technological process. Cause-effect relationships in the analysed production process were identified, allowing for the identification of allocation factors. The ‘system expansion’ method involved expanding the analysis to include five additional variants of electricity production technologies in Poland (alternative technologies). This method revealed environmental consequences of implementation for the analysed technologies. It was found that the LCA of polygeneration technologies based on the ‘system expansion’ method generated a more complete source of information on environmental consequences than the ‘allocation’ method. The analysis shows that alternative technologies chosen for generating LCA results are crucial. Life cycle assessment was performed for the analysed, reference and variant alternative technologies. Comparative analysis was performed between the analysed technologies of methanol and electricity co-production from coal gasification as well as a reference technology of methanol production from the natural gas reforming process. [Display omitted] This paper presents the following:•life cycle greenhouse gas emissions of methanol and electricity co-production based on coal gasification technology•a life cycle assessment of the polygeneration technology based on system expansion and allocation methods•an application of direct system enlargement and avoided burdens approaches to the environmental evaluation of the system•a comparative life cycle assessment of methanol production from coal gasification and natural gas reforming technologies