Greenhouse gas reduction potential by producing electricity from biogas engine waste heat using organic Rankine cycle. (20th July 2016)

• Record Type: Journal Article
• Authors: Uusitalo, A.; Uusitalo, V.; Grönman, A.; Luoranen, M.; Jaatinen-Värri, A.
• Is Part Of: Journal of cleaner production. Volume 127(2016:Jul.)
• Page Start: 399
• Page End: 405
• Publication Date: 2016-07-20
• Subjects: Organic Rankine cycle -- Waste heat recovery -- Life cycle assessment -- Greenhouse gas emissions; CO2 carbon dioxide -- CH4 methane -- CHP combined heat and power -- GHG greenhouse gas -- ISO International Organization for Standardization -- LCA life cycle assessment -- LUT Lappeenranta University of Technology -- NG natural gas -- N2O nitrous oxide -- ORC organic Rankine cycle; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2016.03.125
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Organic Rankine cycles have been identified as a suitable technological option for converting low-grade heat into electricity with relatively high efficiency, and the organic Rankine cycle technology has been successfully implemented in different power production systems and in recovering heat in industrial processes. This paper studies the greenhouse gas emission reduction potential by using organic Rankine cycles for recovering exhaust gas heat of biogas engines. The study concentrates especially on the biogas engine power plants in Europe. Life cycle assessment methods are used and various waste heat utilization scenarios are compared. According to the results, greenhouse gas emissions can be reduced significantly if the thermal energy of the exhaust gases, otherwise lost in the process as waste heat, is utilized for additional electricity production by means of organic Rankine cycle. However, there may already be use for the exhaust gas heat in biogas plants in the form of heat power. In these cases, the use of organic Rankine cycle does not necessarily lead to greenhouse gas emission reductions. The results also indicate, that the working fluid leakages and production as well as the organic Rankine cycle construction materials and production have only marginal effects on the results from greenhouse gas perspective. Highlights: Waste heat recovery of biogas engines was studied by means of ORC. LCA was utilized to calculate GHG emission reduction potential in different cases. Using waste heat in electricity production leads to GHG emission reductions. If heat is already utilized there is a risk that GHG emissions increase with ORC use.