Ranking of Refrigerants by Different Assessment Methods

Transcription

1 Ranking of Refrigerants by Different Assessment Methods University of Bayreuth Monika Weckert EnviroInfo 00, Luneburg, 0- September 00 Environmental Chemistry and Ecotoxicology Introduction All chemicals and products have impact on the environment e.g. energy consumption, toxicity Life Cycle Assessment (LCA) has the goal to investigate and evaluate the environmental impact Several approaches and methods developed Refrigeration is an important aspect of our life style Aim: Exemplary process: air-conditioning system in cars, refrigerants Comparison of different LCA methods with the additional aim to find the most environmental suitable replacement for the presently used substance Refrigerants applied to air-conditioning systems in this study Hydrocarbons Hydrochlorocarbon Hydrofluorocarbons Di(fluoro)alkylethers Alkyl-fluoroalkylethers Refrigerant Chemical formula Chemical name GWP 00 R0 CH Cl Methylene chloride 0 a Ra C H F,,,-Tetrafluoroethane 0 b Ra C H F,-Difluoroethane b R0 C H Propane 0 c R00a C H 0 Isobutane 0 c CF OCHF Pentafluorodimethyl ether 00 d E CHF OCHF,,','-Tetrafluorodimethyl ether 0 d CF (CF ) OCH Heptafluoropropyl methyl ether 0 d E00 CF (CF ) OCH Methyl nonafluorobutyl ether 0 d E00 CF (CF ) OC H Ethyl nonafluorobutyl ether 0 d R CO Carbon dioxide c a IPCC 00, b IPCC 00, c Devotta et al. 00, d Tsai 00 Life Cycle Inventory Input Resources Materials Energy Production of refrigerant Production Assembly of refrigerant, AC system, and car Production of AC system Operation / Servicing Recycling / Disposal Output Emission Waste

2 Assessment Methods. Non-aggregated Method (). Non-aggregated impact assessment: Separate categories. Aggregated method: Eco-Indicator One indicator. Fast method: Total Equivalent One index 0 impact categories - Primary energy demand - Depletion of abiotic resources - Global warming - Ozone depletion - Acidification - Eutrophication - Human toxicology - Photo-oxidant formation (summer smog) - Fresh water aquatic toxicity - Terrestrial ecotoxicity Important: includes complete life cycle!. Eco-Indicator Damage categories (Human Health, Ecosystem Quality, Resources) Normalization EI Weighting. Total Equivalent Direct emissions of refrigerant + Indirect emissions of CO and other greenhouse gases during energy production TEWI Important: EI includes complete life cycle! Important: TEWI focuses on operation phase!

3 Ranking from the Assessment Method Refrigerant ADP ADP ODP PE GWP ODP AP... E E E00. Ra. Ra R0... R R00a... R.. ADP Depletion of of abiotic abiotic resources resources (excluding (excluding primary primary energy); energy); ODP Stratospheric ozone depletion; ODP PE Demand Stratospheric of non-renewable ozone depletion primary energy; GWP Climate change; AP Acidification; EP Eutrophication; POCP Photo-oxidant formation; HT Human toxicity; FAETP Fresh water aquatic toxicity; TETP Terrestrial ecotoxicity; AV average ranking of the CML0 method; EP 0 POCP 0 HT 0 FAETP 0 TETP 0 AV Ranking from the different Assessment Methods Refrigerant AV EI TEWI 0 E. 0. E00. E00. Ra. Ra. R0. R0. R00a. R. AV average ranking of the CML0 method; EI Eco-Indicator ; TEWI Total equivalent warming impact HD{AV, EI, TEWI} HD{EI, TEWI} Ra E00 E R0 R R00a Ra E00 E R0 R R00a E00 Ra R0 AV: Average rank from EI: Eco-Indicator E00 Ra R0 EI: Eco-Indicator

4 HD{AV, TEWI} HD{AV, EI} E E Ra E00 Ra R0 R R00a E00 Ra E00 R R0 Ra E00 R0 AV: Average rank from AV: Average rank from EI: Eco-Indicator R00a R0 Conclusions - Different assessment methods can result in different rankings. Different substances would be chosen as possible replacements. - TEWI does not account for complete life cycle. (Might be suitable for certain applications with low contributions from production and disposal phase.) - and EI account for complete life cycle, but give different results for some refrigerants. Better to apply both methods and compare the results. Conclusions cont. -E (CHF OCHF ) and (CF OCHF ) do not seem to be suitable replacements for Ra (C H F ). - Considering all three assessment methods: 000-series (CF (CF ) OCH, CF (CF ) OCH, CF (CF ) OC H ), Ra (C H F ), R00a (C H 0 ), and R0 (C H ) have smaller environmental impact than Ra. - Considering only two assessment methods: Helps to reduce incomparabilities. - Considering only and EI: R (CO ), R00a (C H 0 ), and R0 (C H ) have smaller environmental impact than Ra and might be the most suitable replacements.

5 Acknowledgements Bavarian State Ministry of the Environment, Public Health and Consumer Protection Prof. Frank and the members of the Department of Environmental Chemistry and Ecotoxicology, University of Bayreuth and YOU