Comparative life cycle assessment of car disc brake systems—case study results and method discussion about comparative LCAs

Comparative life cycle assessment of car disc brake systems—case study results and method discussion about comparative LCAs
In this incision, the results and interpretation of both LCA models are presented and compared. First, the gasoline pulmonary tuberculosis connected to the disk brake is calculated through FRV calculations. The lower gasoline sum is used in the present LCA results and extra results based on the higher gasoline amount are found in supplementary materials. FRV calculations and the results of the fully LCA study are presented. then, followed by the results of the relative LCA with omitted parts are shown. The results of both models are compared and analysed. last, sensitivity analyses are presented .

FRV calculation

The gasoline consumption of the cable car for both brake systems was determined based on the FRV calculation, with a low component of 0.2 and a high gear factor of 0.5 per 100 kilogram and 100 kilometer ( Ridge 1998 ). The gasoline consumption per component was calculated with 240,000 km of use ; please see calculations in the ESM. There was an insignificant difference between the two disk brakes since the bulk difference was alone 100 g. If the lower factor ( 0.2 ) was used, the gasoline consumption was 33.88 and 34.36 fifty for each part, where the higher amount is due to the slightly higher aggregate of the new disk brake. If the higher divisor ( 0.5 ) was used, the life gasoline consumption was 84.70 and 85.90 l respectively. The trace results are calculated with factor 0.2, i.e. the lower gasoline pulmonary tuberculosis. For the results calculated with the higher factor 0.5, i.e. the higher gasoline consumption, please see the ESM.

Results of the full LCA

The differences in impacts of the two disk brakes were distributed over 17 impact categories ( see Table 3 ). The contribution analysis showed that there were some significant differences, e.g. there was a importantly higher impingement by the fresh disc brake in the impact categories of ‘ ionizing radiation sickness ’ and ‘ mineral resource scarcity ’. Eight of the 17 impact categories displayed a decrease of shock and for one category ‘ human carcinogenic perniciousness ’ the impingement decrease was significant .Table 3 The impacts caused by the disc brakes presented in seventeen impact categories Full size table summons contributions in the ‘ ionizing radiation ’ class for the raw disc brake were linked to the coat of the phonograph record. The primary impacts were connected to the thermal spraying of the modern disk, i.e. hungarian electricity mix and liquid oxygen. The hungarian electricity mix was the department of energy used for the thermal spray, and impacts from the liquid oxygen were connected to the energy ( average european electricity mix ) required to produce the oxygen. half of the Hungarian electricity mix is imported dodo fuel, and the other half is domestic grow energy chiefly through nuclear ability and fossil fuel ( IEA 2016 ). In general, the impacts caused by both discs originated from the casting iron and fabrication of the disk. These specific disk impacts were higher for the reference disk bracken due to the motivation for 1.5 disk more compared to the new disk brake. however, due to the favorable effects of cast iron recycling the affect connected to the new application were higher than the impact connected to the disk. In the ‘ mineral resource scarcity ’ affect class, the tungsten carbide used in the new magnetic disk coat gave a noteworthy impact by about 50 % ( 2.83 kilogram Cu equivalent. ) of the total life cycle impact. similarly, the impact of the extra reference disk excess separate did have a noteworthy shock ascribable to manufacture and use of cast iron but was decreased due to cast iron recycling. additionally, it was observed that the embroider fabricate and materials had a meaning contribution to this category. The four categories ‘ very well PM formation ’, ‘ tellurian ecotoxicity ’, ‘ marine ecotoxicity ’ and ‘ human non-carcinogenic toxicity ’ were chiefly alone linked to the brake wear emissions. The impact caused by the new disk brake is slenderly lower due to the reduce measure of PM formation. The ‘ human carcinogenic toxicity ’ was linked to the materials and fabrication of the roll iron disk. Hence, due to the more substantial sum of mention magnetic disk, the shock was higher. The recycle of cast iron lowered the high impact, but the fabricate of the disk had a significant impact. It became clear that the raw magnetic disk brake had limited advantages. The new disc brake alternate used more resources during the fabrication of one phonograph record compared to the citation phonograph record brake. The shorter life distance of the reference phonograph record resulted in a higher demand on the number of fifth wheel part disk to fulfil the same functional unit of measurement, but this impact was reduced due to material recycle. The basal contribute impacts of reference book disc brake materials and processes were linked to the frame iron, the fabricate of the disk, fabricate of pads and materials in the pads clash mix, such as copper and brass. The contributing impacts of the new disc brake were connected primarily to the coat and second to the pad fabricate and materials .

Results of the comparative LCA with omitted parts

A cogitation of the two disk brakes was besides conducted using the comparative LCA with exclude parts. Therefore, all materials, processes and life cycle parts that were identical between the two disk brakes were eliminated and not assessed in this study. The results, presented in the same way as for the full LCA, are shown in board 4. There was a importantly higher environmental impingement by the new disc brake in the two shock categories of ‘ ionizing radiation ’ and ‘ mineral resource scarcity ’. Eight of the 17 affect categories displayed a decrease of shock and for one class ‘ human carcinogenic toxicity ’ the affect decrease was significant .Table 4 The results of the comparative LCA with omitted parts Full size table According to the comparative results, the impacts in the ‘ ionizing radiation ’ class for the fresh disc brake were linked to the coat process, i.e. the thermal spray of the new disk in this case due to a hungarian electricity mix and impacts due to the production of liquid oxygen. The primary coil material processes impacting the ‘ mineral resource scarcity ’ category were tungsten carbide and cobalt. The tungsten carbide gave a significant impact by 52 % ( 2.83 kilogram Cu eq. ). The significant contributors for the reference point option were connected to the pad materials and manufacture, but these impacts were significantly lower than the coating material impacts. The four categories ‘ fine PM constitution ’, ‘ terrestrial ecotoxicity ’, ‘ marine ecotoxicity ’ and ‘ human non-carcinogenic toxicity ’ were chiefly only linked to the brake break emissions. The impact caused by the new magnetic disk bracken is slenderly lower due to the reduce sum of PM formation. The ‘ homo carcinogenic toxicity ’ impingement class were linked to the materials and manufacture of the shed iron magnetic disk. Hence, due to the more hearty come of mention magnetic disk, the affect was higher than for the new alternative.

The relative appraisal shows that the new magnetic disk bracken had meaning impacts on many of the 17 impingement categories. The new magnetic disk bracken used, e.g. fossil department of energy for the disk application and energy demanding liquid oxygen output. The reference disk and plain separate magnetic disk did have a significant impact, with the cast iron contributing to over 54 % of the impact in the ‘ human carcinogenic perniciousness ’ category. The impact was however compensated with the recycling of the iron .

Comparing the results

When comparing the results of the two LCA models, differences were expected in the aggregate environmental impact for each magnetic disk brake. The deviation was due to the omitted parts in the compare LCA, i.e. the impacts of the disk brakes in the simplified LCA were lower. however, it was not the individual impacts that were of pastime but the comparison of differences in impact between the magnetic disk brakes, in this discipline. Comparing the results revealed that the same affect categories were identified as having increased affect due to the new magnetic disk brake. In summation, the shock categories with a noteworthy decrease in shock were besides the lapp. There was no remainder between the full LCA results and in the relative results, i.e. the ‘ difference ’ column in Tables 3 and 4. however, the percentile remainder was different ascribable to the sum being unlike. The lapp meaning impact categories and processes could be identified regardless of the LCA model .

Sensitivity analysis

The relatively high life assumption for the car carrying the disk brake was analysed—the liveliness distance of the car determine the total of spare parts used, i.e. shorter time—less spare parts and longer time—more spare parts. The previously much exploited assumption of 150,000 km based on educated guess represents an underestimate value and should be increased ( Weymar and Finkbeiner 2016 ). In this cogitation, the life was varied between 150,000 km ( Hawkins et aluminum. 2012 ), 240,000 kilometer ( the current case study ) and 330,000 kilometer ( fringy encase ). The numeral of bare parts was adjusted with the changed life ( see Table 5 ) .Table 5 Lifetime adjusted spare part number for the disc brake alternatives Full size table The minus number ( − 0.4 ) of new disk in the 150,000 kilometer life was due to the long life of the disk. To cover 150,000 kilometer of life only 0.6 discs were needed. The longer life had no environmental enhancement effect, concerning the new disk brake, on the eight impact categories ‘ global warming ’, ‘ ionizing radiation ’, ‘ ozone formation, human health ’, ‘ ozone formation, planetary ecosystem ’, ‘ sublunar acidification ’, ‘ fossil resource scarcity ’, ‘ fresh water eutrophication ’ and ‘ mineral resource scarcity ’. This means that the higher affect of the new disc brake did not diminish compared to the reference book disk brake. The relation was similar to the ‘ ionize radiation ’ impacts illustrated in Fig. 6 .Fig. 6figure6 The ‘ ionizing radiation ’ impact difference increased with a longer life Full size persona The impacts in the ‘ fine particulate matter formation ’, ‘ tellurian ecotoxicity ’, ‘ fresh water ecotoxicity ’, ‘ marine ecotoxicity ’, ‘ homo carcinogenic perniciousness ’ and ‘ human non-carcinogenic perniciousness ’ categories developed similarly. The impacts in the six categories, the proportional affect between the disc brake impacts, were not changed with a longer life. The sexual intercourse is illustrated by ‘ human carcinogenic toxicity ’ in Fig. 7. The address disk brake impacts, in these categories, were higher than for the newfangled alternative, regardless of outdistance .Fig. 7figure7 The ‘ human carcinogenic perniciousness ’ impact dispute was not changed by a longer life Full size image For the impact categories ‘ stratospheric ozone depletion ’, ‘ down manipulation ’, and ‘ water consumption ’, the impacts were lower for the newly disc brake for the short distances. But for distances over 330,000 km, the fresh disk brake impact surpassed the referee phonograph record brake impact. Hence, a longer life would not benefit the impact categories for the new disk bracken. The longer life seemed to have a ‘ fracture even ’ life over 240,000 km where the impact of the reference phonograph record brake gained a lower affect than the new phonograph record brake, similarly as illustrated for ‘ water consumption ’ category in Fig. 8.

Fig. 8figure8 The ‘ urine consumption ’ impact class difference increases, and the impact of the mention magnetic disk bracken gained a lower shock than the new phonograph record brake, for a life of over 240,000 km Full size image The sensitivity analysis of the life showed that longer use time, over 240,000 km, was not favorable for the newfangled magnetic disk bracken, in most shock categories. The reference disk brake had a better eco-profile than the new disc brake in most categories, regardless of if the consumption fourth dimension was shorter or longer .

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Category : Car Brakes