Assessment of potential alternatives for improving environmental trouser jeans manufacturing performance in Brazil

摘要

Brazil features prominently in the world's textile industry due to its know-how in cotton cultivation. However, the denim production chain generates relevant environmental impacts due to some characteristics of its production chain. This study investigated the usefulness of actions for improving environmental - measured in terms of Climate Changes (CC) -, and energy performances, represented by Primary Energy Demand (PED), to be implemented in the supply chain of trouser jeans produced in Brazil. A diagnosis of the current process provided by Life Cycle Assessment (LCA) indicated CO2 (liming and mechanization) and N2O (N-fertilizer) emissions in cotton cultivation, and CH4 and CO2 (natural gas) releases from heat for the industrial branch as CC impact sources. Reliance on natural gas (heat supply) industrial processes and the BR grid (energy supply) provided PED contributions. With a view of improving this performance, scenarios based on cotton and yarn imports, and even trouser jeans themselves from the United States, as well as the replacement of natural gas for wood have been proposed. The LCA for such conditions did not offers a unanimous alternative. The lesser impact for CC (4.44 kg CO2eq /FU) refers to the manufacture of trouser jeans in Brazil using wood as a heat source. An Integrated Analysis combined the effects of both analyzed dimensions for all the different scenarios and the same alternative achieved the best combined indicator Moreover, if the CC estimate takes into account CO2 fixation from the air and biogenic CO2 emissions, the use of wood becomes advisable. The current scenario kept the best energy outcomes (124 MJ/FU) given a performance in terms of utilities and transport. Moreover, Sensitivity and Trend Analyzes sought to magnify the effects of the parameter oscillations that integrate the analyzed systems models. Overlap areas among scenarios were identified, confirming that measures to reduce consumptions along the trouser productive cycle are necessary to achieve satisfactory results in terms of environmental and energy performance. (C) 2019 Elsevier Ltd. All rights reserved.