Comparative evaluation of the carbon footprint from margarine and butter production in southern Brazil

ABSTRACT Life Cycle Assessment is a technique for estimating environmental impacts, such as the emission of greenhouse gases (CO2eq), for manufacturing product or process realization. The objective of this study was to establish the carbon footprint for the production of margarine and butter using ISO and PAS standards applied to a food company, located in the southern region of Brazil, from the field stage to its packed form with a functional unit of 500 g for distribution. Three scenarios were addressed for margarine (soybean oil from the South and the Midwest with and without burned deforestation) and two for butter (with mass and economic allocation). The modeling was performed with primary data from the agricultural and industrial production, and secondary data from ecoinvent ® . The economically allocated butter footprint (2.91 kg CO2eq) was higher than that of margarine produced with soybeans from the same region (1.32 kg CO2eq). However, this autonomous co-product of the dairy industry requires mass allocation to avoid overvaluation, being in fact the smallest footprint (0.63 kg CO2eq). The use of soybeans from the Midwest increased margarine’ footprint (1.58 kg CO2eq) and was greatly intensified with burned deforestation (2.69 kg CO2eq). Milk production was the predominant deleterious factor for butter. For margarine there were two other distinct occasions, which were the manufacture when soy from the same region is used or the production with soybeans from a distant region deforested by burning.摘要：生命周期评价（Life Cycle Assessment）是一种用于估算产品制造或工艺实现过程中环境影响的技术，例如温室气体（CO2eq）排放。本研究旨在针对巴西南部地区某食品企业，采用ISO标准与PAS规范，从田间阶段直至成品包装阶段，以500克为配送功能单位，确定人造奶油与黄油生产的碳足迹。研究针对人造奶油设置了三种场景：分别使用来自巴西南部与中西部的大豆油（涵盖有无因森林焚烧导致的毁林两种情况）；针对黄油则设置两种场景，即采用质量分配法与经济分配法。建模工作采用农业与工业生产的一手实测数据，以及ecoinvent®数据库的二手数据。采用经济分配法的黄油碳足迹（2.91 kg CO2eq）高于使用本地产大豆生产的人造奶油碳足迹（1.32 kg CO2eq）。不过，作为乳制品工业的联产副产物，黄油需采用质量分配法以避免估值过高，此时其实际碳足迹最低（0.63 kg CO2eq）。使用中西部大豆会使人造奶油的碳足迹升至1.58 kg CO2eq，若该大豆来自因焚烧导致毁林的产区，则碳足迹会进一步大幅增至2.69 kg CO2eq。对于黄油而言，牛奶生产是其主要的环境有害影响来源。就人造奶油而言，另外两种显著的影响场景分别为：使用本地产大豆的生产环节，以及使用来自远方焚烧毁林产区大豆的生产环节。