Comparative Life Cycle Assessment (LCA) of two tofu industries that uses different energy sources for production processes

Abstract

Tofu industry is engaged in processing food made from soybeans, which has a significant contribution to emissions. Padang City has 12 tofu industries, including the ‘A’ tofu industry and ‘B’ tofu industry. The ‘A’ tofu industry and ‘B’ tofu industry produce 990 kg and 2,400 kg of tofu/day, respectively. The difference between them is the application of briquettes and diesel fuel in ‘A’ tofu industry, while ‘B’ tofu industry uses firewood and electricity for boiling and milling processes. Therefore, this study purpose to analyze the environmental impact of 1 kg of tofu using the Life Cycle Assessment method with SimaPro ver.9.0. A gate-to-gate approach was used. The result of the characterization impact on the environment is ‘B’ tofu industry had the highest impact than ‘A’ tofu industry, marine aquatic ecotoxicity 645.69 and 419.91 kg1.4-DBeq, human toxicity 39.81 and 0.33 kg1.4-DBeq, global warming potential 36.96 and 16.68 kgCO2eq, abiotic depletion 15.02 and 13.27 MJ, fresh water aquatic ecotoxicity 2 kg1.4-DBeq and acidification 0.01 and 0.0075 kgSO2eq. A component that contributes to harmed the environment is the boiling process. From the result, several alternatives can be recommended, replacing fuel for the boiling process with briquettes and treating liquid waste with an aerobic-anaerobic-biofilter.