Implementing sustainability in the industry is a challenge for the scientist as well as for the engineer. It is essential as it ensures the continuation of the fulfillment of human's basic needs. This paper focuses on the application of sustainability concept in the sugar industry in Indonesia. The utilization of waste and side product of sugar production was endeavored by the integration of the sugar milling process with chemical production. Sugarcane bagasse which has a low production value was employed for producing levulinic acid, furfural, and formic acid. While the side product, molasses, was used as the feedstock of bioethanol and lactic acid production. Lactic acid was produced by fermentation of molasses with Lactobacillus delbrueckii for 21 hours with the yield of 90%. On the other hand, levulinic acid was produced by hydrolysis in the two-stage reactor with the minimum yield of 70% and residence time between 25 to 30 minutes. The engineering economic assessment was applied for assessing the feasibility of the integration process. Based on the calculation, the rate of return value is higher than the loan interest. This result implied that the investment in the integration of sugar production and bio-refinery is very promising.
Keywords: sustainability, sugar industry, biorefineries, Levulinic acid, Lactic acid.