Supply Chain of Bioethanol Production from Whey: A Review

Whey, a major byproduct of the cheese and dairy industry, has valuable nutritional constituents but poses a major environmental risk, if disposed off without prior treatment. Whey has a high organic content, its major constituent being lactose (4.5-5% w/v). With a very high BOD and COD load (30,000 – 50,000 ppm and 60.000 – 80,000 ppm respectively) and annual production of over 160 million tonnes, with an estimated growth rate of 1–2% yearly, fermentation of whey to bioethanol has proved to be a lucrative option, both for bioremediation of whey and production of ethanol from waste sources; reducing the costs incurred in otherwise advanced effluent treatment processes required for its disposal. Moreover, with increasing global demand for bioethanol as an alternative to scarce fossil fuels and advocacy by governmental institutions, due to its non-polluting nature aiding in reduced environmental pollution and global warming; conversion of whey to ethanol is progressively more desirable. The aim of this review is to discuss the supply chain involved in the production of ethanol from whey. The study will involve literature survey, experimentation and developing a model.This study looks at the supply chain involved in the production and subsequent distribution of whey, for the purpose of valorization and extraction of valuable constituents, as well as its utilization in production of bioethanol. Based on existing studies, it has been seen that an initial lactose concentration of 200 gL-1 in the whey permeate, provides the maximum yield for ethanol. Under such conditions, maximum ethanol obtained from fermentation of whey was found to be 80.95 kg m-3, proving the economic viability of the process. However, the supply chain of whey for bioethanol production is not well defined, making effectiveness and implementation of ethanol production from whey constricted. Thus, although the environmental risk posed by the vast production of whey, is mitigated by its conversion to ethanol, providing adequate bioremediation of its polluting components, this process is yet to be industrialized widely.