System considerations in converting sugar mill waste to Bio-CNG

Abstract

Sugar mills produce a range of by-products during the sugar extraction process. Bagasse, press-mud (also known as filter cake or mill mud), molasses and alcohol by-products are commonly used for various purposes. Specifically, press-mud, one of the by-products is produced in significant volume. Some of this press-mud is utilized by farmers as fertilizer. However, the supply of press-mud often exceeds the demand leading to stockpiling onsite or spreading it over nearby cane fields as a disposal method. Subsequently, the heavy metal contamination and over-fertilization of cane fields and spillage to nearby waterways due to excess press-mud has raised serious environmental concerns. This study takes a look at a possible method to mitigate air, water and health pollution from sugar manufacturing in India by converting the excess press-mud generated into Biofuel. This operation not only mitigates pollution, but also opens up an income stream for small to large scale sugar mill enterprises in a nascent but promising market in India. Systems thinking methods that we use in this study to examine the Biofuel solution to excess press-mud generation show several benefits to local community, local sugar mill facility owners as well as external constituents. These benefits include higher quality of living through a cleaner environment, enhanced employment opportunities and local access to fuel, which in turn lowers dependence on costly energy imports.