Biological conversion of organic municipal solid waste to lactic acid : a techno-economic performance assessment study for commercialization

Abstract

This thesis assesses the economic viability and commercial potential of a lab-scale microbial technology to produce lactic acid (LA), which was developed as a novel technology option for organic waste treatment. Among various available technologies for the separation and purification of LA, the method of esterification-hydrolysis with reactive distillation was selected for this assessment. The process from organic waste to high-purity LA was designed and modeled using Aspen Plus, from which material and energy balances, equipment costs, and utility costs were derived. An economic performance assessment model was developed to estimate capital and operating expenses as well as net present value (NPV), for evaluating the economic feasibility under various scenarios. Monte Carlo techniques were incorporated into the model to take into account the effect of identified uncertainties on the economic performance, which generates distribution profiles rather than single-value estimates. The baseline NPV for polymer-grade LA (99%) production was estimated to be USD 1.95 million in the U.S. and USD 1.31 million in India. Even though the estimated capital and operating expenses are much lower in India, the process was found to be less profitable than in the U.S. The main reason for this is because landfill tipping fees cannot be relied on as a stable revenue source in India. Moreover, two other applications, which this technology could be potentially commercialized for, were also evaluated using the developed models, and the economic performance of each application was compared. Finally, this thesis proposes a Technology Commercialization Assessment Matrix (TCAM), based on the results and insights gained from the assessment conducted.