Techno-Economic Analysis of a Process for the Aqueous Conversion of Corn Stover into Lactic and Levulinic Acid through Sn-Beta Catalysis

Abstract

A readily available source for renewable fuels and chemicals is corn stover, which consists of the leftover stalks, leaves, husks, and cobs from the corn plant and makes up nearly half of the yield of a corn crop. Common practice is to pretreat it with sulfuric acid to break down the hemicellulose, releasing xylose, followed by enzymatic hydrolysis to convert the cellulose into glucose. Using a Sn-Beta catalyst, it is possible to convert these monomeric sugars into lactic, levulinic, formic, and acetic acids. This paper presents the results of a techno-economic analysis (TEA) of the commercial feasibility of producing these acids from corn stover. Two preliminary process designs were evaluated which represent two separate reaction yields: a balanced yield of both lactic and levulinic acids and the yields from a co-catalysis with CaSO4 to produce primarily lactic acid. Both process designs are scaled to process 230,000 MT/y of corn stover. An AACS Class 4 factored broad capital cost estimate and comparable estimates of operating costs and revenues were used to generate cash flow sheets to evaluate the economic feasibility of both options. The balanced product process has an estimated NPV@20% = 3.3 million USD ± 40%, while the CaSO4-facilited process has an NPV@20% = 110 million USD ± 40% (January 2019 basis). A major hurdle for both processes is the demand for levulinic acid. The balanced product process will produce 135% of the expected global demand and the CaSO4-facilitated alternative will meet 31% of the demand. For the demand to meet production, advances in levulinic acid applications are needed. However, the attractive economics suggest that these technologies warrant further development towards commercialization.

Levulinic acid production from furfural: process development and techno-economics

“…With the above assumptions and results from our experiments, the preliminary TEA suggests that LA can be produced at an MSP of $1.35 and 1.45 per kg from furfural and xylose, respectively, which is lower than the market price of LA. 52,53 Fig. 12 and S3† show the various parameters that accounted for the MSP of LA produced from furfural and xylose, respectively.…”

Heteroatom Lewis acid zeolites: synthesis, characterization and application in the conversion of biomass-derived oxygenates

“…The economic analysis involves fixed capital investment (costs for con-structing a new plant), operating costs (costs for manufacturing and non-manufacturing) and working capital (costs for establishing and operating a plant). 232,233 In addition, the return on investment (ROI), internal rate of return (IRR), net present value (NPV) and payback-period are used as indicators to evaluate the economic risk and set requirements of products. 233 No research on techno-economic assessment for the synthesis of Lewis acid zeolites via various routes is available till date.…”

“…For example, Kohler et al evaluated the economics of the conversion of corn stover-derived sugars into lactic acid or lactic acid and levulinic acid using Sn-Beta. 232 The authors examined two different processes, i.e., conversion of sugars into carboxylic acids via Sn-Beta without and with addition of calcium sulfate (CaSO 4 ). The former process led to the production of both lactic and levulinic acids, while the addition of CaSO 4 significantly increased the selectivity of lactic acid.…”

“…For example, Kohler et al evaluated the economics of the conversion of corn stover-derived sugars into lactic acid or lactic acid and levulinic acid using Sn-Beta. 232 The authors examined two different processes, i.e. , conversion of sugars into carboxylic acids via Sn-Beta without and with addition of calcium sulfate (CaSO 4 ).…”