Economic comparison of calcium fumarate and sodium fumarate production byRhizopus arrhizus

The economics of using Na₂CO₃ rather than CaCO₃ as the neutralizing agent in fumaric acid production byRhizopus arrhizus is investigated and compared with the benzene route. Because sodium fumarate, unlike calcium fumarate, is soluble, downstream processing is simplified by requiring less equipment and no heat, and also allows the reuse of cells. In spite of a fumaric acid productivity (g/L/h) 2.4 x lower than the CaCO₃ case, the Na₂CO₃ alternative with cell reuse has a higher rate of return. However, with the current cost of petroleum, the selling price of fumaric acid from the benzene route is half as much as from an idealized Na₂CO₃ fermentation.