Toward lower cost cellulosic biofuel production using ammonia based pretreatment technologies

Abstract

In response to growing concerns about energy security, environmental sustainability and societal sustainability, cellulosic biomass refining technologies have been extensively developed in recent years. However, these technologies are not yet fully commercialized. High capital cost and high enzyme cost are two major bottlenecks. Capital cost and operating cost (excluding 33% feedstock cost) account for 34% and 33%, respectively, of the total biofuel production cost with enzyme cost alone representing about 47% of the operating cost. Therefore, reducing both capital cost and enzyme cost is imperative. Over the past eight years, with the support from US Department of Energy Great Lakes Bioenergy Research Center (GLBRC), we greatly improved our AFEX™ (Trade mark of MBI, International (Lansing, Michigan)) (Ammonia Fiber Expansion)-related processing technologies, leading to a 66% reduction in enzyme loading (current enzyme loading is as low as 7.5 mg protein per g glucan) and a 129% enhancement in ethanol volumetric productivity (>56% reduction in capital cost for enzymatic hydrolysis and fermentation).