Techno-Economic Analysis of Integrating First and Second-Generation Ethanol Production Using Filamentous Fungi: An Industrial Case Study

Abstract

Abstract:The 2nd generation plants producing ethanol from lignocelluloses demand risky and high investment costs. This paper presents the energy-and economical evaluations for integrating lignocellulose in current 1st generation dry mill ethanol processes, using filamentous fungi. Dry mills use grains and have mills, liquefactions, saccharifications, fermentation, and distillation to produce ethanol, while their stillage passes centrifugation, and evaporation to recycle the water and dry the cake and evaporated syrup into animal feed. In this work, a bioreactor was considered to cultivate fungi on the stillage either before or after the centrifugation step together with pretreated lignocellulosic wheat bran. The results showed that the integrated 1st and 2nd generation ethanol process requires a capital investment of 77 million USD, which could yield NPV of 162 million USD after 20 years. Compared to the fungal cultivation on thin stillage modified 1st generation process, the integrated process resulted in 53 million USD higher NPV. The energy analysis showed that the thin stillage modified 1st generation process could reduce the overall energy consumption by 2.5% and increase the ethanol production by 4%. Such modifications in the 1st generation processes and integration concepts could be interesting for the ethanol industries, as integrating lignocelluloses to their existing setup requires less capital investment.

Review on the Use of Diesel–Biodiesel–Alcohol Blends in Compression Ignition Engines

“…Also, the discovery of new raw materials (filamentous fungi), and the improvement of the process of obtaining bio-ethanol by integrating first-and second-generation ethanol production processes is described in [71] which reports a reduction of energy consumption by 2.5%, and an increase of ethanol production by 4%. Connolly et al [30] have detailed different methods for producing transport fuels, including ethanol and methanol, in terms of the resources, the conversion processes used, and the transport demands met.…”

Nutrient recovery from ethanol co-products by a novel mycoalgae biofilm: attached cultures of symbiotic fungi and algae

“…Thin stillage is generated in large quantities and the evaporation process to condense TS to CDS is the second most energy-intensive step in corn ethanol production after ethanol distillation. 21 By adding the fungal cultivation to thin stillage, the overall energy consumption was reduced to 18.9 GW, which is equivalent to a 2.5% energy reduction at the ethanol plant at the base scenario considered. 22 It was demonstrated that the energy reduction was mainly due to the evaporation costs and the subsequent drying operations for the concentrated syrup.…”

“…22 It was demonstrated that the energy reduction was mainly due to the evaporation costs and the subsequent drying operations for the concentrated syrup. 21 Composition analysis of CDS shows that the majority is composed of yeast biomass as well as some soluble feedstock components. 23 Having TS/CDS as part of DDGS brings many issues to the animal feed materials.…”

Use of Organic Wastes and Industrial By-Products to Produce Filamentous Fungi with Potential as Aqua-Feed Ingredients

“…The techno-economy of the application of filamentous fungi in the treatment of industrial by-products has been considered in different research studies. Rajendran et al [40] studied the techno-economy of the integration of first and second-generation bioethanol production by the cultivation of filamentous fungi on by-product streams of stillage and wheat bran. They reported that although the integrated process imposed greater capital costs than only fungal cultivation on stillage, it could result in up to 48% increase in the net present value (NPV).…”