Integration of first and second generation bioethanol processes
The present invention presents an alternative to the direct implementation of an industrial scale second generation bioethanol process with the integration of the second generation into the existing first generation bioethanol processes, which aims to reduce the current barriers to process change/investments. In particular, the present invention relates to an integrated second generation process for producing bioethanol comprising at least one fungal cultivation stage for producing ethanol and fungal biomass. The present invention also relates to a novel fungal biomass, rich in protein and essential amino acids, which is produced with said integrated second generation process for producing bioethanol for use as a nutritious substitute for human and domestic animal use.
1. A process for producing bioethanol and a fungal biomass, comprising
carrying out a first generation bioethanol process which comprises fermenting starch- or sugar-based raw materials with yeast to produce ethanol and stillage; and
integrating a second generation bioethanol process into the first generation bioethanol process;
wherein the second generation process comprises cultivating filamentous fungi selected from the group consisting of food-related strains of Ascomycetes on whole stillage and/or thin stillage from the first generation process,
wherein the second generation process produces ethanol and fungal biomass.
2. The process of claim 1 , wherein the filamentous fungi are selected from the group consisting of Rhizopus sp.; Fusarium venenatium; Aspergillus oryzae; Monascus purpureus, Neurospora intermedia and combinations thereof.
3. The process of claim 2 , wherein the filamentous fungi are Neurospora intermedia.
4. The process of claim 1 , wherein the integrated second generation process yields an at least 2.5% improvement of ethanol production compared to the ethanol production of the first generation bioethanol process into which the second generation bioethanol process is integrated.
5. The process of claim 1 , wherein the integrated second generation process yields 1-20% improvement of ethanol production, compared to the ethanol production of the first generation bioethanol process into which the second generation bioethanol process is integrated.
6. The process of claim 1 , wherein the integrated second generation process produced 1-30 g/L fungal biomass and 1-50 g/L ethanol from the thin stillage, from the whole stillage, or from the thin stillage and the whole stillage.
7. The process of claim 1 , wherein the integrated second generation process produces 1-20 g/L fungal biomass and 1-5 g/L ethanol from the thin stillage, from the whole stillage, or from the thin stillage and the whole stillage.
8. The process of claim 1 , wherein said starch- or sugar-based raw material comprises wheat.
9. The process of claim 1 , wherein the starch- or sugar-based raw materials comprise lignocellulosic feed-stock.
10. The process of claim 9 , wherein the lignocellulosic feed-stock is supplied into a dry mill.
11. The process of claim 9 , wherein the lignocellulosic feed-stock is selected from the group consisting of corn stover, wheat straw, switch grass and combinations thereof.
12. The process of claim 1 , wherein the fungal cultivation step takes place in an airlift reactor and/or bubble column.