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The more popular methods for production of ethanol and cellulosic ethanol use enzymes that must be isolated first to be added to the biomass and thus convert the starch or cellulose into simple sugars, followed then by yeast fermentation into ethanol. This process does not need the addition of such enzymes as these microorganisms make their own.
Clean production bioethanol [20] is a biofuel obtained by maximizing non-greenhouse gas emitting (renewable) resources: energy directly consumed to make the ethanol is renewable energy . The farm equipment and ethanol plant use an ethanol engine , biodiesel , air engine or electricity cogenerated during ethanol production, or even wind power ...
The advantages of Z. mobilis over S. cerevisiae with respect to producing bioethanol: higher sugar uptake and ethanol yield (up to 2.5 times higher), [3] lower biomass production, higher ethanol tolerance up to 16% (v/v), [4] does not require controlled addition of oxygen during the fermentation,
Ethanol fermentation, also called alcoholic fermentation, is a biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as by-products. Because yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is considered an anaerobic process.
The production of butanol by biological means was first performed by Louis Pasteur in 1861. [5] In 1905, Austrian biochemist Franz Schardinger found that acetone could similarly be produced. [5] In 1910 Auguste Fernbach (1860–1939) developed a bacterial fermentation process using potato starch as a feedstock in the production of butanol. [6]
During ethanol fermentation, glucose and other sugars in the corn (or sugarcane or other crops) are converted into ethanol and carbon dioxide. C 6 H 12 O 6 → 2 C 2 H 5 OH+ 2 CO 2 + heat. Ethanol fermentation is not 100% selective with side products such as acetic acid and glycols. They are mostly removed during ethanol purification.
Recently, due to the popularity of second generation biofuels, the organosolv process has been considered in the context of bioethanol production. Cellulose from the organosolv process is susceptible to enzymatic hydrolysis into glucose followed by fermentation to dilute ethanol.
The fermentation processes to produce propanol and butanol from cellulose are fairly tricky to execute, and the Weizmann organism (Clostridium acetobutylicum) currently used to perform these conversions produces an extremely unpleasant smell, and this must be taken into consideration when designing and locating a fermentation plant.