Ethanol – Classical Methods

A Rapid and sensitive method for the evaluation of cereal grains in bioethanol production using near infrared reflectance spectroscopy

“…Ten grain quality parameters (ash, protein, lipid, fiber, starch according to Ewers (ISO 10520), free sugars according to LuffSchoorl (Van Voorst, 1948), thousand-kernel weight, bulk density (hectolitre weight), fermentable substance and ethanol yield (Senn and Pieper, 1997) were determined and correlations to the ethanol yield established (data not shown). Data for fermentable substance and ethanol yield served as a reference for NIRS calibration establishment.…”

“…The FS in grain is defined as the sum of the glucose and maltose content released in the production process and converted to ethanol by the yeast Saccharomyces cerevisiae. A detailed analysis of the fermentable substance and ethanol yield was outlined by Senn and Pieper (1997). Ground grain samples are hydrolyzed with an excess of enzyme (a-amylase and amyloglucosidase) and the resulting sugar profile is displayed using High Performance Liquid Chromatography (HPLC).…”

“…The amount of fermentable substance was determined by hydrolyzing the sample with an excess of enzyme(Senn and Pieper, 1997). A 10 g ground sample was suspended in 300 ml of double distilled water supplemented with 10 ppm CaCl 2 and homogenized for 20 s using an ULTRA-TURRAX (IKA, Staufen, Germany).…”

Ethanol Production from Traditional and Emerging Raw Materials

“…The fermenting organism in large scale corn-to-ethanol processes is almost exclusively S. cerevisiae , which has high tolerance to low pH and can tolerate ethanol concentrations above 10 % , properties, which permit non-sterile process operation. The yeast is produced on site from a seed culture (Senn and Pieper, 2001 ). In plants with a continuous mode of operation, yeast is propagated in an aerated prefermenter and the yeast containing liquid is then cascaded to the fermentation vessels.…”

Elimination of oscillations in fermentation processes

“…Sugar can be converted to ethanol directly, whereas starch must be hydrolyzed first and cellulose must be converted to sugars by the use of mineral acids. 1 Once the sugars are formed, enzymes from yeast or bacteria can readily ferment them to ethanol. Traditionally, ethanol is produced in fermentation with yeast strains such as Saccharomyces cerevisiae, which under anaerobic conditions, metabolizes glucose to produce ethanol.…”