Distillation is one of the most common liquid-liquid separation processes, and can be carried out in continuous or batch system. Distillation works by the application and removal of heat to exploit differences in relative volatility. The heat causes components with lower boiling points to be vaporized, leaving less volatile components as liquids. This makes separations of close-boiling and azeotropic feeds difficult, so special distillation techniques have to be used to separate these mixtures. Distillation can be used to separate binary or multi-component mixtures. Many variables, such as column pressure, temperature, size, and diameter are determined by the properties of the feed and the desired products. The plate, or tray column is the most widely used type of distillation column. The number of trays, or stages in the column is dependent on the application. A variety of interna devices have been used to obtain more efficient contacting of vapor and liquid. The most widely used devices are the bubble cap plate, the perforated or sieve plate, and the packed column. The bubble cap plate is a horizontal deck with a large number of chimneys over which circular or rectangular caps are mounted to channel and distribute the vapor through the liquid. Liquid flows by gravity downward from plate to plate through separate passages known as downcomers.
The perforated or sieve plate is a horizontal deck with a multiplicity of round holes or rectangular slots for distribution of vapor through the liquid.
Distillation columns are made up of several components, each of which is used either to transfer heat energy or enhance material transfer. A typical distillation columns contains several major components as mentioned below
- A vertical shell where the separation of liquid components is carried out.
- Column internals such as trays/plates and/or packings which are used to enhance component separations.
- A reboiler to provide the necessary vaporisation for the distillation process.
- A condenser to cool and condense the vapor leaving the top of the column.
- A reflux drum to hold the condensed vapor from the top of the column so that liquid (reflux) can be recycled back to the column.
Fermentation is a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation. Fermentation is also used more broadly to refer to the bulk growth of microorganisms on a growth medium. Fermentation takes place in the absence of oxygen and becomes the cell’s primary means of ATP (energy) production. It turns NADH and pyruvate produced in the glycolysis step into NAD+ and various small molecules.
Starch Based Feedstock
Grains : Corn, Wheat, Broken Rice, Sorghum, Rye, Millet etc.
Tubers : Cassava, Tapioca, Potato.
Other : Waste Starch slurries.
Sugar Based Feedstock
Molasses : Different grades of molasses A, B and C
Sugarcane : Sugarcane juice – Primary or Secondary, Sugarcane syrup etc.
Dates : Fresh or Waste Dates
Others : Sweet Sorghum