Production of greases from crude glycerol
Biodiesel is one of the most promising renewable energy source and its production increases every year. But there is one drawback – need of utilization of glycerol, the main by-product of this process. The article presents methods of utilization of crude glycerol by its thickening with various inorganic salts to produce greases. It was discovered that metal salt reacted with soaps contained in glycerol obtained from biodiesel-production facilities with formation of greases. By-products of these processes was methanol contained in crude glycerol and, in some cases, purified glycerol.
Nowadays green chemistry is becoming more popular all over the world. With the increased concern about the environment, chemical technology focused on the designing of products and processes minimizing the environment pollution (1). Green chemistry concerned with production of biodiesel fuel (fatty acid methyl esters, FAMEs).
Biodiesel is renewable and nontoxic fuel, which is produced by transesterification of vegetable oils or animal fats with low alcohols (generally using methanol) over a basic catalyst.
Biodiesel fuels have other advantages as opposed to petroleum-based: a favorable energy balance and lower harmful emissions. Glycerol is the main by-product of transesterification process. Although difference in density of glycerol and biodiesel fuel makes it possible to divide them by separation, this glycerol has many impurities such as unreacted methanol, FAMEs and potassium soaps. It contains only 50-67% of glycerol by weight.
It is called crude glycerol or glycerol layer (2).
Great part of such glycerol is used as a fuel to industrial boiler (3).
But there are some other ways that used crude g ...