There’re four extraction methods for glycerol, namely saponification glycerol, synthetic glycerol, compound glycerol, fermented glycerol. Their performances and uses are basically the same, but their market quotation is much different.
- Saponification Glycerol
Saponification glycerol is the hottest and in great demand on the current market, hydrolyzed from oil. We mainly get it from soap production in our country, commonly known as saponification glycerol. Saponification glycerol is a by-product of saponification of natural oils into soap. In recent years, soap and saponification glycerol production has been restricted due to the gradual replacement of soap by laundry detergent, making it difficult for saponification glycerol to achieve a breakthrough development.
- Synthetic Glycerol
Synthetic Glycerol is synthesized from epoxy chloropropane (ECH), another popular glycerol in the market, as well. The annual production capacity of ECH is about 45000 tons in our country, but due to the serious shortage of chlorine gas and propylene, the production capacity is unable to be exerted. Because the insufficient raw materials, price hanging upside down, manufacturing loss and no incentive to produce for manufacturers, the output of synthetic glycerol is stagnant, hard to be increased in this way. If the production capacity of ECH could be increased greatly, this would be an effective way to produce glycerin.
- Compound Glycerol
Compound Glycerol is produced from distillers’ grains. At present, it occupies a small proportion in the market and its price is about 6.000 Yuan per ton. The production of compound glycerol is simple, with low price, and available raw materials, able to be produced in large numbers. But cannot be blindly developed in view of the sluggish sales. If the quality could be further improved, it’ll undoubtedly be an important way to solve the long-term shortage of glycerin and dependence on import in China. Meanwhile, it could also be exported in large quantities.
- Fermented Glycerol
Fermented glycerol is made by fermentation with starch such as corn, potato and saccharic such as sugar beet and sugar cane as raw materials. It is reported that all the important indicators of fermented glycerol reach international advanced level, and free of arsenic, heavy metals and other harmful substances. Therefore, fermented glycerol could be used not only in the coating industry, but also in other industries like medicine, food, cosmetics, tobacco, toothpaste.
In 1859, Pasteur pointed out that glycerin is formed during the fermentation of yeast alcohol, as a by-product. During the first world war, due to the shortage of oil, glycerol produced by saponification of oil was far from enough to meet the demand in Germany. Therefore, German began to study fermentation method to produce glycerol, and developed the technology of adding sulfite to produce glycerol.
In recent decades, the United States, Japan, Sweden and China all have been actively engaged in the research of glycerol fermentation production, making it get rapid development at home and abroad. Due to the abundant source of raw materials, low price and mature technology, it is expected that in the near future, this kind of glycerol production will become an important method to alleviate the tension of glycerol in China.
