Home > News > Company News

Fatty acid distillation--continuous vacuum distillation technology and hydrolysis technology

Date:Jul 29th, 2022
Fatty acid is an important industrial raw material and the basic raw material of oil chemical industry. It is an urgent task to produce a wide range of fatty acids with high quality and low price to meet the needs of China's rapid economic development. One of the ways to improve the competitiveness of China's fatty acid industry is to develop the products that can make use of low-priced raw materials such as, non-edible fats and oils, miscellaneous oils, waste oils, as well as edible oil refining scraps, acidified oils and dequenched fatty acids are used as raw materials to produce a variety of high-quality separated and purified fatty acids. Dingsheng Machine has successfully developed multi-tower continuous vacuum distillation technology and medium and low pressure continuous hydrolysis technology, which has been realized in the production process.

The use of low and medium pressure single tower intermittent or multi-tower continuous hydrolysis process can hydrolyze all kinds of poor quality oil and grease raw materials without the need for strict pretreatment processing of hydrolyzed raw materials like high pressure hydrolysis, so it can significantly save investment.
The patented technology of multi-stage continuous vacuum vapor evaporator can economically and effectively remove the difficult volatile residue in crude fatty acid, and remove some low boiling point impurities in the condensation process, so that the crude fatty acid of hydrolysis of poor quality raw materials can be turned into high quality distilled fatty acid, which can be directly used as raw materials for coating surfactants, etc. It can also be hydrogenated to produce saturated fatty acid such as stearic acid, thus significantly reducing the production cost.

The distilled fatty acid is then processed by multi-tower continuous vacuum distillation device, which can get distilled fatty acid with 95-99% fatty acid content of the same carbon chain length, with low investment cost and abundant raw material sources. The product is of high quality and low price, and has won in the market with good economic benefits.
The distillation separation process depends on the composition of raw materials and the quality requirements of the product. For example, in order to thoroughly improve the color of the product, it is necessary to set up a special tower to remove low boiling material, in order to remove the aldehydes, ketones and other low boiling material due to the oxidation and decomposition of raw materials, easy to oxidation and discoloration. When the top of the tower fatty acid product color requirements are not high, you can take the side line out of the method, from the top of the tower containing aldehydes and ketones and other discolored fractions, and from the top of the tower side line out of fatty acids. This method can reduce the use of a tower, but only about half of the discolored fraction can be removed, so the fatty acid still has a slight yellow color.

When crude fatty acids from the oil foot of cottonseed oil, soybean oil or palm oil are used as raw material, two distillation columns can be used. The low boiling point discolored fraction is separated at the top of the first tower, and the kettle liquor is pumped to the second distillation tower, from which palmitic acid is obtained. The kettle liquor of the second column is distilled twice to get light-colored oleic acid.

For rapeseed oil fatty acids containing erucic acid, more than three distillation columns are required. From the top of the first column, the palmitic acid with low boiling material is separated. -The fraction at the top of the tower goes to the second tower, where the low boiling material is separated from the top of the second tower and palmitic acid is obtained at the bottom of the second tower. The kettle liquor of the first tower is pumped to the third tower, and the oleic acid is obtained from the top of the third tower. The kettle liquor of the third tower is pumped to the fourth tower, and the C20 fraction is separated from the top of the fourth tower, and the kettle liquor of the fourth tower is distilled again to get erucic acid. When the content of palmitic acid in the raw material is low, the second tower can be omitted, but the color of the resulting palmitic acid is poor.

The main factor of fatty acid distillation and distillation process is to maintain a constant operating pressure (absolute pressure). When the pressure rises, the boiling point rises, and when the allowable operating temperature is exceeded, it will cause the material to decompose. Therefore, it is necessary to maintain a stable pressure at the top of the tower in order to control the distillation temperature according to the corresponding fatty acid boiling point. The constant pressure and temperature at the top of the tower are necessary to obtain a constant product composition and to ensure product quality.

The distillation tower designed by Dingsheng Machine adopts the tube type condenser to regulate the temperature at the top of the tower. Under the condition of constant pressure, the quality of the product at the top of the tower can be controlled by automatically adjusting the temperature at the top of the tower. It is also important to maintain the constant temperature of the tower kettle and the liquid level at the bottom of the tower. For continuous operation, the bottom liquid level position can be maintained by overflow, and the overflowed kettle liquid can be continuously discharged into the next tower by a pump.

Fatty acids are an important class of products that are used in almost all production sectors and by everyone who uses products made from fatty acids as raw materials. With large population, we do not have an abundant source of fats and oils in relative terms. Therefore, it is of great practical importance to develop technologies to produce high quality fatty acids from non-edible fats and oils. If you would like more information on fatty acid distillation technology, please contact us soon.


Share:


TOP