Process for refining crude glycerin and recovering byproducts

Abstract

The invention discloses a process for refining crude glycerin and recovering byproducts. The process for refining the crude glycerin and recovering the byproducts comprises the following steps of: diluting the crude glycerin with water; preheating the crude glycerin to 30 to 60 DEG C; introducing the crude glycerin into an ion exchange column with cation exchange resin; allowing the crude glycerin to enter a storage tank A, preserving the heat to be between 30 and 60 DEG C and standing to layer; after layering, introducing the bottom layer of liquid into an ultrafiltration membrane component and allowing the upper layer of liquid to enter a storage tank B; introducing the permeating liquid of the ultrafiltration membrane into an anion exchange column and then introducing the permeating liquid into a cation exchange column; evaporating, concentrating or distilling effluent to obtain high-purity glycerin; returning the non-permeating liquid to the storage tank A; standing liquid in the storage tank B to layer; separating out the upper layer of oil layer; washing the oil layer with hot water; standing and separating; and taking the upper layer of oil layer to obtain fatty acid. The process is high in processing efficiency, simple in process and low in cost. By the process, the high-purity glycerin can be produced efficiently; the fatty acid can be recovered from the crude glycerin; and production cost is reduced.

Description

technical field [0001] The invention relates to a process for refining crude glycerin, in particular to a process for refining crude glycerin and recovering by-products. Background technique [0002] In the process of biodiesel production, a large amount of by-product crude glycerol will be produced, and approximately 0.1t of glycerol can be produced for every 1t of biodiesel produced. A large amount of crude glycerin water is also produced in the production process of oleochemicals. High-purity glycerin is an important industrial raw material, which is widely used in food, medicine, cosmetics and tobacco industries. my country's demand for high-purity glycerol has been in short supply. Therefore, the recycling of crude glycerin, a by-product of biodiesel, or crude glycerin water produced by oleochemicals can not only reduce the production cost of biodiesel, but also increase the source of high-purity glycerin. [0003] At present, the refining process of crude glycerol in...

AI Technical Summary

Problems solved by technology

[0008] In actual production, the fatty acid, ester content and easily carbonized substances of the refined glycerol refined by the above method generally do not meet the high-grade glycerin standard stipulated by the state.

The main reason is that the method has a low removal rate of fatty acids, and the removal of fatty acid organic substances in crude glycerin is not complete.

At the same time, the above method needs to consume strong acids such as hydrochloric acid or sulfuric acid, which has high requirements on production equipment; the fatty acid is removed by pressure filtration in the form of precipitation, which not only cannot be recycled, but also produces secondary pollutants, and NaCl, Na 2 SO 4 etc. into the final refined glycerin process, affecting its quality