CS239088B1 - Methanol cleaning method from acetylene production process - Google Patents

Abstract

The object of the invention is to remove Cj, C4-acetylenes, olefins, diolefins, ammonia and other volatiles from methanol in the process of acetylene production. This goal is achieved by stripping with methanol vapors in the column at atmospheric pressure and temperature at the column head 40-64 ° C. The gases leave column through the deflector. Methanol is fed per column head and degassed methanol is withdrawn from the digester for further use.

Description

The present invention relates to a process for the purification of methanol from the process of producing ethylene by removing C 1-6 acetylenes, olefins, diolefins, ammonia and other volatile substances.

Partial oxidation of natural gas produces about 6.8% by volume of acetylene and the remainder is CO, CO CO, methane, ethane, ethylene, propylene, propene, 1,3-butadiene, C,,, Cao-oetylones, aromatics Oxygen compounds and other unsaturated polymer-forming substances * The acetylene separator from such a mixture is based on the principle of removing the individual components in selective solvents and solutions. CO / z absorbcle can be used to produce ammonia or methanol *

Methanol is used as an auxiliary raw material in two processes for the production of ethylene · Part of methanol serves for scrubbing of C, C, 4-ethylenes, olefins, diolefins and aromas from process gas * a small amount of ammonia from the preceding node pumped through the ammonia water * The second part of methanol serves at the kono stage for the abovementioned absorption and desorption of acetyl ·

The methanol from the absorbcle is only recovered by desorption and discharged into the reservoir. However, it still contains certain amounts of C, C, acetylenes, olefins, diolefins and other impurities, as evidenced by the fact that all these components are disposed of in ethylene, from the desorption wheel head at tens to thousands of ppm ·

Methanol from the scrubbing of the C 4, C 4 -acetylones, olefins, dlolefins and aromatics is recovered in several stages. First, the acetylene dissolved therein is recovered by pressure reduction and stripping with the tail gas, then diluted with water and stripped of such a solution by stripping of the N, N-acetylenes, olefins and diolefins.

To avoid methanol losses, its vapors from the stripping gas are scrubbed in a water scrubber and the water used in the scrubber is diluted with methanol in the previous step. In this way, however, a certain equilibrium concentration of the substances which are stripped from the methanol is constantly maintained in the water. The aromatics are removed at a later stage by decantation and the methanol is separated from the water by ectification. The distilled methanol then goes to the same reservoir as the methanol from the desorption.

However, distilled methanol still contains certain amounts of acetylenes, olefins, dlolefins, ammonia and other volatile substances produced in the process of natural gas contributing to acetylene, by the fact that already contaminated methane is fed to the head of the scrubbing elbow and, secondly, used to absorb acetylene.

The deterioration of this condition may occur, in particular, due to frequent fouling of the canola assemblies in the recovery section of the methanol washing of the methanol, which greatly reduces the stripping effect of the tail gas. Attempting to maintain the original smear effect, then leads to a sharp increase in methanol losses.

Increased content of C 4, C 4 -acetones, olefins, dlolefins, ammonia, but also other persistent polymers of your and oxygen species

238 in acetylene adversely affects the process of its further processing into acetaldehyde) vinyl acetate and the like. This is manifested by reduced service life of the catalysts used, lower yields, increased consumption standards and hence a worsened economy of the whole production,

This disadvantage removes the process of the present invention, which involves the purification of methanol from the process of acetylene production by removing C, C, acetylenes, olefins, diolefins, ammonia and other volatile substances in such a way that contaminated methanol is fed to the head of the column. at atmospheric pressure and a temperature of 40 to 64 ° C, with vapors of degassed methanol being fed to the bottom of the knee, which is condensed in a deflector, through which the separated volatiles are removed.

Figure 1 shows the process of removing C 1, C 1 -acetylenes, olefins, diolefins, ammonia, and other volatile substances from methanol. Methanol is fed to the head of Coke 1, maintaining a temperature of 40-64 ° C, in which the vapors evolve in the digester 2 and cohesive in the deflegmator 3 · the evapuated volatiles leave the deflegmator for incineration or saler treatment o C-acetylenes, olefins, diolefins and aromatics and acetylene absorption ·

Example 1

1.h methanol (methanol from distillation and desorption 1: 1) is sprayed onto the head of the packed knee where the temperature is maintained at 60 ° C. The knee has a diameter of h cm and 10 theoretical plates. In an electrically heated circulating digester, the temperature was 65 ° C. 3 l »h of degassed methanol was withdrawn from the digester. The methanol injected contained 435» 2 ml / under non-dissolved conditions. 088 thylans in 1 L of three methanol, while only 33.6 ml of methanol has been degassed. 7% guilty of flax lacetes, yfc methyls of flax, 16% 1,3-butadione,

7% methanol, 7% ammonia, 2% propylene + propadlane, 1% ethane + ethylene and 0.3% other volatile substances ·

Claims (1)

BEFORE THE FIND 239 088 Process for purifying methanol from the process of acetylene production by removing C 1, C 4 -acetylones, olefins, diolefins, ammonia and other volatile substances, characterized in that the contaminated methanol is fed to the knee head at atmospheric pressure. pressure and temperature of 40 to 64 ° C, while the bottom of the knee is fed with the vapor of the degassed methanol, which condenses in the deflog of the catheter, through which the separated stagnant substances leave ·