CS239088B1 - A method of purifying methanol from the 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 acetylene production process. This objective is achieved by stripping methanol vapors in a column at atmospheric pressure and a column head temperature of 40 to 64 °C. The gases leave the column through a dephlegmator. The methanol is fed to the column head and the degassed methanol is withdrawn from the reboiler for further use.

Description

1 239 088

The invention relates to a process for the purification of methanol from a process for the production of ethylene, consisting in the removal of C 1-6 acetylenes, olefins, diolefins, ammonia and other volatiles.

In the partial oxidation of natural gas, about 6.8 µmol of ethylene is formed and the moieties are H, CO, CO 2, methane, ethane, propylene, propadene, 1,3-butadiene, C 1-4, C 6 [alpha] -aethylenes, aromatics, oxygenated compounds and other polymers with unsaturated bonds. The separation of the ethylene from such a mixture is based on the principle of removing the individual components in a selective solvent solution. Aoethylene is obtained by absorption into methanol and desorption from this solution, while the tail gas (Ég and <30) from the absorption of the can is used to produce ammonia or methanol.

Methanol is used as an auxiliary raw material in the production of ethylene in two ways. Part of the methanol serves to wash C, C, 6 -alkylene, olefins, diolefins and aromatics from the process gas. Various polymers with unsaturated bonds, oxygen compounds, and a small amount of ammonia from the spinning knot were also charged with ammonia water in methanol. The second part of methanol serves in the concomitant stage for the aforementioned absorption and desorption of oetenene ·

Methanol from absorption is only regenerated by desorption and discarding the reservoir. However, it still contains certain amounts of C, ^, C ^ety-acetylenes, olefins, diolefins and other impurities, as evidenced by the fact that these components aa are found in the ethylene, descending from the desorption knee in the tensile up to 1,000ohppm.

Methanol from washing C, C, 6-azoethyls, olefins, dlolefine aromas and a regenerates in a large scale. First, and by reducing the pressure and stripping through the tail gas, the acetylene dissolved in it is recovered therefrom, then diluted with water and removed from the solution and removed by C, C, -C-acetylenes, olefins and dlolefins.

In order to prevent methanol losses and its vapor from the scrubbing gas, they wash in the water scrubber and the scrubber water used, and again methanol in the previous step, but still maintain some steady water concentration in the water, which is removed from the methanol by attrition. Aromatics aa removed in more methanol are separated from the water by ionisation. The distilled methanol then goes to the same container as the methanol desorption.

However, distilled methanol still contains certain amounts of acetylenes, olefins, dlolefins, ammonia, and volatile matter formed in the natural gas splitting process, which are thus added to the acetylene, in that the already polluted methane is supplied on the one hand. on the head of the scrubbing knee and secondly used to absorb acetylene. The deterioration of this condition can occur mainly due to the frequent clogging of the knee structures in the regeneration of the foaming agent by the polymeric substances, which greatly reduces the shear effect of the tail gas. Attempting to maintain the original shearing effect next to a sharp increase in methanol losses.

The increased content of C,,, C ^ao-ónovoethones, olefins, dlolefins, ammonia, but also other polyvalent and oxygenated materials of 238 - 3 in acetylene adversely affects the process of its further processing into acetaldehyde) vinyl acetate and this is manifested by reduced lifetime the catalysts used, the lower yields, the increased consumption standards, and thus the deteriorated economy of the entire production process, the disadvantages are eliminated by the process of the present invention, which is the purification of methanol from the acetylene production process by removing C 1-6 -acetylenes, olefins, diolefins, ammonia and other volatiles in such a way that the contaminated methanol is fed to the head of the column at atmospheric pressure and temperature of 40 to 64 ° C, with vapors of degassed methanol being fed to the bottom of the knee, which is condensed in the deflector , through which separate volatile substances come from ·

Figure 1 illustrates the removal process of C 1-6 -acetylenes, olefins, diolefins, ammonia and other volatiles from methanol. Methanol is fed to the head of the barrel where a temperature of 40 to 64 ° C is maintained at the volatile substances are stripped off by the countercurrent rising vapors of the methanol · Vapors evolved by the reboiler 2 and co-condensate in the deflector 3 · The stripped volatiles leave through the deflegmator for the combustion or at the Salmon process o · Degassed methanol leaves the reboiler in the yy ~ processes piercing of C 1 -C 4 -acetylenes, olefins, diolefins and aromatics, and acetylene sorption · Example 1 3 1.h Methanol / methanol from distillation and desorption 1: 1 / Squeegees on the head of the packed knee where the temperature is maintained at 60 ° C The elbow has a diameter of h cm and 10 theoretical trays. The temperature of the electrically heated circulating coil was 65 ° C. the methanol to be quenched contained 435.2 ml / under normal conditions / dissolved ace-A - 239,088 tylans in 1 liter of three methanol, the so-called degassed methanol was only 33.6 ml.1 · 1.8 years of gas / under normal conditions (o composition / v / v) 36.5% acetylene, 20% dlaoethylene, 7% vinylacetylene, 3% methylacetylene, 16% 1,3-hutadione, 7% methanol, 7% ammonia, 2% propylene + propadone, 1% ethane + ethylene and 0.5% other volatile substances ok ·

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 ·