The adsorbent for gas purification from h2s and co2
(57) Abstract:The invention relates to an adsorbent for the purification of hydrocarbon gases from H2S and CO2and can be used in gas, oil and chemical industries. This invention for the purification of gases from H2S and CO2contains alkanolamine or a mixture of alkanolamines and water and optionally water-soluble physical solvent, which is used as the methyl ether of polyethylene glycol of the formula CH3-O (CH2CH2O)x- H, where x = 2 to 5, in the following ingredients, wt.%: alkanolamine or a mixture of alkanolamines 10-65; methyl ester of polyethylene glycol 5-15; water - the rest. table 2. The invention relates to gas, oil and chemical industries, in particular to the purification of hydrocarbon gases from H2S and CO2.Known absorbent for cleaning gases from H2S, CO2and COS (see patent SU N 1715195, MKI 5 B 01 D 53/14, 1978). The absorbent contains the physical solvent (sulfolane), amine compound and water in the following ratio, wt.%:
Sulfolan - 20 - 60
Secondary amine (DIPA) - 10 - 30
Tertiary amine (MDEA or DEMEA) - 10 - 60
Water - 10 - 25
Lack of vysheupomyanutomu, therefore, the absorbent has limited application.The closest analogue to this invention is an absorbent for cleaning gases from H2S and CO2containing alkanolamine or a mixture of alkanolamines and water (see patent US 4368095 A, 1983, B 01 D 53/14).As alkanolamines use monoethanolamine (IEA), diethanolamine (deja), methyldiethanolamine (MDEA), monomethylethanolamine (MMEA) and other alkanolamine or mixtures thereof.The disadvantage of this absorbent is that the absorbent has a low dissolving ability in relation to hydrocarbons and has a high cost of thermal energy to regenerate the saturated adsorbent.In the claimed invention was solved the following technical problem: reducing energy consumption for regeneration of the adsorbent or improving the quality of regeneration at the same power consumption.The technical solution provided by the fact that the adsorbent for gas purification from H2S and CO2consisting of alkanolamine or mixture of alkanolamines and water, additionally contains a water-soluble physical solvent, which used the methyl ether of polyethylene glycol (IEP) by the formula CH3- (CH2CHMethyl ether of polyethylene glycol - 5 - 15
Water - the Rest
Example 1. The experiment is carried out in laboratory conditions. In a glass flask with a volume of 0.5 DM3equipped with reverse water-fridge, pour 0.2 DM2the test absorbent, pre-saturated H2S to 0.1 mol H2S per mole of alkanolamine. Then the solution is heated to boiling with electrocomponents and in the moment of boiling served through the absorbent nitrogen at the rate of 2 DM3/hour. After 30 and 60 min after injection of nitrogen selected a sample of absorbent in the analysis is the determination of the residual content of H2S.H2S in the absorbent define method iodometric titration (A. M. Kunin, M. M. Derborence. "Technological control of the gas production." - M.: Costoptimized, 1958).H2S is selected as the control component as the most trudnoperevarivaema admixture.Investigated amines and the results obtained are presented in table. 1.As the map used industrial product produced according to TU 242-220-002-95. The product is a mixture of methyl esters from di - to pentathletes formula
CH3-O(CH2CH2O)XX alkanolamines or their mixtures, while supplying the same amount of heat regenerated with a different speed (experiments 1 - 4). The most characteristic is the 30-minute point - residual content of H2S in the regenerated absorbent in an order of magnitude smaller than in the original.Introduction to the absorbent advanced map reduces to a residual content of H2S by 20-30% in comparison with the known absorbent. This dependence takes place as in the case of individual alkanolamines (experiments 5,6), and their mixtures (experiments 7-11).The greatest effect is observed when the concentration of map in the absorbent 10 - 15 wt. % (experiments 7, 8, 10). Further increasing the concentration up to 20% of the impact is not so significant (experiment 9). In addition, it increases the solubility of hydrocarbons in the absorbent, which is undesirable. Lowering the concentration of map in the absorbent to 5 wt.% and below has no significant effect.Example 2. Experiments in an industrial unit designed for natural gas cleaning composition, % by vol.: H2S - 1,5; CO2to 0.6. Maintenance absorbent is a mixture of MDEA, deja and water. Regeneration of the absorbent is saturated with water vapor. The steam consumption of 120 kg/m3solution. Then in the From table 2 it follows, what if the same flow of heat (steam) on the regeneration of the absorbent, containing 9.1% of the map is regenerated much easier and deeper, the residual content of H2S 30% lower than in the case of known absorbent. Through a deeper regeneration provides better cleaning of the gas - concentration of H2S and CO2in the purified gas is 2-3 times lower (experiments 1 and 2).The evidence also shows that the proposed absorbent reduces the cost of heat for regeneration with 120 kg of steam/m3solution to 100 while maintaining the quality of the purified gas (experiment 3). The adsorbent for gas purification from H2S and CO2containing alkanolamine or a mixture of alkanolamines and water, characterized in that it further contains a water-soluble physical solvent, which is used as the methyl ether of polyethylene glycol of the formula CH3- O(CH2CH2O)x- H, where x = 2 to 5, in the following ingredients, wt.%:
Alkanolamine or a mixture of alkanolamine - 10 - 65
Methyl ether of polyethylene glycol - 5 - 15
Water - The Rest
FIELD: gas treatment.
SUBSTANCE: invention is intended for fine purification of gases with removal of carbon dioxide at elevated pressures, in particular in hydrogen or ammonia production processes. Absorbent is an aqueous solution containing N-methyldiethanolamine, piperazine, potassium carbonate, and morpholine. Invention achieves reduced equilibrium pressure and increased carbon dioxide absorption at low degrees of carbonization (as low as 0.1 mole CO2 per mole tertiary amine) without appreciable N-methyldiethanolamine degradation rate.
EFFECT: enhanced carbon dioxide absorption efficiency.
2 dwg, 6 tbl, 2 ex