POROUS COMPOSITE ABSORBENT FOR SELECTIVE GAS SEPARATION AND METHOD FOR ITS PRODUCTION Russian patent published in 2023 - IPC B01J20/282 B01J20/20 B01J20/22 B01J20/30 B01D53/02 B01D53/62 

FIELD: absorbent technology.

SUBSTANCE: group of inventions relates to technology for producing absorbents and can be used for sorption and selective separation of gas mixtures, including for purification of natural gas from carbon dioxide, concentration of exhaust or industrial carbon dioxide. A method for producing a porous composite absorbent for selective gas separation is presented, which includes the stage of preparation of the initial components, consisting of the preparation of component 1 by dissolving 0.5 mmol of a zinc acetate salt of the formula Zn(OCOCH₃)₂×2H₂O in a 10% solution of ethanol in water with the addition of 33.33 mmol of a carbon absorbent - activated carbon, with a micropore volume of 0.30-35 cm³/g and a mesopore volume of 0.15-0.25 cm³/g, mixing component 1 with a magnetic stirrer at a speed of up to 350 rpm at a temperature of plus 70°C for 2 hours and preparation of component 2 by dissolving in a separate container 0.03 mmol of 5,10,15,20-tetra(4-pyridyl)porphyrinate zinc (II) in dried chloroform, the stage of formation of the structure of the composite absorbent in the Pickering emulsion obtained with portion-wise addition of component 2 to component 1 with vigorous shaking and subsequent stabilization for 30 minutes in an ultrasonic bath at a temperature of plus 35°C and ultrasonic frequency up to 40 kHz, with keeping the finished Pickering emulsion for 2 days in an oven at a temperature of plus 70°C, the stage of isolating the finished composite absorbent precipitated at the stage of formation of its structure, including vacuum filtration of the precipitate, its repeated washing with a 10% solution of ethanol in water until a colourless filtrate is formed, the drying stage, carried out in a lyophilic dryer at a temperature of plus 25°C and a pressure of 20 mbar for 12 hours, followed by sealing the finished composite absorbent and storing it in an opaque container at room temperature. In another variant, a porous composite absorbent is provided for the selective separation of gases containing carbon dioxide produced by said process.

EFFECT: group of inventions ensures the creation and preservation of the structure of a composite absorbent, consisting of mineral and organic parts, having a developed inner surface, represented by pores of micro- and mesopore sizes; uniform distribution of MOF crystals inside the activated carbon matrix; imparting mechanical strength and selectivity to carbon dioxide to the composite material; reduction of material costs in the implementation of the emulsion method for obtaining a composite absorbent by selecting available components, using the same solvents at different stages, using low-temperature freeze-drying at the activation stage.

3 cl, 7 dwg, 1 tbl, 4 ex