Preparation method of phenol-formaldehyde resin-based carbon molecular sieve for adsorbing and separating methane and nitrogen gas

Abstract

The invention discloses a preparation method of a phenol-formaldehyde resin-based carbon molecular sieve for adsorbing and separating methane and nitrogen gas. The preparation method mainly includes the following steps: (1) mixing phenol-formaldehyde resin waste, coal tar, water and a pore-forming agent in a certain proportion evenly, carrying out strip extrusion moulding and drying at low temperature; (2) carbonizing at high temperature under the protection of nitrogen gas to prepare a pre-deposition matrix with suitable pore size; and (3) directly introducing a methane depositing agent and depositing without cooling of the matrix, and adjusting the pore size of the matrix to prepare the carbon molecular sieve sample. The raw materials have low cost, carbonization and deposition are integrated in the preparation process, the energy loss is reduced, more energy is saved, the influence of heat on the pore size change of the matrix during carbonization cooling and deposition heating is reduced, and the pore size is relatively stable; the pore size of the matrix prepared by the method is small, the deposition time is reduced, and the sample after deposition has the adsorption capacityof nitrogen gas of 6.5-7.5 ml / g and the adsorption capacity of methane of 7-10 ml / g at 25 DEG C / 1 atmospheric pressure.

Description

technical field [0001] The patent of the present invention relates to a method for preparing carbon molecular sieves for adsorption and separation of methane and nitrogen based on phenolic resin. Using low-cost phenolic resin waste and adopting suitable carbonization and deposition conditions, the carbon molecular sieve with relatively large nitrogen adsorption capacity and relatively large methane adsorption capacity is prepared. The invention relates to a phenolic resin-based carbon molecular sieve which is small and has a sieving effect, and belongs to the field of inorganic materials. Background technique [0002] PSA gas separation is mainly realized in two ways: equilibrium effect and kinetic effect. The molecular dynamic diameters of methane and nitrogen are 0.380nm and 0.364nm, respectively. Due to the wide pore size distribution of activated carbon, the force between it and methane is greater than that of nitrogen during adsorption, but since both are non-polar mole...

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Problems solved by technology

[0005] Chinese patent CN104801273 Adsorbent for coalbed methane concentration and its preparation method and application, using phenolic resin as a substrate, through carbonization, water vapor and carbon dioxide activation, deposition, to prepare an adsorbent for coalbed methane concentration, due to the increase of the activation process, the process is relatively It is cumbersome and does not elaborate on the pore size structure of the adsorbent and the gas adsorption performance

[0009] Chinese patent 105692613A discloses a method for preparing carbon molecular sieves for methane purification, mainly using aromatic hydrocarbons such as benzene, and adjusting the pore size of the molecular sieve to 0.36-0.40nm. It does not describe in detail the adsorption capacity of nitrogen and methane of carbon molecular sieves, and does not indicate the pore size of the precursor adjustment method

[0010] The existing inventions to prepare phenolic resin-based carbon molecular sieves mainly adopt gas activation process, or carbonized material cooling process. The gas adsorption capacity is described in detail

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