Aluminium modified silica-gel adsorbent material and its preparing process

Abstract

The preparation process of aluminum modified silica gel adsorbent material includes the following steps: soaking inorganic fiber paper in water glass at room temperature for 2-5 hr and drying for 10-24 hr; compounding water solution of soluble aluminum salt, adding dilute acid solution to regulate pH to 0.5-2, heating to 30-80 deg.c, soaking the inorganic fiber paper under powerful stirring for co-precipitation in the surface and interval of the inorganic fiber paper via full reaction for 12-24 hr; washing the inorganic fiber paper with clear water to pH 7, air drying and programmed heating treatment. The aluminum modified silica gel adsorbent material thus prepared has great adsorption amount, high dehumidifying efficiency, low regeneration temperature, high heat resistance, high mechanical strength and long service life, and may be used widely in producing dehumidifying wheel.

Description

technical field [0001] The invention relates to a gas adsorbent technology, in particular to an aluminum-modified silica gel adsorbent material and a preparation method thereof. Background technique [0002] Adsorption gas purification technology has obvious advantages in low-grade energy utilization and environmental protection, and has become one of the sustainable development technologies. In the adsorption gas purification technology, the adsorption working fluid is the key to determine the performance of the adsorption system. There are more than a hundred kinds of adsorption working fluids and their combinations that have been developed, but they are selected based on the practicability of the adsorbent. The adsorbent in the dehumidifier is limited to highly hygroscopic substances such as lithium chloride, silica gel and molecular sieve; lithium chloride has good hygroscopicity and low regeneration temperature, but it is corrosive to surrounding...

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Problems solved by technology

In the adsorption gas purification technology, the adsorption working fluid is the key to determine the performance of the adsorption system. There are more than a hundred kinds of adsorption working fluids and their combinations that have been developed, but they are selected based on the practicability of the adsorbent. The adsorbent in the dehumidifier is limited to highly hygroscopic substances such as lithium chloride, silica gel and molecular sieve; lithium chloride has good hygroscopicity and low regeneration temperature, but it is corrosive to surrounding metal equipment; molecular sieve is suitable for deep dehumidification with low dew point, but The regeneration temperature is high (above 250°C); the performance of silica gel is between the two, which is suitable for both conventional dehumidification (coarse pore silica gel) and low dew point deep dehumidification (fine pore silica gel), among which fine pore silica gel is suitable for making silica gel Dehumidification core, and the key to making silica gel dehumidification core is the organic combination of silica gel and inorganic fiber substrate; it can be made by bonding silica gel powder on inorganic fiber substrate with adhesive, but due to the powder and substrate The interface force between the two materials is weak, and the adhesion is poor. Repeated use at higher temperatures (above 150 ° C) is prone to powder falling, making the performance of the silica gel rotor unstable. At the same time, the use of adhesives will Partially block the substrate and silica gel channels, reducing the specific surface area of ​​silica gel, thereby reducing the adsorption efficiency; the sol-gel method can also be used to impregnate sodium silicate on the inorganic fiber, and then react with acid to obtain silica gel precipitation deposited on the surface of the fiber and its In the void; due to factors such as the stability of the sol and the insolubility of the fiber in water, the amount of the adsorbent on the fiber is small, and it is difficult to form a high-concentration sol, so the amount of the sol attached to the inorganic fiber is small, and the silica gel produced is less , the dehumidification efficiency is low, and the dehumidification core made of it has a low adsorption efficiency

In order to overcome the shortcomings of these technologies, a "preparation method and application of nanoporous silica gel adsorbent material" is disclosed in the invention patent application with the patent application number 02149717.6. This adsorbent material is prepared by adding soluble calcium salt as a precipitant However, this technology also has the following deficiencies: (1) The adsorption performance needs to be improved; (2) The heat resistance performance needs to be strengthened; due to the weak heat resistance of silica gel, the dehumidification rotor core is kept at 80-150 ° C for a long time In the regenerative environment, phenomena such as melting, collapse, and blocked channels are prone to occur, thereby reducing the adsorption efficiency of the system; (3) The mechanical strength needs to be enhanced; due to the weak force between silica gel and ceramic fibers, the mechanical strength of the rotor material is poor. During the operation of the system, it is prone to pulverization and powder loss, which will affect its service life

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