5 results about "Ammonium hexafluorosilicate" patented technology

The application belongs to the technical field of biomass catalytic conversion, and specifically discloses a gallium-modified dealuminized H-ZSM-5 catalyst, a preparation method and application thereof, and the method comprises the following steps: ion exchange is performed on Na-ZSM-5 molecular sieve and an ammonium salt solution; selective dealuminization is performed on NH4-ZSM-5 molecular sieve and an ammonium hexafluorosilicate solution; and the impregnation method is used to load a gallium salt solution to the dealuminized molecular sieve carrier DeAl-H-ZSM-5, so as to obtain the gallium-modified dealuminized H-ZSM-5 catalyst. The application adopts the above-mentioned gallium-modified dealuminized H-ZSM-5 catalyst, the preparation method and application thereof, and the method is characterized in that the composite strategy of purifying the base by selectively dealuminizing first and then precisely loading Ga to regulate the acidity is adopted, the prepared catalyst can efficiently catalyze the preparation of furfural from pentose in a γ-valerolactone / water system, and high conversion rate and high selectivity are realized.

The invention discloses a silicon tetrafluoride resource utilization method, and relates to the field of silicon tetrafluoride resource utilization. The method comprises the following steps: S1, introducing silicon tetrafluoride into an ammonium bifluoride solution, and filtering to obtain ammonium fluosilicate precipitate and first filtrate; s2, adding a desilicication precipitator into the first filtrate, and filtering to obtain fluosilicate precipitate and second filtrate; s3, mixing the second filtrate with concentrated sulfuric acid, heating, evaporating and analyzing, absorbing the obtained gas with water to obtain hydrofluoric acid, and crystallizing and separating out the residual liquid to obtain ammonium salt. The whole process route is mild in reaction condition and high in safety coefficient; high temperature and external electric field are not needed, and energy consumption is low; no secondary waste is generated, and the comprehensive utilization degree of resources is high.

The invention discloses a high-flux anti-pollution composite reverse osmosis membrane and a preparation method thereof, and relates to the technical field of water treatment membranes. The composite material comprises a porous support layer, an in-situ mineralized polyamide separation layer and a metal-polyphenol gradient functional layer. The in-situ mineralized polyamide separation layer is formed by carrying out interfacial polymerization reaction on a m-phenylenediamine aqueous phase solution and a trimesoyl chloride organic phase solution containing ammonium hexafluorosilicate, and fluosilicate nano-clusters are generated through in-situ hydrolysis; the metal-polyphenol gradient functional layer is formed by sequentially assembling and competitively coordinating a zirconium source solution and polyphenol solutions with different sodium citrate concentrations. According to the invention, the internal nano-clusters construct a water molecule transmission channel, the balance of anti-pollution performance and water mass transfer resistance is realized through the surface gradient functional layer, the obtained composite membrane has high flux and excellent anti-pollution performance, the preparation method is simple and controllable, and the composite membrane has a good industrial application prospect.

The invention relates to the technical field of high polymer material recovery, in particular to a composite catalyst for preparing BHET through PET alcoholysis and a preparation method and application of the composite catalyst. The composite catalyst comprises a solid acid material which is obtained by reacting silica gel of which the surface is grafted with aluminum alkyl and ammonium hexafluorosilicate at 300-800 DEG C. The composite catalyst is suitable for the process of degrading PET by dihydric alcohol, when ethylene glycol is used as an alcoholysis agent, the yield of a main product BHET can reach 95% or above, the catalytic efficiency of the composite catalyst is high, the stability of the catalyst in the alcoholysis process is good, and an efficient catalyst is provided for industrial chemical recovery of PET.

The invention belongs to the technical field of biomass catalytic conversion, and particularly discloses a gallium modified dealumination H-ZSM-5 catalyst and a preparation method and application thereof, and the method comprises the following steps: carrying out ion exchange on a Na-ZSM-5 molecular sieve and an ammonium salt solution; reacting the NH4-ZSM-5 molecular sieve with an ammonium hexafluorosilicate solution, and carrying out selective dealumination; and loading a gallium salt solution to the dealumination molecular sieve carrier DeAl-H-ZSM-5 by adopting an impregnation method to obtain the gallium modified dealumination H-ZSM-5 catalyst. According to the gallium modified dealumination H-ZSM-5 catalyst as well as the preparation method and the application thereof, through a composite strategy of selectively dealuminating and purifying a substrate and then precisely loading Ga to regulate acidity, the prepared catalyst can efficiently catalyze pentose in a gamma-valerolactone / water system to prepare furfural, and high conversion rate and high selectivity are realized.