Preparation method of diatomite-based porous ceramic microspheres

Abstract

The invention discloses a preparation method of diatomite-based porous ceramic microspheres. According to the invention, diatomite is adopted as a main material, and the ceramic microspheres with high sphericity (good fluidity), large specific area, and controllable particle sizes are prepared through spray-drying. The diatomite-based porous ceramic microspheres can be used as catalyst carriers in slurry-bed reactions such as Fischer-Tropsch synthesis. The method provided by the invention is advantaged in wide material source, simple technological process, low production cost, and suitabilityfor large-scale continuous industrialized productions. The method has good application values.

Description

technical field [0001] The invention relates to a method for preparing a catalyst carrier, in particular to a method for preparing porous ceramic microspheres using diatomite as a raw material. Background technique [0002] With the progress and development of human civilization, the world's fossil resources are increasingly depleted, and the supply situation of mineral oil is becoming increasingly severe. The problem of energy shortage has become one of the important factors restricting the economic development of all countries in the world. As a green and renewable energy source, new biodiesel (i.e. second-generation biodiesel) has become a research hotspot all over the world due to its many advantages such as wide source of raw materials, low production cost, less pollution, and high quality. The second-generation biodiesel is prepared from biomass (such as rice straw, sawdust, etc.) through gasification, Fischer-Tropsch synthesis, hydrogenation and other processes. Prep...

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Problems solved by technology

The Chinese patent "Preparation Method of Microspherical Silica as Carrier of Olefin Polymerization Catalyst" (200410039492.1) discloses a technology for preparing microspherical silica by sol-gel method, but the process conditions are complicated, the production cost is high, and the sphericity is poor ; U.S. Patent "Macroporous Microspheroids and a Process for Their Manufacture" (US4070286) discloses a method for preparing silica microspheres with a single pore distribution by polycondensation, but the particle size is small, and the average particle size is only 5-9 μm. Difficult to control, single pore size distribution, low yield, poor sphericity; U.S. Patent "Bodies of Siliceous Gels Having Large Pores and Process for Preparing Same" (US3975293) discloses a method for preparing silica microspheres in an autoclave, and also The same harsh reaction conditions, high production cost, low yield, poor sphericity; U.S. Patent "Process for the Production of Hydrocarbons" (US5504118) and Chinese Patent Application "Production Method of Hydrocarbons" (CN1113905A) disclose a method for Catalyst carrier for the synthesis of slurry bed reaction, but the sphericity is poor and the particle size is small, only 5-50 μm, which is not conducive to the online separation of wax and catalyst in the slurry bed; Zhao et al., University of Pittsburgh, USA in Ind. Eng. Chem. Res., 2001, 40, 1065~1075 discloses a preparation method of a catalyst for a slurry bed and a carrier thereof. This technology uses ethyl orthosilicate, copper nitrate, and iron nitrate as raw materials, and obtains precipitation by adding ammonia water slurry, then add KHCO 3 Aqueous solution and a certain amount of SiO 2 Binder, made by beating, spray drying, calcination and other processes

This method adopts ethyl orthosilicate as raw material, the cost is high, and the technological process is complicated at the same time

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