Preparation method of a low-heap specific gravity and high-activity low-temperature shift catalyst

Abstract

Belonging to the technical field of catalyst preparation, the invention relates to a preparation method of a low temperature shift catalyst with low bulk specific gravity and high activity. The catalyst is composed of a copper zinc aluminum ternary system. The preparation method includes: using precipitation method to acquire a copper zinc aluminum ternary material, conducting washing and filtering to obtain a wet filter cake, then carrying out granulation and roasting by two processes respectively to obtain clinkers, mixing the two clinkers and conducting tabletting to obtain the catalyst. The catalyst has moderate strength, low bulk specific gravity, reduced wear rate and enhanced toughness, and the activity and selectivity of the catalyst are both improved. The bulk specific gravity reaches 1.40-1.42Kg / L, the initial activity (CO conversion rate) can reach 79%-80%, the activity after exposure to high temperature (CO conversion) can reach 69%-70%, and the amount of by-product methanol can be controlled within 900ppm. The catalyst is suitable for low temperature shift reaction under the conditions of a use temperature of 140-260DEG C and a use pressure of 1.0-4.0Mpa in large energy-saving (low gas-steam ratio) ammonia plants, and is also suitable for general large ammonia plants, as well as small and medium sized ammonia plants and hydrogen production plants where low temperature shift is carried out at low pressure.

Description

technical field [0001] The invention belongs to the technical field of catalyst preparation, and in particular relates to a preparation method and application of a novel catalyst with low bulk specific gravity, suitable strength, low abrasion and high activity at low temperature. Background technique [0002] The copper-zinc-aluminum ternary material is obtained by the precipitation method, and the wet filter cake is obtained by washing and filtering, and the wet filter cake is dried in an oven, and the dry filter cake is obtained by grinding, granulating, drying, roasting, and tableting by a mixer mill. For catalysts, the particle pore structure is too large or too small, and there is a phenomenon of uneven particle size distribution, which directly has an important impact on the performance of the catalyst. The first impact is that the particle pore structure is not suitable and the particle size distribution is not reasonable, resulting in Catalyst tableting process is di...

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Problems solved by technology

[0002] The copper-zinc-aluminum ternary material is obtained by the precipitation method, and the wet filter cake is obtained by washing and filtering, and the wet filter cake is dried in an oven, and the dry filter cake is obtained by grinding, granulating, drying, roasting, and tableting by a mixer mill. For catalysts, the particle pore structure is too large or too small, and there is a phenomenon of uneven particle size distribution, which directly has an important impact on the performance of the catalyst. The first impact is that the particle pore structure is not suitable and the particle size distribution is not reasonable, resulting in Catalyst tableting process is difficult to form, low strength, high bulk specific gravity, if the strength is further increased, the bulk specific gravity data of the catalyst will be even higher, even reaching above 1.55Kg / L, and the catalyst is brittle, easy to take off the cap, and there are many short pieces, the product The detected attrition rate is high. Due to the crushing of the catalyst during use, the manufacturer will increase the bed resistance and the frequency of starting and stopping. Low, the initial activity of the catalyst and the activity after heat resistance are generally low, which directly affects the use effect of the catalyst on industrial devices

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