Ceramic silk-screen hydrogenation protective agent

Abstract

The invention discloses a ceramic silk-screen hydrogenation protective agent which is obtained by the following steps: forming powder materials formed by raw materials of 20-30 wt% of pseudo-boehmite, 40-55 wt% of alumina powders, 10-20 wt% of silicon carbide powders, 2-5 wt% of rare earth magnesium alloy powders, 2-5 wt% of zirconia powders and 3-5 wt% of kaolin; adding an auxiliary agent and appropriate amount of water in the powder materials, carrying out ball-milling and mixing and carrying out blending until viscosity is 22-30s according to a T-4 viscosity cup, and then, carrying out filtering to obtain slurry; dipping a sponge base into the slurry above, standing still, and then taking the sponge base out and removing the surplus slurry to obtain a green body; and after carrying out drying and shaping on the green body, putting the green body into a calcinator, carrying out heating until the temperature reaches 1100-1280 DEG C, and then, carrying out heat preservation baking to obtain the product. The ceramic silk-screen hydrogenation protective agent is light in specific gravity, high in porosity and small in stacking density; impurity tolerance capability of the ceramic silk-screen hydrogenation protective agent is improved by 30% and the above compared with that of a honeycomb pore ceramic protective agent, and is improved by 50% and the above compared with that of a conventional porcelain ball (porcelain ring); and since the protective agent has multiple holes, circulation velocity of liquid is accelerated, activity is enhanced, catalytic reaction speed is improved, and the hydrodesulfurization processing effect is improved.

Description

technical field [0001] The invention relates to a catalyst protecting agent, in particular to a ceramic screen hydrogenation protecting agent. Background technique [0002] As we all know, fixed bed reactor is an important equipment and device in oil refining, petrochemical, chemical, environmental protection and metallurgy industries. It is mainly used for catalytic reactions in the tower, such as ammonia synthesis tower, sulfur dioxide contact oxidizer, hydrocarbon steam reformer and oil refining Catalytic reforming, hydrodesulfurization, hydrocracking and refining, as well as ethylene oxidation, ethylbenzene dehydrogenation, etc. Residual oil hydrotreating agent is the key to fixed bed hydrodesulfurization treatment technology. During the processing process, metal impurities (such as V, Ni, Ca, Fe, etc.) and scales ( Such as coke) is easy to deposit in the gap between the catalyst surface and the catalyst particles. On the one hand, it will block the catalyst pores and c...

AI Technical Summary

Problems solved by technology

Although ceramic balls have the characteristics of high strength and good acid and alkali resistance, they have the following disadvantages: First, due to the limitation of the structure of the ceramic ball itself, the porosity is low and the specific surface area is small, resulting in an excessive pressure drop in the fixed bed reactor. , increase the flow resistance of the reactants, reduce the frequency of effective contact of the reactants, thus affecting the catalytic reaction efficiency of the fixed bed reactor; second, although the porosity of the ceramic ring is high, the pore size between the particles of the ceramic ring is too large and the distribution is uneven , so that it reduces the ability to intercept impurities, and there are many restrictions on supporting small-scale catalysts, which affects the treatment effect, shortens the life cycle of the fixed-bed reactor, and increases the operating cost

However, as crude oil becomes heavier, its quality deteriorates, and the deep utilization and development of crude oil, the impurity content of heavy oil crude oil is high. In the catalytic reaction of fixed bed reactor in oil refining, the existing honeycomb ceramic protective agent still has the following shortcomings: 1. Although the honeycomb ceramic protective agent has the above advantages, due to the limitation of the mold structure and machine pressing, the honeycomb ceramics cannot form a three-dimensional mesh intercommunicating open-pore structure, and the adsorption and containment of impurities are independent and limited, so its capacity The impurity capacity (impurity capacity) is limited; the second is that due to the increase of crude oil impurities, the impurities are easy to deposit on the interface between the catalyst and the protective agent in the reactor, and the reaction phase cannot form a good catalytic reaction on the interface, which not only causes the reaction The oil and gas channels of the reactor are blocked, which increases the pressure drop in the reactor, and may also cause the catalyst to carbonize and coke too quickly, thereby shortening the service life of the catalyst