Catalyst roasting - plastic dual-purpose rotary kiln

Abstract

The invention relates to two processes of roasting and shaping in a preparation process of a solid phosphoric acid catalyst (SPAC). The catalyst is applied to reactions such as oligomerization of low-carbon olefins and alkylation of propylene. In the past, SPAC preparation, roasting and shaping processes were carried out separately. The static method was used for roasting, and the materials could not be fully and evenly heated; the shredder was used for shaping, resulting in low yield of finished products, high crushing loss, high broken particles and powder, and "memory" inside the particles. crack. The inventor proposed the concept of critical strip length and defined the probability function of particle fracture: ζi=k·(Li‑Lcri)α. During the rotation of the kiln, homogeneous strips fall from the top of the built-in lifting board and hit the bottom. The strip length tends to be the same, and the dual-purpose rotary kiln is designed for roasting and shaping. The obtained SPAC particles have a narrow distribution of length and strength, which improves the conversion rate of the catalytic reaction and the selectivity of oligomers, reduces its muddy tendency, and prolongs the operating life. The particle length of the product of the present invention depends on the effective radius (rbs) of the roasting kiln. The present invention can be implemented industrially.

Description

technical field [0001] The invention belongs to the field of solid phosphoric acid catalyst preparation, in particular to a catalyst roasting-shaping dual-purpose rotary kiln, in particular to a roasting process and shaping process for preparing a solid phosphoric acid catalyst. Background technique [0002] There are two types of oligomerization catalysts, homogeneous and heterogeneous. Although homogeneous catalysts such as sulfuric acid and phosphoric acid have the advantages of high reaction rate and high conversion rate, but there are problems such as difficult product separation and a large amount of waste liquid to be treated, basically no industrial devices are used; heterogeneous oligomerization catalysts mainly include : Zeolite solid acid catalyst, non-zeolite solid acid catalyst and other supported catalysts. Supported oligomerization catalysts can be roughly classified into 3 categories: one is based on BF 3 The representative load Lewis acid or superacid olig...

AI Technical Summary

Problems solved by technology

[0009] (1) After the roasting process, the material is sent to the crusher for crushing and shaping. When the particles are crushed, a large amount of broken particles and dust are generated, and there are problems such as high product wear rate, large crushing loss, and low yield;

[0010] (2) The traditional roasting process adopts a static method. Regardless of the tunnel kiln or the muffle furnace, there are defects such as uneven heating of the processed materials and different degrees of roasting, resulting in uneven product strength;

[0011] (3) The roasted product is shaped by a crusher, and there are residual cracks (commonly known as memory cracks) in the catalyst particles. The particles with poor strength and cracks are easy to break during transportation and loading; Layer pressure drop rises

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