Method for preparing alumina supporter with large pore volume

Abstract

The invention discloses a method for preparing an alumina supporter with large pore volume. The method comprises the following steps: (1) weighing a certain amount of pseudoboehmite dry glue power and a certain amount of extrusion assistant agent to be evenly mixed and then adding an aqueous solution containing a peptizing agent and a chemical pore-enlarging agent; (2) evenly mixing materials obtained in the step (1) and extruding a mixture into strips; and (3) drying and calcinating the material obtained the step (2) to prepare the alumina supporter; wherein the peptizing agent in the step (1) is gluconic acid or mixed organic acid containing the gluconic acid. The using amount of the gluconic acid or the mixed organic acid containing the gluconic acid is 3%-10% by weight of pseudoboehmite dry glue power. The catalyst prepared by means of the preparation method is large in pore volume and pore diameter, concentrated in pore distribution and moderate in mechanical strength and is suitable for the fields of preparation of heavy oil hydrogenation demetalization catalysts, residual oil hydrogenation demetalization catalysts and the like.

Description

technical field [0001] The invention relates to a method for preparing an alumina carrier, in particular to a method for preparing an alumina carrier with large pore volume and diameter and concentrated pore distribution. Background technique [0002] With the continuous reduction of oil resources and the increasing trend of heavy and inferior crude oil, heavy oil deep processing technology has been highly valued by refiners at home and abroad. Hydrodemetallization catalysts used for heavy oil, especially vacuum residue with high metal content, are prone to rapid decline and deactivation of catalyst activity due to the deposition of metal impurities such as nickel and vanadium. Catalysts with larger pore volume and larger pore diameter have strong metal and carbon capacity, which can slow down the deactivation of the catalyst and prolong the operation period of the catalyst. The pore structure of the catalyst is determined by the carrier that constitutes the catalyst. There...

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Problems solved by technology

Since the carbon black powder is added to the carrier by mechanical mixing when the carrier is formed, it is difficult to make the carbon black powder evenly distributed in the carrier by this mechanical mixing, resulting in the dispersion and non-concentration of the final carrier pore distribution and poor mechanical strength.

In addition, most of the peptizers used in the molding process of the prior art are inorganic acids such as nitric acid, hydrochloric acid, phosphoric acid, and organic acids such as citric acid, oxalic acid, formic acid, acetic acid, etc. These acids are easy to damage the pore structure of pseudo-boehmite , resulting in an increase in small pores with a diameter smaller than 14nm