Hydrotreating Catalyst Activation via pH-Adjusted Organic Acid
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrotreating catalysts experience reduced activity after regeneration due to metal sintering and physical instability issues, such as loss-on-attrition (LOA), particularly when treated with pure organic acids, which can corrode and dissolve the alumina carrier.
Innovation Solution
A method involving the use of an organic acid and an alkaline additive to adjust the pH of an aqueous solution to above 3, followed by heat-treating the catalyst, which helps redistribute metals and mitigate carrier dissolution, thereby restoring catalyst activity and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a hydrotreating catalyst is treated with pure organic acid during activation, then metal redistribution is improved, but loss-on-attrition (LOA) increases due to carrier corrosion
Solution Approach 1:
An alkaline additive is introduced as an intermediary substance that mediates between the organic acid and the alumina carrier. The alkaline additive neutralizes the corrosive effect of the organic acid on the carrier while allowing the acid to effectively redistribute the metal components, thus resolving the contradiction between metal dispersion and mechanical stability
Solution Approach 2:
The pH of the activation solution is changed from acidic (pure organic acid) to alkaline or near-neutral (organic acid + alkaline additive). This parameter change reduces the corrosiveness toward the alumina carrier while maintaining or enhancing the metal redistribution capability, thereby improving mechanical stability without sacrificing manufacturing precision
2Reliability
If a spent catalyst is regenerated through thermal treatment, then catalyst activity is restored, but metal sintering occurs reducing dispersion
Solution Approach 1:
The alkaline additive is applied to the catalyst before or during the regeneration process to prevent metal sintering. This preliminary action protects the metal dispersion during the thermal treatment that restores catalyst activity, resolving the contradiction between activity restoration and dispersion maintenance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively rejuvenates hydrotreating catalysts by reducing LOA and maintaining catalyst stability, allowing for improved performance and extended service life with minimal changes to existing processes.
Implementation Method 1
treating the catalyst with a solution containing an organic acid and a base to redistribute the metals after regeneration
Implementation Method 2
heat-treating the catalyst at a temperature of 120-450° C.
Implementation Method 3
adjusting an aqueous activating solution, which contains an organic acid, to pH > 3 with an alkaline additive
Data Source
AI summary
A method for activating an oxidic fresh hydroprocessing catalyst or the catalytically active material of a spent hydroprocessing catalyst comprising a refractory oxide support and one or more base metals selected from Ni, Co, Mo and W comprises optionally regenerating the catalyst, adjusting an aqueous activating solution, which contains an organic acid, to pH > 3 with an alkaline additive, impregnating the catalytically active material with the pH-adjusted aqueous activating solution, and heat-treating the catalyst at a temperature of 120-450° C.