Hydrotreating High Nitrogen Feed with Bulk Catalyst
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Solution Overview
Problem
Conventional hydrotreating processes face difficulties with high nitrogen content feeds, as they suppress catalytic activity and hinder nitrogen removal and aromatic saturation, making it challenging to process feeds with nitrogen levels above 0.3 wt%, especially in fluid catalytic cracking processes.
Innovation Solution
A process involving a supported hydrotreating catalyst followed by a sulfided bulk metal catalyst with a non-noble Group VIII metal molybdate, where some molybdenum is replaced by tungsten, is used to treat hydrocarbon feeds with nitrogen contents above 3000 wppm, under specific conditions to enhance nitrogen removal and aromatic saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional supported hydrotreating catalysts are used, then the process can handle standard feedstocks, but catalytic activity is suppressed when nitrogen content exceeds 0.3 wt%
Solution Approach 1:
The patent changes the physical and chemical parameters of the catalyst by using bulk metal catalysts with specific metal compositions (Ni, Co, Mo, W, Pt, Pd, Rh, Ir) in various ratios, operating temperatures (300-450°C), and pressures (300-2000 psi), thereby maintaining catalytic activity in high nitrogen environments where conventional catalysts fail
Solution Approach 2:
The patent employs composite bulk metal catalysts containing multiple metals (e.g., Ni-Mo-W, Co-Mo, Pt-Re) that work synergistically to maintain catalytic activity in high nitrogen feeds, overcoming the limitations of single-metal or supported catalyst systems
2Productivity
If high nitrogen content feeds (above 0.3 wt% nitrogen) are processed, then the feed utilization is improved, but nitrogen removal and aromatic saturation become difficult
Solution Approach 1:
The patent adjusts process parameters including temperature (300-450°C), pressure (300-2000 psi), and LHSV (0.1-10 hr⁻¹) to optimize both feed processing capability and nitrogen removal efficiency simultaneously, enabling handling of feeds with up to 5 wt% nitrogen
3Reliability
If bulk metal catalysts are used, then catalyst activity is maintained in high nitrogen feeds, but the catalyst composition and process conditions require optimization
Solution Approach 1:
The patent systematically optimizes catalyst composition parameters (metal ratios, sulfidation levels) and process parameters (temperature, pressure, LHSV) to achieve reliable catalytic activity while managing the complexity of bulk metal catalyst systems
Solution Approach 2:
The patent applies different metal compositions and properties to specific catalyst functions (e.g., Ni for hydrodesulfurization, Mo for hydrodenitrogenation, W for stability), creating locally optimized catalyst regions within the bulk metal catalyst system
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
This approach effectively removes nitrogen and sulfur, improves aromatic saturation, and maintains catalyst activity, enabling the processing of high nitrogen content feeds suitable for fluid catalytic cracking, with significant reductions in nitrogen and sulfur levels and improved API gravity.
Implementation Method 1
contacting the hydrotreated hydrocarbon feedstock with a sulfided bulk metal catalyst under second hydrotreating conditions to produce a hydrotreated effluent
Implementation Method 2
hydrotreating a feedstock having a high nitrogen content... to produce a hydrotreated effluent
Implementation Method 3
improves aromatic saturation... with significant reductions in nitrogen and sulfur levels and improved API gravity
Data Source
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AI summary
Methods are provided for hydrotreating high nitrogen feeds with improved results for nitrogen removal, aromatic saturation, and/or sulfur removal. The method includes hydrotreating the feed with a supported hydrotreating catalyst followed by a bulk metal catalyst, the hydrotreated effluent of which can be suitable for use as a feed to an FCC reactor.