Olefin Hydrogenation Catalyst for High Concentration Refinery Gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for hydrogenating refinery fuel gas feeds to steam methane reformers struggle with high olefin concentrations, as they cannot handle levels above 4 to 6 mole% without exceeding temperature limits, leading to catalyst deactivation and hydrocarbon cracking, and require complex and costly solutions to manage variability in feed gas composition.
Innovation Solution
A process using a sulfided metal catalyst on an alumina support with 5-20 wt% NiO and 9-40 wt% MoO3, operating at inlet temperatures from 100°C to 175°C, followed by adiabatic reaction to produce saturated hydrocarbons, and subsequent sulfur removal with ZnO, allowing for higher olefin concentrations up to 30 mole% and adapting to feed gas variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional adiabatic hydrogenation is used with standard catalysts, then the process is simple and cost-effective, but it cannot handle olefin concentrations greater than 4 to 6 mole% without exceeding temperature limits
Solution Approach 1:
The patent changes the catalyst composition parameters by incorporating specific ratios of nickel (5-20 wt%) and molybdenum (9-40 wt%) on an alumina support, which fundamentally alters the reaction kinetics and temperature profile, enabling higher olefin concentrations to be processed within safe temperature limits
Solution Approach 2:
The patent uses a composite catalyst material combining nickel oxide, molybdenum oxide, and alumina support, where the synergistic interaction between these components enables effective hydrogenation of high olefin concentrations while maintaining temperature control through the heat capacity and thermal properties of the composite structure
2Temperature
If natural gas is blended with RFG feed to dilute olefin concentration, then temperature limits are maintained, but RFG utilization is restricted and equipment capacity increases
Solution Approach 1:
Instead of changing the feed composition by dilution, the patent changes the catalyst parameters to achieve complete hydrogenation of high olefin concentrations, thereby maintaining temperature control while maximizing RFG utilization without requiring additional natural gas blending or larger equipment capacity
3Temperature
If isothermal reactor or recycling is used to handle high olefin concentrations, then temperature control is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent achieves temperature control by changing the catalyst composition parameters rather than by adding complex control systems, maintaining the simplicity of the adiabatic reactor design while enabling processing of high olefin concentrations through the improved catalytic activity and heat management properties of the Ni-Mo-Alumina catalyst
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 process effectively handles higher olefin concentrations without catalyst deactivation, simplifies equipment and control systems, and maintains efficiency by operating within safe temperature limits, enabling more flexible and cost-effective utilization of refinery fuel gas feeds.
Implementation Method 1
contacting said olefin and said H2 with said catalyst to react said olefin and said H2 under reaction conditions effective to produce a saturated hydrocarbon
Implementation Method 2
a process for hydrogenating olefins
Implementation Method 3
said reactor is operated adiabatically
Implementation Method 4
removal of H2S with ZnO
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A process for hydrogenating olefins is disclosed. The olefins are present in a feed gas which includes H2 and one or more sulfur compounds. The sulfur compounds may include H2S and organic sulfur compounds. The feed gas is passed through a reactor at an inlet temperature from 100°C to 250°C. The reactor contains a catalyst which is active at the inlet temperature. The reactor may be adiabatic. Saturated hydrocarbons are formed from the olefins. A temperature gradient may be formed in the reactor due to the exothermic nature of the hydrogenation reaction, causing the temperature to increase downstream in the reactor. At temperatures higher than the inlet temperature, H2S may be formed from organic sulfur compounds. A gas mixture including saturated hydrocarbons, H2S and H2 exits the reactor and may be brought into contact with a chemical adsorbent which removes the H2S. The gas stream may then be passed to a steam methane reformer.