Nickel Catalyst Mercaptan Trapping Octane Preservation
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Solution Overview
Problem
Current desulfurization processes for gasoline cuts, particularly those from catalytic cracking units, face challenges in selectively removing mercaptan-type compounds without hydrogenating monoolefins, leading to octane number loss and high hydrogen consumption.
Innovation Solution
A process utilizing a nickel-based active phase with a specific weight ratio of elemental nickel (Ni°) to nickel oxide (NiO) between 0.25 and 4, combined with an inorganic support, to trap mercaptans at a temperature range of 170° C. to 220° C., thereby maximizing retention capacity while minimizing product losses and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If catalytic hydrodesulfurization is used to remove sulfur compounds, then sulfur content is reduced, but monoolefins are hydrogenated leading to octane number loss
Solution Approach 1:
The patent changes the operating parameters by using a specific temperature range (170-220°C) and a nickel-based catalyst with controlled oxidation state (Ni°/NiO ratio between 0.25 and 4). These parameter changes enable selective hydrodesulfurization that removes sulfur compounds while minimizing hydrogenation of monoolefins, thus preserving octane number.
Solution Approach 2:
The patent employs a composite catalyst system combining nickel with specific oxidation states (both metallic Ni° and oxide NiO forms) supported on inorganic supports. This composite material structure allows the catalyst to perform hydrodesulfurization selectively without causing excessive hydrogenation of olefins, resolving the contradiction between sulfur removal and octane preservation.
2Quantity of substance
If deep desulfurization is performed to achieve low sulfur content, then sulfur removal efficiency improves, but hydrogen consumption increases
Solution Approach 1:
The patent optimizes the temperature parameter to the range of 170-220°C and controls the Ni°/NiO ratio between 0.25 and 4. Under these specific parameter conditions, the catalyst achieves deep desulfurization efficiency while minimizing hydrogen consumption, as the selective catalysis reduces unnecessary hydrogenation reactions.
Solution Approach 2:
The patent converts the potentially harmful effect of high hydrogen consumption into a benefit by using the nickel-based catalyst to achieve selective sulfur removal. The controlled oxidation state of nickel allows the process to remove sulfur efficiently without requiring excessive hydrogen, thus transforming what would normally be a harmful byproduct (high hydrogen consumption) into an efficient process.
3Quantity of substance
If conventional hydrodesulfurization is used, then sulfur compounds are removed, but recombination mercaptans are formed from olefin hydrogenation
Solution Approach 1:
The patent changes the temperature parameter to 170-220°C and controls the Ni°/NiO ratio to prevent excessive olefin hydrogenation. Under these parameter conditions, sulfur compounds are removed effectively while the formation of recombination mercaptans is minimized, as the selective catalysis avoids the side reaction of olefin hydrogenation followed by mercaptan recombination.
Solution Approach 2:
The patent converts the harmful effect of mercaptan formation into a benefit by using the nickel-based catalyst system. The controlled catalyst composition (Ni°/NiO ratio) selectively promotes sulfur removal while suppressing the side reactions that lead to mercaptan formation, thus transforming a harmful byproduct issue into an efficient selective removal process.
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 process effectively traps mercaptans, preserving the octane number of gasoline and reducing hydrogen consumption, while maintaining high efficiency in sulfur removal.
Implementation Method 1
a process for trapping mercaptan-type compounds contained in hydrocarbon feedstocks in the presence of a trapping mass comprising a nickel-based active phase
Data Source
AI summary
The present invention relates to a process for trapping mercaptans contained in a sulfur-containing hydrocarbon feedstock which is optionally partially desulfurized, resulting from a step of catalytic hydrodesulfurization, at a temperature of between 170° C. and 220° C., a pressure of between 0.2 MPa and 5 MPa, at an hourly space velocity, defined as the volume flow rate of feedstock at the inlet per volume of trapping mass, of between 0.1 h−1 and 50 h−1, in the presence of a trapping mass comprising a nickel-based active phase with an Ni°/NiO ratio of between 0.25 and 4, and an inorganic support selected from the group consisting of alumina, silica, silica-alumina, and clays.