Sulfur-Tolerant Ionic Liquid Alkylation for Coker LPG
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional alkylation processes in refineries face challenges with sulfur-contaminated feeds, leading to high sulfur content in hydrocarbon products, high final boiling points, and catalyst deactivation, especially when using coker LPG olefins which contain undesirable impurities like butadiene and oxygenates.
Innovation Solution
A sulfur-contaminated ionic liquid catalyst, specifically a chloroaluminate with 300 to 20,000 wppm sulfur, is used to alkylate olefins and isoparaffins, allowing for the production of alkylate gasoline blending components with a final boiling point below 221°C, and a process is developed to treat coker LPG streams to reduce sulfur and oxygenate content before alkylation, using an ionic liquid alkylation reactor that exclusively processes coker LPG olefins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional alkylation catalysts are used with sulfur-contaminated feeds, then the alkylation reaction can proceed, but the hydrocarbon products contain undesirable high sulfur content
Solution Approach 1:
The patent changes the chemical parameters of the catalyst system by using ionic liquid catalysts with specific compositions (e.g., [C2H5NH3][AlCl4], [C4H9NH3][AlCl4]) that can tolerate sulfur contamination. The ionic liquid catalysts operate at controlled temperatures (50-150°C) and pressures, allowing the reaction to proceed while sulfur accumulates in the catalyst phase rather than contaminating the hydrocarbon product, thus resolving the contradiction between maintaining productivity and reducing sulfur content in products.
2Productivity
If conventional alkylation catalysts process sulfur-contaminated feeds, then hydrocarbon production can continue, but the final boiling point of products becomes high
Solution Approach 1:
The patent employs ionic liquid catalysts that operate at optimized temperature and pressure parameters, enabling precise control over the alkylation reaction. The ionic liquid medium provides a controlled reaction environment where temperature (50-150°C) and pressure can be maintained at levels that promote selective alkylation reactions, producing hydrocarbons with controlled molecular weights and corresponding boiling points, thus achieving both productivity and manufacturing precision.
3Productivity
If conventional alkylation catalysts are exposed to sulfur-contaminated feeds, then the alkylation process can operate, but the catalyst deactivates quickly
Solution Approach 1:
The patent converts the harmful effect of sulfur contamination into a beneficial feature by designing ionic liquid catalysts that selectively absorb and accumulate sulfur in their phase. The ionic liquid catalysts are formulated to have high affinity for sulfur species, causing sulfur to partition into the catalyst phase rather than inhibiting the catalytic activity. This allows the catalyst to maintain its alkylation function while sequestering sulfur, thereby extending catalyst lifetime and resolving the contradiction between maintaining productivity and preventing deactivation.
4Adaptability or versatility
If coker LPG olefins are used as feedstock, then the refinery can utilize a valuable stream, but the feed contains undesirable impurities like butadiene and oxygenates
Solution Approach 1:
The patent develops an ionic liquid catalyst system that is universally applicable to various feedstocks including coker LPG olefins with impurities. The ionic liquid catalysts can process feeds containing sulfur (80-500 wppm), oxygenates, and other impurities without requiring extensive pre-treatment. The catalyst system is designed to handle the full range of coker LPG composition, making the refinery able to utilize this valuable feedstock stream directly, thus achieving both adaptability and reducing the impact of harmful factors.
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 produces high-quality alkylate gasoline with a final boiling point below 221°C, maintaining catalyst activity over extended periods, and reduces acid catalyst consumption, even with high sulfur and impurity levels in the coker LPG feed, offering a superior alternative to conventional methods.
Implementation Method 1
alkylating the olefin feed with an isoparaffin using the sulfur-contaminated ionic liquid catalyst to make the alkylate gasoline blending component
Data Source
AI summary
Processes are provided for making an alkylate gasoline blending component, comprising:a. feeding an olefin feed comprising greater than 80 wppm of a sulfur contaminant comprising mercaptans, alkyl sulfides, and alkyl disulfides to a chloroaluminate ionic liquid catalyst, wherein a level of the sulfur contaminant accumulates in the chloroaluminate ionic liquid catalyst to make a sulfur-contaminated ionic liquid catalyst comprising 300 to 20,000 wppm of a sulfur; andb. alkylating the olefin feed with an isoparaffin using the sulfur-contaminated ionic liquid catalyst to make the alkylate gasoline blending component having a final boiling point below 221° C. An alkylation process exclusively utilizing coker LPG olefins is also provided.