Reactive Desulfurization of Olefinic LPG via Ion Exchange Resin
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Solution Overview
Problem
Conventional methods for removing sulfur and impurities from LPG streams generate significant caustic waste and do not effectively remove heavy sulfur compounds, leading to environmental issues and inefficiencies in petrochemical processes.
Innovation Solution
A reactive desulfurization process using a modified ion exchange resin catalyst in a reactor, which treats LPG streams with olefins to convert sulfur compounds into heavier sulfides without requiring caustic, allowing for the reuse of spent catalysts and minimizing waste generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional amine treatment followed by caustic and water wash is used to remove sulfur from LPG, then H2S and mercaptans are removed, but significant caustic waste is generated causing environmental issues
Solution Approach 1:
The invention changes the chemical parameters of the treatment process by using a solid acid catalyst instead of conventional amine-caustic systems. The catalyst contains active sites with specific acidity parameters that enable direct conversion of mercaptans to disulfides without generating liquid caustic waste, thus resolving the contradiction between sulfur removal efficiency and waste generation
Solution Approach 2:
The invention employs a disposable solid acid catalyst that can be easily replaced rather than regenerated. This disposable catalyst system eliminates the need for caustic regeneration equipment and reduces environmental burden, addressing the harmful waste generation issue while maintaining effective sulfur removal
2Quantity of substance
If caustic wash is used to remove mercaptans from LPG, then mercaptan sulfur is removed, but the process does not effectively remove heavy sulfur compounds and generates significant waste
Solution Approach 1:
The invention substitutes the mechanical/chemical caustic wash system with a catalytic conversion system. The solid acid catalyst provides active sites that chemically transform mercaptans and heavy sulfur compounds into disulfides through adsorption and reaction mechanisms, eliminating the need for caustic consumption and associated waste generation
3Ease of manufacture
If spent catalyst from process units is disposed of in landfill, then disposal is simple, but environmental burden increases and valuable catalyst material is wasted
Solution Approach 1:
The invention implements a catalyst recovery and reuse system where spent catalyst from various process units is collected, regenerated through calcination to restore active sites, and reused in the sulfur removal process. This closed-loop approach eliminates landfill disposal, reduces environmental burden, and recovers valuable catalyst materials
Solution Approach 2:
The invention creates a universal catalyst treatment system that can handle spent catalyst from multiple different process units (MTBE, ETBE, TAME, dimerization, etc.). The regenerated catalyst can be applied across different applications, making the disposal and recovery system versatile and economically viable
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 reduces sulfur content in LPG to below 10 ppmw, eliminates caustic waste, and effectively removes heavy sulfur compounds, making it environmentally benign and suitable for downstream petrochemical processes.
Implementation Method 1
a reactive desulfurization process using a modified ion exchange resin catalyst in a reactor, which treats LPG streams with olefins to convert sulfur compounds into heavier sulfides
Data Source
AI summary
Organic sulfur compounds which are generally present in the crude oil undergoes various transformations while processing the crude oil in the secondary processing units such as fluid catalytic cracker, hydrocracker, delayed coker, visbreaker, etc. The sulfur present in the feed which enters into these secondary processing units are distributed into various products coming out of the units. Sulfur compounds which are present in the various product fractions are removed to meet the desired specifications before routing to the final product pool. Conventionally, sulfur present in the LPG has been removed by amine treatment followed by caustic and water wash. The present invention relates to a process for removal of sulfur and other impurities from Liquefied Petroleum Gas (LPG) comprising olefins through reactive desulfurization route. The present invention is an eco-friendly process as it minimizes or eliminates the use of caustic which is conventionally used to remove the sulfur from LPG.