Copper(I) Sulfide Catalyst for Olefin Gas Purification
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Solution Overview
Problem
Current processes for removing acetylene and other impurities from hydrogen-rich olefin-containing gas mixtures are inefficient, leading to catalyst poisoning, corrosion, and the formation of explosive deposits, requiring multiple cleaning steps and catalyst replacements, while existing solutions like nickel-containing catalysts convert valuable olefins to less valuable products and pose environmental risks.
Innovation Solution
A process using a catalyst containing copper(I) sulfide, prepared by reducing copper oxide and sulfiding with sulfur-containing compounds, which effectively removes acetylene, oxygen, nitrogen oxides, and dienes from gas mixtures, maintaining high selectivity and adsorbing toxic compounds without significant olefin conversion to alkanes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel-containing catalysts are used to remove nitrogen oxides and oxygen, then these impurities are converted, but valuable olefins are converted to less valuable paraffins and toxic nickel tetracarbonyl is released
Solution Approach 1:
The invention changes the chemical composition parameters of the catalyst by using copper(I) sulfide instead of nickel-based catalysts. This parameter change allows the catalyst to selectively remove nitrogen oxides and oxygen without converting olefins to paraffins or releasing toxic nickel tetracarbonyl, thus resolving the contradiction between impurity removal and harmful byproduct formation
Solution Approach 2:
The copper(I) sulfide catalyst provides a shorter-lived but more selective catalytic action that removes impurities without the side effects of nickel catalysts. The catalyst can be replaced more frequently at lower cost rather than causing ongoing harmful conversions of valuable olefins
2Productivity
If selective hydrogenation catalysts are used to remove acetylenes and dienes, then these compounds are converted to olefins, but the catalysts are poisoned by accumulated impurities leading to decreased conversion and requiring catalyst replacement
Solution Approach 1:
The invention applies preliminary action by removing poisons such as nitrogen oxides, oxygen, and sulfur compounds before the selective hydrogenation step. This preliminary cleaning prevents catalyst poisoning and maintains high conversion efficiency and selectivity over extended periods, resolving the contradiction between productivity and reliability
Solution Approach 2:
The invention segments the cleaning process into multiple stages: first removing nitrogen oxides and oxygen with copper(I) sulfide, then removing sulfur compounds with zinc oxide, and finally performing selective hydrogenation. This segmentation prevents catalyst poisoning and maintains long-term productivity
3Reliability
If multiple cleaning steps are used to remove different impurities, then comprehensive cleaning is achieved, but process complexity and number of reactors increase
Solution Approach 1:
The invention merges multiple cleaning functions into a single integrated catalyst bed containing both copper(I) sulfide for nitrogen oxide and oxygen removal, and zinc oxide for sulfur compound removal. This consolidation achieves comprehensive impurity removal while reducing the number of reactors and process complexity
Solution Approach 2:
The copper(I) sulfide catalyst performs multiple functions: removing nitrogen oxides, removing oxygen, and preventing catalyst poisoning. The zinc oxide component adds sulfur compound removal. This multi-functionality in a single unit resolves the contradiction between comprehensive cleaning and process complexity
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 copper(I) sulfide catalyst achieves high selectivity in removing impurities, with over 98% removal of acetylene, oxygen, and nitrogen oxides, while minimizing olefin hydrogenation and adsorbing toxic compounds, allowing for a single-step cleaning process that reduces catalyst complexity and environmental risks.
Implementation Method 1
Acetylenes and dienes are formed as by-products in the cracking processes, which are not primary valuable products but can disrupt the further processing of the olefins. In steam crackers in particular, these compounds are produced in the percentage range and are removed there by selective hydrogenation.
Implementation Method 2
Palladium-containing catalysts are preferably used in the selective hydrogenation stages, in which small amounts of the noble metal are used as the active component on an oxidic catalyst support. Alternatively, nickel-containing catalysts can also be used in front-end hydrogenation.
Implementation Method 3
Other impurities include compounds of elements such as: B. Sulfur, arsenic, phosphorus, mercury, vanadium, cadmium or lead. These elements are also strong catalyst poisons and can poison the catalysts in the selective hydrogenation stages. They cannot be chemically converted in such a way that they could remain as harmless compounds in the fission gas. Therefore, these elements are accumulated by physical or chemical adsorption on a suitable cleaning adsorbent and thus removed from the cracked gas.
Data Source
AI summary
The invention relates to a method for eliminating at least one of the components selected from among the group comprising oxygen, nitrogen oxides, acetylenes, and dienes, from a gas mixture containing said at least one component in addition to hydrogen, one or several olefins that are no dienes, and other optional gas components. According to said method, the gas mixture is contacted with a catalyst in a reaction zone. The disclosed method is characterized in that the catalyst contains copper(I) sulfide.