Hydrocarbon Pyrolysis Sulfur Removal via Mercaptan Decomposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pyrolysis processes require multiple sulfur removal steps, which are complex and inefficient, especially when dealing with sulfur-containing molecules like mercaptan, and introduce additional heteroatoms that need separation, complicating the production of unsaturated hydrocarbons like acetylene and ethylene.
Innovation Solution
A method involving thermal pyrolysis at temperatures greater than or equal to 1200°C to convert hydrocarbon and mercaptan mixtures directly into unsaturated hydrocarbons and hydrogen sulfide, simplifying sulfur removal by performing it in a single stage downstream of pyrolysis, without introducing additional heteroatoms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sulfur removal steps are used upstream of pyrolysis, then sulfur-containing molecules are removed from the feed, but the process complexity increases and additional heteroatoms are introduced that require further separation
Solution Approach 1:
The patent converts the harmful effect of sulfur-containing molecules (mercaptans) by allowing them to undergo pyrolysis along with the hydrocarbon feed. The mercaptans are thermally decomposed at high temperature (≥1200°C) to produce hydrogen sulfide and other sulfur compounds that can be removed in a single downstream step, rather than preventing their entry into the pyrolysis zone through multiple complex upstream removal steps
Solution Approach 2:
Instead of the conventional approach of removing sulfur compounds before pyrolysis, the patent inverts the sequence by performing pyrolysis first and then removing sulfur compounds in a single downstream step. This reversal eliminates the need for multiple upstream separation units and avoids introducing additional heteroatoms that would require further processing
2Reliability
If conventional pyrolysis processes are used with mercaptan-containing feed, then sulfur removal is achieved through multiple steps, but the processing time and operational complexity increase
Solution Approach 1:
The patent merges the pyrolysis process with the sulfur removal process by allowing mercaptans to coexist with the hydrocarbon feed through the pyrolysis zone. Both the hydrocarbon conversion and mercaptan decomposition occur simultaneously in the same reactor at high temperature, eliminating the need for separate upstream sulfur removal units and reducing overall processing time
3Reliability
If upstream sulfur removal steps are implemented, then sulfur-containing molecules are eliminated from the feed, but the number of separation units and process steps increases
Solution Approach 1:
The patent converts mercaptan contaminants into removable sulfur compounds by thermal decomposition. The high-temperature pyrolysis environment (≥1200°C) breaks down mercaptan molecules into hydrogen sulfide and carbon-containing species, which can then be efficiently removed in a single downstream wash or absorption step, reducing the need for multiple upstream separation units
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 approach significantly simplifies the processing of hydrocarbon mixtures containing mercaptan by reducing the number of sulfur removal steps and improving the yield of unsaturated hydrocarbons while minimizing the formation of undesirable byproducts like thiophene and COx.
Implementation Method 1
exposing the first mixture under thermal pyrolysis conditions to a temperature sufficient for converting (i) ≧10.0 wt. % of the first mixture's methane to unsaturated hydrocarbon and molecular hydrogen
Data Source
AI summary
The invention relates to processes for converting a mixture of hydrocarbon and sulfur-containing molecules such as mercaptan into products comprising acetylene, ethylene, and hydrogen sulfide, to processes utilizing the acetylene and ethylene resulting from the conversion, and to equipment useful for such processes.