Butadiene Extraction Integrating Selective Hydrogenation
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Solution Overview
Problem
Current butadiene recovery processes from mixed C4 hydrocarbon streams are inefficient, leading to high energy requirements, multiple waste streams, and increased costs due to the separation of 1,2-butadiene and other impurities, which complicates downstream hydrogenation and results in reduced productivity.
Innovation Solution
Integrating post-extraction selective hydrogenation with butadiene extraction unit feed preparation, where the heavies fraction and hydrogenation reactor effluent are co-processed in a separator to recover 1,2-butadiene and reduce waste streams, and using the vaporization drum liquid as reflux to eliminate cooling requirements and consolidate heavy components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional extractive distillation processes are used to separate mixed C4 streams, then butadiene can be recovered, but multiple waste streams are generated and energy consumption increases
Solution Approach 1:
The patent combines the heavies fraction from butadiene extraction with the feed to the selective hydrogenation unit, merging two separate process streams into one. This integration allows 1,2-butadiene and other heavy components to be co-processed, reducing the number of separate waste streams and eliminating the need for separate cooling systems, thereby reducing energy consumption.
Solution Approach 2:
The selective hydrogenation unit is designed to handle both its traditional feed stream and the heavies fraction from butadiene extraction. This multi-functionality allows the same unit to process multiple streams, converting what would otherwise be waste materials into useful products like 1-butene and isobutene, thereby reducing waste and energy requirements.
2Manufacturing precision
If 1,2-butadiene is separated from the butadiene extraction process, then purity is improved, but productivity decreases due to complex downstream processing
Solution Approach 1:
The patent extracts 1,2-butadiene and other heavy components from the butadiene extraction process by combining them with the feed to the selective hydrogenation unit. This separation occurs at the extraction stage rather than requiring complex downstream processing, maintaining purity while simplifying the overall process and improving productivity.
3Reliability
If the heavies fraction is processed separately from the hydrogenation reactor effluent, then separation is achieved, but the number of vessels and unit operations increases
Solution Approach 1:
The patent merges the heavies fraction stream with the feed to the selective hydrogenation unit, combining two streams that would otherwise require separate processing vessels and unit operations. This integration maintains effective separation of components while reducing the overall number of vessels and simplifying the process flow.
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 reduces energy consumption, minimizes waste streams, and enhances the recovery of valuable products by recycling 1,2-butadiene and consolidating heavy components, thereby improving the overall efficiency and cost-effectiveness of butadiene recovery processes.
Implementation Method 1
selectively hydrogenating at least one of the C3 acetylene fraction and the C4 acetylene fraction to produce a hydrogenated effluent comprising olefins, dienes, and oligomer byproducts
Implementation Method 2
feeding the hydrogenated effluent and the fraction comprising the 1,2-butadiene and the C5 hydrocarbons to a separator to recover a heavies fraction comprising the hydrocarbons and the oligomer byproducts and a lights fraction comprising the olefins, dienes, and 1,2-butadiene
Implementation Method 3
butadiene vaporization may require the removal of non-vaporized components from a vaporizer drum
Data Source
AI summary
A process for recovering butadiene from a C4 fraction is disclosed. The process may include: contacting a mixed C4 stream comprising butane, butene, and butadiene, with a solvent comprising an organic solvent and water in a butadiene pre-absorber column to recover an overheads fraction comprising at least a portion of the butane, butene, and water, and a first bottoms fraction comprising the organic solvent, butadiene, and at least a portion of the butene; and feeding the first bottoms fraction to a butadiene extraction unit to recover a butene fraction, a crude butadiene fraction, and a solvent fraction.