Hybrid Adsorption-Distillation for Butene-1 Purity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distillation processes for separating butene-1 from C4 hydrocarbon mixtures result in significant butene-1 loss due to small differences in relative volatilities among components, leading to high energy consumption and investment costs.
Innovation Solution
A hybrid process combining adsorption separation of paraffins from C4 olefins/paraffins mixtures followed by distillation to produce high-purity butene-1, utilizing π-complex adsorbents like type X or Y zeolites and C5/C6 hydrocarbons as desorbents, with sequential adsorption, rinse, and desorption steps in multiple towers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If distillation process is used to separate butene-1 from C4 hydrocarbon mixture, then butene-1 can be obtained with high purity, but energy consumption and investment costs increase significantly
Solution Approach 1:
The separation process is divided into two distinct stages: (1) adsorption stage where paraffins are selectively removed from the C4 mixture using molecular sieve adsorbents, and (2) distillation stage where butene-1 is separated from the enriched olefin stream. This segmentation allows each stage to focus on a specific separation task, reducing the overall complexity and energy requirements compared to direct distillation of the full mixture.
Solution Approach 2:
The adsorption process performs a preliminary separation by removing paraffins (isobutane and normal butane) before the distillation step. This preliminary action concentrates the olefins and removes components that would otherwise require additional distillation stages, thereby reducing the energy consumption and equipment size needed for the subsequent distillation process.
2Manufacturing precision
If distillation towers with large number of fractionation plates are used, then separation precision improves, but device complexity and investment costs increase
Solution Approach 1:
The separation functionality is segmented between two different types of equipment: molecular sieve adsorption towers for paraffin removal and a reduced-scale distillation tower for butene-1 purification. This segmentation replaces the need for a single large, complex distillation tower with many fractionation plates with a combination of simpler adsorption vessels and a smaller distillation unit.
Solution Approach 2:
The molecular sieve adsorbent acts as an intermediary substance that selectively binds paraffins from the C4 mixture. This intermediary material enables the first separation stage to occur in relatively simple adsorption towers rather than requiring complex distillation equipment, thereby reducing overall device complexity while maintaining high separation precision.
3Manufacturing precision
If sequential distillation towers are used to remove isobutane and obtain butene-1, then butene-1 purity increases, but butene-1 loss increases due to discharge with isobutane stream and bottom mixture
Solution Approach 1:
The adsorption process extracts and removes paraffins (isobutane and normal butane) from the C4 hydrocarbon mixture in the first stage. By taking out these paraffinic components that would otherwise carry butene-1 away in the distillation overhead and bottom streams, the process prevents butene-1 loss while still achieving high purity in the final product.
Solution Approach 2:
The adsorption step performs a preliminary removal of paraffins before distillation, preventing butene-1 from being lost in the isobutane overhead stream and normal butane bottom stream. This preliminary action preserves butene-1 in the olefin-rich intermediate stream that proceeds to the distillation tower, thereby reducing overall butene-1 loss while maintaining high purity.
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 hybrid process reduces butene-1 loss and investment costs by selectively removing paraffins through adsorption, lowering normal butane concentration in distillation, thereby increasing butene-1 yield and purity.
Implementation Method 1
utilizing π-complex adsorbents like type X or Y zeolites and C5/C6 hydrocarbons as desorbents
Implementation Method 2
separating the butene-1 from the C4 olefins/paraffins mixture by using a hybrid process composed of an adsorption process and a distillation process
Data Source
AI summary
The present invention relates to a hybrid process comprising an adsorption process and a distillation process for the separation of butene- 1 from a C4 hydrocarbon mixture gas including butene-1, trans-2-butene, cis-2-butene, normal butane, isobutane, etc. The above hybrid process comprises introducing a gaseous C4 mixture into the adsorption tower loaded with adsorbents which adsorb olefins selectively to discharge C4 paraffins to the outlet of the tower, desorbing C4 olefins selectively adsorbed in the adsortion tower to produce high purity C4 olefins mixture gas in which isobutane and normal butane was removed, and separating the high C4 olefins mixture gas (a mixture of butene-1, trans-2-butene, cis-2-butene, and a trace amount of C4 paraffins) via distilletion to obtain high purity butene-1 including a trace amount of isobutane in the top of the distillation tower and obtain a mixture gas including trans-2-butene, cis-2-butene and a trace amount of normal butane in the bottom of the tower.