C4 Stream Separation via Segmented Hydrogenation and Adsorption
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Solution Overview
Problem
Current methods for separating and purifying C4 streams to produce valuable petrochemical products, such as methyl tertiary-butyl ether (MTBE), are costly and inefficient, requiring significant capital investment and not effectively removing acetylinic and butadiene impurities.
Innovation Solution
The process involves selectively hydrogenating a crude C4 stream to remove acetylinic impurities, followed by distillation to remove butadiene impurities, and then using solid adsorbents to separate 1-butene and isobutene streams, which are reacted with methanol to produce MTBE, allowing for flexible configuration and cost-effective purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods are used to separate C4 fractions, then separation can be achieved, but significant capital investment is required
Solution Approach 1:
The separation process is divided into distinct functional stages: hydrogenation unit for acetylinic impurity removal, distillation unit for butadiene separation, and adsorption units for selective C4 fraction separation. This segmentation allows each unit to be optimized independently and reduces overall capital investment by using simpler, more targeted equipment rather than complex integrated systems.
Solution Approach 2:
The process utilizes changes in physical and chemical parameters at different stages: hydrogenation changes chemical composition to remove impurities, distillation exploits boiling point differences to separate butadiene, and adsorption utilizes surface area differences to separate C4 fractions. These parameter changes enable efficient separation with lower capital investment than conventional methods.
2Productivity
If conventional separation methods are used, then C4 fractions can be separated, but operating costs are high
Solution Approach 1:
The method extracts and removes specific impurities (acetylinic compounds and butadiene) through targeted hydrogenation and distillation steps, preventing them from interfering with subsequent separation and MTBE synthesis operations. This extraction approach reduces energy waste by eliminating impurity-related issues before they affect productivity.
Solution Approach 2:
The process introduces intermediary substances and steps: hydrogenation uses hydrogen gas as an intermediary to convert acetylinic impurities into saturated hydrocarbons, distillation uses temperature gradients as an intermediary mechanism to separate butadiene, and adsorption materials act as intermediaries to selectively capture specific C4 fractions. These intermediaries enable efficient separation with lower operating costs.
3Reliability
If conventional methods are used to remove impurities, then separation can proceed, but acetylinic and butadiene impurities remain
Solution Approach 1:
The process performs preliminary hydrogenation to convert acetylinic impurities into saturated hydrocarbons before distillation, and preliminary distillation to remove butadiene before adsorption. These preliminary actions simplify subsequent separation steps and improve reliability by ensuring impurities are removed in advance, reducing the need for complex multi-stage purification.
Solution Approach 2:
The method replaces complex mechanical separation systems with chemical and physical field-based approaches: hydrogenation uses chemical reactions to transform impurities, distillation uses thermal fields to separate components based on volatility, and adsorption uses surface fields to selectively capture molecules. These substitutions reduce process complexity while improving impurity removal efficiency.
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 method achieves a 20-30% increase in MTBE production with a modest increase in feedstock flow, reducing operating costs and improving the efficiency of C4 separation and purification processes.
Implementation Method 1
selectively hydrogenating a crude C4 stream to remove acetylinic impurities contained therein
Implementation Method 2
distilling the hydrogenated crude C4 stream to remove butadiene impurities contained in the hydrogenated crude C4 stream, forming a distillate stream and a bottoms stream
Implementation Method 3
exposing the distillate to a separation unit comprising a solid adsorbent to produce a first product stream comprising 1-butene and a second product stream comprising isobutene
Implementation Method 4
reacting the second product stream with a methanol stream to produce methyl tertiary-butyl ether
Data Source
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AI summary
The present invention provides, among other things, new processes for separating and purifying C4 fractions from a crude C4 stream. Compared to prior methods, the processes of the present invention simplify the C4 separation processes, afford more possible configurations for separation and purification, and are more cost effective. The processes and systems provided herein can be used as part of a cost-effective and efficient method for synthesizing methyl tertiary-butyl ether.