Selective Hydrogenolysis for MTBE Production
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Solution Overview
Problem
Conventional methods for producing methyl tert-butyl ether (MTBE) from field-grade butane streams are capital and energy intensive due to the need for isomerization and separation steps to convert n-butane to i-butane, which are not complete, leading to inefficiencies in MTBE production.
Innovation Solution
Integrating a butane hydrogenolysis reactor with a dehydrogenation reactor and an etherification unit, using a hydrogenolysis catalyst to selectively convert n-butane to ethane and minimize i-butane conversion, allowing for reactive separation and subsequent production of isobutylene for MTBE synthesis, thereby reducing the need for separate isomerization and separation units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional isomerization and separation steps are used to convert n-butane to i-butane, then MTBE production is enabled, but capital cost and energy consumption increase significantly
Solution Approach 1:
The patent combines the isomerization function and separation function into a single integrated reactor system. The zeolite catalyst performs both n-butane isomerization to i-butane and simultaneous separation of the isobutylene product, eliminating the need for separate isomerization and separation units, thereby reducing capital cost and energy consumption while maintaining MTBE production efficiency
Solution Approach 2:
The zeolite catalyst in the integrated reactor performs multiple functions: it acts as an isomerization catalyst for converting n-butane to i-butane, serves as a separation medium for isolating isobutylene, and provides structural support for the reactor. This multi-functionality reduces the number of required process units and associated energy requirements
2Productivity
If conventional isomerization and separation steps are used to convert n-butane to i-butane, then MTBE production is enabled, but device complexity increases
Solution Approach 1:
The patent merges multiple process functions (isomerization, separation, and product formation) into a single integrated reactor unit. This consolidation simplifies the overall process flow, reduces the number of equipment items, and lowers operational complexity while maintaining the ability to produce MTBE efficiently from field-grade butane streams
3Productivity
If complete conversion of n-butane to i-butane is achieved, then MTBE production efficiency improves, but separation requirements increase
Solution Approach 1:
The zeolite catalyst performs preliminary separation of isobutylene from the reaction mixture as it forms during the isomerization process. This preliminary action within the reactor eliminates the need for extensive downstream separation operations, allowing for high n-butane conversion while keeping the separation unit load minimal
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 enhances n-butane conversion and ethane production, reducing the load on separation units and increasing the efficiency of MTBE production by allowing direct recovery and dehydrogenation of i-butane to isobutylene, while also producing additional olefins like ethylene and propylene.
Implementation Method 1
a hydrogenolysis reactor, wherein the hydrogenolysis reactor comprises a hydrogenolysis catalyst, wherein the butane feed stream comprises n-butane and i-butane, and wherein the hydrogenolysis product stream comprises hydrogen, methane, ethane, propane, i-butane, and optionally n-butane
Implementation Method 2
feeding at least a portion of the butane stream to a dehydrogenation reactor to produce a dehydrogenation product stream, wherein the dehydrogenation reactor comprises a dehydrogenation catalyst, and wherein the dehydrogenation product stream comprises hydrogen, i-butane, and isobutylene
Implementation Method 3
feeding at least a portion of the dehydrogenation product stream and methanol to an etherification unit to produce an unreacted methanol stream, an unreacted isobutylene stream, and a methyl tert-butyl ether (MTBE) stream
Data Source
AI summary
A process for producing methyl tert-butyl ether (MTBE) comprising introducing a butane feed stream (n-butane, i-butane) and hydrogen to a hydrogenolysis reactor comprising a hydrogenolysis catalyst to produce a hydrogenolysis product stream comprising hydrogen, methane, ethane, propane, i-butane, and optionally n-butane; separating the hydrogenolysis product stream into a first hydrogen-containing stream, an optional methane stream, a C2 to C3 gas stream (ethane, propane), and a butane stream (i-butane, optionally n-butane); feeding the butane stream to a dehydrogenation reactor to produce a dehydrogenation product stream, wherein the dehydrogenation reactor comprises a dehydrogenation catalyst, and wherein the dehydrogenation product stream comprises hydrogen, i-butane, and isobutylene; and feeding the dehydrogenation product stream and methanol to an etherification unit to produce an unreacted methanol stream, an unreacted isobutylene stream, and an MTBE stream.