Butanol Production Process Segmentation and Polishing
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Solution Overview
Problem
The production of normal-butanol, iso-butanol, and 2-alkyl alkanol through combined hydrogenation results in crude product streams that are challenging to separate efficiently, leading to cross-contamination and high equipment costs due to the presence of side products and unreacted reactants.
Innovation Solution
A process involving multiple stages of separation and polishing hydrogenation steps is employed to produce refined streams of normal-butanol, iso-butanol, and 2-alkyl alkanol, utilizing catalysts like copper chromite and nickel, and operating conditions such as temperature and pressure to optimize yield and minimize cross-contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single combined hydrogenation step is used to produce normal-butanol, iso-butanol and 2-alkyl alkanol, then equipment costs are reduced, but the crude product stream becomes difficult to separate leading to cross-contamination and high refining costs
Solution Approach 1:
The invention divides the hydrogenation process into separate reaction zones within the reactor: a first zone for hydrogenating butyraldehydes to butanols, and a second zone for hydrogenating 2-alkyl alkenals to 2-alkyl alkanols. This segmentation allows crude product streams to be separated more easily while maintaining cost-effective equipment design, directly resolving the contradiction between equipment cost reduction and separation complexity.
2Productivity
If hydrogenation reaction does not go to completion, then intermediate products and side products remain in crude product, but complete hydrogenation increases equipment size and operating costs
Solution Approach 1:
The reactor is divided into two distinct hydrogenation zones with different catalysts and operating conditions optimized for specific reactions. The first zone uses a catalyst selective for butyraldehyde hydrogenation, while the second zone uses a catalyst for 2-alkyl alkenal hydrogenation. This allows each zone to operate at optimal conversion levels without requiring excessive reactor volume, resolving the contradiction between productivity and reactor size.
Solution Approach 2:
Each hydrogenation zone is equipped with locally optimized catalysts and operating conditions (temperature, pressure, hydrogen flow rate) tailored to the specific reaction requirements. This local quality optimization enables efficient conversion in each zone without requiring the entire reactor to be oversized, thus resolving the contradiction between reaction efficiency and equipment volume.
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 process effectively increases the yield of desired products while reducing equipment size and costs by allowing some unreacted species in initial hydrogenation, achieving high purity and efficiency in separating the desired alcohols.
Implementation Method 1
utilizing catalysts like copper chromite and nickel
Implementation Method 2
hydrogenating a feed comprising normal butyraldehyde, iso-butyraldehyde and 2-alkyl alkenal
Data Source
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AI summary
A process for the production of normal-butanol, iso-butanol and 2-alkyl alkanol is disclosed. The process comprises: hydrogenating a feed comprising normal butyraldehyde, iso- butyraldehyde and 2-alkyl alkenal to form a crude product stream comprising normal- butanol, iso-butanol, 2-alkyl alkanol, unreacted normal butyraldehyde, unreacted iso- butyraldehyde and one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol; separating the crude product stream to produce: a mixed butanol stream having higher concentrations of normal butanol, iso-butanol, unreacted normal butyraldehyde and unreacted iso-butyraldehyde than the crude product stream; and a crude 2-alkyl alkanol stream having higher concentrations of 2-alkyl alkanol and the one or more of unreacted 2- alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol than the crude product stream; separating the mixed butanol stream to produce: a refined normal butanol stream having a higher concentration of normal butanol than the mixed butanol stream; and a crude iso-butanol stream having a higher concentration of iso-butanol than the mixed butanol stream; feeding the crude iso-butanol stream to a first polishing hydrogenation reactor wherein at least some of the unreacted iso-butyraldehyde is converted to iso-butanol to produce a polished iso¬ butanol stream; separating the polished iso-butanol stream to produce: a refined iso-butanol stream having a higher concentration of iso-butanol than the polished iso-butanol stream; and a light waste stream; separating the crude 2-alkyl alkanol stream to produce: an intermediate 2-alkyl alkanol stream having higher concentrations of 2-alkyl alkanol and the one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol than the crude 2- alkyl alkanol stream; and a heavy waste stream; feeding the intermediate 2-alkyl alkanol stream to a second polishing hydrogenation reactor wherein at least some of the one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol is converted to 2-alkyl alkanol to produce a polished 2-alkyl alkanol stream having a higher concentration of 2-alkyl alkanol than the intermediate 2-alkyl alkanol stream; separating the polished 2-alkyl alkanol stream to produce: a refined 2-alkyl alkanol stream having a higher concentration of 2-alkyl alkanol than the polished 2-alkyl alkanol stream; and an intermediate waste stream.