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US 8,273,313 B2Granted
System for producing methacrylic acid
AssigneeSaudi Basic Industries Corporation
InventorFrederick Merrill Galloway
Life of this patent
Estimating the term…
Abstract
A system and process for separating methacrolein (MA) from methacrylic acid (MAA) and acetic acid in the gas phase product from partial oxidation of isobutylene (IB) in two oxidation steps is disclosed. The process and system maximize recovery of all three components at minimum capital and energy cost, under conditions that minimize polymerization conditions and plugging by solids deposition in compressors, columns, etc.
Claims12
A methacrylic acid production system comprising:
- an oxidation subsystem adapted to oxidize a feed stream including isobutene and an methacrolein (MA) recycle stream into a hot oxidized stream including MA, methacrylic acid (MAA) and acetic acid (AA);
- a quench/distillation subsystem adapted to quench the hot oxidized stream with an amount of a quench stream sufficient to reduce the hot oxidized stream from an initial temperature of about 280° C. to a final temperature below about 75° C. instantaneously or near instantaneously and to distillatively form an MAA rich bottoms stream including a major portion of the AA produced in the system and an MA rich overhead stream;
- an MAA recycle subsystem adapted to form a first MAA product stream, the quench stream and an MAA rich overhead recycle stream;
- an MA overhead separation and recycle subsystem adapted to separate an MA rich overhead stream into an MA rich vapor stream and an MA lean recycle stream;
- an absorber/stripper system adapted to recover MAA and AA present in the MA rich vapor stream and to produce the MA recycle stream, a second MAA product stream and a lights waste stream, and
- an optionally a stripper gas system adapted to form a stripper gas stream formed by incinerating an incineration stream including the lights waste stream.
3 more elements
A methacrylic acid production system comprising:
- an oxidation subsystem including:
- at least one oxidation reactor having a feed stream inlet and an oxidized stream outlet,
- where the oxidation subsystem is adapted to oxidize a feed stream including isobutene into a hot oxidized stream including methacrolein (MA), methacrylic acid (MAA) and acetic acid (AA);
- a quench/distillation subsystem including:
- a column having:
- a sump portion including:
- a crude oxidized stream inlet, and
- a quench stream inlet,
- a bottoms stream outlet,
- an overhead stream outlet, and
- a reflux stream inlet,
- where the quench/distillation subsystem is adapted to instantaneously or near instantaneously quench the hot oxidized stream from an initial temperature of about 280° C. to a final temperature below about 75° C. and to separate a column contents into an MAA rich bottoms stream including most of the AA produced in the system and an MA rich overhead stream, an MAA recycle subsystem including:
- a pump to increase a pressure of the MAA rich bottoms stream,
- a dividing valve adapted to divide the MAA rich bottoms stream into the recycle stream and an MAA product stream,
- a first heat exchanger adapted to cool the recycle stream,
- a second dividing valve adapted to divide the recycle stream into the quench stream and an overhead MAA recycle stream;
- a first combining valve adapted to combine the overhead MAA recycle stream and a pressurized liquid overhead stream to form a combined stream,
- a third dividing valve adapted to divide the combined stream into a reflux stream and a venturi valve stream, where the reflux stream is fed into the reflux stream inlet of the column,
- an MA overhead separation and recycle subsystem including:
- a venturi adapted to remove fine particulate material from the MA rich overhead stream using the MA rich overhead stream and the venturi valve stream,
- a first separator adapted to separate the MA rich overhead stream into a first vapor stream and first liquid stream,
- a compressor to increase the pressure of the vapor stream,
- a second heat exchanger adapted to cool the vapor stream to form a partially condensed stream,
- a second separator adapted to separate the partially condensed stream into a second vapor stream and a second liquid stream,
- a second combining valve adapted to combine the first and second liquid streams to form a combined liquid stream, and
- a pump to increase a pressure of the combined liquid stream,
- a second compressor to increase a pressure of the second vapor stream,
- an absorber/stripper system including:
- an absorber column adapted to receive the second vapor stream to remove unconverted MA for recycle to the oxidation subsystem and
- a stripper column adapted to produce an MA recycle stream, an absorber stream and a second MAA rich product stream, which is combined with the MAA product stream;
- and
- an optionally a stripper gas system including:
- an incinerator adapted to incinerate absorber column overheads into a stripper gas stream used in a stripper column to strip unreacted MA for recycle to the oxidation subsystem.
30 more elements
Dependencies are inferred from the claim text.