Back to results
US 2003/0205451 A1Published application
Process for manufacturing high purity methacrylic acid
AssigneeRohm and Haas Company
InventorsKeith Frederick Briegel, James Clarence Day, Michael Stanley DeCourcy, Donald Alan Ebert, Jamie Jerrick John Juliette
Life of this patent
Estimating the term…
Abstract
A process is provided herein for the high yield production of high purity glacial methacrylic acid (“HPMAA”) that is substantially pure, specifically 99% pure or greater with a water content of 0.05% or less. This improved process comprises providing a crude MAA stream and purifying the crude methacrylic acid stream in a series of successive distillation steps
Claims13
A process for the preparation of high purity methacrylic acid, said process comprising:
- (i) providing a first distillation column, a second distillation column and a third distillation column;
- (ii) feeding a crude methacrylic acid to an upper section of said first distillation column, said crude methacrylic acid comprising methacrylic acid, light ends and heavy ends;
- (iii) distilling said crude methacrylic acid in said first distillation column to form a first overhead vapor stream comprising light ends and a first bottom liquid stream comprising methacrylic acid and heavy ends;
- (iv) feeding said first bottom liquid stream to a center section of said second distillation column;
- (v) distilling said first bottom liquid stream in said second distillation column to form a second overhead vapor stream comprising methacrylic acid and light ends and a second bottom liquid stream comprising heavy ends;
- (vi) feeding at least a portion of said second overhead vapor stream to an upper section of said third distillation column;
- (vii) distilling said at least a portion of said second overhead vapor stream in said third distillation column to form a third overhead vapor stream comprising light ends and a third bottom liquid stream comprising methacrylic acid wherein said methacrylic acid has an impurity level of not more than 1% by weight wherein no more than 0.05% by weight is water.
4 more elements
A process for the preparation of high purity methacrylic acid, said process comprising:
- (i) providing a first distillation column, a second distillation column and a third distillation column;
- (ii) feeding a crude methacrylic acid to an upper section of said first distillation column, said crude methacrylic acid comprising methacrylic acid, light ends and heavy ends;
- (iii) distilling said crude methacrylic acid in said first distillation column to form a first overhead vapor stream comprising light ends and a first bottom liquid stream comprising methacrylic acid and heavy ends;
- (iv) feeding said first bottom liquid stream to a center section of said second distillation column;
- (v) distilling said first bottom liquid stream in said second distillation column to form a second overhead vapor stream comprising methacrylic acid and light ends and a second bottom liquid stream comprising heavy ends;
- (vi) feeding at least a portion of said second overhead vapor stream to an upper section of said third distillation column;
- (vii) distilling said at least a portion of said second overhead vapor stream in said third distillation column to form a third overhead vapor stream comprising light ends and a third bottom liquid stream comprising heavy ends, while withdrawing a first liquid sidestream from a lower section of said third distillation column, said first liquid sidestream comprising methacrylic acid wherein said methacrylic acid has an impurity level of not more than 1% by weight wherein no more than 0.05% by weight is water;
- (viii) feeding said third bottom liquid stream to said center section of said second distillation column.
5 more elements
A process for the preparation of high purity methacrylic acid, said process comprising:
- (i) providing a first distillation column, a second distillation column and a third distillation column;
- (ii) feeding a crude methacrylic acid to a center section of said first distillation column, said crude methacrylic acid comprising methacrylic acid, light ends and heavy ends;
- (iii) distilling said crude methacrylic acid in said first distillation column to form a first overhead vapor stream comprising methacrylic acid and light ends and a first bottom liquid stream comprising heavy ends;
- (iv) feeding at least a portion of said first overhead vapor stream to an upper section of said second distillation column;
- (v) distilling said at least a portion of said first overhead vapor stream in said second distillation column to form a second overhead vapor stream comprising light ends and a second bottom liquid stream comprising methacrylic acid and heavy ends;
- (vi) feeding said second bottom liquid stream to a center section of said third distillation column;
- (vii) distilling said second bottom liquid stream in said third distillation column to form a third overhead vapor stream comprising methacrylic acid wherein said methacrylic acid has an impurity level of not more than 1% by weight wherein no more than 0.05% by weight is water and a third bottom liquid stream comprising heavy ends;
- (viii) feeding at least a portion of said third overhead vapor stream to an upper section of said third distillation column;
- (ix) feeding said third bottom liquid stream to said center section of said first distillation column.
6 more elements
An apparatus for the preparation of high purity methacrylic acid, said apparatus comprising:
- (i) a first distillation column, said first distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (ii) a second distillation column, said second distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iii) a third distillation column, said third distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iv) a first inlet line connected to said upper section of said first distillation column;
- (v) a first outlet line connected to said top of said first distillation column;
- (vi) a second outlet line connecting said bottom of said first distillation column and said center section of said second distillation column;
- (vii) a third outlet line connecting said top of said second distillation column with said upper section of said second distillation column and said upper section of said third distillation column;
- (viii) a fourth outlet line connected to said bottom of said second distillation column;
- (ix) a fifth outlet line connected to said top of said third distillation column;
- (x) a sixth outlet line connected to said bottom of said third distillation column.
7 more elements
An apparatus for the preparation of high purity methacrylic acid, said apparatus comprising:
- (i) a first distillation column, said first distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (ii) a second distillation column, said second distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iii) a third distillation column, said third distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iv) a first inlet line connected to said upper section of said first distillation column;
- (v) a first outlet line connected to said top of said first distillation column;
- (vi) a second outlet line connecting said bottom of said first distillation column and said center section of said second distillation column;
- (vii) a third outlet line connecting said top of said second distillation column with said upper section of said second distillation column and said upper section of said third distillation column;
- (viii) a fourth outlet line connected to said bottom of said second distillation column;
- (ix) a fifth outlet line connected to said top of said third distillation column;
- (x) a sixth outlet line connected to said lower section of said third distillation column;
- (xi) a seventh outlet line connecting said bottom of said third distillation column to said center section of said second distillation column.
8 more elements
An apparatus for the preparation of high purity methacrylic acid, said apparatus comprising:
- (i) a first distillation column, said first distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (ii) a second distillation column, said second distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iii) a third distillation column, said third distillation column having a top, a bottom, an upper section adjacent said top, a lower section adjacent said bottom and a center section intermediate said upper section and said lower section;
- (iv) a first inlet line connected to said center section of said first distillation column;
- (v) a first outlet line connecting said top of said first distillation column with said upper section of said first distillation column and said upper section of said second distillation column;
- (vi) a second outlet line connected to said bottom of said first distillation column;
- (vii) a third outlet line connected to said top of said second distillation column;
- (viii) a fourth outlet line connecting said bottom of said second distillation column with said center section of said third distillation column;
- (ix) a fifth outlet line connecting said top of said third distillation column with said upper section of said third distillation column and with a product withdrawal line;
- (x) a sixth outlet line connecting said bottom of said third distillation column with said center section of said first distillation column.
7 more elements
An apparatus for the preparation of high purity methacrylic acid, said apparatus comprising at least one distillation column and its ancillaries, said at least one distillation column and its ancillaries being designed to operate at less than atmospheric pressure, said at least one distillation column comprising perforated plate trays, said at least one distillation column and its ancillaries being constructed, at least in part, of a corrosion resistant material selected from the group consisting of 300 series stainless steel, 904L stainless steel, 6-moly stainless steel, Hastelloy®, tantalum, zirconium and covered base metal
A process for the preparation of high purity methacrylic acid, said process comprising:
- (i) providing an apparatus for the preparation of high purity methacrylic acid comprising at least one distillation unit, said distillation unit comprising a distillation column and column ancillaries;
- (ii) providing a crude methacrylic acid feed to said apparatus;
- (iii) purifying said crude methacrylic acid feed by distillation in said at least one distillation unit;
- (iv) providing MEHQ inhibitor to said at least one distillation unit;
- (v) providing an O2-containing gas to said at least one distillation unit;
- (vi) adjusting the addition rate of MEHQ to said at least one distillation unit to maintain a ratio of MEHQ addition to crude methacrylic acid feed between 1 kg MEHQ/10,000 kg crude methacrylic acid feed and 15 kg MEHQ/10,000 kg crude methacrylic acid feed;
- (vii) adjusting the addition rate of O2-containing gas to said at least one distillation unit to maintain a molar ratio of O2 to MEHQ between 1.0 mole O2/mole MEHQ and 11.5 moles O2/mole MEHQ.
4 more elements
A process for the preparation of high purity methacrylic acid, said process comprising:
- (i) providing an apparatus for the preparation of high purity methacrylic acid comprising at least one distillation unit, said distillation unit comprising a distillation column and column ancillaries;
- (ii) providing a crude methacrylic acid feed to said apparatus;
- (iii) purifying said crude methacrylic acid feed by distillation in said at least one distillation unit;
- (iv) providing HQ inhibitor to said at least one distillation unit;
- (v) providing an O2-containing gas to said at least one distillation unit;
- (vi) adjusting the addition rate of HQ to said at least one distillation unit to maintain a ratio of HQ addition to crude methacrylic acid feed between 1 kg HQ/10,000 kg crude methacrylic acid feed and 10 kg HQ/10,000 kg crude methacrylic acid feed;
- (vii) adjusting the addition rate of O2-containing gas to said at least one distillation unit to maintain a molar ratio of O2 to HQ between 0.65 mole O2/mole HQ and 10 moles O2/mole HQ.
4 more elements
Dependencies are inferred from the claim text.