Dehydration of glycols

• US 4,941,976 A
• Filed: 08/23/1988
• Issued: 07/17/1990
• Est. Priority Date: 09/17/1987
• Status: Expired due to Fees

• Current Assignee: Texas A&M University System
• Original Assignee: Texaco Incorporated (Chevron Corp.)
• Inventors: Bartels, Craig R., Reale, John Jr.
• Primary Examiner(s): JONES, WILLIAM G
• Application Number:
  US07/235,082
• Time in Patent Office: 693 Days
• Field of Search: 210/500.41, 210/500.42, 210/490, 428/220, 428/319.9, 428/419, 428/524
• US Class Current: 210/490
• CPC Class Codes: B01D 61/362 Pervaporation
• CPC Class Codes: B01D 69/125 In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
• CPC Class Codes: B01D 71/381 Polyvinylalcohol
• CPC Class Codes: B01D 71/383 Polyvinylacetates
• CPC Class Codes: C07C 29/76 by physical treatment
• CPC Class Codes: C07C 31/202 Ethylene glycol
• CPC Class Codes: Y10T 428/249993 Hydrocarbon polymer
• CPC Class Codes: Y10T 428/31533 Of polythioether
• CPC Class Codes: Y10T 428/31942 Of aldehyde or ketone condensation product

Abstract

Concentration of aqueous solutions of ethylene glycol may be effected by a composite membrane including a glutaraldehyde-crosslinked polyvinyl alcohol bonded to a porous layer of polysulfone on a polyester backing.

Claims

1. A non-porous separating layer of thickness of 1-10 microns of cast polyvinyl alcohol of molecular weight M_n of 20,000-200,000 which has been cross-linked, in the presence of acid catalyst, with an aliphatic polyaldehyde containing at least three carbon atoms including those in said aldehyde groups, the mole ratio of aldehyde to vinyl alcohol being 0.05-0.30, and thereafter cured at 100°

-200°

C.

2. A non-porous separating layer of thickness of 1-5 microns of cast polyvinyl alcohol of molecular weight M_n 20,000-200,000 which has been cross-linked in the presence of acid catalyst, with glutaraIdehyde, the mole ratio of aldehyde to vinyl alcohol being 0.05-0.30, and thereafter cured at 100°

C.-200°

C.

3. A non-porous separating layer of thickness of 1-10 microns of cast polyvinyl alcohol of molecular weight M_n of 20,000-200,000 which has been cross-linked in the presence of acid catalyst, with an aliphatic polyaldehyde containing at least three carbon atoms including those in said aldehyde groups, the mole ratio of aldehyde to vinyl alcohol being 0.05-0.30, and thereafter cured at 100°

C.-200°

C.; and

a porous support layer, onto which said separating layer is cast, of a polysulfone of molecular weight cutoff less than about 25,000.

4. A porous support layer of isopropylidene--free polysulfone of molecular weight M_n of 25,000-100,000, a thickness of about 40-80 microns, and a molecular weight cutoff of about 20,000 having cast thereon a non-porous separating layer of thickness of 1-10 microns of cast polyvinyl alcohol of molecular weight M_n of 20,000-200,000 which has been cross-linked, in the presence of acid catalyst, with glutaraldehyde, the ratio of aldehyde to vinyl alcohol being 0.05-0.30, and thereafter cured at 100°

C.-200°

C.

5. A porous support layer of isopropylidene-free polysylfone of molecular weight M_n 25,000-100,000, a thickness of about 40-80 microns, and a molecular weight cutoff of about 20,000 having cast thereon a non-porous separating layer of thickness 1-10 microns of cast polyvinyl alcohol of molecular weight M_n of 20,000-200,000 which has been cross-linked, in the presence of acid catalyst, with glutaraldehyde, the mole ratio of aldehyde to vinyl alcohol being 0.05-0.30, and thereafter cured at 100°

C.