Polybenzimidazole based membrane for deacidification

Patent metadata

Field	Value
Publication number	US-9415352-B2
Application number	US-201013127395-A
Country	US
Kind code	B2
Filing date	Feb 24, 2010
Priority date	Feb 25, 2009
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A membrane comprising polybenzimidazole and aromatic polyester wherein said aromatic polyester is removed is disclosed. The membrane is used for a process of deacidification.

First claim

We claim:

1. A membrane comprising polybenzimidazole and aromatic polyester, wherein
said polybenzimidazole comprises recurring units of the formula II

(i) wherein, R belongs to the tetraamine monomer having structure III(a)-III(f) and R′ is from dicarboxylic acid as shown in structure IV:

wherein, each of R 1 , R 2 , R 3 , R 4 is independently selected form a group consisting of H, CH 3 , CF 3 , F, CI, Br, I, NO 2 or C 1-24 alkyl or aryl groups and X can be any of the following: —CH 2 —, —O—, —SO 2 —, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(Ph) 2 -, —CH 3 C(Ph)-, —CH 3 C(isopropyl)-, —CH 3 C(t-butyl)-, —CH 3 C(n-propyl)-, —CH 3 C(ethyl)- or any other C 1-24 containing alkyl or aryl groups,

where, k=1-30 containing alkyl, aryl, aromatic ring, arylene, alkylene, arylene-ether or heterocyclic ring such as pyridine, pyrazine, furan, quinoline or thiophene groups as straight chain, branched, cyclic, aromatic or combination of these; Y═O, N, S, halogen or combination thereof, n=0-10 and m=appropriate numbers of hydrogen
(ii) the aromatic polyester has recurring units of structural formula V

wherein, R″ is derived from phenolphthalein or its derivatives as shown in formula VI, and R′″ is from dicarboxylic acid as shown in IV:

wherein R 1 -R 4 are as defined above.

2. A membrane for deacidification, wherein said membrane is prepared by a process comprising:
a) preparing a blend pre-membrane by dissolving a polybenzimidazole (PBI) and a aromatic polyester (PAr) in appropriate proportion in a first solvent and subsequently evaporating the first solvent; wherein
said polybenzimidazole comprises recurring units of the formula II

(i) wherein, R belongs to the tetraamine monomer having structure III(a)-III(f) and R′ is from dicarboxylic acid as shown in structure IV:

wherein, each of R 1 , R 2 , R 3 , R 4 is independently selected form a group consisting of H, CH 3 , CF 3 , F, Cl, Br, I, NO 2 or C 1-24 alkyl or aryl groups and X can be any of the following: —CH 2 —, —O—, —SO 2 —, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(Ph) 2 -, —CH 3 C(Ph)-, —CH 3 C(isopropyl)-, —CH 3 C(t-butyl)-, —CH 3 C(n-propyl)-, —CH 3 C(ethyl)-or any other C 1-24 alkyl or aryl groups,

where, k=1-30 containing alkyl, aryl, aromatic ring, arylene, alkylene, arylene-ether or heterocyclic ring such as pyridine, pyrazine, furan, quinoline or thiophene groups as straight chain, branched, cyclic, aromatic or combination of these; Y═O, N, S, halogen or combination thereof, n=0-10 and m=appropriate numbers of hydrogen (ii) the aromatic polyester has recurring units of structural formula V

wherein, R″ is derived from phenolphthalein or its derivatives as shown in formula VI and R′″is from dicarboxylic acid as shown in IV:

wherein R 1 -R 4 are as defined above,
b) leaching out the polyester from the pre-membrane by treating the pre-membrane with a base solution at a temperature ranging between 20 to 80° C. for a period ranging between 1 to 15 days, and
c) washing the membrane with a second solvent,

wherein the membrane has molecular size porosity.

3. The membrane as claimed in claim 1 wherein said membrane is in the form of flat sheet, hollow fiber, tubular form, thin film composite, asymmetric membrane or any adaptable form.

4. A process of deacidification using the membrane of claim 2 wherein: R is derived from tetramine as shown in Figure VII (a)- VII (e) and R′ is from dicarboxylic acid as shown in Figure VIII (a)- VIII (k),

where; R d 1 , R d 2 , R d 3 , R d 4 ═H, CH 3 , CF 3 , F, Cl, Br, I, NO 2 or C 1-18 alkyl or aryl groups,

where; R e 1 , R e 2 , R e 3 , R e 4 ═H, CH 3 , CF 3 , F, Cl, Br, I, NO 2 or C 1-15 containing alkyl or aryl groups and X′ can be any of the following: —CH 2 —, —O—, —SO 2 —, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(Ph) 2 -, —CH 3 C(Ph)-, —CH 3 C(isopropyl)-, —CH 3 C(t-butyl)-, —CH 3 C(n-propyl)-, —CH 3 C(ethyl)- or any other C 1-15 containing alkyl or aryl groups,

where; R′ 1 , R′ 2 , R′ 3 , R′ 4 , R′ 5 , R′ 6 ═H, CH 3 , CF 3 , F, Cl, Br, I, NO 2 or C 1-15 containing alkyl, aryl, aromatic ring, arylene, alkylene, arylene-ether or heterocyclic ring such as pyridine, pyrazine, furan, quinoline, thiopene groups.

5. A process for deacidification as claimed in claim 4 , wherein said process of deacidification comprises the steps of:
a) optional pre-treatment of the membrane with the solution of acid intended to be separated;
b) circulating the feed solution containing the acid that is intended to be separated on the feed side of the membrane and
c) circulating the stripping agent on the permeate side of the membrane.

6. The process as claimed in claim 4 , wherein the feed solution comprises at least one acid in concentration greater than 0.001%.

7. The process as claimed in claim 6 , wherein said feed solution comprises organic acid, inorganic acid, organic salt, inorganic salt, sugar, polymer, oligomer, protein, living or dead cell and pigment, alone or in combinations thereof.

8. The process according to claim 4 , wherein said process is operated in the temperature range from −70° C. to 200° C.

9. The process as claimed in claim 4 , wherein said stripping agent comprises of water, organic solvents, organic bases, inorganic bases, ionic liquid and supercritical carbon dioxide.

10. The process as claimed in claim 8 , wherein said organic solvents is selected a group consisting of from acetone, alcohols, ethyl acetate, diethyl ether, hexane, toluene, methyl ethyl ketone, tetrahydrofuran, dioxane, dimethyl formamide and dimethyl acetamide, alone or in combinations thereof.

11. The process as claimed in claim 8 , wherein said inorganic bases are selected from a group consisting of NaOH, KOH, ammonia, Na2CO3 and NaHCO3, alone or in combinations thereof.

12. The process as

Assignees

• Kharul Ulhas Kanhaiyalal
• Gadre Ramchandra Vitthal
• Jogdand Vithal Venkatrao
• Chendake Yogesh Jayasing
• Council Scient Ind Res

Inventors

• Kharul Ulhas Kanhaiyalal
• Gadre Ramchandra Vitthal
• Jogdand Vithal Venkatrao
• Chendake Yogesh Jayasing

Classifications

• B01D2325/20

  Specific permeability or cut-off range · CPC title

• B01D61/00

  Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor (separation of gases or vapours by diffusion B01D53/22) · CPC title

• B01D2323/225

  Use of supercritical fluids · CPC title

• B01D71/62 Primary

  Polycondensates having nitrogen-containing heterocyclic rings in the main chain · CPC title

• Y02P20/142

  Cross-Sectional Technologies · mapped topic