PROCESS FOR PRODUCING AMMONIUM (METH-) ACRYLATE

Abstract

The present invention relates to a process for preparing ammonium (meth-) acrylate, aqueous ammonium (meth-) acrylate solutions obtainable by such process, and (meth-) acrylic acid homopolymers or copolymers obtainable by polymerizing such ammonium (meth-) acrylate. The invention furthermore relates to a modular, relocatable bioconversion unit for manufacturing aqueous ammonium (meth-) acrylate solutions.

Claims

1. A process for producing ammonium (meth-) acrylate, said process comprising the following steps: (a) adding the following components (i) to (iii) to a reactor to obtain a composition for bioconversion: (i) a biocatalyst capable of converting (meth-) acrylonitrile to ammonium (meth-) acrylate; (ii) (meth-) acrylonitrile; (iii) aqueous medium; and (b) performing a bioconversion on the composition obtained in step (a) in a reactor; wherein the reactor is a relocatable bioconversion unit.

2. Process according to claim 1, wherein the (meth-) acrylonitrile concentration of the composition at the end of the bioconversion is below 10.0% (w/w), is below 1.0% (w/w), is below 0.1% (w/w), preferably below 0.01% (w/w), more preferably below 0.001% (w/w), most preferably below 0.0001% (w/w) by weight of the (meth-) acrylonitrile in the aqueous medium.

3. Process according to claim 1, wherein the concentration of ammonium (meth-) acrylate at the end of the bioconversion is at least 10% (w/w), at least 15% (w/w), at least 20% (w/w), at least 25% (w/w), at least 30% (w/w), at least 35% (w/w), preferably at least 40% (w/w), at least 45% (w/w), more preferably at least 50% (w/w), more preferably at least 51% (w/w), more preferably at least 52% (w/w), more preferably at least 53% (w/w), even more preferably at least 54% (w/w), most preferably at least 55% (w/w) by weight of the ammonium (meth-) acrylate monomers in the aqueous medium.

4. Process according to claim 1, wherein the biocatalyst is an enzyme having nitrilase activity.

5. Process according to claim 1, wherein the biocatalyst having nitrilase activity is one selected from the group consisting of an isolated nitrilase, a recombinant construct, a recombinant vector comprising the recombinant construct, a recombinant microorganism comprising the recombinant construct, and a recombinant microorganism comprising the recombinant vector.

6. Process according to claim 1, wherein the biocatalyst is a recombinant microorganism selected from the group consisting of Bacillus licheniformis, Bacillus pumilus, Bacillus subtilis, Escherichia coli, Saccharomyces cerevisiae, Rhodococcus rhodocrous, and Pichia pastoris.

7. Process according to claim 1, wherein the relocatable bioconversion unit comprises a double-walled reaction vessel having a volume from 10 m3 to 150 m3, means for mixing the composition of step (a) and means for controlling the temperature of the composition of step (a).

8. Process according to claim 7, wherein the relocatable bioconversion unit comprises a frame, a double-walled reaction vessel mounted into the frame having a volume from 10 m3 to 150 m3, and an external temperature control circuit comprising at least a pump and a temperature control unit, wherein the composition of step (a) is circulated by means of a pump from the reaction vessel into the temperature control unit and back into the reaction vessel, thereby simultaneously controlling the temperature and mixing the composition of step (a).

9. Process according to any of claim 1, wherein the relocatable bioconversion unit comprises a single walled reaction vessel having a volume from 10 m3 to 150 m3, means for mixing the composition of step (a) and means for controlling the temperature of the composition of step (a).

10. Process according to any of claim 1, wherein the relocatable bioconversion unit comprises a frame, a single walled reaction vessel mounted into the frame having a volume from 10 m3 to 150 m3, and an external temperature control circuit comprising at least a pump and a temperature control unit, wherein the composition of step (a) is circulated by means of a pump from the reaction vessel into the temperature control unit and back into the reaction vessel, thereby simultaneously controlling the temperature and mixing the composition of step (a).

11. Process according to claim 10, wherein the amount of the composition of step (a) cycled per hour through the temperature control circuit is from 100% to 1000% of the total volume of the composition of step (a) in the bioconversion unit.

12. Reactor for manufacturing aqueous ammonium (meth-) acrylate solutions according to the process of claim 1, wherein the reactor is a relocatable bioconversion unit.

13. Reactor according to claim 12, wherein the reactor comprises an external cooling circuit and wherein the reactor comprises no stirrer.

14. Reactor according to claim 12 comprising a relocatable storage unit for (meth-) acrylonitrile, a relocatable bioconversion unit for hydrolyzing (meth-) acrylonitrile in water in the presence of a biocatalyst capable of converting (meth-) acrylonitrile to ammonium (meth-) acrylate, optionally, a relocatable unit for removing the biocatalyst from an aqueous ammonium (meth-) acrylate solution, optionally, a relocatable storage unit for an aqueous ammonium (meth-) acrylate solution, and optionally, at least one relocatable unit for further processing an aqueous ammonium (meth-) acrylate solution.

15. Reactor according to claim 12 for manufacturing aqueous ammonium (meth-) acrylate solutions according to the process of anyone of claims 1 to 9, wherein the reactor is used at a fixed production facility.

16. Reactor according to claim 12 for manufacturing aqueous ammonium (meth-) acrylate solutions according to the process of anyone of claims 1 to 9, wherein the reactor is combined with a relocatable bioconversion unit for manufacturing an aqueous acrylamide solution.

17. Aqueous ammonium (meth-) acrylate solutions obtainable by the process according to anyone of claim 1.

18. (Meth-) acrylate homopolymers or copolymers obtainable by polymerizing the ammonium (meth-) acrylate of the aqueous solution according to claim 17.

19. Use of aqueous ammonium (meth-) acrylate solutions prepared according to claim in a reactor or an aqueous ammonium (meth-) acrylate solution for preparing aqueous solutions of (meth-) acrylate homopolymers or copolymers.

20. Use of aqueous solutions of (meth-) acrylate homopolymers or copolymers according to claim 19 as surface coatings, adhesives, sealants, for mining applications, oilfield applications, water treatment, waste water treatment, paper making or agricultural applications.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0162] FIG. 1: Schematic representation of a bio ammonium (meth-) acrylate reactor

[0163] FIG. 2: Schematic representation of a bio ammonium (meth-) acrylate reactor having eight single walled reaction vessel.

DETAILED DESCRIPTION OF THE FIGURE

[0164] FIG. 1 schematically represents an embodiment of the relocatable bioconversion unit with an integrated temperature control circuit. The bioconversion unit comprises a frame (10), a double-walled reaction vessel mounted into the frame comprising an outer wall (11) and an inner wall (12). Preferred volumes of the reaction vessel have already been mentioned. In other embodiments, the reaction vessel is self-supporting and there is no frame (10). The reaction vessel is filled with the reaction mixture. The bioconversion unit furthermore comprises an external temperature control circuit comprising at least a pump (13) and a temperature control unit (14). The reaction mixture is circulated by means of a pump (13) from the reaction vessel to the temperature control unit (14) and is injected back into the storage vessel, preferably via an injection nozzle (16). In the depicted embodiment, (meth-) acrylonitrile is injected into the temperature control circuit thereby ensuring good mixing (15). It may be added before or after the temperature control unit. FIG. 1 shows an embodiment in which (meth-) acrylonitrile is added into the temperature control circuit between the pump and the heat exchanger. The stream of reaction mixture injected back into the reaction vessel causes a circulation of the reaction mixture in the reaction vessel which ensures sufficient mixing of the contents of the reaction mixture. No stirrer is installed.

[0165] FIG. 2 schematically represents an embodiment of the relocatable bioconversion unit with an integrated temperature control circuit. The bioconversion unit comprises a frame (10), a reaction vessel mounted into the frame comprising a single wall (11). Preferred volumes of the reaction vessel have already been mentioned. In other embodiments, the reaction vessel is self-supporting and there is no frame (10). The reaction vessel is filled with the reaction mixture. The bioconversion unit, furthermore, comprises an external temperature control circuit comprising at least a pump (12) and a temperature control circuit (13). The reaction mixture is circulated by means of a pump (12) from the reaction vessel to the temperature control unit (13) and is injected back into the storage vessel, preferably via an injection nozzle (15). In the depicted embodiment, (meth-) acrylonitrile is injected into the temperature control circuit thereby ensuring good mixing (14). It may be added before or after the temperature control unit. No stirrer is installed.

EXAMPLES

[0166] The invention is further described by the following examples. The examples relate to practical and in some cases preferred embodiments of the invention that do not limit the scope of the invention.

Example 1 (Comparative)

Copolymer of Purified Ammonium Acrylate and Acrylamide (NH.SUB.4.AA/AM):

[0167] Copolymer comprising 70.54 wt. % (75.0 mol %) of acrylamide and 29.46 wt. % (25 mol %) of ammonium acrylate, stabilized with 0.25 wt. % Na-MBT (relating to polymer).

[0168] A 5 L beaker with magnetic stirrer, pH meter and thermometer was initially charged with 550.14 g of a 43% aqueous solution of ammonium acrylate (purified/centrifugated), and then the following were added successively: 1800 g of distilled water, 1089.29 g of acrylamide (52% by weight in water, bio acrylamide) 10.5 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid pentasodium salt, and 4 g of a 50% aqueous solution of the stabilizer sodium 2-mercaptobenzothiazole (Na-MBT).

[0169] After adjustment to pH 6.4 with a 20% by weight solution of sulfuric acid and addition of the rest of the water to attain the desired monomer concentration of 23% by weight (total amount of water 1824.37 g minus the amount of water already added, minus the amount of acid required), the monomer solution was adjusted to the initiation temperature of 0° C. The solution was transferred to a Dewar vessel, the temperature sensor for the temperature recording was inserted, and the flask was purged with nitrogen for 45 minutes. The polymerization was initiated with 21 g of a 10% aqueous solution of the water-soluble azo initiator 2,2′-azobis(2-methylpropionamidine) dihydrochloride (Wako V-50; 10h t½ in water 56° C.), 1.75 g of a 1% t-butyl hydroperoxide solution and 1.05 g of a 1% sodium sulfite solution. With the onset of the polymerization, the temperature rose to 60° C. within about 50 min. A solid polymer gel was obtained.

[0170] After the polymerization, the gel was incubated overnight at 60° C. and the gel block was comminuted with the aid of a meat grinder. The comminuted aqueous polyacrylamide gel was kept for further testing without drying.

Example 2 (Inventive)

[0171] Copolymer of Crude (Unpurified) Ammonium Acrylate and Acrylamide (cNH.sub.4AA/AM):

[0172] Copolymer comprising 70.54 wt. % (75.0 mol %) of acrylamide and 29.46 wt. % (25 mol %) of crude (unpurified/non-centrifugated) ammonium acrylate (ammonium acrylate is used directly after synthesis without a cleaning step), stabilized with 0.25 wt. % Na-MBT (relating to polymer)

[0173] A 1 L screw glass bottle with magnetic stirrer, pH meter and thermometer was initially charged with 62.87 g of a 43% aqueous solution of crude ammonium acrylate, and then the following were added successively: 200 g of distilled water, 124.49 g of acrylamide (52% by weight in water, bio acrylamide) 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid pentasodium salt, and 0.46 g of a 50% aqueous solution of the stabilizer sodium 2-mercaptobenzothiazole (Na-MBT).

[0174] After adjustment to pH 6.4 with a 10% by weight solution of sulfuric acid and addition of the rest of the water to attain the desired monomer concentration of 23% by weight (total amount of water 208.50 g minus the amount of water already added, minus the amount of acid required), the monomer solution was adjusted to the initiation temperature of 0° C. The solution was transferred to Dewar vessel, the temperature sensor for the temperature recording was inserted, and the flask was purged with nitrogen for 45 minutes. The polymerization was initiated with 2.40 g of a 10% aqueous solution of the water-soluble azo initiator 2,2′-azobis(2-methylpropionamidine) dihydrochloride (Wako V-50; 10h t½ in water 56° C.), 0.20 g of a 1% t-BHP solution and 0.12 g of a 1% sodium sulfite solution. With the onset of the polymerization, the temperature rose to 55° C. within about 120 min. A solid polymer gel was obtained. After the polymerization, the gel was incubated 3 hours at 60° C. The comminuted aqueous polyacrylamide gel was kept for further testing without drying.

Testing

Gel Fraction/Solid Content

[0175] A 5000 ppm polymer solution in pH 7 buffer is diluted to 1000 ppm with pH 7 buffer. The gel fraction is given as mL of gel residue on the sieve when 250 g 1000 ppm polymer solution are filtered over 200 μm sieve and consequently washed with 2 l of tab water.

Viscosity of the Polymers in Aqueous Solution

[0176] Measurements were performed in “pH 7 buffer”: For 10 l of pH 7 buffer fully dissolve 583.3±0.1 g sodium chloride, 161.3±0.1 g disodium hydrogenphosphate.12 H.sub.2O and 7.80±0.01 g sodium dihydrogenphosphate.2 H.sub.2O in 10 l dist. or deionized water. A 5000 ppm polymer solution was obtained by dissolving the appropriate amount of aqueous polymer gel in pH 7 buffer until being fully dissolved. Viscosity measurements were performed at a Brookfield RS rheometer with single gap geometry.

Filtration Ratio

Determination of MPFR (Millipore Filtration Ratio)

[0177] The filterability of the polymer solutions was characterized using the MPFR value (Millipore filtration ratio). The MPFR value characterizes the deviation of a polymer solution from ideal filtration characteristics, i.e. when there is no reduction of the filtration rate with increasing filtration. Such a reduction of the filtration rate may result from the blockage of the filter in course of filtration.

[0178] To determine the MPFR values, about 200 g of the relevant polyacrylamide solution having a concentration of 1000 ppm were filtered through a polycarbonate filter have a pore size of 5 μm at a pressure of 2 bar and the amount of filtrate was recorded as a function of time.

[0179] The MPFR value was calculated by the following formula

MPFR=(t.sub.180 g−t.sub.160 g)/(t.sub.80 g−t.sub.60 g).

[0180] T.sub.x g is the time at which the amount solution specified passed the filter, i.e. t.sub.180g is the time at which 180 g of the polyacrylamide solution passed the filter. According to API RP 63 (“Recommended Practices for Evaluation of Polymers Used in Enhanced Oil Recovery Operations”, American Petroleum Institute), values of less than 1.3 are acceptable.

Long-Term Storage

[0181] 100 g of the gel was sealed under vacuum in a plastic bag and stored at 60° C. for one week. Subsequently, the gel was cooled tor room temperature and used for further testing.

Results

[0182]

TABLE-US-00001 TABLE 1 T.sub.max Solid content Viscosity.sup.1) ID [° C.] [%] [mPas] MPFR.sup.2) Example 1 58.4 24.72 65 1.15 (comparative) Example 2 52.8 23.97 66 1.10 (inventive) Example 2 52.8 27.01 63 1.20 (inventive), stored for one week at 60° C. .sup.1)@ 5000 ppm; pH = 7 buffer, rt; 100 s.sup.−1 .sup.2)@ 1000 ppm; pH = 7 buffer

CONCLUSION

[0183] From table 1 it becomes obvious that the polymer of the inventive example shows similar properties and performance as the polymer of the comparative example. Unexpectedly, it is possible to produce a polymer, a copolymer of acrylamide and ammonium (meth-) acrylate, wherein the ammonium (meth-) acrylate is obtained in form of an aqueous ammonium (meth-) acrylate solution from the process of the present invention. From the MPFR value is become clear that the inventive polymer and the comparative polymer show similar properties. Both MPFR values are below 1.3 and with that in the acceptable range. Consequently, it is a surprise that with the process of the present invention for examples aqueous ammonium (meth-) acrylate solutions can be produced, which are suitable for further processing to polymers without a cleaning and/or drying step. Surprisingly, the resulting polymers of the present invention do not degrade during storage for one week at 60° C.