SYSTEM FOR PRESSURISING PARALLEL BATCH REACTORS AND METHOD OF USING SUCH

Abstract

A system for pressurising parallel batch reactors, and a process for using such to pressurize batch reactors to a pressure of between 20 and 150 barg. The reactors are closed by a removable reactor closure system for covering the mouth of such reactor, wherein the closure system comprises an elastomeric septum and a rigid member with a small hole covering the septum. The septum may be pierced with a specific hollow needle, e.g. to force pressurized gas in the reactor, which pressure can be maintained for prolonged periods after withdrawing the needle. The closure system does not require moving parts.

Claims

1. A system for pressurising parallel batch reactors, which system comprises a plurality of reactors and at least one movable hollow needle connectable to a pressure source, wherein a reactor comprises: a reactor body having a volume of 0.5-50 ml and a reactor mouth with a diameter of between 2 and 30 mm; a removable reactor closure system for covering said reactor mouth; and wherein said hollow needle has an outer diameter of 2 millimeter or less, and which hollow needle has an opening of the inner canal of the needle, which opening is located at the lateral side of the needle at a distance from the tip of the needle equal or larger than the diameter of the needle, to at most 5 cm from the tip of the needle, wherein the removable reactor closure system for covering said reactor mouth comprises: an elastomeric septum having a thickness of at least 200% of the diameter of the hollow needle, and a rigid member covering the septum at the reactor mouth except for an opening in the rigid member leaving the septum exposed to the atmosphere, which opening has a diameter of not more than 200% of the diameter of the hollow needle, wherein the removable reactor closure system comprises no moving parts, and wherein the elastomeric septum has a Shore A hardness of less than 75.

2. The system according to claim 1, removable closure system contains no rigid parts that move or are moved from one position when open for pressurising the reactor to a different position when closed after pressurising the reactor.

3. The system according to claim 1, wherein the removable reactor closure system contains no parts other than the septum and the rigid member and fastening means for the rigid member.

4. The system according to claim 1, wherein the movable hollow needle has a diameter of less than 1.5 mm.

5. The system according to claim 1, wherein the needle is a Gertie-Marx needle, Sprotte needle or Whitacre needle.

6. The system according to claim 1, wherein the end of the needle opposite the point of the needle is connectable to a pressurized gas source and/or a device for sampling and/or analyzing gaseous or liquid samples.

7. The system according to claim 1, wherein the elastomeric septum has a thickness of between 300 and 800% of the diameter of the hollow needle.

8. The system according to claim 1, wherein the elastomeric septum has a thickness of at between 2 mm and 10 mm.

9. The system according to claim 1, any of the preceding claims, wherein the elastomeric septum has a Shore A hardness of less than 75.

10. The system according to claim 1, wherein the opening of the rigid member has a diameter of not more than 150% of the diameter of the hollow needle.

11. The system according to claim 1, wherein the system comprises at least 4 reactors.

12. The system according to claim 1, wherein each batch reactor can maintain a pressure of at least 20 barg for at least 10 minutes.

13. The system according to claim 1, wherein each reactor comprises a rigid reactor body capable of withstanding pressures of up to 150 barg and optionally a liner made of glass, quartz or polymeric material.

14. A process for performing batch reactions in parallel, which reactions occur under pressurized atmosphere, wherein a plurality of batch reactors is pressurized with the system according to claim 1, and wherein the pressure in the pressurized reactors is between 20 and 150 barg.

15. The process according to claim 14, wherein after the pressurising the reactors the contents of the reactors are heated to induce chemical reaction inside the reactors, followed by sample-taking from the reactor content using a hollow needle which has an outer diameter of 2 millimeter or less, and which hollow needle has an opening of the inner canal of the needle, which opening is located at the lateral side of the needle at a distance from the tip of the needle equal or larger than the diameter of the needle, to at most 5 cm from the tip of the needle, and which needle enters the reactor via the septum.

Description

EXAMPLE

Example 1

[0062] A reactor vessel (stainless steel) was tested for leak rate after installing a pressure sensor as part of the reactor to be able to continuously monitor the gas pressure inside the reactor.

[0063] The reactor had a volume of about 9.5 ml, and was equipped with tubing at the bottom connected to a pressure sensor. Outer diameter of the flange of each reactor: 17.9 mm, inner diameter of the flange: 13.2 mm.

[0064] The reactor mouth was closed first with a elastomeric septum (17.2 mm diameter, 3.4 mm thickness, Viton base material with a PTFE coating of 0.2 mm facing the reactor), and closed off with a cover plate (stainless steel) pressing the septum onto the reactor. The coverplate plate had a hole with a diameter of 1.0 mm.

[0065] The reactor was closed (with intact septum and cover plate) at atmospheric pressure, and subsequently pressurized by inserting a needle through the hole in the coverplate and subsequently through the septa. The septum was pierced by the needle. The needle was a custom-made hollow needle (stainless steel, diameter 0.79 mm) with an opening (oval, 1×0.25 mm) to the side of the tip of the needle, and is of a similar kind as used in spinal tap medical treatment.

[0066] The end of the needle not inserted into the reactor was connected to a source of pressurized gas (formergas, containing 90% nitrogen and 10% hydrogen), and the reactor was pressurized by letting into the reactor the pressurized gas through the needle and through the opening in the coverplate and the pierced septum, to a pressure of about 100 barg.

[0067] After the reactor was pressurized, the needle was removed after which the pressure was monitored in time. The reactor was kept at room temperature.

[0068] The result was that the pressure was well kept for the period of measurement (16 hours), only a very small amount of gas was leaking from the reactor. The leak rate measured was: 0.04 bar/hr, equal to 0.04% of a reactor operated at 100 barg. A graph of the pressure in the reactor for 16 hours is in FIG. 1.

Example 2

[0069] In a set-up for 12 reactors as in example 1 in parallel the pressure was simultaneously monitored over time, twice, comparing two different septa of different hardness. One set of septa had a Shore A hardness of 72, the other a Shore A hardness of 77.

[0070] The septum was for both trials Viton FPM/FKN of thickness 3.3, with a liner of 0.2 mm teflon at the inside.

[0071] The reactors were pressurized by inserting a needle (same needle as example 1) to 40 barg with (100%) hydrogen gas, and withdrawing the needle. After 10 minutes the pressure inside each reactor was measured. The results are set out in table 1.

TABLE-US-00001 TABLE 1 comparing septa with different hardness Reactor Vessel 72 Shore Pressure (barg) 77 Shore Pressure (barg) 1 40 38 2 40 38 3 40 29 4 40 36 5 40 36 6 40 22 7 40 35 8 39 13 9 40 17 10 39 37 11 40 36 12 40 29

[0072] The results in table shows that the vessels equipped with the septum having a Shore A hardness of 72 (more flexible) was less likely to be prone to leaking, when using pure hydrogen, than a septum having a Shore A hardness of 77 (stiffer, tougher). It should be noted that any leakage shows much quicker with hydrogen than with nitrogen.