Method for Recovering HCl from a HCl Containing Gas Stream

Abstract

The invention relates to a needle assembly (1) comprising: a needle hub (2) adapted to be connected to a distal end of a medicament cartridge or cartridge holder (3), a hollow needle (4) attached to the needle hub (2), the hollow needle (4) comprising a distal pointed tip (4.1), a needle catch arm (5) attached to the needle hub (2) and adapted to be tilted toward the needle (4) for covering the distal pointed tip (4.1).

Claims

1. A method for recovering HCl from a HCl containing gas stream wherein a HCl containing gas stream with a temperature of 20 to 25 C. is provided to an adiabatic absorption unit where it is contacted with water as an absorbent, resulting in the formation of a top gas stream and a aqueous HCl product solution, wherein the temperature of the top gas stream is at least 70 C. and at most 95 C. and wherein the aqueous HCl product solution has a HCl concentration in the range of 5-20 wt. %.

2. The method according to claim 1, wherein the absorbent provided to the unit generally has a HCl concentration of below 1 wt. %.

3. The method according to claim 1, wherein the HCl-containing gas stream is obtained as a by-product of a hydrogenation step wherein a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA) is reacted with hydrogen to form a HCl-containing gas stream and a product stream comprising MCA and a reduced amount of DCA.

4. The method according to claim 1, wherein steam is added to the adiabatic absorption unit, at a pressure of above 1 to 12 bar (absolute).

5. The method according to claim 1, wherein the top gas stream has a temperature of at least 77 C.

6. The method according to claim 1, wherein the temperature of the HCl-containing gas stream provided to the absorption unit is in the range of 5 to 20 C.

7. The method according to claim 1, wherein the aqueous HCl product solution has a HCl concentration in the range of 10-20 wt. %.

8. The method according to claim 1, wherein the HCl product solution is diluted to a concentration of 1-8 wt. %, and the diluted solution is used as absorbent in a second absorption step, wherein HCl is absorbed from a further HCl-containing gas stream to form a second aqueous HCl solution.

9. The method according to claim 7, wherein the further HCl-containing gas stream is obtained as a by-product of a chlorination step wherein acetic acid is reacted with chlorine, resulting in the formation of the further HCl-containing gas stream and a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA).

10. The method according to claim 7, wherein the second absorption step is carried out under isothermal conditions and/or at a temperature in the range of 20-60 C.

11. The method according to claim 7, wherein the second HCl solution has a HCl concentration in the range of 25-34 wt. %.

12. The method for recovering HCl from a HCl containing gas stream comprising the steps of providing a HCl containing gas stream with a temperature of 20 to 25 C., which is obtained as a by-product of a hydrogenation step wherein a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA) is reacted with hydrogen to form a HCl-containing gas stream and a product stream comprising MCA and a reduced amount of DCA, feeding the HCl containing gas stream to an adiabatic absorption unit where it is contacted with water as an absorbent, resulting in the formation of a top gas stream and a aqueous HCl product solution, wherein the temperature of the top gas stream is at least 70 C. and wherein the aqueous HCl product solution has a HCl concentration in the range of 5-20 wt. %, diluting the aqueous HCl product solution to a concentration of 1-8 wt. %, and providing the diluted solution as absorbent in a second absorption step, wherein HCl is absorbed from a further HCl-containing gas stream to form a second aqueous HCl solution, which further HCl-containing gas stream is obtained as a by-product of a chlorination step wherein acetic acid is reacted with chlorine resulting in the formation of the second HCl-containing gas stream and a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA).

13. The method of claim 2, wherein the HCl concentration is below 0.5 wt. %

14. The method of claim 4, wherein the steam added to the adiabatic absorption unit has a temperature of 100-200 C. and at a pressure of 1 to 4 bar (absolute).

15. The method of claim 5, wherein the top gas stream has a temperature of at least 87 C. and at most 92 C.

16. The method of claim 6, wherein the temperature of the HCl-containing gas stream provided to the absorption unit is in the range of 10 to 15 C.

17. The method of claim 7, wherein the aqueous HCl product solution has a HCl concentration in the range of 13-18 wt. %.

18. The method of claim 11, wherein the second HCl solution has a HCl concentration in the range of 30-34 wt. %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0025] FIG. 1 is a schematic view of an exemplary embodiment of a needle assembly according to the present invention prior to use,

[0026] FIG. 2 is a schematic view of the needle assembly during use,

[0027] FIG. 3 is a schematic view of the needle assembly during use,

[0028] FIG. 4 is a schematic view of the needle assembly during use,

[0029] FIG. 5 is a schematic view of another exemplary embodiment of a needle assembly according to the present invention prior to use,

[0030] FIG. 6 is a schematic view of the needle assembly during use,

[0031] FIG. 7 is a schematic view of the needle assembly during use,

[0032] FIG. 8 is a schematic view of the needle assembly during use,

[0033] FIG. 9 is a schematic view of the needle assembly during use, and

[0034] FIG. 10 is a schematic view of the needle assembly during use.

[0035] Corresponding parts are marked with the same reference symbols in all figures.

DETAILED DESCRIPTION

[0036] FIG. 1 is a schematic transparent view of an exemplary embodiment of a needle assembly 1 according to the present invention prior to use. In an exemplary embodiment the needle assembly 1 comprises: [0037] a needle hub 2 adapted to be connected to a distal end of a medicament cartridge or a cartridge holder 3 for a medicament cartridge, [0038] a hollow needle 4 (cf. FIG. 2) attached to the needle hub 2, the hollow needle 4 comprising a distal pointed tip 4.1, [0039] a needle catch arm 5 attached to the needle hub 2 and adapted to be tilted toward the needle 4 for covering the distal pointed tip 4.1.

[0040] In an exemplary embodiment the needle catch arm 5 extends from the needle hub 2 in a distal direction D in a neutral position N, e.g. substantially in parallel with the needle 4, wherein a substantially tubular protective needle sheath 6 is removably arranged on the needle hub 2 radially inward of the needle catch arm 5 with respect to a longitudinal axis L for covering the needle 4 prior to use. The protective needle sheath 6 comprises an annular proximal collar 6.1 having a greater diameter than the tubular part of the protective needle sheath 6.

[0041] In an exemplary embodiment the needle catch arm 5 is connected to the needle hub 2 by a first live hinge 7.1 which is arranged such that in the neutral position N a tangential slot 13 is formed at a proximal end of the needle catch arm 5 radially inward of the first live hinge 7.1, wherein the annular proximal collar 6.1 of the protective needle sheath 6 engages in the slot 13 such that the protective needle sheath 6 cannot be moved in the distal direction D without tilting the needle catch arm 5 away from the needle 4.

[0042] In an exemplary embodiment a second live hinge 7.2 is arranged distally from the first live hinge 7.1 adapted to allow for tilting the catch arm 5 toward the needle 4.

[0043] In an exemplary embodiment the needle catch arm 5 comprises a recess 8 for receiving the needle 4, wherein the recess 8 is limited by a distal end wall 9 arranged to catch the distal pointed tip 4.1 of the needle 4.

[0044] In an exemplary embodiment the needle assembly 1 further comprises a needle cap 10 removably arranged over the needle hub 2 for covering the needle 4 and the needle catch arm 5.

[0045] In FIG. 1 the needle assembly 1 is in a state as delivered prior to use. The protective needle sheath 6 is in place over the needle 4, the needle catch arm 5 is in the neutral position N and the needle cap 10 is arranged over the needle hub 2, the protective needle sheath 6 and the needle catch arm 5.

[0046] In an exemplary embodiment, in order to prepare the needle assembly 1 for an injection the needle assembly 1 is attached to a distal end of a cartridge holder 3 or medicament cartridge. The needle cap 10 may then be gripped and pulled in the distal direction D off the needle hub 2 thus exposing the needle catch arm 5 and the protective needle sheath 6. This state of the needle assembly 1 is illustrated in FIG. 2.

[0047] The protective needle sheath 6 may then be pulled off the needle 4 in the distal direction D exposing the needle 4 and rendering the needle assembly 1 ready to be used for an injection. Due to the annular collar 6.1 engaged in the slot 13 the needle catch arm 5 is tilted about the first live hinge 7.1 from the neutral position N towards a medicament delivery position MD when removing the protective needle sheath 6.

[0048] FIG. 3 shows the needle assembly 1 with the needle catch arm 5 in the medicament delivery position MD, in which the needle catch arm 5 is tilted radially outward from the neutral position N thus facilitating insertion of the needle 4 into an injection site.

[0049] The needle 4 may now be inserted into an injection site and a medicament may be displaced from the medicament cartridge through a lumen in the needle 4.

[0050] Subsequently or at any other point in time the needle catch arm 5 may be brought into a needle safe position S in which the needle 4 can no longer be accessed. FIG. 4 shows the needle assembly 1 with the needle catch arm 5 in the needle safe position S, in which the needle catch arm 5 is tilted toward the needle 4 for covering the distal pointed tip 4.1 of the needle 4. In an exemplary embodiment a user may bring the needle catch arm 5 from the neutral N or delivery position MD into the needle safe position S by pressing the needle catch arm 5 against a surface, e.g. a table.

[0051] When the needle catch arm 5 is tilted into the needle safe position S the needle 4 is received within the recess 8. The distal end wall 9 prevents the distal pointed tip 4.1 of the needle 4 from protruding beyond the distal end of the needle catch arm 5.

[0052] In an exemplary embodiment the needle catch arm 5 is arranged to be tilted toward the needle 4 to such an extent that the needle 4 is plastically deformed, e.g. bent by the needle catch arm 5. In an exemplary embodiment the distal end wall 9 limiting the recess 8 within the needle catch arm 5 engages the distal pointed tip 4.1 of the needle 4 while the needle catch arm 5 is being tilted towards the needle safe position S and the needle 4 is bent within the recess 8. This results in the needle 4 being at least slightly tensioned within the recess 8 such that the distal pointed tip 4.1 may ingress into the material of the distal end 9 wall further improving post injection needle safety. The material of the distal end wall 9 may be particularly soft for improving this effect.

[0053] The needle assembly 1 may now be removed from the cartridge holder 3 or medicament cartridge and disposed.

[0054] FIG. 5 is a schematic transparent view of another exemplary embodiment of a needle assembly 1 according to the present invention prior to use. FIG. 6 shows the needle assembly 1 after removal of a sterility tab 12. In an exemplary embodiment the needle assembly 1 comprises: [0055] a needle hub 2 adapted to be connected to a distal end of a medicament cartridge or a cartridge holder 3 for a medicament cartridge, [0056] a hollow needle 4 (cf. FIG. 7) attached to the needle hub 2, the hollow needle 4 comprising a distal pointed tip 4.1, [0057] a needle catch arm 5 attached to the needle hub 2 and adapted to be tilted toward the needle 4 for covering the distal pointed tip 4.1.

[0058] In an exemplary embodiment the needle catch arm 5 extends from the needle hub 2 in a distal direction D in a neutral position N, e.g. substantially in parallel with the needle 4, wherein a protective needle sheath 6 is removably arranged on the needle hub 2 radially inward of the needle catch arm 5 with respect to a longitudinal axis L for covering the needle 4 prior to use. The protective needle sheath 6 comprises an annular proximal collar 6.1 having a greater diameter than the tubular part of the protective needle sheath 6.

[0059] In an exemplary embodiment the needle catch arm 5 is connected to the needle hub 2 by a first live hinge 7.1 which is arranged such that in the neutral position N a tangential slot 13 is formed at a proximal end of the needle catch arm 5 radially inward of the first live hinge 7.1, wherein the annular proximal collar 6.1 of the protective needle sheath 6 engages in the slot 13 such that the protective needle sheath 6 cannot be moved in the distal direction D without tilting the needle catch arm 5 away from the needle 4.

[0060] In an exemplary embodiment a second live hinge 7.2 is arranged distally from the first live hinge 7.1 adapted to allow for tilting the catch arm 5 toward the needle 4.

[0061] In an exemplary embodiment the needle catch arm 5 comprises a recess 8 for receiving the needle 4, wherein the recess 8 is limited by a distal end wall 9 arranged to catch the distal pointed tip 4.1 of the needle 4.

[0062] In an exemplary embodiment the needle assembly 1 further comprises a needle cap 10 removably arranged over the needle hub 2 for covering the needle 4 and the needle catch arm 5.

[0063] In an exemplary embodiment the needle cap 10 comprises a longitudinal slot 11 in an outer wall of the needle cap 10 extending to a proximal opening in the needle cap 10. The longitudinal slot 11 has a width at least as great as a width of the needle catch arm 5.

[0064] In an exemplary embodiment a sterility tab 12 may be removably arranged over the longitudinal slot 11 prior to use indicating an unused needle assembly 1 when intact. The sterility tab 12 may extend over both the longitudinal slot 11 and the proximal opening of the needle hub 2 thus keeping the entire needle assembly 1 sterile prior to use.

[0065] In FIG. 5 the needle assembly 1 is in a state as delivered prior to use. The protective needle sheath 6 is in place over the needle 4, the needle catch arm 5 is in the neutral position N and the needle cap 10 is arranged over the needle hub 2, the protective needle sheath 6 and the needle catch arm 5. The sterility tab 12 is in place over the longitudinal slot 11.

[0066] In an exemplary embodiment, in order to prepare the needle assembly 1 for an injection the needle assembly 1 is attached to a distal end of a cartridge holder 3 or medicament cartridge.

[0067] The user may peel the sterility tab 12 off exposing the longitudinal slot 11 at this point or at any other point during operation. FIG. 6 shows the needle assembly 1 after removal of the sterility tab 12.

[0068] The needle cap 10 may then be gripped and pulled in the distal direction D off the needle hub 2 thus exposing the needle catch arm 5 and the protective needle sheath 6. This state of the needle assembly 1 is illustrated in FIG. 7.

[0069] The protective needle sheath 6 may then be pulled off the needle 4 in the distal direction D exposing the needle 4 and rendering the needle assembly 1 ready to be used for an injection. Due to the annular collar 6.1 engaged in the slot 13 the needle catch arm 5 is tilted about the first live hinge 7.1 from the neutral position N towards a medicament delivery position MD when removing the protective needle sheath 6.

[0070] FIG. 8 shows the needle assembly 1 with the needle catch arm 5 in the medicament delivery position MD, in which the needle catch arm 5 is tilted radially outward from the neutral position N thus facilitating insertion of the needle 4 into an injection site.

[0071] The needle 4 may now be inserted into an injection site and a medicament may be displaced from the medicament cartridge through a lumen in the needle 4.

[0072] Subsequently or at any other point in time the needle catch arm 5 may be brought into a needle safe position S in which the needle 4 can no longer be accessed. FIG. 9 shows the needle assembly 1 with the needle catch arm 5 in the needle safe position S, in which the needle catch arm 5 is tilted toward the needle 4 for covering the distal pointed tip 4.1 of the needle 4. In an exemplary embodiment a user may bring the needle catch arm 5 from the neutral N or delivery position MD into the needle safe position S by pressing the needle catch arm 5 against a surface, e.g. a table.

[0073] When the needle catch arm 5 is tilted into the needle safe position S the needle 4 is received within the recess 8. The distal end wall 9 prevents the distal pointed tip 4.1 of the needle 4 from protruding beyond the distal end of the needle catch arm 5.

[0074] In an exemplary embodiment the needle catch arm 5 is arranged to be tilted toward the needle 4 to such an extent that the needle 4 is plastically deformed, e.g. bent by the needle catch arm 5. In an exemplary embodiment the distal end wall 9 limiting the recess 8 within the needle catch arm 5 engages the distal pointed tip 4.1 of the needle 4 while the needle catch arm 5 is being tilted towards the needle safe position S and the needle 4 is bent within the recess 8. This results in the needle 4 being at least slightly tensioned within the recess 8 such that the distal pointed tip 4.1 may ingress into the material of the distal end 9 wall further improving post injection needle safety. The material of the distal end wall 9 may be particularly soft for improving this effect.

[0075] Subsequently the needle cap 10 is replaced over the needle hub 2. FIG. 10 shows the needle assembly 1 with the re-attached needle cap 10. After re-attaching the needle cap 10 the needle catch arm 5 protrudes radially through the longitudinal slot 11 providing a clear indication that the needle assembly 1 has been used. If the sterility tab 12 has not been removed prior to removal of the needle cap 10 as in FIG. 6 it may likewise be removed prior to replacing the needle cap 10 over the needle hub 2.

[0076] The needle assembly 1 may now be removed from the cartridge holder 3 or medicament cartridge and disposed.

[0077] In all illustrated embodiments the needle cap 10 may comprise grip features (not illustrated) such as corrugations for improving ergonomics. Furthermore, the needle catch arm 5 and the needle hub 2 may comprise corresponding locking features (not illustrated) locking the needle catch arm 5 in the needle safe position S thus preventing re-exposure of the needle 4.

[0078] In an exemplary embodiment the needle hub 2 may comprise a screw thread (not illustrated) adapted to engage a corresponding screw thread on the medicament cartridge or cartridge holder 3. The screw thread may be arranged on an inner surface of a cavity within the needle hub 2. Likewise, the screw thread may be on an outer surface of the needle hub 2 and the medicament cartridge or cartridge holder 3 may have a corresponding thread on an inner surface. In other embodiments the needle hub 2 and the medicament cartridge or cartridge holder 3 may comprise corresponding bayonet features or they may have conical surfaces for frictionally fitting the needle hub 2 to the medicament cartridge or cartridge holder 3 (not illustrated).

[0079] In an exemplary embodiment the needle 4 may further comprise a proximal pointed tip (not illustrated) extending within a cavity of the needle hub 2 for establishing a fluid communication between the needle 4 and the medicament cartridge by the proximal pointed tip piercing a septum on the cartridge while the needle assembly 1 is being attached to the medicament cartridge.

[0080] Those of skill in the art will understand that modifications (additions and/or removals) of various components of the apparatuses, methods and/or systems and embodiments described herein may be made without departing from the full scope and spirit of the present invention, which encompass such modifications and any and all equivalents thereof.