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US 2024/0075423 A1Published application
A process for separating h2 from a gas mixture
AssigneeBASF SE
InventorsPaul-Vinzent STROBEL, Emiel Jan KAPPERT, Kai Rainer EHRHARDT, Juergen Jose VARGAS SCHMITZ, Martin GALL
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Abstract
The present invention relates a process for separating H2, preferably both H2 and CH4, from a gas mixture comprising H2 and CH4 by means of a series of selective membrane units that avoids compressors and vacuums as well as an apparatus for carrying out said separation.
Claims22
-21. (canceled)
A process for separating H2 from a gas mixture comprising H2 and CH4, the process comprising
- (i) a separation stage comprising
- (i.1) passing a feed gas stream F1 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(F1), 0<x(F1)≤0.5, through a membrane unit A comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10, at a pressure ratio φ across said at least one membrane, calculated as (pressure of feed gas stream F1/pressure of permeate gas stream P1) at constant temperature, of greater than 1, obtaining
- a permeate gas stream P1 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(P1);
- x(P1)>x(F1);
- and
- a retentate gas stream R1 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(R1);
- x(R1)<x(F1);
- (i.2) passing retentate gas stream R1 as a further feed gas stream F2 through a further separation stage, F2 having the same composition as R1;
- (ii) a further separation stage comprising
- (ii.1) passing F2 through a membrane unit B comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10, at a pressure ratio φ across said at least one membrane, calculated as (pressure of feed gas stream F2/pressure of permeate gas stream P2) at constant temperature, of greater than 1, obtaining
- a permeate gas stream P2 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(P2) of at least 1.4;
- x(P2)>x(F2);
- and
- a retentate gas stream R2 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(R2) of <0.17;
- x(R2)<x(F2);
- (ii.2) optionally passing retentate gas stream R2 as a further feed gas stream F3 through a further separation stage (iii), F3 having the same composition as R2;
- (iii) an optional further separation stage comprising
- (iii.1) passing F3 through a further membrane unit C comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10, at a pressure ratio φ across said at least one membrane (calculated as the (pressure of feed gas stream F3/pressure of permeate gas stream P3) at constant temperature), of greater than 1, obtaining
- a permeate gas stream P3 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(P3) of at least 0.39;
- x(P3)>x(F3);
- and
- a retentate gas stream R3 comprising H2 and CH4 at a molar ratio n(H2):n(CH4)=x(R3) of ≤0.01.
19 more elements
An apparatus for separating H2, from a gas mixture comprising H2 and CH4, the apparatus comprising
- (I) a unit comprising
- (I.a) a feeding means for passing a feed gas stream F1 comprising H2 and CH4 to a membrane unit A;
- (I.b) the membrane unit A connected to the feeding means for passing a feed gas stream F1 according to (I.a), said membrane unit comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10;
- (I.c) an exiting means connected to the membrane unit A, for removing a permeate gas stream P1 from the membrane unit A;
- (Id) an exiting means connected to the membrane unit A for removing a retentate gas stream R1 from the membrane unit A;
- (II) a unit comprising
- (II.a) a feeding means, connected to the exiting means according to (Id), for passing the gas stream R1 as a feed gas F2 to a membrane unit B;
- (II.b) the membrane unit B connected to the feeding means for passing a feed gas stream F2 according to (II.a), said membrane unit comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10;
- (II.c) an exiting means connected to the membrane unit B for removing a permeate stream P2 from the membrane unit B;
- (II.d) an exiting means connected to the membrane unit B for removing a retentate stream R2 from the membrane unit B;
- (III) optionally a unit comprising
- (III.a) a feeding means, connected to the exiting means according to (II.d), said feeding means for passing the gas stream F3 to a membrane unit C;
- (III.b) the membrane unit C connected to the feeding means according to (III.a), said membrane unit comprising at least one membrane, the at least one membrane having a H2/CH4 selectivity of at least 10;
- (III.c) an exiting means connected to the membrane unit C for removing a permeate stream P3 from the membrane unit C;
- (III.d) an exiting means connected to the membrane unit C for removing a retentate stream R3 from the membrane unit C.
12 more elements
Dependencies are inferred from the claim text.