Improvements relating to gas separation

The method according to any preceding claim, wherein the first gas is acetylene and the second gas is ethane.

The method according to any preceding claim wherein the first sorbent material is an ultramicroporous material having a three-dimensional lattice of metal species (M) and linker groups;

• wherein the metal species (M) are linked together in a first and second dimension by first linker groups (L1) and are linked together in a third dimension by second linker groups (L2) to form the three-dimensional lattice;
• and wherein one of L1 and L2 is an organic linker group and the other of L1 and L2 is either an inorganic or an organic linker group;
• and wherein the ultramicroporous material has the formula Mx(L1)2(L2)Yz wherein x=1 to 3, Y is an inorganic anion and z=0 to 3.

The method according to any preceding claim, wherein the second sorbent material is an ultramicroporous material of formula Zn2(A)2(B);

• wherein A is an amino-substituted heterocyclic ligand and B is a dicarboxylate ligand, preferably wherein the second gas is ethane.

The method according to any preceding claim, wherein the gaseous composition comprises a third gas, as an impurity;

• and wherein the sorbent media comprises a third sorbent material which has a higher adsorption selectivity for the third gas than for the target gas;
• preferably wherein the third gas is carbon dioxide and the target gas is ethylene.

The method according to any preceding claim, wherein the target gas is obtained with a purity of at least 99 wt %, suitably at least 99.9 wt %.

The method according to any preceding claim, wherein the contacting of the gaseous composition with the sorbent media is carried out at a pressure of from 0.5 to 2 bar and a temperature of from 0° C. to 40° C.

A method of removing acetylene from a gaseous composition, the method comprising the step of contacting the gaseous composition with a sorbent material to remove at least some of the acetylene, wherein the sorbent material comprises an ultramicroporous material of formula Mx(L1)2(L2)Yz wherein the metal species (M) is selected from atoms or ions of Co, Cu, Zn and Ni, wherein x is an integer from 1 to 3, L1 is a two-connected nitrogen ligand, L2 is a dicarboxylic acid, Y is an anion and z is an integer from 0 to 3.

A sorbent media comprising a first sorbent material and a second sorbent material;

• wherein the first sorbent material has a higher adsorption selectivity for the first gas than for the target gas;
• wherein the second sorbent material has a higher adsorption selectivity for the second gas than for the target gas;
• and wherein the first sorbent material and the second sorbent material are different ultramicroporous materials.

Use of an ultramicroporous material of formula Mx(L1)2(L2)Yz to separate acetylene from a gas mixture comprising acetylene, wherein the metal species (M) is selected from atoms or ions of Co, Cu, Zn and Ni, wherein x is an integer from 1 to 3, L1 is a two-connected nitrogen ligand, L2 is a dicarboxylic acid, Y is an anion and z is an integer from 0 to 3.

An ultramicroporous material of formula [Co2(bpy)2(Tzba)F2].