Patent GB-787865-A (GB)
Title: Improvements in or relating to the separation of acetylene
Inventor: CLARK ARTHUR MAURICE
IPC: C07C7/11
Filed: 1955-07-25
Abstract: <PICT:0787865/IV (b)/1> Acetylene is separated in high purity from a gas containing it by contacting the dry gas with an organic solvent, in which acetylene is highly soluble, at a temperature below 0 DEG C. and preferably at superatmospheric pressure, raising the temperature of the resultant solution to above 0 DEG  C. and contacting it with a gas of high acetylene content whereby gases less soluble than acetylene are displaced from solution, removing the remaining dissolved gases by heating the solution and contacting the disengaged gases with a smaller amount of the same or another organic solvent in which acetylene is highly soluble to remove gases more soluble than acetylene and leave acetylene of high purity.  In a preferred method the acetylene containing gas is dried and fed by line 1 at a pressure of 3 atmospheres through the regenerative refrigerator B where it is cooled to -20 DEG  to -50 DEG  C. and into the absorber D. Cold acetone from storage tank F is fed into the top of the absorber D and a solution of acetylene with other gases passes by line 4 and, after heating to 10-30 DEG  C., into the stripper H. Unabsorbed gases are passed through a second regenerative refrigerator B1 to remove condensed water vapour therefrom before the gas passes to storage.  In the stripper H a gas of high acetylene content introduced by line 13 strips out gases less soluble than acetylene from the solution.  The overhead gases are recycled to the absorber D and the solution passes to the intermediate heater J where it is heated sufficiently to provide enough acetylene containing gas to pass into the stripper H. Thence the solution is passed into the stripper K where all gases are removed by solvent vapour provided by a heating coil at the bottom of the stripper.  The solvent is cooled and returned to the storage tank F.  The acetylene passes into the bottom of the absorber L into the top of which is fed acetone saturated with acetylene, this process preferably being carried out at about the same temperature as the original absorption, i.e. -20 DEG  to -50 DEG  C. Product acetylene leaves by line 15.  Acetone containing acetylene and more soluble gases passes to the stripper N wherein acetylene is driven off.  This acetylene is used to presaturate acetone in the absorber M before it is passed to the top of absorber L. Finally the acetone from stripper N is stripped of all remaining absorbed gases in stripper P and is returned to the storage tank F.  Other solvents which may be used are N,N-dimethylformamide, N - methyl - 2 - pyrrolidone and 3 - butyrolactone.  Specification 624,617 is referred to.ALSO:Acetylene is separated in high purity from a gas containing it by contacting the dry gas with an organic solvent, in which acetylene is highly soluble, at a temperature below 0 DEG  C. and preferably at superatmospheric pressure, raising the temperature of the resultant solution to above 0 DEG  C. and contacting it with a gas of high acetylene content whereby gases less soluble than acetylene are displaced from solution; removing the remaining dissolved gases by heating <PICT:0787865/III/1> the solution and contacting the disengaged gases with a smaller amount of the same or another organic solvent in which acetylene is highly soluble to remove gases more soluble than acetylene and leave acetylene of high purity.  In a preferred method the acetylene-containing gas is dried and fed by line 1 at a pressure of 3 atmospheres gauge through the regenerative refrigerator B where it is cooled to - 20 DEG  to - 50 DEG  C. and into the absorber D. Cold acetone from storage tank F is fed into the top of the absorber D and a solution of acetylene with other gases passes by line 4 and, after heating to 10-30 DEG  C., into the stripper H. Unabsorbed gases are passed through a second regenerative refrigerator B1 to remove condensed water vapour therefrom before the gas passes to storage. In the stripper H a gas of high acetylene content introduced by line 13 strips out gases less soluble than acetylene from the solution. The overhead gases are recycled to the absorber D and the solution passes to the intermediate heater J where it is heated sufficiently to provide enough acetylene-containing gas to pass into the stripper H. Thence the solution is passed into the stripper K where all gases are removed by solvent vapour provided by a heating coil at the bottom of the stripper.  The solvent is cooled and returned to the storage tank F.  The acetylene passes into the bottom of the absorber L into the top of which is fed acetone saturated with acetylene, this process preferably being carried out at about the same temperature as the original absorption, i.e. - 20 DEG  to - 50 DEG  C.  Product acetylene leaves by line 15.  Acetone containing acetylene and more soluble gases passes to the stripper N wherein acetylene is driven off.  This acetylene is used to presaturate acetone in the absorber M before it is passed to thetop of absorber L.  Finally the acetone from stripper N is stripped of all remaining absorbed gases in stripper P and is returned to the storage tank F.  Other solvents which may be used are N,N - dimethylformamide, N - methyl - 2 - pyrrolidone and 3-butyrolactone.  Specification 624,617 is referred to.