Impurity control for a high pressure CO2 purification and supply system

An improvement for a process for producing a purified, pressurized liquid carbon dioxide stream, the process comprising distilling a feed stream including carbon dioxide vapor from a liquid carbon dioxide supply (10) for providing a carbon dioxide vapor feed stream, introducing the carbon dioxide vapor feed stream into at least one purifying filter (13,14), condensing a first portion of a purified carbon dioxide vapor feed stream from the at least one purifying filter within a condenser (18) to form an intermediate liquid carbon dioxide stream, accumulating the intermediate liquid carbon dioxide stream in a receiver (20), introducing the intermediate liquid carbon dioxide stream from the receiver (20) into at least one high-pressure accumulation chamber (30), heating the at least one high-pressure accumulation chamber (30) to pressurize the intermediate liquid carbon dioxide stream contained therein to a delivery pressure, delivering a pressurized liquid carbon dioxide stream from the at least one high-pressure accumulation chamber (30), and discontinuing delivery of the pressurized liquid carbon dioxide stream for replenishing the at least one high-pressure accumulation chamber (30), wherein the improvement comprises:

• introducing a second portion (O) of the carbon dioxide vapor feed stream (L) downstream of the at least one purifying filter (13,14) into a distillation column (M) having packing (N) therein;
• condensing the second portion (O) of the carbon dioxide vapor feed stream (L) within the condenser (18) in fluid communication with the distillation column (M) to form another intermediate liquid carbon dioxide stream (S) and a liquid vent stream (Q);
• and
• introducing the another intermediate liquid carbon dioxide stream (S) into the receiver (20), and venting the liquid vent stream (Q) from a bottom of the distillation column (M).

An improvement for a process for producing a purified, pressurized liquid carbon dioxide stream, the process comprising providing a liquid carbon dioxide supply (10), introducing a carbon dioxide vapor feed stream into at least one purifying filter (13,14), condensing a purified vapor feed stream from the at least one purifying filter within a condenser (18) to form an intermediate liquid carbon dioxide stream, accumulating the intermediate liquid carbon dioxide stream in a receiver (20), introducing the intermediate liquid carbon dioxide stream into at least one high-pressure accumulation chamber (30), heating the at least one high-pressure accumulation chamber (30) to pressurize the intermediate liquid carbon dioxide stream contained therein to a delivery pressure, delivering a pressurized liquid carbon dioxide stream from the at least one high-pressure accumulation chamber (30), and discontinuing delivery of the pressurized liquid carbon dioxide stream for replenishing the at least one high-pressure accumulation chamber (30), wherein the improvement comprises:

• withdrawing a liquid carbon dioxide stream (A) from the liquid carbon dioxide supply (10);
• introducing the liquid carbon dioxide stream (A) into a distillation column (B) having packing (C) therein, and stripping volatile impurities from the liquid carbon dioxide stream with the packing;
• vaporizing the liquid carbon dioxide stream (A) in a sump (D) of the distillation column (B) for providing a carbon dioxide vapor;
• withdrawing from a vaporized portion (F) of carbon dioxide vapor in the sump (D) a first vapor stream (G) vented from the distillation column (B);
• withdrawing from the vaporized portion (F) of the carbon dioxide vapor in the sump (D) a second vapor portion (H) vented from the sump into a conduit (I);
• introducing the second vapor portion (H) in the conduit (I) into the carbon dioxide vapor feed stream upstream of the at least one purifying filter (13,14);
• introducing a carbon dioxide vapor feed stream (L) downstream of the at least one purifying filter (13.14) into a distillation column (M) having packing (N) therein;
• condensing a first portion (O) of the carbon dioxide vapor feed stream (L) within the condenser (18) in fluid communication with the distillation column (M) to form another intermediate liquid carbon dioxide stream (S) and a liquid vent stream (Q);
• and
• introducing the another intermediate liquid carbon dioxide stream (S) into the receiver (20), and venting the liquid vent stream (Q) from a bottom of the distillation column (M).