公开(公告)号：US3770683A

公开(公告)日：1973-11-06

申请号：US3770683D

申请日：1972-02-14

Applicant: GAF CORP

Inventor： BARABAS E ,  FEIN M

IPC: C08F271/02 ,  C08F19/00 ,  C08F41/00

CPC classification number: C08F271/02 ,  C08F220/12

Abstract: GRAFTED TERPOLYMERS OF A POLYMERIC N-VINYL LACTAM, SUCH AS POLYVINYL PYRROLIDONE, WITH ALKYL ACRYLATES AND ACRYLIC ACID UNITS, ARE PREPARED AS STABLE AQUEOUS SOLUTIONS.

公开(公告)号：US3733780A

公开(公告)日：1973-05-22

申请号：US3733780D

申请日：1972-04-17

Applicant: GAF CORP

Inventor： BELLISIO A ,  PSYRAS H ,  FEIN M

IPC: B01D53/14 ,  B01D53/50 ,  C01B17/60

CPC classification number: B01D53/1481 ,  B01D53/1418 ,  B01D53/1425 ,  B01D53/1493 ,  B01D53/507 ,  C01B17/60

Abstract: Sulfur dioxide is stripped from a gas stream by N-alkyl lactam sufficient to permit the non-polluting discharge or use of the treated gas stream, the stripped sulfur dioxide being recovered as essentially pure liquid SO2. A gas stream to be treated is passed through an absorption zone generally 5-85 ft in length and containing said lactam, e.g., N-lower alkyl pyrrolidone, preferably N-methyl pyrrolidone, at a gas mass flow velocity of about 200-3,000 lbs/hr/ft2 at a gas temperature of 0*-75*C, preferably 35*-65*C, to reduce its SO2 content to less than about 250 ppm, preferably less than 100 ppm, and/or to remove at least 90 percent by volume, desirably 95 percent and advantageously 98 percent or more, of its SO2 content. The treated gas stream, together with entrained or vaporized lactam, is passed, prior to discharge to the atmosphere or other disposal or use, directly to a water scrubber zone in which at least about 90 percent by weight, advantageously at least about 98 percent and preferably at least about 99 percent of the lactam content is removed therefrom, permitting the gas stream to be discharged or otherwise disposed of without undesired SO2 pollution of the atmosphere and without an unacceptable loss of lactam. A water stream having recovered lactam therein from the scrubber zone and a lactam stream having SO2 dissolved therein from the absorption zone are passed to a distillation zone in which SO2 and at least a portion of the water content of said streams is removed overhead and a lactam-rich stream is recycled to the absorption zone, in which a solution of lactam having up to about 25 percent by weight of water is maintained. The SO2-water overhead stream from the distillation zone is compressed and cooled to produce an aqueous solution of sulfur dioxide, said aqueous solution being heated in a second distillation zone to distill off the sulfur dioxide, which is thereafter condensed and recovered as an essentially pure liquid SO2 product containing at least about 9095 percent SO2 by volume.

公开(公告)号：US3733781A

公开(公告)日：1973-05-22

申请号：US3733781D

申请日：1972-04-17

Applicant: GAF CORP

Inventor： BELLISIO A ,  PSYRAS H ,  FEIN M

IPC: B01D53/14 ,  B01D53/50 ,  C01B17/60

CPC classification number: B01D53/1481 ,  B01D53/1418 ,  B01D53/1425 ,  B01D53/1493 ,  B01D53/507 ,  C01B17/60

Abstract: A gas stream from an absorption zone in which sulfur dioxide is stripped therefrom by N-alkyl lactam is passed to a watercontaining scrubber zone at a gas mass flow velocity of 200-3,000 lbs/hr/ft2 in a gas temperature of 0*-75*C, preferably 35*-65*C, wherein at least about 90 percent by weight, advantageously at least about 98 percent, preferably at least about 99 percent, of the lactam vaporized or entrained in the gas stream is recovered. The gas stream leav-ing the scrubber zone, with an SO2 content of less than about 250 ppm and/or at least 90 percent of its SO2 content stripped therefrom, can be discharged to the atmosphere or otherwise disposed of without unacceptable loss of lactam. A water stream having the thus recovered lactam dissolved therein is removed from the scrubber zone and may be passed directly into the absorption zone or to a distillation zone from which a lactam-rich liquid stream can be recycled to the absorption zone. The scrubber zone will generally have a length of from about 2 ft to about 25 ft, typically from about 3 ft to about 15 ft. The water flow rate to the scrubber zone to replace the lactamcontaining stream withdrawn therefrom will generally be from about 0.05 to about 2.0, advantageously about 0.05 to about 0.25, gals of water per MCF of gas passing through the scrubber zone.

公开(公告)号：US3738086A

公开(公告)日：1973-06-12

申请号：US3738086D

申请日：1972-04-17

Applicant: GAF CORP

Inventor： BELLISIO A ,  PSYRAS H ,  FEIN M

IPC: B01D53/14 ,  B01D53/50 ,  C01B17/60

CPC classification number: C01B17/60 ,  B01D53/1418 ,  B01D53/1425 ,  B01D53/1481 ,  B01D53/1493 ,  B01D53/507 ,  Y02A50/2349

Abstract: N-alkyl lactam is used to strip sulfur dioxide from gas streams sufficiently to permit the non-polluting discharge of said gas streams to the atmosphere with an SO2 content of less than about 250 ppm, advantageously of less than 100 ppm or even less than 50 ppm and/or to remove at least 90 percent, desirably 95 percent or more, preferably 98 percent or more, by volume of the SO2 content of said streams. The gas stream is passed through an absorption zone containing said N-alkyl lactam, e.g. N-lower alkyl pyrrolidone, preferably N-methyl pyrrolidone, at a gas mass flow velocity of 200-3,000 lbs/hr/ft2, the absorption zone having a length of generally from about 5 to about 85 ft. The gas temperature in the absorption zone is about 0*C-75*C, preferably about 35*C-65*C. The treated gas leaving the absorption zone and having lactam vaporized or entrained therein is passed directly to a water scrubbing zone at the indicated temperature and flow rate. At least about 90 percent by weight, advantageously at least about 98 percent and preferably 99 percent or more, of the lactam contained in the treated gas stream is removed therefrom in said scrubber zone, permitting the non-polluting discharge of the gas stream to the atmosphere without unacceptable loss of lactam therein. A water stream from the scrubber zone and a lactam stream having SO2 absorbed therein from the absorption zone are passed to a distillation zone wherein said streams are heated to 100*C-200*C to remove SO2 and at least a part of the water content of the streams. A lactam-rich stream is recycled from the distillation zone to the absorption zone which aqueous solution of lactam is maintained, said solution generally containing up to about 25 percent by weight water. The SO2 removed from the distillation zone is readily recovered for nonpolluting disposal or use. Recycle of the lactam-rich stream is advantageously at about 5 to about 40 gals of lactam per MCF of gas being treated. Water is fed to the scrubber zone at a rate of about 0.05-2.0, advantageously about 0.05-0.25, gals/MCF of gas being treated.

公开(公告)号：US3733779A

公开(公告)日：1973-05-22

申请号：US3733779D

申请日：1972-04-17

Applicant: GAF CORP

Inventor： BELLISIO A ,  PSYRAS H ,  FEIN M

IPC: B01D53/14 ,  B01D53/50 ,  C01B17/60

CPC classification number: C01B17/60 ,  B01D53/1418 ,  B01D53/1425 ,  B01D53/1481 ,  B01D53/1493 ,  B01D53/507 ,  Y02A50/2349

Abstract: Sulfur dioxide is stripped from a gas stream by N-alkyl lactam, particularly an N-lower alkyl pyrrolidone, e.g., N-methyl pyrrolidone, sufficiently to permit the non-polluting discharge of the gas stream to the atmosphere. Gas streams containing from about 0.05 percent to about 10 percent sulfur dioxide by volume can thus be passed at a gas mass flow velocity of 200-3,000 lbs/hr/ft2 through an N-alkyl lactam-containing contacting zone of 5-85 ft in length, to reduce the sulfur dioxide content thereof to less than about 250 ppm, advantageously to less than 100 ppm, or even 50 ppm, prior to discharge to the atmosphere. Gas streams having SO2 contents of from about 0.01 percent to about 50 percent by volume can thus be treated to achieve at least about 90 percent SO2 removal by volume, desirably at least about 95 percent, and advantageously at least about 98 percent removal. Gas temperatures of about 0*-75*C, preferably about 35*65*C, are employed. Lactam entrained in the gas stream discharged from the contacting zone is conveniently recovered in a water scrubbing zone. Lactam from the contacting zone and lactam in water removed from the scrubbing zone can conveniently be recovered in a distillation zone by heating to 100*-200*C. The lactam recovered can be recycled to the contacting zone, and the SO2 stripped from said lactam can be conveniently recovered for non-polluting disposal or use.