公开(公告)号：US3514483A

公开(公告)日：1970-05-26

申请号：US3514483D

申请日：1966-11-22

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO ,  INOUE SHIGERU

IPC: C07C273/04 ,  C07C127/00

CPC classification number: C07C273/04

公开(公告)号：US3607937A

公开(公告)日：1971-09-21

申请号：US3607937D

申请日：1968-06-26

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO

IPC: C07C273/04 ,  C07C127/00

CPC classification number: C07C273/04

Abstract: Two-stage synthesis of urea comprising synthesizing urea in a first urea synthesis zone without recycle of the unreacted starting materials, separating the unreacted starting material from the resulting synthesis effluent, absorbing the unreacted starting material separated into an absorbent, subjecting to the resulting absorbate to the distillation at a pressure in a second urea synthesis zone and utilizing the unreacted starting material separated by the distillation in the second urea synthesis zone.

公开(公告)号：US3573173A

公开(公告)日：1971-03-30

申请号：US3573173D

申请日：1968-07-24

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO ,  INOUE SHIGERU ,  HASHIMOTO NOBUYOSHI ,  YAKABE MASATOSHI ,  KIMURA TETSUO

IPC: C07C273/04 ,  C07C127/10

CPC classification number: C07C273/04

Abstract: A PROCESS FOR REMOVING EXCESS AMMONIA IN UREA SYNTHESIS WHICH COMPRISES SEPARATING EXCESS AMMONIA FROM A UREA SYNTHESIS EFFLUENT IN THE FORM OF AN AMMONIA GAS, MAKING THE AMMONIA GAS FREE OF CARBON DIOXIDE IF NECESSARY AND BRINGING THE AMMONIA GAS FREE OF CARBON DIOXIDE WITH RAW MATERIAL LIQUID AMMONIA THEREBY THE AMMONIA GAS IS CONDENSED TO FORM LIQUID AMMONIA AT HIGH TEMPERATURE.

公开(公告)号：DE1593596A1

公开(公告)日：1972-04-20

申请号：DE1593596

申请日：1966-11-24

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO ,  INOUE SHIGERU

IPC: C07C273/04 ,  C07C127/00

Abstract: Urea is obtained by reacting ammonia and carbon dioxide to form an effluent containing urea, water, and unreacted ammonia and carbon dioxide, adding to the effluent a compound selected from n-paraffins and n-olefins having 6 to 25 carbons and such n-paraffins and n-olefins having a substituent chosen from phenyl, cyclohexyl, phenyloxycarbonyl and cyclohexyloxycarbonyl on a terminal carbon atom thereof in an amount of 0.25 to 0.55 parts by wt. per part by wt. of urea to be removed from the effluent thereby forming a crystalline adduct of urea and the said compound, separating the said crystalline adduct from the said effluent, decomposing the separated adduct by heating to release urea and the said compound and recovering the said released urea. The adduct is preferably formed at a temperature not greater than 40 DEG C. and it may be decomposed by heating at 90-130 DEG C. The effluent, after removal of the adduct, may be recycled to the urea synthesis zone and the said compound released by decomposition of the adduct may be returned to the adduct-forming step. In examples adducts are formed from urea and n-hexadecane, n-octadecane and 1-hexadecene.

公开(公告)号：CA835425A

公开(公告)日：1970-02-24

申请号：CA835425D

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO

公开(公告)号：CA879729A

公开(公告)日：1971-08-31

申请号：CA879729D

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  INOUE SHIGERU ,  SAKAI TADAO ,  KANAI KAZUMICHI ,  HASHIMOTO NOBUYOSHI ,  YAKABE MASATOSHI ,  KIMURA TETSUO

公开(公告)号：DE1643092A1

公开(公告)日：1971-03-11

申请号：DE1643092

申请日：1967-05-02

Applicant: MITSUI TOATSU CHEMICALS

Inventor： OTSUKA EIJI ,  KANAI KAZUMICHI ,  SAKAI TADAO ,  INOUE SHIGERU

IPC: C07C273/04