公开(公告)号：JPH0625066A

公开(公告)日：1994-02-01

申请号：JP10063693

申请日：1993-04-27

Applicant: BASF AG

Inventor： OIGEN GEERAA ,  BUORUFUGANGU HAADAA ,  HERUBERUTO FUOOGERU ,  BERUNHARUTO KUNUUTO ,  KURAUSU EEBERU ,  KARUSUTEN GUREENINGU

IPC: C07B61/00 ,  C07C45/00 ,  C07C45/75 ,  C07C49/17

公开(公告)号：JPS6429339A

公开(公告)日：1989-01-31

申请号：JP15702288

申请日：1988-06-27

Applicant: BASF AG

Inventor： RIHIARUTO KURABETSUTSU ,  GERUTO DEYUMUGEN ,  FURANTSU MERUGAA ,  MIHAERU IEEGAA ,  FURITSUTSU CHIISEN ,  HERUBERUTO FUOOGERU

IPC: B01J27/19 ,  C07B63/04 ,  C07C51/00 ,  C07C51/235 ,  C07C51/25 ,  C07C57/05 ,  C07C57/055 ,  C07C57/07 ,  C07C67/00

Abstract: Methacrylic acid can be prepared with advantage by gas phase oxidation of methacrolein or isobutyraldehyde over Mo- and P-containing catalysts at from 250 DEG to 400 DEG C. with cooling of the hot reaction gas to below 100 DEG C., absorption of the methacrylic acid in a water-operated absorption column, at below 100 DEG C. and partial recycling into the oxidation reactor after admixture of methacrolein or isobutyraldehyde and oxygen by feeding a quantity of methacrolein or isobutyraldehyde equal to the quantity of methacrolein or isobutyraldehyde consumed in the reaction in liquid form together with a polymerization inhibitor into the reactor gas in the lower two-thirds of the absorber column and upstream of the feed point for the fresh methacrolein or isobutyraldehyde or down-stream of the absorption column splitting off the reactor off-gas a side stream which is washed in a wash column operated with water at