Butyne-diol prepn. by reacting acetylene with aq. formaldehyde soln. - in liq. phase using fixed bed copper acetylide catalyst

摘要

Butynediol (I) is prepd. by charging a C2H2 satd. aq. HCHO soln. prepd. outside reaction compartment and contg. also finely divided C2H2 in excess to saturation concn. to the reaction compartment which is filled completely with an aq. HCHO soln. and with Cu acetylide catalyst bed solidly fixed on both sides. The liq. phase reaction of C2H2 with aq. HCHO soln. takes place in reaction compartment at working pressure 1-1.5 bar. The C2H2 proportion of gas-phase discharged from reaction compartment is 20 vol %. (I) is an intermediate for the prepn. of butenediol-1,4, butanediol-1,4, tetrahydrofuran or pyrrolidone. The reaction temp. in reaction compartment can be lowered from 90 degrees C in standard process, to 75-80 degrees C. Depletion of dissolved CH2H is prevented. Lower reaction temp. and high liq. circulation prevent cupreine formation. Space-time yields are improved, e.g. to 1.4-1.48 kg(I)/1 catalyst. day, w.r.t. catalyst bed vol.