Catalyst for methanol prodn. from synthesis gas - consisting of oxide(s) of copper and opt. chromium and zinc on silica carrier

摘要

A catalyst for the prodn. of methanol from synthesis gas, comprises as precursor of the active phase predominantly oxides of copper, these being mounted on a silica carrier. The catalyst active phase may also contain oxides of Cr with a wt. ratio of Cu:Cr of 50:50 to 95:5, pref. 70:30 to 93:7; and oxides of Zn in wt. ratio of Cu:Zn of 60:40 to 98:2, pref. 80:20, esp. 95:5. The catalyst particles are e.g. comprised of a core of silica and a mantle comprising a precursor of the active phase contg. predominantly oxides of Cu, Cr and Zn, esp. where the mantle consists predominantly of copper chromate; or the active phase may be distributed over the internal surface of the carrier. Pref. (a) the pores of the silica are partially filled with a soln. of a Cr III+ or VI+ cpd. and dried or calcined and (b) in a second phase Cu and Zn are copptd. on the suspended silica carrier and subsequently calcined. Pref. the silica is first impregnated with a Cr cpd. and calcined to form predominantly CrO3, then copper and zinc ions are copptd., esp. from urea soln. by thermal decompsn. of the urea to form a mantle of metal cpds.; or the silica is impregnated with Cr cpds. and calcined to form predominantly Cr2O3, then copper and zinc ions are copptd. on the interior surface of the carrier. Pref. methanol is prepd. by passing a gas mixt. contg. hydrogen and oxides of carbon in contact with the catalyst at 230-300 deg.C, esp. 250-270 deg.C and a press. of 10 power 6-10 power 7 Pa, esp. 4-10 power 6 to 7.10 power 6 Pa. The catalyst is esp. in the form of a fluidised bed.