Chromium-free water gas shift catalyst
Catalyst for use in the high temperature shift reaction comprising in its active form a mixture of zinc alumina spinel and zinc oxide in combination with an alkali metal selected from the group consisting of Na, K, Rb, Cs and mixtures thereof. The catalyst has a Zn/Al molar ratio in the range 0.5 to 1.0 and a content of alkali metal in the range 0.4 to 8.0 wt % based on the weight of oxidized catalyst.
1. Catalyst for use in the high temperature shift reaction consisting in its active form of a mixture of zinc alumina spinel and zinc oxide in combination with an alkali metal selected from the group consisting of Na, K, Rb, Cs and mixtures thereof, said catalyst having a Zn/Al molar ratio in the range 0.5 to 1.0 and a content of alkali metal in the range 0.4 to 8.0 wt % based on the weight of oxidized catalyst.
2. Catalyst according to claim 1 , wherein the alkali metal is potassium and is present in an amount of 1 to 3 wt %.
3. Catalyst according to claim 1 , wherein the alkali metal is cesium and is present in an amount of 5 to 8 wt %.
4. Catalyst according to claim 1 , in which the catalyst has a Zn/Al molar ratio in the range 0.5 to 0.8.
5. Catalyst according to claim 1 , wherein the Zn/Al molar ratio is 0.65-0.7 and the catalyst contains Zn in an amount of 31-34 wt %, and K in an amount of 2.7-3.0 wt %.
6. Catalyst according to claim 1 , wherein the Zn/Al molar ratio is 0.7 and the catalyst contains Zn in an amount of 34-36 wt % and Cs in an amount of 7-8 wt %.