Conversion of carbon dioxide to methanol using bi-reforming of methane or natural gas
The invention provides for \ a method of forming methanol by combining a mixture of methane, water and carbon dioxide under reaction conditions sufficient to form a mixture of hydrogen and carbon monoxide. Hydrogen and carbon monoxide are reacted under conditions sufficient to form methanol. The molar ratio of hydrogen to carbon monoxide is at least two moles of hydrogen to one mole of carbon monoxide and the overall molar ratio between methane, water and carbon dioxide is about 3:2:1. Methane, carbon dioxide and water are bi-reformed over a catalyst. The catalyst includes a single metal, a metal oxide, a mixed catalyst of a metal and a metal oxide or a mixed catalyst of at least two metal oxides.
1. A method of preparing methanol from carbon dioxide and a methane source which comprises:
combining a wet reforming of methane from the methane source with water and a dry reforming of methane from the methane source with carbon dioxide to form carbon monoxide and hydrogen;
combining the carbon monoxide and hydrogen from the wet and dry reforming without separation of components to produce a molar mixture of hydrogen and carbon monoxide in a specific ratio of between 2:1 and 2.1:1, wherein the combining of the wet and dry reforming is combined in a single step and the methane, carbon dioxide and water are present in sufficient stoichiometric amounts to provide the recited molar mixture and ratio of hydrogen and carbon monoxide, and the combining is conducted at a temperature of about 800 to 1100° C.; and
converting molar mixture of hydrogen and carbon monoxide under conditions sufficient to exclusively form methanol,
wherein the combined wet and dry reforming is conducted in the presence of an added catalyst that includes single or mixed catalysts based on V, Ti, Ga, Mg, Cu, Mo, Bi, Fe, Mn, Co, Nb, Zr, La or Sn.
2. The method of claim 1 , wherein the catalyst is supported on a high surface or nanostructured support.
3. The method of claim 2 , wherein the support comprises silica, alumina, a metal oxide or a metal.
4. The method of claim 1 , wherein the methane, carbon dioxide and water are reacted in the single combined bi-reforming step at a mole ratio of about 3:1:2 to provide the recited molar mixture and ratio of hydrogen and carbon monoxide.
5. The method of claim 1 , wherein the molar mixture of hydrogen and carbon monoxide is present at a ratio of 2.05 to 1 and substantially all of the carbon monoxide and hydrogen reactants are exclusively converted to methanol.
6. The method of claim 1 , wherein the catalyst is a catalyst combination of Ni and V 2 O 5 ; Ni 2 O 3 and V 2 O 5 ; or Ni 2 V 2 O 7 and Ni 3 V 2 O 8 .
7. The method of claim 6 , wherein the catalyst combination is supported on a high surface or nano structured support.
8. The method of claim 7 , wherein the support comprises silica, alumina, a metal oxide or a metal.
9. The method of claim 1 , wherein the methane source is natural gas, coal bed methane or methane hydrates.
10. The method of claim 1 , which further comprises dehydrating the methanol thus produced to form dimethyl ether.