Coal compositions for catalytic gasification
Particulate compositions are described comprising an intimate mixture of a coal and a gasification catalyst in the presence of steam to yield a plurality of gases including methane and at least one or more of hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, ammonia and other higher hydrocarbons are formed. Processes are also provided for the preparation of the particulate compositions and converting the particulate composition into a plurality of gaseous products.
1. A process for preparing a particulate composition, the process comprising the steps of:
(a) providing a first coal feedstock, a second coal feedstock, and a third coal feedstock, each in particulate form;
(b) contacting the first coal feedstock with a first aqueous solution comprising a transition metal gasification catalyst to form a first slurry;
(c) contacting the second coal feedstock with a second aqueous solution comprising alkaline earth metal source to form a second slurry;
(d) contacting the third coal feedstock with a third aqueous solution comprising an alkali metal gasification catalyst to form a third slurry; and
(e) dewatering the first slurry, the second slurry, and the third slurry to form a first wet cake, a second wet cake, and a third wet cake, respectively;
wherein the process comprises the further steps of (1) or (2):
(1) (f1) thermally treating the first wet cake, the second wet cake, and the third wet cake with a dry inert gas to provide a first particulate, a second particulate, and a third particulate, each having a residual moisture content of less than about 4 wt %; and
(g1) blending at least a portion of the first particulate, at least a portion of the second particulate, and at least a portion of the third particulate to form a particulate composition;
or
(2) (f2) combining at least a portion of the first wet cake, at least a portion of the second wet cake, and at least a portion of the third wet cake to form a final wet cake;
(g2) thermally treating the final wet cake with a dry inert gas to provide a particulate composition having a residual moisture content of less than about 4 wt %.
2. The process according to claim 1 , wherein the process comprises the further steps of (1).
3. The process according to claim 1 , wherein the process comprises the further steps of (2).
4. The process according to claim 3 further comprising: providing a fourth coal feedstock in particulate form that comprises a dry-ground low-moisture coal; and combining the fourth coal feedstock in particulate form with the first wet cake, the second wet cake, and the third wet cake in step (f2) to form a final wet cake.
5. The process according to claim 1 , wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium.
6. The process according to claim 1 , wherein the alkaline earth metal source comprises a source of calcium, magnesium and/or barium.
7. The process according to claim 1 , wherein the transition metal gasification catalyst comprises Fe, Mn, or mixtures thereof.
8. The process according to claim 1 , wherein the alkali metal gasification catalyst comprises a source of potassium and/or sodium; the alkaline earth metal source comprises a source of calcium, magnesium and/or barium; and the transition metal gasification catalyst comprises Fe, Mn or mixtures thereof.