Desulfurization of coal

Claim 2

A PROCESS FOR THE DESULFURIZATION OF COAL WHICH CONTAINS PYRITIC SULFUR AND SULFUR-CONTAINING ORGANIC COMPOUNDS COMPRISING: A. DIGESTING IN A DIGESTION ZONE THE COAL AND A GROUP 1A OR IIA METAL OXIDE SALT OR MIXTURES THEREOF IN THE PRESENCE OF A FUSED METAL CHLORIDE SALT MEDIUM, WHICH MEDIUM IS CAPABLE OF DISSOLVING AT LEAST 50 PERCENT OF THE SULFUR-CONTAINING ORGANIC COMPOUNDS PRESENT IN THE COAL AND WHICH HAS A MELTING POINT BELOW BELOW THE DIGESTION TEMPERATURE UNTIL AT LEAST PART OF THE PYRITIC SULFUR AND THE DISSOLVED SULFURCONTAINING ORGANIC COMPOUND HAVE BEEN CONVERTED TO GROUP IA OR IIA METAL SULFIDES SAND METAL OXIDE OR MIXTURES THEREOF BEING PRESENT IN AN AMOUNT WHICH PROVIDES AT LEAST A STOICHIOMETRIC MOLE RATIO OF SAID METAL OXIDE SALT TO THE AMOUNT OF SULFUR PRESENT IN SAID PURITIC SULFUR AND SAID DISSOLVED ORGANIC COMPOUNDS SAID FUSED METAL CHLORIDE SALT MEDIUM BEING PRESENT IN AN AMOUNT WHICH WILL RESULT IN A RELATIVELY LIQUID DIGESTION MIXTURE, B. FEEDING ANHYDROUS HYDROGEN CHLORIDE TO THE DIGESTION ZONE SUBSEQUENT TO THE DIGESTION PERIOD TO CONVERT THE FOMRED GROUP IA OR IIA METAL SULFIDES GROUP IA OR IIA METAL CHLORIDES RESPECTIVELY AND HYDROGEN SULFIDE AND C. REMOVING FRO THE DIGESTION ZONE AN AT LEAST PARTIALLY MOLTEN MIXTURE CONTAINING DESULFURIZED COAL THE FORMED GROUP IA OR IIA METAL CHLORIDE SALTS AND THE METAL CHLORIDE SALT MEDIUM.

Claim 3

The process of claim 1 wherein the metal oxide salt is calcium oxide or sodium oxIde.

Claim 4

The process of claim 1 wherein the metal oxide salt is calcium oxide.

Claim 5

The process of claim 1 wherein the metal chloride salt medium is zinc chloride, a mix of zinc chloride and ferric chloride or a mix of zinc chloride and calcium chloride.

Claim 6

The process of claim 1 wherein the metal chloride salt medium in zinc chloride.

Claim 7

The process of claim 1 wherein the desulfurized coal in the molten mixture is separated from at least part of the formed chloride salts and the metal chloride salt medium by a refining process which comprises: a. cooling the removed at least partially molten material so as to solidify the molten components; b. crushing the solidified material; c. extracting from the crushed material with alcohol at least part of the metal chloride salt used as the medium and the formed Group IA or IIA metal chlorides; and d. separating the desulfurized coal from the alcohol-salt solution.

Claim 8

The process of claim 6 wherein the separated desulfurized coal is further refined to reduce the content of any remaining metal chloride salt medium and Group IA or IIA metal sulfides or chlorides by a second refining process which comprises: a. contacting the separated desulfurized coal with a dilute aqueous acid to extract at least part of the remaining metal chloride salt medium and the remaining Group IA or IIA metal sulfides or chlorides in the separated desulfurized coal; b. separating the contacted desulfurized coal from the resultant dilute aqueous acid-metal chloride salt-sulfide solution; and c. drying and pelletizing the dsulfurized coal from Step (b).

Claim 9

The process of claim 6 wherein the metal oxide salt is calcium oxide or sodium oxide.

Claim 10

The process of claim 6 wherein the metal oxide salt is calcium oxide.

Claim 11

The process of claim 6 wherein the metal chloride salt medium is zinc chloride, a mix of zinc chloride and ferric chloride or a mix of zinc chloride and calcium chloride.

Claim 12

The process of claim 6 wherein the metal chloride salt medium is zinc chloride.

Claim 13

A process for the desulfurization of coal which contains pyritic sulfur and sulfur-containing organic compounds comprising: a. digesting, in a digestion zone, the coal and a Group IA or IIA metal oxide salt or mixtures thereof in the presence of a fused metal chloride salt medium, which medium is capable of dissolving at least 50 percent of the sulfur-containing organic compounds present in the coal and which has a melting point below the digestion temperature, until at least part of the pyritic sulfur and the dissolved sulfur-containing organic compounds have been converted to Group IA or IIA metal sulfide; said metal oxide salt or mixtures thereof being present in an amount which provides at least a stoichiometric mole ratio of said metal oxide salt to the amount of sulfur present in said pyritic sulfur and said dissolved organic compounds, said fused metal chloride salt medium being present in an amount which will result in a relatively liquid digestion mixture; b. removing from the digestion zone an at least partially molten mixture containing desulfurized coal, the formed Group IA or IIA metal sulfide and the metal chloride medium; c. cooling the removed at least partially molten material so as to solidify the molten components; d. crushing the solidified material; e. contacting the crushed material with an alcohol-hydrogen chloride solution so as to convert the formed Group IA or IIA metal sulfides to Group IA or IIA metal chlorides respectively and hydrogen sulfide, and to extract from the desulfurized coal at least part of the metal chloride salt used as the medium and the formed Group IA or IIA metal chlorides; and f. separating the desulfurized coal from the alcohol-salt solution.

Claim 14

A process for the desulfurization of coal which contains pyritic sulfur and sulfur-containing organic compounds comprising: a. digesting, in a digestion zone, the coal and a Group IA or IIA metal oxide salt or mixtures thereof in the presence of a fused metal chloride salt medium, which medium is capable of dissolving at least 50 percent of the sulfur-containing organic compounds present in the coal and which has a melting point below the digestion temperature, until at least part of the pyritic sulfur and the dissolved sulfur-containing organic compounds have been converted to Group IA or IIA metal sulfide; said metal oxide salt or mixtures thereof being present in an amount which provides at least a stoichiometric mole ratio of said metal oxide salt to the amount of sulfur present in said pyritic sulfur and said dissolved organic compounds, said fused metal chloride salt medium being present in an amount which will result in a relatively liquid digestion mixture; b. removing from the digestion zone an at least partially molten mixture containing desulfurized coal, the formed Group IA or IIA metal sulfide and the metal chloride medium; c. cooling the removed at least partially molten material so as to solidify the molten components; d. crushing the solidified material; e. contacting the crushed material with an alcohol-hydrogen chloride solution so as to convert the formed Group IA or IIA metal sulfides to Group IA or IIA metal chlorides respectively and hydrogen sulfide, and to extract from the desulfurized coal at least part of the metal chloride salt used as the medium and the formed Group IA or IIA metal chlorides; and f. separating the desulfurized coal from the alcohol-salt solution.

Claim 15

The process of claim 12 wherein the separated desulfurized coal is further refined to reduce the content of any remaining metal chloride salt Medium and Group IA or IIA metal chlorides or sulfides by a second refining process which comprises: a. contacting the separated desulfurized coal with a dilute aqueous acid to extract at least part of the remaining metal chloride salt medium and the remaining Group IA or IIA metal sulfides or chlorides in the separated desulfurized coal; b. separating the contacted desulfurized coal from the resultant dilute aqueous acid-metal chloride salt-sulfide solution; and c. drying and pelletizing the desulfurized coal from Step (b).

Claim 16

The process of claim 12 wherein the metal oxide salt is calcium oxide or sodium oxide.

Claim 17

The process of claim 12 wherein the metal oxide salt is calcium oxide.

Claim 18

The process of claim 12 wherein the metal chloride salt medium is zinc chloride, a mix of zinc chloride and ferric chloride or a mix of zinc chloride and calcium chloride.

Claim 19

The process of claim 12 wherein the metal chloride salt medium is zinc chloride.

Claim 20

The process of claim 1, wherein when said metal oxide salt is a Group IA metal oxide salt, the mole ratio of said salt to said sulfur ranges from about 2:1 to about 4:1; and when said metal oxide salt is a Group IIA metal oxide salt, the mole ratio of said salt to said sulfur ranges from about 1:1 to about 2:1.

Claim 21

The process of claim 1, wherein said fused metal chloride salt medium is present in a weight ratio range of said medium to said coal and said metal oxide salt of from about 6:1 to about 2.1.

Claim 22

The process of claim 12, wherein when said metal oxide salt is a Group IA metal oxide salt, the mole ratio of said salt to said sulfur ranges from about 2:1 to about 4:1; and when said metal oxide salt is a Group IIA metal oxide salt, the mole ratio of said salt to said sulfur ranges form about 1:1 to about 2:1.

Claim 23

The process of claim 12, wherein said fused metal chloride salt medium is present in a weight ratio range of said medium to said coal and said metal oxide salt of from about 6:1 to about 2: