Carbonaceous fuels and processes for making and using them

This application claims priority under 35 U.S.C. §119 from U.S. Provisional Application Ser. No. 61/017,311 (filed Dec. 28, 2007), the disclosure of which is incorporated by reference herein for all purposes as if fully set forth.

The present invention relates to carbonaceous fuels and processes for making them. Moreover, the invention also relates to processes using the carbonaceous fuels in the production of cement products.

In view of numerous factors such as higher energy prices and environmental concerns, the production of value-added gaseous products from lower-fuel-value carbonaceous feedstocks, such as petroleum coke and coal, is receiving renewed attention. The catalytic gasification of such materials to produce methane and other value-added gases is disclosed, for example, in U.S. Pat. No. 3,828,474, U.S. Pat. No. 3,998,607, U.S. Pat. No. 4,057,512, U.S. Pat. No. 4,092,125, U.S. Pat. No. 4,094,650, U.S. Pat. No. 4,204,843, U.S. Pat. No. 4,468,231, U.S. Pat. No. 4,500,323, U.S. Pat. No. 4,541,841, U.S. Pat. No. 4,551,155, U.S. Pat. No. 4,558,027, U.S. Pat. No. 4,606,105, U.S. Pat. No. 4,617,027, U.S. Pat. No. 4,609,456, U.S. Pat. No. 5,017,282, U.S. Pat. No. 5,055,181, U.S. Pat. No. 6,187,465, U.S. Pat. No. 6,790,430, U.S. Pat. No. 6,894,183, U.S. Pat. No. 6,955,695, US2003/0167961A1, US2006/0265953A1, US2007/000177A1, US2007/083072A1, US2007/0277437A1 and GB1599932.

Catalytic gasification processes can result in relatively large quantities of waste materials. For example, formation of a particulate carbonaceous feedstock by grinding processes can result in quantities of small particulates (i.e., “fines”) that are too small in particle size to be effectively used in gasification processes. The amount of fines generated can be on the order of 15-40% of the input feedstock. Moreover, gasification of lower-fuel-value carbonaceous feedstocks will often result in large quantities of char residue in which unconverted carbonaceous material is intermixed with ash and catalyst. Both fines and char residue represent a loss of potentially useful carbon, and can present issues with respect to waste handling and disposal. Accordingly, processes are needed which can efficiently utilize fines and char residue.

In one aspect, the present invention provides a carbonaceous fuel comprising: (a) unconverted fines of a carbonaceous feedstock, the carbonaceous feedstock having an ash content of greater than 1 wt % (based on the weight of the carbonaceous feedstock), the fines having an average particle size less than about 45 μm; and (b) a char residue formed by catalytic gasification of the carbonaceous feedstock, the char residue having an ash content of greater than about 30 wt % (based on the weight of the char residue), wherein the ash includes at least one aluminum-containing compound or silicon-containing compound; and having a weight ratio of fines to char residue in the range of from about 4:1 to about 1:4, and a total dry basis wt % of carbon of least about 40 wt % (based on the weight of the carbonaceous fuel).

In a second aspect, the present invention provides a process for making one or more gaseous products and a carbonaceous fuel, the process comprising the steps of: (a) providing (1) unconverted fines of a carbonaceous feedstock, the carbonaceous feedstock having an ash content of greater than about 1 wt % (based on the weight of the carbonaceous feedstock), the fines having an average particle size less than about 45 μm, and (2) particulates of the carbonaceous feedstock suitable for gasification in a reactor; (b) reacting the particulates in the reactor in the presence of steam and a gasification catalyst under suitable temperature and pressure to form the one or more gaseous products and a char residue having an ash content greater than about 30 wt % (based on the weight of the char residue), wherein the ash includes at least one aluminum-containing compound or silicon-containing compound; and (c) combining the fines with the char residue in a weight ratio in the range of from about 4:1 to about 1:4 to form the carbonaceous fuel, wherein the carbonaceous fuel has a dry basis wt % carbon of at least about 40% (based on the weight of the carbonaceous fuel).

In a third aspect, the present invention provides a process of making a cement product comprising: (a) providing a carbonaceous fuel as described above, or a carbonaceous fuel made by the process as described above; (b) passing the carbonaceous fuel into a cement-making zone; and (c) at least partially combusting the carbonaceous fuel to provide heat for a cement producing reaction within the cement-making zone.

The present invention relates generally to carbonaceous fuels and to processes for making and using them. Generally, a carbonaceous fuel of the present invention includes unconverted fines of a carbonaceous feedstock and a char residue formed by catalytic gasification of the carbonaceous feedstock. This carbonaceous fuel can be used, for example, in a cement-making process. Such carbonaceous fuels and processes can provide for an economical and commercially practical process for catalytic gasification of carbonaceous feedstocks to yield methane and/or other value-added gases, as well as utilize the byproducts of gasification in an industrially-useful manner. The conversion of the fines and the char residue to a carbonaceous fuel can result in less overall waste and lower disposal costs. The carbonaceous fuel can be used, for example, to provide heat in a cement-making process, thereby yielding additional value-added products from the carbonaceous feedstock. Moreover, the carbonaceous fuels of the present invention can have a relatively high fuel value, and therefore can supply a significant portion, if not all, of the heat necessary for the cement-making process.

The present invention can be practiced, for example, using any of the developments to catalytic gasification technology disclosed in commonly owned US2007/0000177A1, US2007/0083072A1 and US2007/0277437A1; and U.S. patent application Ser. No. 12/178,380 (filed 23 Jul. 2008), Ser. No. 12/234,012 (filed 19 Sep. 2008) and Ser. No. 12/234,018 (filed 19 Sep. 2008). Moreover, the processes of the present invention can be practiced in conjunction with the subject matter of the following U.S. patent applications, each of which was filed on even date herewith: Ser. No. ______, entitled “CONTINUOUS PROCESSES FOR CONVERTING CARBONACEOUS FEEDSTOCK INTO GASEOUS PRODUCTS” (attorney docket no. FN-0018 US NP1); Ser. No. ______, entitled “CATALYTIC GASIFICATION PROCESS WITH RECOVERY OF ALKALI METAL FROM CHAR” (attorney docket no. FN-0007 US NP1); Ser. No. ______, entitled “PETROLEUM COKE COMPOSITIONS FOR CATALYTIC GASIFICATION” (attorney docket no. FN-0011 US NP1); Ser. No. ______, entitled “PETROLEUM COKE COMPOSITIONS FOR CATALYTIC GASIFICATION” (attorney docket no. FN-0008 US NP1); Ser. No. ______, entitled “CATALYTIC GASIFICATION PROCESS WITH RECOVERY OF ALKALI METAL FROM CHAR” (attorney docket no. FN-0014 US NP1); Ser. No. ______, entitled “COAL COMPOSITIONS FOR CATALYTIC GASIFICATION” (attorney docket no. FN-0009 US NP1); Ser. No. ______, entitled “PROCESSES FOR MAKING SYNTHESIS GAS AND SYNGAS-DERIVED PRODUCTS” (attorney docket no. FN-0010 US NP1); Ser. No. ______, entitled “CATALYTIC GASIFICATION PROCESS WITH RECOVERY OF ALKALI METAL FROM CHAR” (attorney docket no. FN-0015 US NP1); Ser. No. ______, entitled “CATALYTIC GASIFICATION PROCESS WITH RECOVERY OF ALKALI METAL FROM CHAR” (attorney docket no. FN-0016 US NP1); Ser. No. ______, entitled “STEAM GENERATING SLURRY GASIFIER FOR THE CATALYTIC GASIFICATION OF A CARBONACEOUS FEEDSTOCK” (attorney docket no. FN-0017 US NP1); and Ser. No. ______, entitled “PROCESSES FOR MAKING SYNGAS-DERIVED PRODUCTS” (attorney docket no. FN-0012 US NP1). All of the above are incorporated herein by reference for all purposes as if fully set forth.

All publications, patent applications, patents and other references mentioned herein, if not otherwise indicated, are explicitly incorporated by reference herein in their entirety for all purposes as if fully set forth.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

Except where expressly noted, trademarks are shown in upper case.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Unless stated otherwise, all percentages, parts, ratios, etc., are by weight.