Carbonaceous Fuels and Processes for Making and Using Them

Abstract

The present invention provides carbonaceous fuels and processes for making them. Moreover, the invention also relates to processes using the carbonaceous fuels in the production of cement products. One embodiment of the invention is a carbonaceous fuel comprising (a) unconverted fines of a carbonaceous feedstock, the carbonaceous feedstock having an ash content of greater than 1%, 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%, 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 about 4:1 to about 1:4, and a total dry basis wt % of carbon of least about 40%. Another embodiment of the invention is a process of making a cement product comprising: (a) providing a carbonaceous fuel 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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]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.FIELD OF THE INVENTION[0002]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.BACKGROUND OF THE INVENTION[0003]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. 4,092,1...

AI Technical Summary

Benefits of technology

[0005]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, t

Problems solved by technology

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.

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.