Patent Application
20080016770
For a more complete understanding of the present invention, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:
The term “biomass” as used herein refers broadly to material which is, or is obtained from, agricultural products, wood and other plant material, and/or vegetation, and their wastes. The biomass is mixed with water at the desired weight percentage, generally from 30 to 70 wt % while at a temperature in the range of 170 to 250° C., most preferably about 200° C., under non-oxidative gas pressure of 100 to 400 psi, most preferably about 150 psi. The mixture can be placed in an autoclave at room temperature and ramped to the reaction temperature, or the vessel can be preheated to the desired temperature before being pressurized. The reaction temperature can range from 10 minutes to an hour or more.
While any non-oxidative gas can be used, such as argon, helium, nitrogen, hydrogen, carbon dioxide, or gaseous hydrocarbons, or mixtures thereof, nitrogen is preferred because of its economic availability. Another preferred non-oxidative gas is hydrogen if available internally from the process, and which can be particularly advantageous if carried with the slurry into a hydro-gasification reactor. While it is desirable to eliminate oxidative gas, one can use a commercial grade, or less pure, of the non-oxidative gas so long as no substantial oxidation takes place.
The following examples will illustrate the invention.
Referring to
The result is shown in
The procedure of Example 1 was followed but the vessel was preheated to >200° C. before being put in the heater. The autoclave was found to reach 230° C. in 15 minutes or less and then it was held for 30 minutes. The time needed to reach the target temperature did not have a noticeable physical impact on the resulting product
The method of Example 1 can be carried out but in which the starting mixture is non-pumpable agricultural waste containing 60 weight percent solids. The result will be a pumpable slurry containing 60 wt. % solids in water.
The method of Example 1 can be carried out but in which the starting mixture is vegetation containing 40 weight percent solids. The result will be a pumpable slurry containing 40 wt. % solids in water.
The slurry of carbonaceous material resulting from the process of this invention can be fed into a hydro-gasifier reactor under conditions to generate rich producer gas. This can be fed along with steam into a steam pyrolytic reformer under conditions to generate synthesis gas, as described in Norbeck et al. U.S. patent application Ser. No. 10/503,435, referred to above. Alternatively, the resultant slurry can be heated simultaneously in the presence of both hydrogen and steam to undergo steam pyrolysis and hydro-gasification in a single step, as described in detail in Norbeck et al. U.S. patent application Ser. No. 10/911,348, referred to above.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process and apparatus described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes and apparatuses, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include such processes and use of such apparatuses within their scope.
