Process and apparatus for the production of useful products from carbonaceous feedstock
View Patent ↗A carbonaceous feedstock to alcohol conversion process in which carbon dioxide is removed from the syngas stream issuing from a feedstock reformer, to yield a carbon dioxide depleted syngas stream including hydrogen, carbon monoxide and methane. This carbon dioxide depleted syngas stream is then passed through a Fischer-Tropsch reactor ultimately yielding a mixed alcohol product which is preferably largely ethanol. The removed carbon dioxide stream is passed through a methane reformer along with methane, which is produced in or has passed through a Fischer-Tropsch reactor, to yield primarily carbon monoxide and hydrogen. The carbon monoxide and hydrogen stream from the methane reformer are passed through the alcohol reactor. Also disclosed are a unique catalyst, a method for controlling the content of the syngas formed in the feedstock reformer, and a feedstock handling system.
1. A method for controlling the proportions of carbon monoxide, hydrogen and methane in a syngas stream leaving a feedstock reformer, in which a non-char solid organic material based feedstock having a moisture content in a range of about 5% to 20% is introduced into the feedstock reformer at an elevated temperature, said process comprising:
adjusting a contact time of the feedstock at elevated temperatures in the reformer within a range of from about 0.4 seconds to about 5.0 seconds, wherein the contact time is a function of the internal volume of the reformer divided by the flow rate of the syngas exiting the reformer, and
adjusting the exit gas temperature of the syngas as it leaves the reformer to between about 871° C. (1600° F.) and about 1204° C. (2200° F.), to achieve proportions of carbon monoxide, hydrogen and methane most closely approximate those desired given the intended use of the syngas.
2. The process of claim 1 which includes introducing said feedstock and superheated steam into the feedstock reformer at about 204° C. (400° F.).
3. The process of claim 2 in which said syngas exit temperature and contact time are adjusted to produce a syngas most optimally proportioned to produce lower alcohols, by adjusting said syngas exit temperature from about 898° C. (1650° F.) to below 926° C. (1700° F.), and said contact time from about 1.0 seconds to about 3.0 seconds.
4. The process of claim 3 in which said contact time is adjusted to from about 1.4 seconds to about 2.0 seconds.
5. The process of claim 1 wherein the feedstock is introduced into the reformer at a pressure in a range of about 241 kilopascal (35 psig) to about 276 kilopascal (40 psig).
6. The process of claim 1 wherein the feedstock is introduced into the reformer with steam.
7. The process of claim 1 further comprising the step of adjusting the amount of steam introduced with the feedstock into the reformer.