Production of hydrogenated hydrocarbons - Patent 4162959
Yet another oil company, Occidental Petroleum, "OXY", hopped onto what seems to have been the Coal conversion bandwagon three decades ago.
Herein, they are seen as having been awarded a US Patent for, seemingly, a version of what we have earlier documented as Shell Oil's Middle Distillate System, most often abbreviated as "MDS" and which is now in the process of being, for the conversion of both natural gas and Coal-derived synthesis gas into liquid fuels, reduced to commercial practice in a few places around the world, including, as we've reported, Bahrain and Malaysia.
Some excerpts:
"Production of hydrogenated hydrocarbons - United States Patent 4162959
Inventors: Duraiswamy, Kandaswamy (Laverne, CA)
Date: July 31, 1979
Assignee: Occidental Petroleum Corporation (Los Angeles, CA)
Abstract:
In a continuous process for recovery of values from a solid carbonaceous material, the carbonaceous material is pyrolyzed in the presence of a particulate source of heat to yield a particulate carbon containing residue of pyrolysis and volatilized hydrocarbons while simultaneously the volatilized hydrocarbons are hydrogenated. The particulate source of heat is formed by oxidizing carbon in the solid residue to heat the particles. Hydrogen for hydrogenation is obtained by reacting at least a portion of the hot particulate carbon containing residue of pyrolysis with steam prior to feeding the hot particulate residue to the pyrolysis reaction zone. Steam and/or carbon dioxide can be introduced into the pyrolysis reaction zone to interact with carbon containing residue contained therein. The particulate source of heat can be introduced to the pyrolysis reaction zone over an overflow weir.
What is claimed is:
1. A continuous process for recovery of liquid hydrocarbon values from a solid carbonaceous material feed comprising the steps of:
(a) oxidizing particulate carbon containing residue resulting from pyrolysis of the carbonaceous material in an oxidation zone in the presence of a source of oxygen to produce hot particulate carbon containing residue and a combustion gas;
(b) passing carbon containing residue and combustion gas from the oxidation zone to a separation zone and separating in the separation zone hot particulate carbon containing residue from the combustion gas;
(c) forming hydrogen gas in a conversion zone by reacting at least a portion of the separated hot particulate carbon containing residue with steam in the substantial absence of unpyrolyzed solid carbonaceous material;
(d) simultaneously pyrolyzing the carbonaceous material and hydrogenating pyrolysis products of the carbonaceous material by combining hydrogen gas from the conversion zone, the carbonaceous material feed, and a particulate source of heat including carbon containing residue from the conversion zone in a flash pyrolysis reaction zone having a temperature of from about 600 to about 2000 F., a pressure from ambient up to about 10,000 psig, and a solids residence time less than about 5 seconds to yield a pyrolysis product stream containing as solids, a particulate carbon containing residue of pyrolysis and particulate source of heat, and a vapor mixture comprising volatilized hydrocarbons including middle distillates;
(e) introducing steam to the pyrolysis reaction zone for reacting with carbon containing residue therein to generate additional hydrogen gas to further hydrogenate the volatilized hydrocarbons resulting from the pyrolysis of the carbonaceous material feed; and
(f) condensing hydrocarbons including middle distillates from the vapor mixture."
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Oxy, herein, as in many other Big Oil company documents available concerning these matters, avoid as much as possible any use of the offensive four-letter word "Coal", preferring the more polite phrase "solid carbonaceous material". That, actually, as we've earlier reported, is a good thing. It could well include such renewable and Carbon Dioxide-recycling resources as cellulose and used, natural rubber auto tires; and, might thus afford some "carbon offsets" for the Coal that is used in the process.
Currently, though, Coal is the only "solid carbonaceous material" which could offer the economies of scale to enable such enterprise; and, Coal is what such an undertaking would have to be based primarily upon.