British petroleum has applied for a United States Patent on what is, in essence, a refinement of established processes for making liquid fuels from coal.
We provide excerpts from the lengthy patent application below.
Unsurprisingly, although the application is all about making liquid fuel from "synthesis gas", use of the word "coal", offensive four-letter word that it must be, is avoided to the point of absurdity.
We found it mentioned only once in the lengthy application, where the authors felt compelled, by some inescapable sense of duty, to explain where "synthesis gas" might originate. The quote, from deep within the text, is:
"The hydrocarbon feedstock used for syngas generation is preferably a carbonaceous material, for example biomass, plastic, naphtha, refinery bottoms, smelter off gas, municipal waste, coal and/or natural gas, coal and natural gas being the preferred ones, most preferably natural gas."
See if you can find it.
Actually, they have done a service by revealing that, along with coal, such synthesis gas technology affords us the opportunity, as we have already several times documented to be possible, to effect some recycling of wastes, with an element of sustainability. Herein, appropriate feeds for a primarily coal-to-liquid conversion process could include, in addition to coal, "biomass, plastic, naphtha, refinery bottoms, smelter off gas, (and) municipal waste", all of which we have, from other reputable sources, documented to have potential as feeds for liquid fuel conversion processes.
They do say that coal is "preferred", even though they mention it only once.
And, we'll note especially their mention of "smelter off gas", and remind you of earlier research we've reported, wherein coke oven flue gas could be recovered and used for liquid fuel synthesis.
Finally, we call your attention to their frequent referencing of the Fischer-Tropsch technology, which should now be synonymous, in the minds of all our readers, with coal-to-liquid conversion.
In any case, here are some excerpts from this recent US Patent application. With some comment interspersed and following:
"Process for the conversion of synthesis gas to oxygenates United States Patent Application 20090170966
The present invention relates to an improved process for the conversion of carbon oxide(s) and hydrogen containing feedstocks to oxygen containing hydrocarbon compounds in the presence of a particulate catalyst.
Inventors: Atkins, Martin Philip (Middlesex, GB); Bolton, Leslie William (Hampshire, GB); Gracey, Benjamin Patrick (East Riding of Yorkshire, GB); Sunley, John Glenn (East Yorkshire, GB) Application Number: 11/920724; Publication Date: 07/02/2009; Filing Date: 05/18/2006 Assignee: BP CHEMICALS LIMITED (Middlesex, GB)
Claims: 1. Process for the conversion of carbon oxide(s) and hydrogen containing feedstocks to oxygen containing hydrocarbon compounds in the presence of a particulate catalyst comprising the step of reacting carbon oxide(s) and hydrogen in the presence of a particulate catalyst in a conversion reactor to form oxygen containing hydrocarbon compounds characterized in that a saturated monocarboxylic acid having from 1 to 3 carbon atoms and/or an ester of a saturated monocarboxylic acid having from 1 to 3 carbon atoms with a monohydric aliphatic paraffinic alcohol having from 1 to 4 carbon atoms are added to the conversion reactor.
2. Process according to claim I wherein the carbon oxide(s) and hydrogen containing feedstocks are synthesis gas or syngas, the oxygen containing hydrocarbon compounds are alcohols, the particulate catalyst is a particulate modified molybdenum sulphide based catalyst, or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst.
(Much is left unsaid, perhaps to protect trade secrets or to keep the scope as broad as possible. But, note that "hydrogen containing feedstocks " covers a lot of ground, with a lot of possible options for the use of botanical, CO2-recycling, wastes. And, note that the processing options include methanol synthesis or the old coal-to-liquids technology, Fischer-Tropsch.)
3. Process for the conversion of hydrocarbon to alcohols comprising the steps of a. converting hydrocarbon to a mixture of carbon oxide(s) and hydrogen in a syngas reactor, b. passing the mixture of carbon oxide(s) and hydrogen from the syngas reactor to a conversion reactor, and c. reacting said mixture in said conversion reactor in the presence of a particulate modified molybdenum sulphide based catalyst, and/or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst to form alcohols, characterized in that a saturated monocarboxylic acid having from 1 to 3 carbon atoms and/or an ester of a saturated monocarboxylic acid having from 1 to 3 carbon atoms with a monohydric aliphatic paraffinic alcohol having from 1 to 4 carbon atoms are added to the conversion reactor.
Description: This invention relates to an improved process for the conversion of carbon oxide(s) and hydrogen containing feedstocks to oxygen containing hydrocarbon compounds in the presence of a particulate catalyst. In particular, the present invention relates to an improved process for the conversion of carbon oxide(s) (CO and CO2) and hydrogen containing feedstocks, e.g. synthesis gas or syngas, to alcohols in the presence of a particulate modified molybdenum sulphide based catalyst, or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst.
(The immediately foregoing might be of special importance. As we have from other sources documented, the potential exists for adding supplemental Carbon Dioxide to synthesis gas, if the additional Carbon could be balanced by adding more "hydrogen containing feedstocks", such as botanical and agricultural wastes, perhaps, to the reaction mix.)
The catalyst is promoted with a Fischer-Tropsch promoter like an alkali or alkaline earth series metal or a smaller amount of thorium and is further treated by sulfiding. The composition of the mixed alcohols fraction can be selected by selecting the extent of intimate contact among the catalytic components.
Journal of Catalysis 114, 90-99 (1988) discloses a mechanism of ethanol formation from synthesis gas over CuO/ZnO/Al2O3.The formation of ethanol from CO and H2 over a CuO/ZnO methanol catalyst is studied in a fixed-bed microreactor by measuring the isotopic distribution of the carbon in the product ethanol when 13 C. methanol was added to the feed.
(As we've earlier documented, if we want ethanol, we can make it, too, from coal, via synthesis gas.)
In particular, the present invention relates to an improved process in term of selectivity and catalyst activity and operating life for the conversion of carbon oxide(s) and hydrogen containing feedstocks, e.g. synthesis gas or syngas, to alcohols in the presence of a particulate modified molybdenum sulphide based catalyst, or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst.
According to a preferred embodiment, the present invention provides a process for the conversion of hydrocarbon to alcohols comprising the steps of:
1. converting hydrocarbon to a mixture of carbon oxide(s) and hydrogen in a syngas reactor, 2. passing the mixture of carbon oxide(s) and hydrogen from the syngas reactor to a conversion reactor, and 3. reacting said mixture in said conversion reactor in the presence of a particulate modified molybdenum sulphide based catalyst, and/or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst to form alcohols ... . According to a preferred embodiment of the present invention, the oxygen containing hydrocarbon compounds are alcohols, mainly methanol, propanol, ethanol and butanols ... . According to another preferred embodiment of the present invention, the saturated monocarboxylic acid having from 1 to 3 carbon atoms and/or the ester of a saturated monocarboxylic acid having from 1 to 3 carbon atoms with a monohydric aliphatic paraffinic alcohol having from 1 to 4 carbon atoms which are added to the conversion reactor are preferably selected from methyl acetate or ethyl acetate or a mixture thereof.
... other advantages have also been found when applying the present process invention, amongst others: (i) less waste, less by-products and thus higher carbon efficiency. (ii) less capital, fewer separations, reduced storage tanks. (iii) alcohol product free from esters suitable for dehydration. Though esters can be dehydrated to carboxylic acid and olefin, the presence of carboxylic acids adds complexity to the process and may cause additional corrosion duty (iv) no corrosion and metallurgy constraints due to the potential hydrolysis of the esters during subsequent purification and storage stages
As indicated, the particulate catalyst used in the conversion reactor is preferably a modified molybdenum sulphide based catalyst, and/or a modified methanol based catalyst and/or a modified Fischer-Tropsch catalyst.
The hydrocarbon feedstock used for syngas generation is preferably a carbonaceous material, for example biomass, plastic, naphtha, refinery bottoms, smelter off gas, municipal waste, coal and/or natural gas, coal and natural gas being the preferred ones, most preferably natural gas.
The alcohol synthesis catalysts can also catalyze the water gas shift reaction. A consequence of this is that hydrogen and carbon dioxide are interconvertable with carbon monoxide and water. For high partial pressures of carbon dioxide (at or above the water gas shift equilibrium), carbon dioxide can act as a carbon monoxide source and a hydrogen sink and this can effect the apparent preferred syngas ratio. Useful feed streams include natural gas (mainly methane, but natural gas composition can vary depending on location and source), naphtha, refinery off-gas, LPG, gas oil, vacuum residuals, shale oils, asphalts, various types of fuel oils, coal based /lignin deposits and hydrocarbon containing process recycle streams.
(In other words, a source of additional hydrogen enables the inclusion of straight Carbon Dioxide in the feed, and the "water gas shift reaction", which we have previously documented, proceeds concurrently to consume and utilize the Carbon Dioxide.)
According to a preferred embodiment of the present invention, methane is used as the hydrocarbon-containing feed stream to be converted into carbon oxides(s) and H2.
(And, keep in mind, Methane can be itself produced from Carbon Dioxide, via the Sabatier Process, or, from Coal, via long-established gasification techniques.)
The conversion to oxygenates reaction can be carried out by passing the mixture of hydrogen and carbon monoxide over the conversion catalyst as a vapor phase reaction or as a liquid phase reaction, e.g., slurry reaction or trickle bed fluidized bed reactor."
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So, there you have it. Yet another coal-to-liquid fuel conversion technology owned, and so far unused, by another Big Oil major.
However, it is only a patent application; and, less than a year old.
In reality, it is, in fact, only a refinement of some technologies, such as Fischer-Tropsch, that have been around for nearly a century.
But, sometimes we have to clean our antiques off and polish them up before people can see just how beautiful they are, and how valuable they might be.
Let's try to make certain this one doesn't get stuffed back up into a dusty old attic.
