Patent Application
20090071873
The present application claims priority to Ukrainian Patent Application No. a200509452 filed Oct. 10, 2005, and published as a publication No. UA 74,762 C2 on Jan. 16, 2006, both of which are incorporated herein by reference in their entirety. The present application also claims priority to Ukrainian Patent Application No. a200509544 filed Oct. 11, 2005, and published as a publication No. UA 74,763 C2 on Jan. 16, 2006, both of which are incorporated herein by reference in their entirety.
The present invention relates to methods and apparatuses for transforming organic compounds and more particularly to methods and apparatuses for transforming organic compounds utilizing a liquefied metal alloy.
Natural gas is a major source of methane. Other sources of methane have been considered for fuel supply, e.g., the methane present in coal deposits or formed during mining operations. Relatively small amounts of methane are also produced in various petroleum processes.
The composition of natural gas at the wellhead varies, but its major hydrocarbon is methane. For example, the methane content of natural gas may vary within the range from about 40 to about 95 volume percent. Other constituents of natural gas include ethane, propane, butanes, pentane (and heavier hydrocarbons), hydrogen sulfide, carbon dioxide, helium and nitrogen.
Natural gas is classified as dry or wet depending upon the amount of condensable hydrocarbons that is contains. Condensable hydrocarbons generally comprise hydrocarbons having 3 or more carbon atoms, although some ethane may be included. Gas conditioning is required to alter the composition of wellhead gas, with processing facilities usually being located in or near the production fields. Conventional processing of wellhead natural gas yields processed natural gas containing at least a major amount of methane.
Large scale use of natural gas often requires a sophisticated and extensive pipeline system. Liquefaction has also been employed as a transportation means, but processes for liquefying, transporting, and revaporizing natural gas are complex, energy-intensive and require extensive safety precautions. Transport of natural gas has been a continuing problem in the exploitation of natural gas resources. It would be extremely valuable to be able to convert methane (e.g., natural gas) to more readily handleable or transportable products. Moreover, direct conversion to olefins, such as ethylene or propylene would be extremely valuable to the chemical industry.
A common method for methane conversion is a steam methane reforming performed at a high temperature of 600° C. to 840° C. at a high pressure of about 5 to 100 atmospheres in the presence of nickel or other metal based catalyst. The disadvantages of the steam methane reforming include the use of the catalyst, high pressure and temperature, which a) are costly to produce and b) require a sturdy reaction apparatus, and low yield of the method.
U.S. Pat. No. 5,093,542 discloses an alternative method of methane conversion, in which a gas containing methane and a gaseous oxidant is contacted with a nonacidic catalyst at temperatures within the range of about 700° to 1200° C. in the presence of a halogen promoter and in the substantial absence of alkali metals or their compounds. U.S. Pat. No. 4,962,261 discloses another alternative method of methane conversion to higher molecular weight hydrocarbons in a process using a catalyst containing boron, tin and zinc at temperatures ranging from 500 to 1000° C.
US 2004/0120887, US 2005/0045467, US 2003/0182862, U.S. Pat. No. 6,413,491 and GB 2,265,382 disclose other alternative methods of methane conversion.
Still, a need exists to develop low temperature methods for transforming methane and other organic compounds that do not necessarily require a metal catalyst, nor subject the organic compounds to excessive pressure.
According to one embodiment, a method for transforming at least one organic compound comprises initiating a second order phase transition in a liquefied metal alloy; and exposing the at least one organic compound to an energy of the second order phase transition, wherein the exposing results in transforming the at least one organic compound.
According to another embodiment, a method of transforming at least one organic compound comprises passing a heat flow through a liquefied metal alloy; and then exposing the at least one organic compound to the heat flow, wherein the exposing results in transforming the at least one organic compounds.
Yet in another embodiment the invention provides an apparatus comprising a heat source; a liquefied metal alloy in thermal contact with the heat source; and a vessel containing at least one organic compound, wherein the at least one organic compound is in thermal contact with the alloy and wherein a heat flow from the heat source passes through the alloy to transform the at least one organic compound.
And in yet another embodiment, the invention provides an apparatus comprising a heat source; a liquefied metal alloy in thermal contact with the heat source; and means for passing at least one organic compound, wherein a heat flow from the heat source passes through the alloy to melt the alloy and to transform the at least one organic compound.
And yet in another embodiment, the invention provides a method of producing hydrogen, comprising passing a heat flow through a liquefied metal alloy, and then exposing at least one organic compound to the heat flow, wherein the exposing results in producing hydrogen from the at least one organic compound.
Unless otherwise specified “a” or “an” means one or more.
The inventor has discovered that a heat flow passed through a melted metal alloy can transform the organic compound.
The inventor has also discovered that organic compounds can be transformed by being exposed to an energy of the second order phase transition initiated in a melted metal alloy.
The transformation of the organic compounds in the above methods occurs without contacting them with a metal catalyst, without directly exposing the organic compounds to high temperatures above 500° C. and without exposing the organic compounds to an excessive pressure above the atmospheric pressure.
The metal alloy can be a metal alloy with a low melting temperature. For instance, the melting temperature of the alloy can be below 200° C., such as below 150° C. The melting temperature can be either liquidus temperature of the alloy or solidus temperature of the alloy.
The metal alloy can be an alloy comprising one or more metals selected from metals of the 5th period of the periodic table, such as Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd. Ag, Cd, In, Sn, Sb, Te, and I, and metals having an atomic number higher than 79, such as Hg, Ti, Pb and Bi. Preferably, the metal alloy does not comprise radioactive isotopes. Preferably, the metal alloy comprises one or metals of the 5th period of the periodic table and one or more metals having an atomic number ranging from 80 to 83.
In some embodiments, the metal alloy can comprise Bi and Sn. In some embodiments, the metal alloy can further comprise Pb. Examples of such alloys include Wood's alloy (50% Bi, 13.3% Sn, 26.7% Pb, 10% Cd), which has a melting temperature around 70° C. and Rose's alloy (50% Bi, 25% Sn, 25% Pb), which has a melting temperature around 100° C. Other alloys that comprise Bi and Sn can also be used.
Initiating a second order transition in the metal can involve heating the alloy above its melting temperature. The initiation of the second order transition can further include stirring the metal alloy.
Passing a heat flow through the metal alloy can involve heating the metal alloy above its melting temperature to a temperature above 60° C. In some embodiments, the temperature of the metal alloy can be from about 80° C. to about 175° C. Yet, in some cases the temperature of the alloy can be above 175° C. The temperature of alloy can be, for example, from 300° C. to 450° C. or from 320° C. to 400° C. or from 360° C. to 410° C.
The organic compound can be any organic compound. The organic compound can be an organic compound having an unsaturated C—H bond. Examples of such organic compounds are a hydrocarbons such as alkanes or cycloalkanes.
The transformation of an organic compound means that, as the result of the exposure to the heat flow passed through the metal alloy, one or more products that have a chemical structure different from the starting organic compound are formed. The transformation of an organic compound can be direct or indirect, i.e. the transformation can be a direct or indirect result of exposing the organic compound to the heat flow that passed through the metal alloy. For example, the transformation of hydrocarbons, such as alkanes or cycloalkanes, can involve their decomposition into products that comprise hydrogen as a direct result of the exposure to the heat flow that passed through the metal alloy. The products of the direct transformation can be used for transforming one or more additional organic compounds. For example, hydrogen formed in the hydrocarbon transformation can be used for transforming a substituted nitrocompound into a substituted aminocompound. Such a transformation is an example of the indirect transformation.
In some embodiments, the organic compound or compounds to be transformed can be a raw hydrocarbon material, such as raw oil or natural gas. For such a transformation, the exposure of the hydrocarbon material can last from 0.1 to 50 seconds or from 0.2 to 12 seconds or from 2 to 40 seconds.
When exposed to the heat flow that passed through the metal alloy, the raw hydrocarbon material can be in a liquid phase at a temperature ranging from 80 to 175° C. In some embodiments, the raw hydrocarbon material can provided in a zone of exposure to the heat flow together with ballast materials that can increase the heat and mass transfer of the raw hydrocarbon material. The ballast materials can be metals, ceramics or other inert materials that do not react with the raw hydrocarbon material. Preferably, the ballast materials do not change a viscosity of the raw hydrocarbon material.
The products of the raw hydrocarbon material transformation can have a molecular weight different that the starting hydrocarbons. The products can comprise a light fraction, i.e. hydrocarbons having a molecular weight lighter than the starting raw material and enriched with hydrogen, and a heavy fraction, i.e. hydrocarbons having a molecular weight heavier than the starting raw material. To separate the light fraction from the heavy one, the former can be evaporated and then condensed using an appropriate cooling system in a separate volume. The heavy fraction can be removed from an area of exposure to the heat flow in a liquid state.
The exposure to the heat flow that passed through the liquefied metal alloy can be periodic or continuous. The continuous exposure means that an entire amount of organic compounds to be transformed is supplied to a zone of exposure to the heat flow that passed through the metal alloy continuously, i.e. without interruptions. The periodic exposure means that the exposure includes at least two exposure periods separated by a non-exposure period, i.e. a period when the organic compound is not exposed to the heat flow passed through the metal alloy. The periodic exposure can be accomplished by interrupting the organic compounds' supply to an area exposed to the heat flow.
The apparatus for transforming at least organic compound includes a heat source, a metal alloy in thermal contact with a heat source and a device for passing the at least one organic compound. The device for passing the at least one organic compound can be any vessel, conduit or chamber that can expose the organic compound passing through to the heat flow that passed through the metal alloy. For example, the vessel or conduit that has an inlet for supplying one or more organic compounds to be transformed and an outlet for removing the products of transformation. Such a vessel or conduit can be, for example, a pipe. In some embodiments, to maximize the exposure of the organic compound to the heat flow, the pipe can have a spiral shape. In some embodiments, the vessel can be immersed in the liquefied metal alloy. In some embodiments, the organic compound and the metal alloy are not in direct physical contact. For example, the organic compound passing through the vessel can be separated from the metal alloy by one or more vessel walls. Such vessel walls can be made of non-magnetic metal comprising steel, copper or copper alloys such as brass. Preferably, the walls do not comprise materials that are permanent magnets. The thickness of the walls can range from 0.1 to 10 mm.
The vessel can have any volume chosen depending on an amount of organic compounds desired to be transformed.
To prevent it from oxidation, the melted metal alloy in the apparatus can be protected from a surrounding environment. For example, the metal alloy can be sealed in the apparatus from the surrounding environment.
The heat source can be a heat source of any type. The heat source can have an intensity of at least 30 kW/m2, preferably of at least 35 kW/m2. In some embodiments, the heat source can be a jacket heated by burner gases. The heat source may also comprise resistance heater(s), heat lamp(s), radio frequency heating coil(s) etc.
The heat source can be separated from the alloy by, for example, a wall. The material of such a wall can be, for example, steel. The wall can also comprise any non-ferromagnetic material. The thickness of the wall can range from about 0.1 to about 10 mm.
In some embodiments, the apparatus can further comprise a stirrer immersed in the metal alloy. Such a stirrer can be an anchor stirrer or nozzle equipped impeller.
In some embodiments, the apparatus can further comprise a cooling system coupled to the vessel. The cooling system can be used for condensing an evaporated fraction of transformation products.
The invention is further illustrated by, though in no way limited to, the following examples.
After heating up the metal alloy 5 to a temperature of 80 to 175° C. to melt the alloy, the stirrer 4 located underneath the spiral pipe 2 is turned on. The stirrer 4 can be an anchor stirrer having a frequency ranging from 60 to 120 Hz, or a nozzle equipped impeller having a frequency ranging from 150 to 300 Hz.
After letting the stirrer 4 run for approximately 15 minutes in the heated reactor 1, methane is introduced into the spiral pipe 2 through inlet 6. Methane supply rate is selected to be such that methane can pass through the spiral pipe in 0.2-12 seconds. Although the present invention is not limited by a particular theory, heating and stirring is believed to cause an imitation of a phase transition in the metal alloy. The energy of the phase transition is believed transform methane into carbon and hydrogen (CH4->2H2+C), which are removed through pipe outlet 7.
The apparatus depicted in
Although the foregoing refers to particular preferred embodiments, it will be understood that the present invention is not so limited. It will occur to those of ordinary skill in the art that various modifications may be made to the disclosed embodiments and that such modifications are intended to be within the scope of the present invention.
All of the publications, patent applications and patents cited in this specification are incorporated herein by reference in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200509452 | Oct 2005 | UA | national |
| 200509544 | Oct 2005 | UA | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US06/39269 | 10/10/2006 | WO | 00 | 10/1/2008 |
