Recently, as accessible via:
West Virginia Coal Association | WVU June 18, 2013, Carbon-Recycling Coal Liquefaction | Research & Development; concerning: "United States Patent 8,465,561 - Hydrogenated Vegetable Oil in Coal Liquefaction; 2013; Inventors: Alfred H. Stiller and Elliot B. Kennel, Morgantown, WV; Assignee: West Virginia University; Abstract: The present disclosure provides methods and systems for coal liquefaction using a hydrogenated vegetable oil"; and:
West Virginia Coal Association | WVU May 28, 2013, Carbon-recycling Coal Liquefaction | Research & Development; concerning: "United States Patent 8,449,632 - Sewage Material in Coal Liquefaction; 2013; Inventor: Alfred H. Stiller, Morgantown, WV; Assignee: West Virginia University; Abstract: The present disclosure provides methods and systems for coal liquefaction using a sewage material";
we made report of technologies developed at West Virginia University, wherein Coal can be processed along with more sustainable, Carbon-recycling substances, like "vegetable oil" and "sewage material", with all of them being converted into a "de-ashed coal extract" which can, in WVU's words, "be added to a pipeline of petroleum crude for delivery to a petroleum refinery".
There are, in the full Disclosures of "United States Patent 8,465,561 - Hydrogenated Vegetable Oil in Coal Liquefaction" and "United States Patent 8,449,632 - Sewage Material in Coal Liquefaction", passages like those following:
"In embodiments, a plurality of hydrogenated solvents may be used for the coal liquefaction process. The hydrogenated solvents may include, but are not limited to, ... rubber tires, animal waste, anything with the potential of adding a proton to an aromatic or breaking a chemical bond, ... rubber, plastics, recycled plastics (e.g. polystyrenes), recycled rubber"; and:
"In an aspect, a method of obtaining a de-ashed coal extract may include exposing a coal to a rubber material in the presence of a coal-derived solvent to form a slurry, elevating the temperature of the slurry to facilitate liquefying the coal and liberating a volatile matter, and separating the insoluble components from the slurry to obtain a de-ashed coal extract, wherein the coal extract is suitable for downstream processing. The rubber material may be from a rubber tire";
which emphasize, or at least point out, how a pernicious waste, used "rubber tires" can be consumed, and utilized as one source of the needed solvent, in Coal liquefaction processes.
And, we note that such potentials for co-processing Coal and, perhaps especially, waste rubber, and other polymers, which auto tires are basically made of, in direct liquefaction processes, for the production of a synthetic crude petroleum that can "be added to a pipeline of petroleum crude for delivery to a petroleum refinery", have been the subject of study and development at WVU for quite some time, as seen separately in our reports of:
West Virginia Coal Association | WVU & Coal AND Waste Tire Liquefaction | Research & Development; concerning: "'Free radical monitoring of the coprocessing of coal with chemical components of waste tires'; Manjula M. Ibrahim and Mohindar S. Seehra;
West Virginia University, Morgantown, WV; Abstract: The effects of a Michelin tire tread and its various chemical components (butadiene rubber, aromatic oil, carbon, sulfur, ZnO) on the free radical intensities N of Blind Canyon coal using in-situ electron spin resonance spectroscopy are reported from ambient to 500°C. These experiments show that the tire tread and its components lower the temperature of thermal cracking of the coal and promote enhanced cracking as evidenced by increased magnitudes of N for temperatures below 440°C. These results support the reported improved liquefaction of the coal with waste tire polymers"; and:
West Virginia Coal Association | WVU Improves CTLYield with Waste Tires | Research & Development; concerning: "Effect of process conditions on co-liquefaction kinetics of waste tire and coal; Ramesh K. Sharma, Jianli Yang, John W. Zondlo and Dady B. Dadyburjor;
West Virginia University, 1998".
Further, we document herein that WVU's development work, focused on the use of waste rubber to facilitate the direct conversion Coal into substitute crude petroleum, is actually derivative of earlier, closely-related efforts undertaken directly by our United States Government, in the USDOE's Pittsburgh, PA, Energy Technology Center.
As seen in excerpts from the initial link in this dispatch to:
"United States Patent 5,061,363 - Method for Co-processing Waste Rubber and Carbonaceous Material
Patent US5061363 - Method for co-processing waste rubber and carbonaceous material - Google Patents
Date: October 29, 1991
Inventors: Marvina Farcasiu and Charlene Smith, Pittsburgh, PA
Assignee: The United States of America
Abstract: In a process for the co-processing of waste rubber and carbonaceous material to form a useful liquid product, the rubber and the carbonaceous material are combined and heated to the depolymerization temperature of the rubber in the presence of a source of hydrogen. The depolymerized rubber acts as a liquefying solvent for the carbonaceous material while a beneficial catalytic effect is obtained from the carbon black released on depolymerization the reinforced rubber. The reaction is carried out at liquefaction conditions of 380 - 600 C and 70-280 atmospheres hydrogen pressure. The resulting liquid is separated from residual solids and further processed such as by distillation or solvent extraction to provide a carbonaceous liquid useful for fuels and other purposes.
Government Interests: The U.S Government has rights in this invention pursuant to the employee/employer relationship of one of the inventors to the U.S. Department of Energy at the Pittsburgh Energy Technology Center.
Claims: A method for co-processing carbonaceous material and rubber comprising: forming a mixture of the rubber and the carbonaceous material; heating the mixture to the depolymerization temperature of the rubber in the presence of a source of hydrogen to form a hydrogenated liquid hydrocarbon and residual solids; and separating the liquid hydrocarbon from the residual solids.
The method ... wherein the mixture is heated to a temperature in the range of 380 to 600 C at a hydrogen pressure of 70 to 280 atmospheres.
(This is, no doubt, a high-temperature and high-pressure, and thus high-energy demand, process. In that regard, if you study the temperature and pressure requirements specified in the full disclosures of "United States Patent 8,465,561 - Hydrogenated Vegetable Oil in Coal Liquefaction" and "United States Patent 8,449,632 - Sewage Material in Coal Liquefaction", as cited above, and as exemplified by these passages excerpted from the full Disclosures:
"In embodiments, the coal liquefaction process may proceed at a lower pressure than is usually required for coal liquefaction e.g., 400 psig. (One) embodiment ... may enable the coal liquefaction process to be run at lower temperature and lower pressure with less hydrogen"; and (other embodiments employ) "a pressure of less than 200 psi" and "a temperature less than 200 C", and directly confirm that such processes "require less processing energy", since the "generation of high temperature and pressure" in precedent direct Coal liquefaction processes "may be energy-intensive";
it's clear - - since, to translate, the "200 psi" to "400 psig" pressures of WVU's processes, which equate to, roughly, 13 to 27 atmospheres, is much less than the "70 to 280 atmospheres" specified by our subject herein, just as WVU's specified temperature of "less than 200 C" is much less than the "380 to 600 C" of this USDOE process - - that, West Virginia University has made great strides in reducing the amount of energy needed to convert Coal, and various carbonaceous wastes, into synthetic crude petroleum.)
The method ... wherein the mixture contains a liquefaction catalyst including finely divided carbon (and)wherein the finely divided carbon comprises carbon black embedded as reinforcing pigment in particulate rubber and wherein the carbon black is released on depolymerization of the rubber into contact with the carbonaceous material.
(The above explains why, as in the references cited above, WVU was able to confirm, both, that "tire tread and its components lower the temperature of thermal cracking of the coal", and, "the reported improved liquefaction of the coal with waste tire polymers".)
The method ... wherein the carbonaceous material is coal and the rubber is selected from the group of materials consisting of natural rubber, synthetic rubber, plastics having rubber-like properties and mixtures thereof.
The method ... wherein the heating step is conducted in the presence of a coal liquefaction catalyst including a catalytically active, transition metal compound (and) wherein particulate rubber obtained from used vehicle tires containing vulcanized polymeric material and embedded carbon black is included in the mixture (and)wherein the heating at pressure is conducted at sufficient levels and for a sufficient time to liquefy at least a portion of the rubber and release the carbon black into contact with the formed liquid.
A method for the co-processing of waste rubber and carbonaceous material to form a useful liquid product comprising: combining the rubber in mixture with the carbonaceous fuel; heating the mixture to the depolymerization temperature of the rubber in the presence of a source of hydrogen to form a hydrogen-rich liquid having constituents from both the rubber and the carbonaceous fuel.
The method ... wherein the hydrogen rich liquid is further processed to remove residual solids and to separate liquid fractions by distillation (and) wherein selected distillation fractions are removed as product and at least a portion of other liquid fractions recycled into mixture with the rubber and the carbonaceous fuel (and) where the carbonaceous material is coal.
Description and Background: The present invention relates to a method for the co-processing of waste rubber and carbonaceous material. More particularly, it relates to an improved method for liquefying waste rubber in mixture with a carbonaceous material such as coal to permit use of depolymerized rubber as a hydrogen donor solvent and carbon black reinforcing pigment as a liquefaction catalyst.
In the United States, worn and used rubber products are creating an increasingly large disposal problem. During the past few years, it is estimated that about 200 million used tires are discarded each year. Each tire contains about 15 pounds (7 kilograms) of organic materials and 2 kilograms of carbon black. If the rubber in these tires could be reprocessed with coal at about a 1-to-1 weight ratio, approximately 40,000 barrels per day of transportation fuels could be produced. In addition to the used tires, there is also a substantial amount of other waste rubber products that could be reprocessed. At the present time, most of these tires and rubber products are serving no useful purpose but are occupying significant space in waste dumps, vacant lots, and other vacant facilities.
Coal liquefaction is typically achieved by heating the coal in the presence of a hydrogen donor solvent often with an added liquefaction catalyst.
The most common solvent used are fractions derived from the liquefied coal.
The liquefaction of coal is dependent on its hydrogenation which can be a function of the hydrogen donor solvent or the ability of the catalysts to promote reaction with hydrogen gas.
(This process for the co-liquefaction of Coal and Carbon-recycling wastes, like used auto tires, does require a supply of elemental, molecular Hydrogen for transfer to the carbonaceous starting materials. And, as seen for only one example in our report of:
West Virginia Coal Association | USDOE Renewable Hydrogen for Coal Liquefaction | Research & Development; concerning: "Renewable Hydrogen Production for Fossil Fuel Processing; OSTI ID: 10180379; DOE Contract Number: AC05-84OR21400; 1994; Oak Ridge National Lab., TN; Sponsor: USDOE; Abstract: The objective of this mission-oriented research program is the production of renewable hydrogen for fossil fuel processing. This program will build upon promising results that have been obtained in the Chemical Technology Division of Oak Ridge National Laboratory on the utilization of intact microalgae for photosynthetic water splitting. In this process, specially adapted algae are used to perform the light-activated cleavage of water into its elemental constituents, molecular hydrogen and oxygen";we do have some intriguing technological options available to us for the production of Hydrogen.)
Typically, particulate coal feed is slurried in a coal-derived recycle solvent and the resulting slurry is preheated to near the reaction temperature and fed with hydrogen into a catalytic reactor. The reactor operates at relatively high temperature and pressure conditions to hydroconvert and liquefy a major portion of the coal and thereby produce hydrocarbon gas and liquid fractions. Unfortunately, a large fraction of the coal liquefaction product is a residual oil containing preasphaltenes and asphaltene compounds having a low hydrogen content. It is these heavy, hydrogen-lean fractions that are often recycled for slurrying with the incoming coal to place an additional burden on the hydrogenation reactor.
Description and Summary: Therefore in view of the above, it is an object of the present invention to provide a method for co-processing waste rubber with carbonaceous material.
It is also an object of the invention to provide a method for converting waste rubber into useful carbonaceous liquids and fuels.
It is a further object of the invention to provide a method for using the carbon black content of reinforced rubber tires as a liquefaction catalyst (and) to provide a source of liquefaction solvent for slurrying carbonaceous material in a hydrogenation process.
In accordance with the present invention, a method is provided for the liquefaction of carbonaceous material by forming a solid dry mixture of rubber with the carbonaceous material and heating the mixture to the depolymerization temperature of the rubber in the presence of hydrogen to form a liquid hydrocarbon and residual solid material. The liquid hydrocarbon is then separated as product from the residual solid material.
This invention also contemplates a method for co-processing waste rubber and carbonaceous material to form a useful liquid product. The method includes combining the rubber with carbonaceous fuel and heating the mixture to the depolymerization temperature of the rubber in the presence of a source of hydrogen to form a hydrogen-rich liquid having constituents from both the rubber and the carbonaceous fuel.
In more specific aspects of the method, a vulcanized rubber with reinforcing carbon black is combined in mixture with the carbonaceous fuel and the resulting hydrogen-rich liquid is further processed to remove residual solids and separate the carbonaceous liquid into fractions by distillation.
In one manner of carrying out the present invention, a carbonaceous material such as coal in combination with rubber or rubber-like material is heated to a temperature in excess of the depolymerization temperature of the rubber or rubber-like material in the presence of hydrogen gas under pressure to liquify both the rubber and the carbonaceous material.
Typically, a waste rubber material is co-processed with the carbonaceous material. Natural rubber, synthetic rubber and certain plastics having rubber-like properties are contemplated for use. Unless otherwise indicated the term "rubber" as used in this application is intended to include natural rubber, synthetic rubber and other rubber-like materials.
Waste rubber, particularly that used in vehicle tires, is ordinarily a vulcanized rubber including carbon black as a reinforcing agent for strength. The inventors have found the carbon black to have an advantageous catalytic effect in the cleavage of methylene and ethylene bridges between condensed polyaromatic rings. Such chemical functionalities are abundant in coal."
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In sum, our own US Government, more than two decades ago, confirmed that we could synergistically combine some pernicious wastes and environmental contaminants, i.e., "used in vehicle tires" and other waste rubber and polymers, with our abundant Coal in a process that directly synthesized "a carbonaceous liquid useful for fuels" - "fuels" which, we submit, could free us from bondage to OPEC and put a whole lot more Americans to work in good-paying jobs.
West Virginia University has, subsequently, made some great, even startling, improvements, in terms especially of energy efficiency, on that USDOE process - which USDOE process each and every US citizen owns a share of.
And, it's far, far past time each and every US citizen was given at least the privilege of reading all about it.