USA's Rockwell Liquefies Coal

 
We've documented patents held by the Department of Defense, through corporate proxies, for the recycling of Carbon Dioxide into liquid fuels for Navy ships; and, their research efforts, with several universities, into the liquefaction of coal.into aviation fuel for the Air Force.
 
Herein, we present, from a well-known defense contractor, what might be a "progress report" on the DoD's coal liquefaction research. Note, though, that this report, like many we've cited documenting domestic, US, enterprises centered on the further development of practical coal-to-liquid conversion technologies, was made two decades ago.
 
Comment follows: 
 
"Liquefaction of bituminous coal at moderate temperatures  

Raymund P. Skowronski and Laszlo A. Heredy

Rockwell International, Rocketdyne Division, 6633 Canoga Avenue, Canoga Park, CA 91303, USA

February 1987
 

Abstract

Coal hydrogenation was investigated in the temperature range 275 to 325 °C in order to minimize the number of thermal side reactions that take place. Gas-phase hydrogen was used in batch experiments without an added donor solvent, to avoid the additional analytical complexities introduced by such a solvent. It was found that significant oil yields (up to 72% of the daf coal) can be obtained from the hydrogenation of bituminous coal at 325 °C. Furthermore, at this temperature, the data indicate that cleavage of certain C---O bonds may have an important role in oil formation. The metal surfaces of the liner and impeller of the autoclave had a strong catalytic effect on the liquefaction reactions under these conditions. The oil yield was 48% when the metallic surfaces were exposed and only 19% when these components were coated with glass. Catalysis by nickel, applied as nickel acetate impregnated into the coal, gave higher overall conversion, lower oil yield, and a more saturated oil product than catalysis by the autoclave surfaces."

Confirming reports by other researchers, roughly three-fourths, "72%", of the coal was converted into liquid hydrocarbons, although some other, perhaps more recent, research we've cited for you, which, unlike this Rockwell effort, did employ a hydrogen donor solvent, indicates that 90%, or more, of the carbon in coal can be converted.

Interesting, sadly, that, "to avoid ... analytical complexities", these researchers spared themselves from making the extra effort to see just how effectively coal could be converted into liquids by performing their "experiments without an added donor solvent".

They, for some reason, did not, apparently, want the process of converting coal into liquid hydrocarbons to be as good as it could be.

Strange attitude for a defense contractor. But, they just might have corrected that oversight. More, and much more current, news on Rockwell and Rocketdyne, and their coal conversion technology, will follow.

Coal and Rubber/Plastic Waste Co-Processing

 
The company, Hydrocarbon Research, Inc, (HRI) behind this coal-plastic co-liquefaction development was, in the 1970's and ' 80's, the technical contractor in the USDOE's "H-Coal" coal liquefaction pilot plant in Catlettsburg, Kentucky, wherein their managing partners were, unfortunately, some Big Oil stalwarts, such as Mobil and Ashland.
 
They have since left New Jersey, for Utah, and changed their name - to Headwaters, which might be familiar to some of our readers from earlier posts. More on them will follow.
 
For now, we submit this excerpt from the enclosed link which confirms, as we have reported from numerous other sources, that coal can be synergistically combined with scrapped tires and waste plastics to manufacture liquid fuels, in a process made more efficient by the various properties of the components.
 
The excerpt:
 
"Studies in coal/waste coprocessing at Hydrocarbon Research, Inc
 
Pradhan, V.R.; Comolli, A.G.; Lee, L.K.T.; Stalzer, R.H.
 
Source: American Chemical Society, Division of Fuel Chemistry; Journal Volume: 40; Journal Issue: 1; Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995
 
Abstract:
 
The co-liquefaction of waste plastics with coal and waste tire rubber with coal was successfully demonstrated at a combined processing rate of 3 TPD at the Proof-of-Concept facility of Hydrocarbon Research, Inc. in Lawrenceville, N.J. The POC Program is jointly funded by the U.S. DOE, Hydrocarbon Research, Inc., and Kerr McGee Corporation. A total of 12 tons of plastics & coal and 5 tons of waste rubber tire & coal were processed to produce clean light distillates (IBP-343{degrees}C) with less than 40 ppm of nitrogen and 20 ppm of sulfur. Coal conversion was well maintained (92 W% maf) and nearly complete conversion of the organic waste to oils was achieved (65 W%+ maf distillate yields). Both the plastics and rubber contributed hydrogen to the liquefaction thereby reducing the hydrogen consumption by as much as 2 W% of the maf feed. This has a direct impact on reducing the cost of premium fuels from coal. Co-liquefaction of waste organic materials with coals provides for the recovery and recycle of waste materials back into the economy as premium fuels and feedstocks for petrochemicals. A concerted effort is underway to optimize the process to produce more value-added products with improved energy efficiency."
 
In closing, we'll note a few things:
 
First, people might not have heard of HRI, but the USDOE and Kerr-McGee, and the American Chemical Society, are not speculative, start-up enterprises. And, Kerr-McGee, especially, would not have involved themselves had there been nothing to it.
 
Most importantly, though, note the statement: "The co-liquefaction of waste plastics with coal and waste tire rubber with coal was successfully demonstrated".
 
If it was "successfully demonstrated", why aren't we now just "successfully" doing it?

More CO2 Recycling Via Trees to Gasoline

 
According to web-based references, about 50% of the dry weight of "typical" wood is cellulose. Another 25 to 30% is an organic compound called lignin, which acts, again according to web-based references, in concert with cellulose to form a sort of "composite" that gives wood it's strength and rigidity.
 
We have thoroughly documented, in references recorded and published by the WV Coal Association, in their R&D Blog, that cellulose, like coal, can be converted into petroleum-type liquids compatible with existing petroleum refining and transport infrastructure.  
 
Significantly, so can lignin. 
 
Comment follows the excerpt:
 
"The production of gasoline range hydrocarbons from Alcell® lignin using HZSM-5 catalyst  

Ronald W. Thring, Sai P. R. Katikaneni and Narendra N. Bakhshi

Department of Chemical Engineering, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick, Canada E3B 5A3

Department of Chemical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C4

January 2000.
 
Abstract

The conversion of a solvolysis lignin to useful chemicals and fuels was investigated using HZSM-5 catalyst. The study was carried out in a fixed bed reactor operating at atmospheric pressure, over a temperature range of 500°C–650°C, and weight hourly space velocities of 2.5 to 7.5 h−1. The major objective was to investigate the use of HZSM-5 catalyst in the production of both liquid and gaseous hydrocarbon products directly from the lignin. Conversion was high and ranged between 50% and 85% for the reaction conditions used. Using a WHSV of 5 h−1, the liquid product (LP) yield was 39 wt.% at 500°C but decreased to 34 wt.% at 600°C and then to 11 wt.% at 650°C. The highest yield of liquid product (43 wt.%) was obtained at 550°C with a WHSV of 5 h−1. In all the experiments, the liquid product mainly consisted of aromatic hydrocarbons (mostly benzene, toluene and xylene — with toluene dominating). The yield of toluene increased from 31 wt.% of the liquid product at 600°C (WHSV=2.5 h−1) to 44 wt.% at 650°C (WHSV=5 h−1). The total gas yield increased dramatically with increasing temperature but only moderately with increasing WHSV. The yields of the major components in the gas stream (propane, ethylene, propylene, carbon dioxide and carbon monoxide) were greatly affected by temperature."

We've no idea what a "weight hourly space velocity (WHSV)" might be, but:

"HZSM-5 catalyst" is a zeolite, in all likelihood very similar to, or exactly the same as, the one specified by Exxon-Mobil in their "MTG", methanol-to-gasoline, Process; wherein the methanol is posited to be made from coal.

Since both lignin and, as we've earlier documented, cellulose, can both be converted into gasoline precursor hydrocarbons, 80% of a tree's weight can be converted into liquid transportation fuels, and most of that weight will be carbon recycled from atmospheric Carbon Dioxide.

Moreover, "benzene, toluene and xylene" are all useful as raw materials for synthesizing plastics, among other things, in addition to their use as building blocks for gasoline. Any of those compounds directed into plastics manufacturing would be, for all intents and purposes, along with their Carbon content, permanently "sequestered". Moreover, they, and their Carbon, would be sequestered for a profit, and not for a huge loss as would be incurred by pumping CO2 through miles of pipelines, and then stuffing it deep underground at high pressure, all to help Big Oil squeeze more of the stuff he extorts the rest of us with out of his drying-up reservoirs.

Greece and Canada Liquefy Coal & Plastics

 
Enclosed are two links, and two excerpts, from sequential reports made by collaborating researchers on two continents, which confirm the synergies which can be realized through converting blends of waste plastic and, in this case, low-rank coal into liquid fuels.
 
We find this collaboration between Greece and Canada to be of some special interest. Canada does have  significant lignite deposits in her prairie provinces. Greece, though, isn't blessed with appreciable coal reserves; but, with a modern European population of some significant size, likely does generate a notable volume of plastic waste.
 
The point of that deliberation is, there must be a good reason the two nations' universities have joined research forces on this topic.
 
As other research we've cited has shown, combining waste plastic, as a hydrogen donor, with coal improves the process of converting both into liquid hydrocarbons. That's true even, as in this case, when the coal is lower-rank, with lower overall carbon content and higher ash.
 
Comment follows the two excerpts and additional link, following:
 
"Organic solvent effects on waste plastics–lignite coliquefaction 

K Gimouhopoulos, D Doulia, A Vlyssides and D Georgiou

Department of Chemical Engineering, National Technical University of Athens, Zografou Campus, Athens 157 80, Greece

Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Str., Toronto, Ont. M5S 3E5, Canada

July 1998

Abstract

The disposal of municipal solid waste (MSW) is currently one of the main environmental concerns especially in the industrialized regions. Converting the organic fraction of MSW into useful products, e.g. gas and liquid fuels, seems to be an option of a great interest both environmentally and economically. This paper examines the results of coliquefaction of low-grade coal, e.g. lignite, with post-consumer plastics. Special catalysts were prepared for this purpose and tested along with different types of organic solvents. The presence of these solvents during the coliquefaction process almost doubled total solids conversion into gas and liquid products. Decane and toluene were found to be the best organic solvents for coliquefaction of lignite with high density polyethylene (HDPE) and polystyrene, respectively. Total solids conversion reached almost 90% when a two-stage process was employed.


 
Waste plastics–lignite coliquefaction innovations  

K. Gimouhopoulos, D. Doulia, A. Vlyssides and D. Georgiou

Department of Chemical Engineering, National Technical University of Athens, Zografou Campus, Athens 157 80, Greece

Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Str., Toronto, ON MSS 3E5, Canada

March 1999
 

Abstract

This paper presents a detailed study of post-consumer polymers coliquefaction with lignite assessing the feasibility of the new processes. The results of four series coprocessing experiments undertaken with and without catalysts on a suite of four heavy organic solvents are summarized initially. Taking into consideration the prescribed findings two newer series of experiments were also designed and carried out aiming at the optimization of this complex transformation using this time lignite oxidatively pretreated. The conversion of reacting solids into gaseous and liquid products and in particular into hexane and tetrahydrofuran (THF) soluble material was determined. It was found that the mentioned hydroliquefaction is a promising way of hydrocarbon synthesis and that oxidatively pretreated lignite proved more effective than the raw material since it promoted coliquefaction product yields sufficiently. It was also found that interactions and synergy of the catalysts employed was changing as a function of the solvents nature, influencing thus the efficacy of the conversions achieved."

As in other reputable research we've cited, the conversion of solids into liquid hydrocarbons was in the range of 90% when some specific waste plastics were combined with coal in a liquefaction process, even in the case of lower-rank, higher ash, lower-Btu coal such as Canadian lignite.

And, yet again, the word "synergy" is applied to describe the effect of adding what otherwise might become an environmental contaminant, or landfill occupant, to coal to enhance the productivity of coal-to-liquid conversion.

Kentucky Liquefies Coal with Plastic


 
We have been informed of a conference upcoming, or even now taking place, in Kentucky which might relate to, or present some info related to, coal-to-liquid conversion technology. We'll continue our research, and try to keep you apprised.
 
In the meantime, herein is yet more documentation of the very real coal liquefaction developments that are, and, as we have documented, for decades have been, taking place in that state.
 
What is sadly lacking in all of this is attentive, public reportage that would keep programs like this on track, maintain their momentum, and prevent their being buried by special interests that have no interest in seeing our own domestic coal solve our own nation's liquid fuel shortage.
 
The excerpt:
 
"Direct liquefaction of waste plastics and coliquefaction of coal-plastic mixtures 

Zhen Feng, Jianmin Zhao, Jeff Rockwell, Dan Bailey and Gerald Huffman

CFFLS, 533 South Limestone St., Room 111 University of Kentucky, Lexington, KY 40506-0043, USA


February 1999. 
 

Abstract

We have conducted further investigations of the direct liquefaction reactions of waste plastics, medium and high density polyethylene (PE), polypropylene (PPE) and coal-plastic mixtures, varying the catalyst, temperature, gas, pressure, time and solvent. The experiments used four types of catalysts: a commercial HZSM-5 zeolite catalyst, and three catalysts synthesized in our laboratory, ferrihydrite treated with citric acid, coprecipitated Al2O3---SiO2, and a ternary ferrihydrite-Al2O3---SiO2. For direct liquefaction of plastics alone, a solid acid catalyst such as HZSM-5 or Al2O3---SiO2 markedly improves oil and total liquid yields, as determined by pentane and THF solubility, respectively. Yields are higher when using either a waste oil solvent or no solvent than using tetralin as the solvent. For PE, temperatures of 430 °C or higher are required for good yields, while PPE gives excellent yields at 420 °C. A commingled plastic provided by the American Plastics Council (APC) exhibited peak oil and total liquid yields at 445–460 °C. The oil yields and total liquid from PE (HZSM-5, 430 °C) and the APC commingled waste plastic decreased only slightly with decreasing hydrogen pressure (from 800 to 100 psig H2 (cold)). Furthermore, yields were as high under nitrogen (200–600 psig, cold) as under hydrogen.

Coliquefaction experiments were conducted on 50-50 mixtures of PE, PPE and the APC plastic with Black Thunder coal. For these experiments, the best results were obtained when the solvent was tetralin or a mixture of tetralin and waste oil. Lower yields were observed with only waste oil or with no solvent. Either HZSM-5 or Al2O3---SiO2-ferrihydrite increased oil and total yields by approximately 10% at 460 °C. Under the same conditions, yields from a PPE-coal mixture were substantially higher than those from a PE-coal mixture."

We'll note the utility of a zeolite catalyst which sounds very much like the one employed by Exxon-Mobil in their "MTG", methanol-to-gasoline, Process; wherein the methanol is posited to be made from coal.