Coke Oven Wastes to Liquid Fuel

 
 
We have reported on environmental cleanups underway at hazardous waste sites left behind by both coke oven batteries and early coal-to-liquid conversion facilities.
 
Those wastes didn't have to be dumped and left behind, but they unfortunately were.
 
We have reported that coke oven by-products, once treated as wastes, can be collected and utilized. Coke oven gas, as we've detailed, can be harvested and used, either directly as an auxiliary fuel for steel furnaces, or converted and condensed, synthesized, into liquid fuels.
 
Coke itself can be reformed with steam or super critical water, as we've documented, into liquid fuels, or fuel precursors that can even be fed as a co-stream into some conventional petroleum refineries.
 
Various "coal tars" are another residuum of coking operations that were frequently "dumped" into the environment, and they now, at many sites, present what are perceived to be great environmental hazards.
 
Those coal tars, where they are still contained at the older coal processing facilities in high-enough volumes and concentrations, are carbonaceous enough that they, too, could be harvested as part of a clean up, and transformed into liquid fuels - just, as we've earlier documented, some older coal mine waste accumulations can be processed, as is planned in Schuykill, PA, into liquid fuels and valuable organic chemicals.
 
We submit that, even at smaller facilities where the tar accumulations aren't great enough to enable profitable harvesting and conversion, any return realized by sales of fuel or chemicals produced from the waste would at least subsidize the costs of it's remediation.
 
And, in such a scenario, the waste coal tar would actually be cleaned up and removed from the environment. Most of the clean up plans being executed today only lead to the, hopefully, long-term stabilization of the wastes in-place. The current clean-ups don't actually "clean up"; and, the efforts represent only sunken cost. There is zero return on the sometimes massive investment.
 
If we were to focus our efforts on actually reclaiming the coal tar wastes with the intent of converting them into liquid fuels and chemicals, then we would get at least some return on the cost, and, perhaps more importantly, the objectionable wastes would actually be removed from the environment. It would be a true "clean-up", not just an expensive "containment".
 
The enclosed report indicates one avenue of approacht. An excerpt:
 
"Refined chemical oil (RCO), a coal tar by-product from metallurgical coke production, was blended with light cycle oil (LCO) from United Refinery, in a 1:1 ratio. The feeds were hydrotreated in the first stage to remove sulfur and nitrogen, then hydrogenated in a second stage to saturate the ring compounds, with fractionation taking place at various stages. The main variation in the process has been the location of the fractionation units, either before hydrotreatment, after the first stage, or after the second stage. When fractionating the product after both hydrotreatments, the co-processed material yields a product distribution of 6% gasoline, 80% jet fuel, 10% diesel and 4% fuel oil. The fuels produced are being tested in real systems."
 
Again, it's unlikely that such a recycling focus would actually make the clean up of old coke ovens and other coal processing facilities a profitable endeavor. But, if we had a coal-to-liquid conversion industry in place in the United States, then the collection and conversion of coke oven tar wastes would help at least to defray the costs of clean-up. And, an actual clean up, as opposed to an expensive containment in place, would be effected. We would be better off both economically and environmentally.
 

Japan Liquefies Coal & Waste Plastic

 
There are two things we find interesting about this study on combining coal and waste plastics together to form a raw material for liquid fuel manufacture.
 
First, the inclusion of plastic actually provides at least some of the needed Hydrogen to convert the primarily carbonaceous coal into liquid hydrocarbons, as in: "The waste plastics having high H/C ratio are expected to play the role of hydrogen source".
 
Second, the process can be refined, especially in terms of coal-to-plastic combination ratios, so that the non-organic minerals in the coal can capture and immobilize, as various salts, the chlorine which might be present in the plastics.
 
Excerpt as follows:
 

"The Influence of PVC on the Coprocessing of Coal and Plastics

Author(s): Koyano Koji, et. al., Nihon University College of Science and Technology
 
Journal Title: Journal of the Japan Institute of Energy
 
Abstract;The coprocessing with coal is one of the beneficial technologies to convert waste plastics into alternative liquid hydrocarbon for fuel oil and chemical feedstock. The waste plastics having high H/C ratio are expected to play the role of hydrogen source. On the other hand, the waste plastics include chlorine-containing plastic such as polyvinyl chloride (PVC). Hydrogen chloride generated from pyrolysis of PVC causes the problems such as the corrosion of equipment. In the coprocessing reaction, it is expected that the hydrogen chloride is captured by the minerals in coal. In this paper, the influence of PVC on the coprocessing with Wyoming subbituminous coal and the mixture of high density polyethylene, polypropylene, polystyrene, and PVC was investigated under decalin solvent. A part of hydrogen chloride generated from PVC was fixed as chlorides by the minerals in coal, but the rest formed chlorinated organic compounds. These reactions occurred competitively. When a sufficient amount of hydrogen chloride was not captured, the chain reactions of polymer radicals were inhibited by chlorine radical. This inhibitation resulted in the increase of heavy oil yield. To avoid it, the optimization of the ratio of coal and plastics was desired."
 
In other words, not only can coal and waste plastics be combined to produce liquid fuels, but, the ratio of coal and plastics can be optimized, both for maximum liquid fuel output based on the hydrogen content of the plastic and for immobilization of the chlorine contained by the plastic, based on the inorganic mineral content of the coal. The two raw materials can be synergistic. Combing coal and plastics to synthesize liquid fuels can be done, and we know it can be done. People are at work on fine-tuning the process.

Manufactured Gas

 

We have reported that, as been known for hundreds, perhaps thousands, of years, coal can be "reduced" by heat in a low-oxygen environment to produce both coke, for steel making and other uses, and, a flammable "coke oven gas". The gas in early days was most often vented and flared, but was sometimes collected, and piped into the steel furnaces for additional heating.
 
We have also reported on facilities in some major cities, Boston and Seattle, for instance, where coal was processed in "Gas Works", which were essentially just large coke ovens, and the gas produced from the coal, the coke oven gas, was then distributed for residential and industrial heating and lighting use as "town" or "producer" gas.
 
Coke oven gas was also known as "manufactured gas", and, as it happens, it's use was very widespread. It was made commercially in Manufactured Gas Plants, "MGP's".
 
Herein an excerpt from the enclosed link to New York State's Department of Environmental Conservation, with some commentary following:

"General Information About MGPs

What's an MGP?

MGP is an abbreviation for Manufactured Gas Plant. A manufactured gas plant was an industrial facility at which gas was produced from coal, oil and other feedstocks. The gas was stored, and then piped to the surrounding area, where it was used for lighting, cooking, and heating homes and businesses. The first MGPs in New York were constructed in the early 1800s, prior to the Civil War. Most were closed during the early-to-middle 1900s, and the last one ceased operations in 1972.

Gas from MGPs was used for all the same purposes that natural gas is used for today. In addition, in the late 1800s, gas was used for lighting prior to the introduction of electricity.

When and Where Did MGPs Operate?

For a period of over 100 years, manufactured gas plants (MGPs) were an important part of life in cities and towns throughout New York State and the United States as a whole. They had their beginnings in the early 1800s, providing small amounts of gas for street lighting systems. By 1900, production had greatly increased, and gas was being widely used for heating and cooking. Most towns in New York with populations of over 5000 had at least one gas plant, and larger towns often had more than one. New York City had several dozen.

Small-town facilities began to close in the 1920s and 1930s as the industry consolidated production at larger facilities and connected smaller systems together with new pipeline networks. As World War II approached, interstate pipelines were built, making natural gas from the Midwest more widely available, and cheaper than manufactured gas. Most New York State MGPs closed by 1950, but a few remained in operation in remote areas, or on standby status in areas where the interstate pipelines could not meet peak demand. The last MGP in New York State ceased operations in 1972.

How Was the Gas Produced?

Two main processes were used to produce the gas. The older and simpler process was coal carbonization. In this process, coal was heated in closed retorts or beehive ovens. Inside these ovens, the coal was kept from burning by limiting its contact with outside air. Volatile constituents of the coal would be driven off as a gas, which was collected, cooled, and purified prior to being piped into the surrounding areas for use. The solid portion of the coal would become a black, granular material called coke. Coke was a valuable fuel for many industrial uses and for home heating, because it burned hotter and more cleanly than ordinary coal. Sometimes, the coke was the primary product, and the gas was a by-product, and the facility was called a coke plant."

Mike, another synonym for Manufactured Gas is, of course, as you be able to guess from all our earlier dispatches, Syngas; so named because, once it's produced, it can be catalyzed and condensed, synthesized, into more complex hydrocarbons - liquid fuels and organic chemical manufacturing raw materials.

Moreover, coke itself is not, given the changes in the steel industry, the valuable commodity it once was. But, once you have it, you can liquefy and reform it with steam or supercritical water or hydrogen-donor catalysts, and get - liquid fuels and organic chemical manufacturing raw materials.

The contaminants New York is concerned with in this report should not be a concern of modern Manufactured Gas Plants. They consist primarily of coal tars and could themselves be collected and converted, by steam reforming or hydrogen-donor catalysis into - liquid fuels and organic chemical manufacturing raw materials.

We'll document further, in some future dispatches, the breadth of public knowledge that once existed in the US about coal-based syngas, as it was produced and used under it's various synonyms. But, one thing is clear: The knowledge and technologies required to convert our coal into more versatile liquid and gaseous fuels has been around for a very long time.

We could have been free of gas station lines, oil embargoes, unemployment, some foreign wars, and oil cartel and oil company extortion long ago. There can be no good reason why we're not employing coal conversion technology on a broad scale to break the economic chains with which foreign petroleum powers hold us in subservient, royalty-paying bondage.

Coal & PlasticTL - Utah

 
Coliquefaction of coal and waste polymers 
 
Confirming the work of the researchers in Pakistan and at the University of Kentucky, scientists  at the University of Utah also find great potential value in liquefying coal and some types of plastic waste together to generate the raw materials for liquid fuel synthesis.
 
The excerpt:

"L.L. Anderson, W. Tuntawiroon and W.B. Ding

Chemical & Fuels Eng. Department - University of Utah Salt Lake City, UT 84112 USA

It has been shown that processing of coal to liquids can be done with high yields of liquids. Plastic materials. either pure as a commingled plastic waste containing different colors and impurities, can be processed with nearly 100% conversion to liquids and gases. Combinations of coal with plastic material can be processed to final products but with less conversion than expected from interpolation of the data from processing coal alone and plastic alone. Polymerization catalysts such as Titanium compounds can be utilized to depolymerize plastic materials containing HDPE at temperatures above 420 Bifunctional hydrogenation/hydrocracking catalysts can improve the conversion of coal/plastic mixtures but the highest conversions and oil yields were obtained when a two step procedure was used with liquefaction of plastic done in one step and coprocessing of plastic-derived liquids and coal in a second step."

Unlike some other references we've cited, which suggest that combining coal and some plastic wastes in liquefaction processes can increase the yield, this report indicates there could be some loss of efficiency.

However, it does seem that process modifications can overcome those inefficiencies, and coal and plastic wastes can be co-processed effectively into gases and liquids for further refining.

Coal-to-Liquid is a profitable, win-win, technology that can clean up the environment while it provides us with much-needed liquid hydrocarbon fuels.

Coal can do all of that.

CoalTL Technology Converts Wate Plastic

 
Although coal isn't the focus of this release about the University of Kentucky's work in converting waste plastic into liquid fuels, coal-to-liquid conversion technology is at the heart of the research this article describes. And, it is noted in the report that waste plastics can be liquefied with coal..
 
Explanatory note follows the excerpt:

"Waste plastic yields high-quality fuel oil.

Ironically, after all the trouble of reclaiming plastic waste from gooey trash, recycled products often cost more and look worse than virgin plastics -- a situation that displeases consumers.

But fuel chemists M. Mehdi Taghiei and his colleagues at the University of Kentucky in Lexington report a new, efficient way of converting plastic waste into high-quality, saturated fuel oil.

"It's good oil, too--much like imported crude oil," Taghiei said this week in Chicago at a meeting of the American Chemical Society. "This oil is even lighter and easier to refine into high-octane fuel than imported oil. It has no sulfur and fewer impurities." Similarly, the chemists found they could liquefy plastic with coal, also producing high-quality fuel.

The researchers mixed various types of plastic with zeolite catalysts, including HZSM-5 and tetralin

Furthermore, oil yields proved high: Milk jugs generated 86 percent oil, soda bottles, 93 percent. Polyethylene, another common soft plastic, eked out 88 percent. When liquefied with coal in a roughly half-and-half mixture, the plastics turned into even better oil.

"In terms of the economics of this process, we have done some estimates," says Kentucky chemist Gerald P. Huffman, a coauthor of the report. "To convert coal and plastic simultaneously into oil right now costs about $27 or $28 per barrel, compared with $18 to $20 per barrel for imported oil. But we're quite confident that we can drive the cost of converted oil down to roughly the cost of imported oil. This process may be commercially viable within five to 10 years."

The reporter, we believe, seems to inadvertently and erroneously identify "tetralin", above, as a zeolite catalyst. It is not. It is, however, as we understand it, a Hydrogen-donor solvent employed by West Virginia University in their "West Virginia Process" for converting coal into liquid fuels and chemicals. The "HZSM-5" is, though, a zeolite, and likely to be the same one used by Exxon-Mobil in their "MTG" (r) process for converting methanol, derived from coal and other sources, into gasoline.

In any case, this research confirms that coal and some types of waste plastic can be converted together into liquid fuels. Coal can lead us to domestic liquid fuel self-sufficiency, and help us to clean up the environment, by enabling the profitable recycling of waste plastic, while it does so.