- Details
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
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.
- Details
Li Wang and Peng Chen
Faculty of Chemical and Environmental Engineering, Shandong University of Science and Technology, No. 17, Shenglizhuang Road, Jinan 250031, PR China
Beijing Research Institute of Coal Chemistry, China Coal Research Institute, Beijing 100013, PR China
Abstract
Polyethylene (PE), polypropylene (PP), and polystyrene (PS), etc. have been successfully converted to oil under typical direct liquefaction conditions with Chinese coal. A series of liquefaction experiments were run using ground coal and plastic waste, individually and in combination. Results on individual plastics showed that high density PE (HDPE) was by far the most difficult of the model plastics to convert, higher conversions could be obtained with higher temperatures. Co-liquefaction experiments were performed on coal–plastic mixtures (usually 1:1 mixtures) using a Chinese Xianfeng lignite with the fly ash of molybdenum concentrates calcined as catalyst. The oil yields except Xianfeng lignite–HDPE co-liquefaction were as high as 60.3–78.1%, while the total conversions reached levels of over 95%. Anyway, oil yields for Chinese coal–plastic co-liquefaction were higher, typically by 5.1–22.6%, than the average of the oil yields for the coal and plastic alone, hydrogen consumption was also reduced by 7.7–17.9%, implying synergistic effects in co-liquefaction reaction of Chinese coal and waste plastics (WP)."
Interesting, isn't it, that Chinese scientists can casually refer to "typical" coal "liquefaction conditions"? Our guess is that your average UMWA member, or WV citizen, wouldn't be so jaded as to find the concept so routine as to be "typical".
As with coal and cellulose co-liquefaction results we've earlier reported, "total conversions reached levels of over 95%" when coal was combined with certain waste plastics. And, "oil yields" for Chinese coal–plastic co-liquefaction were significantly higher "than the average of the oil yields for the coal and plastic alone".
Moreover, the need for supplemental hydrogen, presumably from a hydrogen-donor solvent, as in our previous posts regarding China's patent applications for what we believe to be a pirated version of the West Virginia Process for direct coal liquefaction, which uses such a solvent, most commonly referred to by it's abbreviated name, Tetralin, "was also reduced".
In any case, this research confirms earlier reports we've made, drawn from other sources. Waste plastic can donate hydrogen to a coal liquefaction process, and thereby reduce the need for supplemental hydrogen, increase oil yields by more than 20%, and, again, achieve "total conversions" into liquids of "over 95%".
By combining certain waste plastics with coal, nearly 100% of the total mass can be converted into liquid hydrocarbons.
Not bad.
- Details
Anthony Warren and Mahmoud El-Halwagi
Chemical Engineering Department, Auburn University, Auburn, AL 36849, USA
Abstract
The objective of this paper is to assess the technical and economic feasibility of a new process for co-liquefying coal and plastic wastes. This assessment is based on incorporating recent experimental data on plastic/coal liquefaction within a conceptual process framework. A preliminary design was developed for two process configurations. The primary difference between the configurations is the source of hydrogen (coal versus cellulosic waste). The assessment was based on co-liquefying 720 tons per day of plastic waste with an equivalent amount of coal on a weight basis. The plant products include hydrocarbon gases, naphtha, jet fuel and diesel fuel. Material and energy balances along with plant-wide simulation were conducted for the process. Furthermore, the data on plastic-waste availability, disposal and economics have been compiled. The results from the economic analysis identify profitability criteria for gross profit and thus return on investment based on variable conversion, yield and tipping fee for plastic waste processed."
Although the financial projections aren't revealed in the Abstract, the prospect of co-liquefaction is, at least, technically feasible. And, "cellulosic waste" is once again named as a hydrogen-donating raw material which could be processed with both plastic waste and coal; thus, perhaps, drawing down the costs even further; and, through making additional hydrogen available, rendering the process even more productive and efficient.
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"$2 million goes to UK coal research
The grant will go to UK's Center for Applied Energy Research, according to a news release from Republican U.S. Reps. Harold "Hal" Rogers of Somerset and Geoff Davis of Fort Mitchell.
The two Republicans got the money for the center into the federal budget signed by President Obama this week, according to the release.
The money will allow the center to expand on existing research by building a small-scale refinery, Rogers and Davis said."
Well, for 2 million bucks, it would be a very "small-scale refinery".
And, we remind you of our earlier reports on Kentucky's "H-Coal" coal liquefaction research, undertaken with others, back in the 1980's.
Sadly, those "others" consisted not just of Hydrocarbon Research, Inc, the lead H-Coal contractor, but of oil companies, as well, including Mobil, who were responsible for some for some of the public reportage to the DOE, and who now, as part of Exxon-Mobil, hold commercial rights to the "MTG", methanol-to-gasoline, Process, where the methanol is proposed to be made primarily from coal.
- Details
"Summary
The United States’ future economic security will remain linked to an efficient transportation system of air, rail, and highway vehicles that depend on a continuous supply of affordable liquid fuels with characteristics enabling vehicle manufacturers to meet increasingly stringent environmental regulations. In the current supply/demand situation, the Nation’s transportation fuel requirements are met in part by crude oil and refined products from unstable regions of the world. Crude oil delivery and refining in the Untied States is concentrated in the Gulf Coast region, which presents concerns regarding destructive weather conditions. Additional challenges, including urban and regional air pollution, greenhouse gas emissions, and the availability and cost of transportation fuels, present unique issues that must be addressed to safeguard economic growth, social stability and public health.
Technology is now in hand for producing synthetic oil, and oil products from coal. Liquid fuels from coal are clean, refined products requiring little if any additional refinery processing, are fungible with petroleum products and, therefore, can use the existing fuels distribution and end-use infrastructure. There are preliminary analyses [Mitretek Technical Report 2005-08, “A Technoeconomic Analysis of a Wyoming Located Coal-To-Liquids Plan”] that indicate synthetic oil costs may drop into the $35 per barrel range after several initial higher cost plants are built. This estimate assumes near-zero atmospheric emissions of criteria pollutants, assumes reduced water use through air coolers instead of water cooling, and assumes carbon capture and sequestration. However, no commercial U.S. plants have been built. The primary barrier to commercial introduction of the technology has been the volatility and uncertainty of world oil prices. The private sector financial markets are best positioned to evaluate whether, when, and how to build coal to liquids plants given this market uncertainty.
At present, no requirements exist in the United States to manage carbon emissions from fossil fuel sources. However, in full recognition of the importance of carbon management an extensive research and development program is underway to develop technology, processes and systems to capture and store the carbon dioxide produced during the conversion process. The carbon dioxide could be stored in deep saline formations or sold for use in enhanced oil recovery operations. It is possible that CTL plant emissions and the emissions from utilization of CTL products would be comparable to those associated with the production and consumption of petroleum-based fuels.
The greatest market barrier for CTL is the volatility and uncertainty of future world oil prices. The private sector is best positioned to evaluate market or oil price risk and respond accordingly with an appropriate deployment strategy.
Although past department efforts and some Congressionally directed funding has focused on production of liquid fuels from coal, the FY 2007 Budget does not support these activities. Coal to liquids is a mature technology receiving funding from the private sector for evolutionary advances and incremental improvements and therefore not consistent with the Administration’s Research and Development Investment Criteria. Although the FY 2007 Budget does not directly support CTL technology, there are some overlapping activities directed at electricity and hydrogen generation that the private sector could apply to reducing production costs and technical risks, and improving environmental performance of coal to liquids plants. The FY 2007 Budget supports production of hydrogen from coal and some funding will be used for development of liquids that while not applicable for conventional internal combustion engines because their hydrogen content is too high, could be an efficient way to move fuel for hydrogen applications through existing infrastructure. The FY 2007 Budget promotes the goal of reducing dependence on foreign sources of oil through development of technologies consistent with the Research and Development Investment Criteria, such as cellulosic ethanol, battery technology, and hydrogen, among others. Over the mid to long term, these technologies could reduce demand for conventional sources of petroleum and ease pressures on world oil prices.
The resource exists, current technology is available and it is possible that continued evolutionary R&D will produce advanced processes that will continue to modify the private sector’s analysis of whether the economic and environmental performance of the processes used in the implementation of a coal-to-liquids industry for the production of alternate fuels justify plant construction, in tandem with the primary consideration of petroleum market risk.
If economic, these fuels could contribute to reducing our dependence on oil imports and significantly contribute to the Nation’s energy security."
First: "Although past department efforts and some Congressionally directed funding has focused on production of liquid fuels from coal, the FY 2007 Budget does not support these activities."
Why? When and how will that gross inadequacy be corrected?
Second: "At present, no requirements exist in the United States to manage carbon emissions from fossil fuel sources. However, in full recognition of the importance of carbon management an extensive research and development program is underway to develop technology, processes and systems to capture and store the carbon dioxide produced during the conversion process."
They are still genuflecting to carbon "storage" - in obeisant service to Big Oil's scavenging efforts. Why - when the Department of Defense has patented technologies to capture Carbon Dioxide and recycle it into liquid fuels; and, when NASA is using Nobel Prize-winning technology to recycle it aboard the International Space Station - all as we have thoroughly documented; and, all in addition to the carbon-recycling potentials, also thoroughly documented, of liquefying botanical cellulose as a co-fed raw material, with coal, in an appropriate liquefaction process - of which, there are several?
Third: "The greatest market barrier for CTL is the volatility and uncertainty of future world oil prices."
Where, in the world, is there "uncertainty of future world oil prices"? Everyone, in the world, is pretty darned certain they will continue to do what they have always done: GO UP.
Finally, we already know that coal-derived liquid fuels are "economic" - the author's word. South Africa has demonstrated that fact for many decades. China is convinced. So, why don't we cut the BS and just let our coal people put our coal to work, and thereby reduce our "dependence on oil imports and significantly contribute to the Nation’s energy security"?
Does it just make too much sense? Is it too obvious? Or, as other evidence we've cited indicates, have some pretty slick Big Operators managed somehow to hide the facts from those of us who most deserve to know?
