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."
In addition to coal, there are many waste materials like cow dung, municipal solid waste, industrial waste, rice husk, wheat and rice straw and other composite materials which can be used to produce bio gas, which can be used a substitute of natural gas for winter heating and CNG filling stations for vehicle fuels. If this waste-to-energy technology is adopted in Pakistan on a fast track basis, then the problem of gas shortage can be overcome within a few years.
Coal gasification offers one of the most versatile and cleanest ways to convert the energy content of coal into electricity, hydrogen, and other energy forms."
"Imtiaz Ahmad, Mohammad Arsala Khan, Mohammad Shakirullah, Mohammad Ishaq, Rashid Ahmad, Habib ur Rehman and Saeed ur Rehman
Department of Chemical Engineering, Yanbu Industrial College, Yanbu Al Sinayah, Saudi Arabia
Pakistan Atomic Energy Commission, Islamabad, Pakistan
The influence of a group of metal oxide, hydroxide and chloride catalysts on the yields of liquefied products has been identified. The results of hydrogenation experiments performed with varying coal to catalyst ratio for a slurry of lignite coal in toluene demonstrated that metal loadings even as low as 1% proved effective for enhancement of yields. Among the catalysts employed, halide catalysts proved to be the most effective in terms of high yields of desirable liquefied products."
Note that "halide" catalysts are identified as being most effective. Could something as common as table salt be a key to the more profitable and more productive conversion of coal into liquid fuels?
We find it interesting that, as we have discovered in other coal-to-liquid research efforts in other places, representatives from the Oil Cartel nations, as in the Yanbu, Saudi Arabia, College researchers noted above, have insinuated themselves into coal liquefaction research efforts around the world. Just keeping their friends close, but their enemies closer, we suppose.
Mohammad Ishaq, Imtiaz Ahmad, Mohammad Shakirullah, Mohammad Arsala Khan, Habib ur Rehman and Ali Bahader
Department of Chemistry, University of Peshawar, Peshawar NWFP 25120, Pakistan
Abstract
This paper demonstrates the thermal and catalytic pyrolysis of some whole plastics and plastic–coal mixtures with and without solvent in an inert atmosphere of N2 using a micro autoclave. The temperature was varied between 300 and 400 °C. The effect of some catalysts, i.e., AlCl3 and Co–Mo, on the liquid yield was also studied. The results demonstrate that temperature has a promising effect on the yield; however high temperature, as well as high catalyst loading, caused a decline in liquid yield. The effect of the solvent was found to be significant. None of the catalysts show an impressive effect on the yield of the desired products. Among the plastics studied, high density polyethylene (HDPE) and polypropylene (PP) gave high yields even in the absence of a solvent and catalyst. The results are quite promising in terms of resource recovery, both from coal as well as plastics. The idea will also help in combating the environmental problems associated with plastics and coal."
Note that the results "are quite promising" relative to extracting value from "coal as well as (waste) plastics".