There are a number of what we think to be interesting things going on in this Japanese research into coal liquefaction.
It confirms a conjecture we earlier presented, and should help, we think, to pave the way for the full utilization of coal in liquefaction processes; and, point the way to one route of Carbon Dioxide recycling.
Excuse the following, over-long, prologue, but:
We have documented that some, especially "indiect", coal liquefaction technologies leave behind a residual material that still has a significant carbon content. We suggested that such residual carbon could itself be recovered and liquefied, made available for hydrogenation and refining, through direct, hydrogen-donor solvent technologies, such as WVU's West Virginia Process for direct coal liquefaction.
We did, in fact, document that coal liquefaction residue from FMC Corporation's New Jersey, "COED", coal conversion facility was sent to Spain for further liquefaction processing.
We cited reports from several sources, especially from some in the United Kingdom, that rubber waste from used auto tires could, like coal and coal indirect liquefaction residues, be converted into liquid hydrocarbons appropriate for refining; and, in at least one other report, that used tires actually improved coal liquefaction processes, presumably by supplying additional Hydrogen.
Herein, Japanese researchers confirm that used tires can enhance the liquefaction, the recycling, of indirect coal liquefaction residues produced by their own, "NEDOL", coal liquefaction technology, about which we have also earlier reported.
And, interestingly, they describe the use of tetralin, the hydrogen donor solvent we believe specified by WVU in the West Virginia direct coal liquefaction Process, as has other research we've brought to your attention, as being effective in the liquefaction of tire rubber; and, in, as suggested, the extraction of remaining carbon from indirect coal liquefaction residues.
The excerpt:
"Effects of reaction conditions on the hydrogenolysis reaction of tire and coal liquefaction residue.
Authors: Onda Daigoro, Oba Toshiaki, Koyano Koji (Nihon Univ., Coll. of Sci. and Technol.)
Journal: Nippon Enerugi Gakkai Sekitan Kagaku Kaigi Happyo Ronbunshu; Vol.37th; Pages 245-248 (2000)
Abstract: The NEDOL process produced coal liquefaction residue(CLR) in about 30% yield. The amount of waste tire is increasing every year. In this study, the hydrogenolysis reaction of CLR(1t/d PSU) with pulverized waste tire was carried out by using tetralin. Compared with the result from each reaction of CLR or tire alone, the synergistic effects to upgrading, such as the increase of the yield of volatile products and the decrease of n-hexane insoluble-acetone soluble materials, were observed."
In other words, as we interpret this, combining residue from a primary indirect coal liquefaction process with pulverized waste auto tires, in a secondary direct liquefaction process using tetralin as the Hydrogen donor solvent, resulted in "synergistic effects", with an "increase of the yield of" desired "volatile products" and a decrease in the yield of, seemingly undesired, "hexane insoluble" products.
Note, again, that using waste tires in such liquefaction processes would, to the extent that the tires might be composed of natural latex compounds, represent an indirect route of atmospheric carbon dioxide recycling through botanical agents.