The enclosed might seem unrelated to our core concern of converting coal into liquid fuels.
CoalTL in the broader sense, though, to us, means making the fullest use possible of the resources we have available. That economic concept is, in fact, the true essence of Thoreau's Walden Pond philosophy, from which, without genuine acknowledgement or understanding, our modern-day ecological movement has sprung.
In any case, liquid fuels can be made from coal "fines" - which are essentially coal "dust". It gets entrained in typical run-of-mine product, and, due to customer requirements, shipping constraints and processing limitations, is often separated from coal and, again depending on commercial circumstances, collected for shipment elsewhere. But, because of the expense required to achieve full cleaning and separation, and their limited commercial outlets, many coal fines are, or used to be, discarded along with mine refuse.
There might be better, profitable, ways to separate and capture coal fines, through the use of another "waste".
The excerpt:
"Fine Coal Recovery Utilizing Landfill-Derived Liquids
Hall S.T.; International Journal of Surface Mining Reclamation, March, 2002
Abstract:
Liquid effluents that arise in the landfilling of municipal solid wastes, both leachate and gas condensates, can replace some or all of the conventional coal flotation reagents. The waste management industry currently must treat these effluents, to destroy contained organics, prior to their discharge to the environment and hence they are available at no cost, or even with “dollars attached”. These landfill-derived liquids contain valuable short-chain fatty acids (e.g. valeric and caproic acids) that act as both frother and collector in flotation processes. They can be further concentrated by membrane filtration to reduce the transport costs of such liquids and the ease of their use in coal recovery systems. This paper will discuss how these liquids are formed in landfills, their typical compositions and how they can be employed to recover fine coal."
We'll follow up this submission with some other reports affirming that coal fines, once recovered using organic compounds, such as organic landfill "extract" and vegetable oils, can be employed in the manufacture of liquid fuels.
Accomplished coal-to-liquid conversion specialist Sasol has been using coal fines in South Africa for liquid fuel manufacture, but a US company is getting into that act, as well.