I've been following the current hooraw about low-temperature carbonization with some confusion. I can't quite tell what the commotion is about. This is not new technology - it was used in primitive form to make "retort gas" for industrial and domestic use from the late 19th century through (in some places like Germany) the middle of the 20th century.
There can't be any doubt of its feasibility, for the obvious reason that it was practiced for years. Its usefulness, however, is questionable. The bye-product coal oils and gases are produced in fixed proportion to the char (or coke), so their availability and ultimate production cost are governed by the market for solid fuel. While that market is still large, it is well served at present (in the USA at least) by low-sulfur western coal that requires no prior processing and thus develops its entire heat of combustion under the boiler; there's no reason to suppose that coke from the same feedstock could compete. As for using high-sulfur coals, I have my doubts. Whether the sulfur is driven off during coking, thus needing to be scrubbed out of the gases and/or liquids, or remains in the char, it still must be cleaned up, which imposes a further cost no matter how it is done. The gas and liquid hydrocarbons produced are completely irrelevant to the argument, as, without a market for the char, the entire cost of operating the process, including cracking or separating the tars, scrubbing the sulfur and giving away or otherwise disposing of the char, must be charged to what CAN be sold, making the retort gas and combustible oils far too expensive. I believe this is why low-temperature coking was abandoned as a commercial fuel production process in the first place, and absent a very large increase in the cost of petroleum (leading stationary power producers to switch to solid fuel), I can't see it coming back. Marc de Piolenc Iligan, Philippines Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
