GAS-L: MSW and Biosolids

[CAVM@aol.com]

As far as I know, MSW is unsorted municipal garbage.  It can be sent through a MRF, material recovery facility, at great expense to sort out recyclables and unsuitable materials.  There is some talk of gasifing the sorted MSW after a MRF but not much of trying it with unsorted MSW.  We have been talking to Phil Moss of Kentucky about an MSW gasifier he has had running for some time in Alaska.  Phil can be reached at    pamoss@kih.net

Biosolids (sewer sludge) can be digested as Kevin says.  For my part, I would prefer to combust them and extract all of the energy value.  For a district heating system using steam the biosolids could be a good fuel, depends on the combustion technology and the metal content of the biosolids.  But this is a very doable project for any interested municipality. Same is true for feed lot, dairy and hog manure.

If the supply was steady and reliable generation of electrical power is a real option.   15 tons per hour supply at about 40% moisture mixed with about 2 tons per hour of sawdust and 8 - 10 MW is possible with about $800/kW capital cost. This comes to $.025/kw production cost plus cost of fuel.

Land application of biosolids is very controversial as Jerry says.  Not at all a settled issue even when properly composted and tested for metals.  I have been in composting for 18 years and know some of the issues.  Marketing compost is a bear.  It is an ill-defined product marketed to an uninformed consumer.   
    

Neal Van Milligen
Kentucky Enrichment Inc.
CAVM@AOL.com