Data Summary of Municipal Solid Waste Management Alternatives. Volume 1: Report Text Page: 90 of 216
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
For example, the finance charge for the capital investment for a given facility would be
significantly affected by the interest rate prevalent at the time of project financing, but many
sources fail to note that interest rate. Over time, requirements governing the Best Available
Control Technologies (BACT), or Best Demonstrated Technology (BDT) tend to become more
stringent, and the additional cost of more advanced technologies will increase the capital costs of
more recent projects to an unpredictable extent. Moreover, capital investment in general would
be affected by the type and composition of the wastes and the plant site conditions, but many
sources fail to provide data on these matters.
Similarly, the operation and maintenance (O&M) costs are affected by site-specific
conditions such as labor rates, labor contracts, safety rules, the size of the crew, and so on.
Again, information on these factors is rarely provided in the literature.
In mass burning, MSW is directly fed to a furnace. The only required pretreatment of the
waste is removal of large objects and potentially dangerous materials. Mass burning is in-
creasingly being preceded by processing to remove materials of value, however; in that sense, the
distinction between mass burning and RDF preparation (covered in the next subsection) is start-
ing to blur. Virtually all the organics in MSW are consumed in mass burning, and the volume of
material that needs to be landfilled is smaller with mass burning than with RDF combustion.*
Facilities for mass burning include smaller units (25-300 tons per day of MSW) that are
fabricated in a shop before installation on site (modular units), as well as larger field-erected
plants (200-3,000 tons per day). Figure 5.1 presents a block diagram of the flows of MSW
through both types of facility. A variety of grates, boiler designs, feeding arrangements, and air
pollution controls are possible. Individual systems are described in Appendix B. This sub-
section describes typical units in both size ranges.
In typical large, field-erected facilities, packer trucks empty waste into a large pit in a
building. The MSW is retrieved by a crane and dropped into a hopper that feeds the combustor.
Field-erected combustors have a variety of designs to move the waste on grates through the
furnace as the MSW burns. The grates move under the waste by reciprocating, rocking, rolling,
moving as an endless belt, or rotating as a large tilted cylinder. Air is forced up through the grate
to support combustion.
In a typical modular facility, packer trucks unload inside a building on a tipping floor, where
front-end loaders are used to move the waste. At some facilities, oversized waste, such as
household appliances, and tires are separated for disposal before combustion begins. The front-
end loaders will break down some furniture and boxes by driving on them or by using their
buckets. The MSW is then pushed onto a conveyor for feed to the combustor.
* "Shred-and-burn" plants are a technical exception to this statement. They are considered RDF plants because
they do shred the MSW before combustion; however, like mass burn units, shred-and-burn plants remove almost
no combustibles before combustion. Five shred-and-burn plants were operating in the United States in 1991.
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
SRI International. Data Summary of Municipal Solid Waste Management Alternatives. Volume 1: Report Text, report, October 1992; Golden, Colorado. (https://digital.library.unt.edu/ark:/67531/metadc1310776/m1/90/: accessed May 27, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.