SPECIAL PUBLICATION NO. 27


the ASTM include: 1) Sphagnum moss peat which must contain at least
66.66 percent Sphagnum fibers by weight, 2) Hypnum moss peat which
must contain at least 33.33 percent fibers with one-half of those identifi-
able as Hypnum moss, 3) reed-sedge peat which must contain at least
33.33 percent fibers, one-half of which are reed-sedge and other non-
mosses, 4) peat-humus must contain less than 33.33 percent fiber, and
5) other peat, which accounts for all peat not previously classified in
ASTM Designation D-2607-69 (ASTM, 1969).
 The ASTM classification as discussed in the previous paragraph is
currently under revision. Two major factors were considered in this revi-
sion. The classification of peat should meet the needs of three major user
groups including engineers, energy users and agricultural users. In addi-
tion, the classification should be based on parameters which may be
measured objectively. These parameters include ash, botanical composi-
tion, pH, and water holding capacity. In order to be called peat, a material
will have to contain 75 percent or more organic material on a dry basis.
Although peats will still be categorized as fibric, hemic or sapric (based
on fiber content), these general terms will be modified by ash content,
botanical composition, pH and water holding capacity (A. Cohen, personal
communication, 1983).
 One essential characteristic that is associated with peat is moisture
level, but there are no current regulated standards for moisture in peat.
The United States Bureau of Mines considers a "commonly accepted"
value in the United States to be 55 percent moisture by weight for air
dried peat (Searls, 1980).
 The U.S. Department of Agriculture divides peat into three categories
(Searls, 1980). Fibric peat must contain more than 66.66 percent plant
fibers. Hemic peats are more decomposed than fibric peats. They must
have a fiber content which ranges between 33.33 percent and 66.66
percent fibers. Sapric peat consists of the most extensively decomposed
plant material. Sapric peat contains less than 33.33 percent recognizable
plant fragments of any type.
 Peat in the United States has often been classified into three general
categories (Searls, 1980; U.S. Department of Energy, 1979). Moss peat
is comprised of Sphagnum, Hypnum and other mosses. Reed-sedge peat
is mainly the product of reeds, sedges and other swamp plants. Humus is
simply too decomposed for evidence of its origin to be retained.

 Parameters Affecting Peat Use for Fuel

 The parameters which bear most directly on peat's usefulness as a fuel
source are measured by proximate analysis. In this procedure, peat is
analyzed in the laboratory for its volatile content, fixed carbon, ash con-
tent and moisture. The volatile content of peat refers to substances other
than moisture which are emitted as gas and vapor when peat is burned.
Peat has a very high volatile content compared to coal. This is a positive
attribute for peat which is to be gasified since the reactivity of peat in the