Environmental Engineering Reference
In-Depth Information
NCV
net calorific value
ND
not determined
PCDD/F
polychlorinated dibenzo-p-dioxin/furan
RNA
ribonucleic acid
TGA
thermogravimetric analysis (or analyzer)
VM
volatile matter
XRD
X-ray diffraction
XRF
X-ray fluorescence
SYMBOLS
specific surface area [m
2
m
−3
]
a
v
kg
−1
]
HHV higher heating value [J
kg
−1
]
LHV lower heating value [J
kmol
−1
]
MW molecular weight [kg
Y
mass fraction [
-
]
2.1 PHYSICOCHEMICAL PROPERTIES
The entire processing track of biomass as renewable energy source (its supply chain,
pretreatment, conversion techniques, and emissions) is influenced by the type of bio-
mass and its physical characteristics and chemical composition. In the past few decen-
nia, comprehensive studies of the physical characteristics and chemical composition
of biomass fuels have been carried out, and these are still being continued to obtain
more insight into the reactive behavior of these fuels under different processing
conditions.
Table 2.1 presents an overview of the most important physical properties of solid
biomass (and derived solid products) that are relevant for its behavior in the chain
from harvesting to conversion processes. There is a great variation among the property
values for different biomasses and their derived products. Some properties are directly
related to the biomass type (e.g., particle density and porosity), but fuel preparation
changes such characteristics as particle size and shape. A more in-depth discussion on
pretreatment of biomass is presented in Chapter 8.
The organic part of plants mainly consists of carbon, hydrogen, and oxygen, with
a minor portion of nitrogen, sulfur, and phosphorus, which are vital for the plant
s
metabolism and physiology (Jenkins et al., 1998). Table 2.2 shows an overview of
the elements composing biomass and their major effects in the bioenergy conver-
sion chain.
Figure 2.1 shows a so-called
'
diagram that presents the atomic H/C
ratio on the vertical axis and the O/C ratio on the horizontal axis. The diagram maps
different coal types, with the anthracites near the origin and young biomass (consti-
tuents) in the upper right corner. Biomass is characterized by a relatively large content
“
Van Krevelen
”
Search WWH ::
Custom Search