Environmental Engineering Reference
In-Depth Information
cellulose, hemicellulose, and lignin. Moreover, the content of minor organic and
inorganic species in biomass is dealt with. Characterization of biomass by means
of proximate and ultimate analysis is useful for determining its global reactivity
and composition data. The heating value of biomass, important for thermochemical
conversion processes, is defined in terms of the HHV and LHV (GCV and NCV).
Also, the fuel bases are discussed, namely, ar (or wet), db, and daf. Finally, ash melt-
ing (fusion) behavior and determination of its elemental composition are dealt with.
KEY CONCEPTS
Biomass composition
Van Krevelen diagram, coalification
Fuel bases (db, daf, ar)
Proximate analysis
Thermogravimetric analysis (TGA)
Ultimate analysis
Basic combustion calculations based on stoichiometry and elemental
fuel
composition
Organic constituents
Inorganic constituents (mineral matter)
Ash fusion characterization
Lower heating value (LHV), higher heating value (HHV), and their difference
SHORT-ANSWER QUESTIONS
2.1
Which effects can a high moisture content have on storage and handling, and
which in combustion processes?
2.2
Why would a high porosity of the fuel lead to more fines when combusting a
solid biofuel?
2.3
Discuss the effects of particle shape and size on storage and handling of biomass.
2.4
What are the main biopolymers on Earth?
2.5
What is the difference between homopolysaccharides and heteropolysacchar-
ides? Give a few examples of both.
2.6
What are similarities and differences between starch and cellulose?
2.7
In Figure 2.3 (bottom part), indicate the intra- and intermolecular hydrogen
bonds in cellulose.
2.8
Why would lignin have a higher heating value than carbohydrate constituents
of biomass? In which ways does the lignin content influence biomass combus-
tion behavior?
2.9
What distinguishes fats from oils?
Search WWH ::
Custom Search