**1. Introduction**

208 Sustainable Growth and Applications in Renewable Energy Sources

Nikitina V.S., Orazov O.E. (2001). The dynamics of total flavonoids in leaves and tannides in

Pohjamo S.P, Willfor S., Reunanen M., Hemming J., Holmbom B. (2002). Bioactive phenolic

Pohjamo S.P., Hemming J.E., Willfor S.M., Reunanen M.H.T., Holmbom B.R. (2003).

Porębska G., Ostrowska A. (1999). Heavy Metal Accumulation in Wild Plants: Implications

Prakash A., Rigelhof F., Miller E. (2011). Medallion Laboratories. Analytical Progress.

Reski R., Abel, W.O. (1985) Induction of budding on chloronemata and caulonemata of the

Salt D.E., Blaylock M., Kumar P.B.A.N., Dushenkov S., Ensley B.D., Chet I., Raskin I. (1995).

Shah K., Nongkynrih J.M. (2006). Metal hyperaccumulation and bioremediation, Biol.

Smith R.A.H., Bradshaw A.D. (1979). The use of metal tolerant plant populations for the

Tegelberg R., Julkunen-Titto R. (2001). Quantitative changes in secondary metabolites of

Walton B.T., Anderson T.A. (1992). Plant-microbe treatment systems for toxic waste. Current

de Wild P.J., van der Laan R.R., Wilberink R.W.A. Thermolysis of lignin for value-added

Wolski T., Kalisz O., Gerkowicz M., Morawski M. (2007). The role and the significance of

Zabrocki R., G. Ignacek G. (2008). Wykorzystanie wierzby energetycznej w gospodarce

radiation. Physiol. Plant, 113, (4), pp. (541-547), ISSN: 0031-9317.

Opinion in Biotechnology, 3, (3), pp. (267-270), ISSN: 0958-1669.

Willd. Rastitelnye Resursy, 37, (1), pp. (65-72), ISSN: 0033-9946. . Nyman T., Julkunen-Tiitto R. (2005). Chemical variation within and among six northern willow species. Phytochem., 66, (24), pp. (2836-2843), ISSN: 0031-9422. Pilon-Smits E, Pilon M (2000). Breeding mercury-breathing plants for environmental clean-

up. Trends in Plant Sci., 5, (6), pp. (235-236), ISSN: 1360-1385.

www.medallionlabs.com/Downloads/Antiox\_acti\_.pdf.

Plantarum, 51, (4), pp. 618-634, ISSN: 0006-3134.

Fitoterapii, 2, pp. (82-90), ISSN: 1509-8699.

9, (3), pp. ( 234-238), ISSN: 1508-3535.

Skogsprodukternas Kemi, B1-02.

169), ISSN: 0031-9422..

358), ISSN: 0021-9258.

1485.

0156.

2664.

2010.

the bark of branches in heterosexual specimens of Salix triandra L. and S. acutifolia

substances in fast-growing tree species. Abo Akademi. Laboratoriet for

Phenolic extractives in Salix caprea wood and knots. Phytochem., 63, (2), pp. (165-

for phytoremediation. Pol. J. Environ. Stud., 8, (6), pp. (433-442), ISSN: ISSN: 1230-

moss, Physcomitrella patens, using isopentenyladenine. Planta, 165, (3), pp. (354-

Phytoremediation: A novel strategy for the removal of toxic metals from the environment using plants. Nature Biotechnol., 13, (5), pp. (468-474), ISSN: 1087-

reclamation of metalliferous wastes. J. Appl. Ecol., 16, (2), pp. (595-612), ISSN: 1365-

dark-leaved willow (Salix myrsinifolia) exposed to enhanced ultraviolet-B

products. ftp://ftp.ecn.nl/pub/www/library/report/2010/l10071.pdf. Presented at 15th Meeting of the International Humic Substances Society, Tenerife, June-July

antioxidants in medicine with particular respect to eye disorders. Postępy

rolnej. Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu.

The use of biomass as a source of energy varies in different countries and depends in part on the country's level of development. In many developing countries, biomass provides most of the basic energy needs, mostly as fuelwood, animal wastes or crop residues while in developed countries only a fraction of their energy requirement comes from agriculture and agro-industrial wastes. In the United States for example, biomass conversion amounts to about 3.25% of the energy supply (EIA, 2002 and Haq, 2002) while in Bhutan, the share of biomass energy in total energy use accounts for about 87% (Victor, and Victor, 2002).

Biomass resources could play a significant role in meeting the future energy requirements. However, the approach in their utilization should be carefully analyzed in view of diverse cultural, socio-economic and technological factors in a given locality. Agricultural and agro-industrial wastes can provide an inexpensive source of energy and effective low sulphur fuel. It could be processed into other fuels thereby reducing environmental hazards (e.g. biomass from sewage). Also, there is relative ease with which it could be gathered and generated. However, the conversion of light energy into biomass by plants is relatively of small percentage and there is relatively low concentration of biomass per unit area of land and water. The additional land for biomass production is getting scarce, and the high moisture content of fresh biomass makes collection and transport expensive. Thus, biomass energy conversion could be relatively inefficient. Moreover, extensive utilization of these resources may compete with the demand for these as food. These are some of the issues concerning the extensive utilization of biomass resources.

In view of the depleting forest and agricultural resources for energy use, attention should be focused on new and emerging technologies for their efficient conversion. There are a number of sources of energy for both rural or agricultural and urban or industrial residues. There is a need to diversify the traditional resources for energy to meet the demands. These include, among others: (1) planting high energy value crops, fast growing trees, sugar and starchy crops, aquatic plants, oil and hydrocarbon crops, and (2) getting energy from municipal sewage and solid wastes. Some common properties of biomass resources will be reviewed to gain perspective of biomass as a source of energy compared with traditional fossil fuel sources.

The primary advantage in the use of biomass as an energy resource is that it is a renewable feedstock and does not contribute to global warming.

Biomass Energy Conversion 211

Example. From the ultimate analysis data shown in Table 1, estimate the heating value in

Note that the heating value from the table is given as 21.3 MJ/kg, an 8.45% difference. The Dulong equation is valid when the oxygen content of the biomass is less than 10%. In this example, the oxygen content of douglas fir is 40.5% and way above 10% , hence a large

HV (kJ/kg) = 35,160\*C + 116,225\*H – 11,090\*O + 6,280\*N + 10,465\*S (2)

The proximate analysis is a good indicator of biomass quality for further conversion and processing. Proximate analysis is important for thermal conversion processes since the process require relatively dry biomass (normally less than 10% moisture). If gaseous combustible fuel from biomass is to be produced, the feedstock with the highest volatile matter content is ideal to use. For slagging and fouling issues, the feedstock with the lowest ash content is an excellent choice. The fixed carbon is used to relate the heating value of the product and co-

products. Table 2 shows some proximate analysis data for some biomass resources.

Proximate Analysis (% weight, wet basis)

(Stout, 1985) 15.0 76.60 7.00 1.40 90.12 8.23 1.65 Stover (Stout, 1985) 35.0 54.60 7.15 3.25 84.00 11.00 5.00 CGT 9.01 64.78 14.36 11.85 71.20 15.78 13.02 Switchgrass 10.31 73.24 13.01 3.44 81.67 14.51 3.82 Sorghum 22.11 55.62 11.25 11.02 71.40 14.45 14.15 Woodchips 21.05 67.46 10.07 1.42 85.44 12.76 1.80

The development of conversion technologies for the utilization of biomass resources for energy is growing at a fast pace. Most developing countries find it hard to catch up because

MC VCM FC Ash VCM FC Ash

Proximate Analysis (% weight, dry basis)

HV (kJ/kg) = 33,823\*C + 144,250\*(H-O/8) + 9,419\*S (1)

The Dulong equation is given by the following equation (1),

MJ/kg of douglas fir.

2. Thus, the heating value is calculated as

**2.2 Proximate analysis of biomass** 

Material

Corn cob

Solution.

difference.

where C, H, O, N and S are the elemental mass fractions in the material.

HV (kJ/kg) = 17,689 + 1,785 + 0 = 19,474 kJ/kg (19.5 MJ/kg).

where C, H, O, N and S are the elemental mass fractions in the material.

The Boie equation is given by the following equation (2),

Table 2. Proximate analysis data for selected biomass.

**3. Biomass conversion processes** 

1. Substituting the mass fractions of the elements into the equation, we have HV (kJ/kg) = 33,823\*(0.523) + 144,250 (0.063-((0.405)/8)) + 9,419\*(0)
