Energy & Fuels 2007, 21, 1181-1182
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Annatto Fruit Pericarp: Newer Source As a Potential Fuel R. Parimalan, P. Giridhar,* T. Rajasekaran, and G. A. Ravishankar Plant Cell Biotechnology Department, Central Food Technological Research Institute, Mysore-570 020, India ReceiVed July 17, 2006. ReVised Manuscript ReceiVed NoVember 17, 2006
Efficient utilization of pericarp of fruits of Bixa orellanasa major byproduct from the annatto color extraction industriesshas been mentioned here. The lower calorific value (LCV) had been experimentally determined for the postharvest dried pericarp of fruits of B. orellana by ultimate analyses. The experimentally determined LCV is compared with the calculated fuel value index (FVI). The higher LCV of annatto pericarp than the LCV of some plant biomass that are prominently used as a fuel source, viz., tamarind shell, paddy husk, coconut font, paper waste, and groundnut husk, indicates their utility as a potential fuel. Thus, annatto color extraction industries can utilize the major byproductspericarpsas a fuel source, and it can also be used as a supplementary source of fuel mainly for third world countries, which can grow this plant primely for the purpose of fuel and with annatto as a secondary benefit in the near future.
Introduction Production of wood as a source of energy and fiber amounts to about 3700 million m3, of which 38% are softwood and 62% are hardwood species. About 45% of this quantity of wood is required as a source for energy.1 Wood as a fuel is always advantageous on various aspects, viz., energy, ecology, and economy, in particular for developing and the third world countries. Biomass fuels still account for 35% of the energy supply in developing countries.2 In Africa, 90% of the population uses fuel wood for cooking, the equivalent of roughly 1.5 tons of oil for each family per year.3 According to Food and Agriculture Organization (FAO) estimates, it is predicted that the availability of fuel wood and charcoal is estimated to be between 2265 and 2425 million m3, by the year 2010.4 However, the production of fuel wood and charcoal during 1993 was only 1875.9 million m3. Biomass contributes 14% of primary energy needs and stands as the fourth largest source of energy following coal, oil, and natural gas.5 Due to the renewable nature of biomass energy, it is necessary for us to exploit newer sources of fuel that may be of primary sourcessthose crops that have the sole purpose of energy productionsor secondary sources that mainly result from agricultural activities or wastes, but the only thing to be noted is their renewable nature. Commercial extract of the aril portion of seeds of B. orellana Linn. (family Bixaceae) is a rich source of the orange-red edible dye “bixin” (annatto), and in purified form, it is used in coloring * Corresponding author. Dr. Parvatam Giridhar, Scientist, Plant Cell Biotechnology Department, Central Food Technological Research Institute, Mysore-570 020, India. Phone: 91+821-2516501. Fax: 91+821-2517233. E-mail:
[email protected]. (1) Hagler, R. W. The global wood fiber balance: What is it? What it means? In Proceedings of the TAPPI Global Fiber Symposium, Chicago, IL, October 5-6; TAPPI Press: Atlanta, 1995. (2) World Bank. World DeVelopment Report 1992; Oxford University Press: New York, 1992. (3) Jepma, C. J. Tropical deforestation: a socio-economic approach; Earthscan Ltd.: London, 1995. (4) Food and Agriculture Organization. Non-wood forest products 3, Report of the International Expert Consultation on Non-Wood Forest Products; FAO: Rome, Italy, 1995. (5) Yang, Y. B.; Ryu, C.; Khor, A.; Yates, N. E.; Sharifi, V. N.; Swithenbank, J. Fuel 2005, 84, 2116-2130.
various food stuffs and also for cosmetic and pharmaceutical products.6 Being a safe, economical, and easy-to-use product, among naturally occurring colorants, annatto ranks second in economic importance.7 At an average, approximately of 2.5 kg of dried fruits yield 1 kg of seed which is used for dye extraction and hence 1.5 kg of pericarp is left unutilized. It is estimated that the yield of annatto fruit is in the range of 800-1500 kg/ ha. The seed yield ranges from 300-600 kg/ha, and thereby, 500-900 kg/ha of pericarp were left unutilized for any purpose and went to waste. World production of annatto seeds is estimated as 14 500 t/y on a dry weight basis.8 This shows that at an average 21 400 t of pericarp are disposed off, and the same can be used as a fuel source. In order to consider the pericarp as a fuel source, the lower calorific value (LCV) and density are the important factors, so also is the fuel value index (FVI). Through this paper, we prove the efficiency of dried fruit pericarp as a fuelswhich is normally considered as a waste after collecting seeds for annatto color extractionsthat is of renewable nature and of easy access. The objective and purpose of this paper was to make use of dried pericarp that had been considered as waste in the annatto dye extraction industry. This also does not require any land or area for specialized cultivation to meet the energy needs because they are the secondary sources. This new fuel sourceswhich is considered as a waste in the seed extraction industryscan be used as an additional energy source to meet the energy needs and thereby adding value to this plant utility. Experimental Section In this study, fruits of two varieties, viz., obovate fruiting variety and conical fruiting variety of B. orellana (4 year old plants at our department), had been harvested during September 2005 and the seeds are removed and used for the extraction of dye. Pericarp (6) Jondiko, I. J. O.; Pattenden, G. Phytochemistry 1989, 28, 31593162. (7) Satyanarayana, A.; Prabhakara, P. G.; Rao, D. G. J. Food Sci. Technol. 2003, 40, 131-141. (8) Levy, L. W.; Rivadeneira, D. M. In Natural food colorants science and technology; Lauro, G. J., Francis, F. J., Eds.; Marcel Dekker: New York, 2000; pp 115-152.
10.1021/ef060326e CCC: $37.00 © 2007 American Chemical Society Published on Web 01/11/2007
1182 Energy & Fuels, Vol. 21, No. 2, 2007
Parimalan et al.
Table 1. Ultimate Analyses and FVI for the Pericarp of Two Fruiting Varieties of B. orellana L s. no
biomass sample
LCV (MJ/kg)
ash (%)
density (kg/m3)
MC (%)
FVI
1 2
pericarp (obovate) pericarp (conical)
16.224 ( 0.326 16.148 ( 0.274
4.32 ( 0.018 4.99 ( 0.011
259.462 ( 1.145 323.804 ( 1.245
7.3 ( 0.16 7.1 ( 0.09
1335.393 1476.201
Table 2. LCVs for Different Biomass Samples s. no
biomass sample
LCV (MJ/kg)
1 2 3 4 5 6 7 8 9 10 11 12
casuarina wood coconut font coffee husk corn cob corn leaves cutting wood eucalyptus wood ground nut husk paddy husk paper waste saw dust tamarind shell
12.333 ( 0.11 13.434 ( 0.29 12.450 ( 0.47 17.615 ( 0.17 17.426 ( 0.19 16.849 ( 0.27 10.538 ( 0.16 13.455 ( 0.19 14.011 ( 0.22 10.124 ( 0.28 15.705 ( 0.25 15.970 ( 0.34
remaining after the removal of seeds is sun dried until the moisture content reaches 8-10%. Hence, dried pericarp is powdered down to particles of size 0.85 mm using a portable plate grinder (C/11/1, Glen mills Inc., Clifton, NJ), and these are used for further analyses like calorific value, ash content, and density. Ultimate analyses were performed as per ASTM standards. The calorific value of the biomass was measured by using bomb calorimeter (B 206, J. G. enterprises, Bangalore, India) according to the ASTM D2015 standard method. The ash content of the biomass samples was carried out according to AOAC official method 942.05. The bulk density was also measured. The fuel value index (FVI) was determined using the formula as reported earlier.9 FVI )
Calorific value (kJ/g) × Density (g/m3) Ash content (g/g) × Moisture content (g/g)
Results and Discussion The experimentally analyzed LCVs (MJ/kg), ash content (% w/w), and calculated FVIs of powdered pericarp samples are summarized in Table 1. The LCVs for different types of other biomass samples were given in Table 2 for general comparison. Values in tables represent the mean of five replicates. The LCVs for the obovate and conical fruiting varieties are 16.224 and 16.148 MJ/kg, respectively. In spite of lesser changes in moisture content and ash content, there is a marginal variation in FVIs between two varieties due to the variation in density. The FVI for the obovate fruiting variety is 1335.393, whereas (9) Goel, V.; Behl, H. M. Biomass Bioenergy 1996, 10, 57-61.
it is 1476.201 for the conical fruiting variety. As the particle size has a function with the burning rate,5 the particle size was maintained at 0.85 mm so as to maintain the burning rate at a constant level. The LCVs estimated for different types of biomass indicate that the pericarp of fruits of B. orellana possess higher LCVs when compared to other prominently used biomass species, viz., tamarind shell, paddy husk, coconut font, paper waste, ground nut husk, etc., proving their potential as a fuel. Also, LCVs of different biomasses, viz., tamarind shell, paddy husk, etc., that are obtained here are compared with the earlier published LCVs and are satisfactory; however, some values, like wood chips, etc., gave marginally higher values. Conclusion The pericarp of fruits of B. orellana possessing higher LCVs than other prominently used biomasses, viz., tamarind shell, paddy husk, coconut font, paper waste, ground nut husk, etc., proves its potential that can be exploited as a source of energy. Higher heating values for softwood are 20-22 MJ/kg, and those for hardwood are 19-21 MJ/kg.10 Pericarp shows an LCV of 16.224 MJ/kg, which is also equally valuable when compared with the hardwood values. This huge resource that has been disposed as waste until now can thereon be tagged with a value and tapped for use as a source of fuel for additional energy needs. Also, in third world countries where fuel itself is a scarce resource, we can plant this tree that starts yielding from the second year. As an added advantage, they grow in a wide variety of soils and require minimal management and maintenance practices until it starts yielding, and it is also a drought-tolerant species. This may supplement current strategies as a better solution for third world countries to meet their energy demands at the earliest possible stage and simultaneously provide a renewable source of energy. Acknowledgment. Financial support of Department of Science and Technology, New Delhi, India, is gratefully acknowledged, and R.P. is thankful to CSIR, India, for a research fellowship. EF060326E (10) Demirbas, A. Fuel 1997, 76, 431-34.
