Biomass Characterization of Pigeon Pea (Cajanus cajan) Wood for Thermochemical Conversion
Mari Rowena C. Tanquilut1, Jessie C. Elauria2, Rossana Marie C. Amongo3, Delfin C. Suministrado2, Kevin F. Yaptenco4, and Marilyn M. Elauria5
Physical, thermochemical, and compositional analyses were performed on pigeon pea (Cajanus cajan) wood to determine its overall biomass characteristics. Pigeon pea is a minor crop locally known as kadios, usually grown in backyards, marginal lands, and insignificant land portions in the Philippines. In this study, pigeon pea wood is identified as a new potential lignocellulosic bio-resource for producing renewable energy due to its several attractive agro-energy features. Proximate analysis showed that mean moisture content (MC) dry basis, volatile combustible matter (VCM), and ash contents of pigeon pea wood were 10%, 66%, and 12%, respectively, which fall within the range of recommended values for biomass feedstock. The fixed carbon (FC) content of pigeon pea wood is 22%, the highest value among common biomass materials. Ultimate analysis of pigeon pea wood reveals carbon (C) content of 41%, similar to its nitrogen (N) content. Its hydrogen (H) content is 6.17%, which falls on the upper limit for most agricultural biomass (5-6%). Pigeon pea wood thus showed the highest H/C and O/C molar ratios. Moreover, its heating value (HV) is 17.13 MJ/kg, which also falls within the mean range of the other biomass. It also contained 15-25% lignin, 30-50% cellulose, and 20-40% hemicellulose. Based on these results, it can be concluded that pigeon pea wood has potential biofuel properties as new feed or co-feed for thermochemical conversion processes (i.e., pyrolysis, torrefaction, and gasification).
Keywords: Pigeon pea, biomass, characterization, pyrolysis, bioenergy, biofuel
1Professor 3, Pampanga State Agricultural University, PAC Magalang, 2011 Pampanga, Philippines
2Professor 12, 3Associate Professor 6, and 4Professor 2, Institute of Agricultural Engineering, College of Engineering and Agro-Industrial Technology, University of the Philippines Los Baños, 4031 College, Laguna, Philippines
5Professor 4, Department of Agricultural and Applied Economics, College of Economics and Management, University of the Philippines Los Baños, 4031 College, Laguna, Philippines
Tanquilut, M.R.C., Elauria, J.C., Amongo, R.M.C., Suministrado, D.C., Yaptenco, K.F. and Elauria, M.M. (2019). Biomass Characterization of Pigeon Pea (Cajanus cajan) Wood for Thermochemical Conversion. Philippine Journal of Agricultural and Biosystems Engineering, (15):39-52.