%0 Journal Article
%T Thermal with Mass Spectroscopic Analysis of Wood and Cereal Biomass Torrefaction
%A Ren¨¦ Laryea-Goldsmith
%A Chris Woolard
%J ISRN Renewable Energy
%D 2013
%R 10.1155/2013/508965
%X Torrefaction is a mild form of pyrolysis that, when applied to biomass, has the effect of improving the energy density of biomass-derived solid fuels. In this study, thermogravimetric analysis (coupled with mass spectrometry) was applied to two biomass fuels (pine wood and white maize ear) to investigate a potential representative torrefaction thermal treatment process. The mass loss from the torrefaction process was indicative of emission of aliphatic hydrocarbons, evidenced by mass spectroscopic data and it is evident that optimal torrefaction conditions are determined by the type of biomass to which torrefaction processing is applied. 1. Introduction Torrefaction is a relatively benign thermolysis process, whereby a substance is subjected to a typical temperature range of 230¨C300¡ãC in the absence of oxygen (i.e., a form of the ancient practice of pyrolysis). When applied to biomass, the primary purpose of torrefaction is to increase significantly the energy density of biomass, making transportation for subsequent thermal conversion (such as gasification) more cost effective. Other advantages of torrefaction of biomass are (a) improved friability (therefore facilitating comminution especially beneficial for cofiring with coal), (b) reduction of water content to negligible quantities (increasing calorific content), and (c) conversion of biomass to become hygroscopic [1]. 2. Materials and Methods This paper is a brief communication of ubiquitous thermal analysis, of two biomass types of significance to South Africa: loblolly pine (Pinus taeda) as an example wood resource and maize (Zea mays) as an example of agricultural crop waste (after cultivation for food supply). For this study, the maize ear (both the core and the residue remaining after removal of the maize grain) was chosen for analysis to represent a waste resource (i.e., not used directly for human consumption). Thermal analysis was performed using a TA Instruments model Q5000IR Thermogravimetric analyser (TGA) coupled with an MKS Instruments model Cirrus 2 mass spectrometer (MS). These instruments were supplied with high purity nitrogen gas to produce a nitrogen flow rate of 25£¿mL£¿ to the TGA. The Curie points of Ni (354¡ãC) and Fe (770¡ãC) were used for the temperature calibration of the TGA. The MS was calibrated using synthetic air and the thermogram test parameters are summarised as follows:(i)gas supply to sample, nitrogen (99.999% purity) at 25£¿mL£¿ ;(ii)initial temperature 29¡ãC, maintained for 1£¿min;(iii)temperature ramp rate 54¡ãC£¿ , to 300¡ãC (maximum maintained for 1 minute). 3. Results
%U http://www.hindawi.com/journals/isrn.renewable.energy/2013/508965/