Assessment of Variation in the Fibre Characteristics of the Wood of Vitex doniana Sweet and Its Suitability for Paper Production

The study investigated the fibre characteristics and chemical composition of Vitex doniana towards determining its potentials for pulp and paper. Fibre dimensions are of great importance because of the strong correlation between it and the strength properties of wood and paper. Axial and radial examinations of fibre characteristics of naturally grown wood of Vitex doniana were investigated to determine its suitability for paper production. Wood slivers were prepared from slices, introduced into wash bottles containing equal volume (1:1) of glacial acetic acid and 30% hydrogen peroxide and investigated on a Rheichert Visopam microscope. Variations existed in the axial and radial direction of the wood. The mean values of fibre characteristics are: fibre length (1.48mm), fibre diameter (21.9μm), fibre lumen width (12.7μm) and fibre wall thickness of Vitex doniana was 4.9μ. The mean lignin, cellulose and extractive contents were 28.1%, 41.2% and 3.5% respectively. Based on the derived values: Slenderness ratio, flexibility coefficient and Runkel ratio, species of Vitex doniana were considered to be good paper making materials.Key Words: Fibre dimensions, axial variation, radial variation, Vitex doniana, lesser known wood specie

Combustion Properties of Briquettes Produced from Maize Cob of Different Particle Sizes

Maize cobs sieved into three different mesh sizes of 2.36mm, 4.75mm, and 6.36mm were densified into briquettes using starch as binder. Combustion related properties namely percentage volatile matter, percentage ash content, percentage fixed carbon and calorific or heating value of the briquettes were determined. Results showed that different mesh sizes produced briquettes of different properties. Densities of the briquette produced ranged from 0.15-0.27g/cm3 with particle size 2.36mm having a percentage volatile matter of 57.82%, 4.75mm had 59.37% respectively while 6.30mm had the highest volatile matter of 62.90. The higher the particle size the higher the heating values which ranged from 20.93 to 24.97kj/kg. There is significant difference (P<0.05) in the heating values of the briquette produced from the three particle sizes. Assessment of the burning characteristics showed that briquette produced with particle size 6.30mm gave the highest energy value (24.97) and percentage volatile (62.91%) matter with moderate ash content.Keywords: Briquette, maize cob, combustion properties, mesh sizes, binding agen