Preparation and Characterisation of Bio-Oil Produced from Sawdust of Selected Wood Species

Abstract

Renewable energy is of growing importance in satisfying environmental concerns over fossil fuel usage. The study was carried out to determine bio-fuel characteristics of pyrolytic oil produce from sawdust of selected wood species (Gmelina arborea, and Nesogordonia papaverifera). Sawdust samples of 200 gramms each were collected from Forestry Research Institute of Nigeria sawmill and oven-dried at 103±2°C for 24 hours to 12% moisture content. While four replicates of bio-oil were produced at each temperature regime for each of the samples, two different temperature regimes were used (500°C and 600°C). The metallic container (pyrolytic chamber) was filled with 200 grammes of the samples of each species and placed inside the Reactor which was connected to a condenser. Using standard test, physical properties, chemical and thermal characterization of bio oil and proximate analysis of the Bio-Char were assessed. Analysis of Variance (ANOVA) in Randomized Complete Block Design (RCBD) was used to ascertain significance difference in the oil yield produced at different temperature. The result shows that there was general increase in the volume of oil yield as the temperature increases. The volume of the oil ranged between 35.97±1.82 to 49.33±3.21 and 52.93±0.51 to 63.63±5.83, the highest and least mean of the pH of pyrolytic oil yield ranged from 3.52±0.02 to 3.54±0.02 and 3.64±0.36 to 3.73±0.01 for G. arborea and N. papaverifera respectively. There was significant difference in the means of the volume of bio-oil obtained as pyrolysis temperture increases. It further shows that the sawmill wood residues differs significantly at P<0.05 within the two temperature regime. The study established that pyrolysis is an efficient way to produce liquid fuels from biomass. The physical properties of the bio-oil obtained from sawmill wood residues falls within the acceptable range for fuel production. The selected wood species are therefore suitable for production of bio-oil with acceptable physical and chemical properties. Based on the result of the study, it is therefore among others recommended that residence time be taken for each temperature range to convert the feedstock to oil, and quantity of oil yield per specie.