Thermal and gaseous emissions of biodiesel feed-stocks: sandbox tree, fluted pumpkin, black date and wild melon whose potentials as biodiesel fuels have been established in the earlier works of Igbum et al. (2012) were evaluated in order to ascertain and establish their environmental and emission impacts on the local and global environment. Effects of blending ratios on the thermal/gaseous emissions of the biodiesel fuels from the seed oils were also investigated. The study involved the extraction of oils from the seeds using petroleum ether in a soxhlet apparatus, transesterification of the oils with methanol at the ratio of 6:1 and sodium hydroxide as a catalyst, reaction temperatures of 30°C and 55°C and at a reaction time of five minutes. Thereafter, the methyl esters were blended with automotive gas oil (AGO) at different proportions and ratios to produce B5, B10, B15, B20 and B100 of each seed oil and AGO. Blends were subjected to chemo-physical and gaseous emission analysis using different ASTM methods and GC mass spectrophotometer for the trapping and subsequent analysis of the effluents. Results showed that all the blends samples of the biodiesel possess lower gaseous emissions than AGO and are also within the ASTM standards. They are therefore more environmentally friendly than their fossil fuel counterpart. Their impact on the global and immediate environment are however friendly.
Keywords: gaseous emissions, evaluation, biodiesel fuels, blends, environmental impact, feedstock, sandbox tree, fluted pumpkin, black-date, wild melon