Influence of Operating Parameters on the Product Yields During Pyrolysis of Oil Palm Husk

Abstract

The influence of operating parameters on the product yields during the pyrolysis of Oil Palm Husk (OPH) was investigated in this study. 0.5 kg of dried sample of OPH was loaded into a steel retort, and the retort interior was rendered airtight. The retort was then placed into the furnace chamber and the OPH was pyrolysed at 300 ^oC between 10 - 30 minutes at 5 minutes interval. This was repeated for temperatures of 400, 500, 600 and 700 ^oC and in each case, the quantities of char, tar and pyro - gas produced were determined. Response surface methodology (RSM) was used to develop polynomial regression model and investigate the effect of  changes in the level of pyrolysing temperature and duration on the product yields using Full Factorial Design (FFD). The contribution of pyrolysis temperature, duration and their squares (A, B, A² and B²) to the model developed are significant model terms. It was observed that the experimental data fitted better because of the Pred R-Squared of 0.8283 is in reasonable agreement with the Adj R-Squared of 0.9690. The agreement between the predicted and experimental values describe the accuracy of the model developed and can be used to navigate within the design space. The product yields minimum value of 1.54% was achieved at pyrolysis temperature and duration values of 300 ^oC and 10 min respectively. The optimum conversion yields of oven-dried weight of OPH char, tar and gas products at their respective pyrolysis conditions were 97 wt% char at 302 ^oC and 10 min., 51 wt% tar at 559 ^oC and 25 min., and 47 wt% gas at 700 ^oC and 30 min. The results obtained showed that OPH can be readily pyrolised to obtain optimum yield of bio fuels (gas, tar and char).

Keywords: Pyrolysis, Oil-palm Husk, Bio fuels, Gas, Tar, Char and Response surface methodology.