A one stage process was used to produce furfural from cotton stalks by hydrolysis in hydrochloric acid. A full factorial design of experiments was used to examine the effect of reaction time, liquor to solid ratio as well as the acid concentration (at constant temperature of 140°C) on the yield of furfural. A regression relating the effect of each parameter as well as binary and ternary interactions was deduced. Insignificant terms were deleted using the student test, and a regression having only four terms was left to express the effect of time, concentration and their interaction and a numerical constant on the yield, the adequacy of this regression to express the system was tested using Fisher's test, where the regression proved to be adequate. The optimum conditions for furfural production were obtained using the steepest ascent technique. These conditions are: as follows; the time of hydrolysis is 3.5 hrs, acid concentration 11.5% (w/s) and Liquid/Solid ratio = 30: 1. The effect of adding some metal oxides such as calcium oxide, zinc oxide, aluminum oxide and titanium oxide was examined at the optimum conditions. All catalysts showed a promoting effect to some extent, the best result was achieved on using zinc oxide at a concentration of 2% (based on dry Cotton stalls) followed by calcium oxide and titanium oxide at a concentration of 1%.
