DETERMINATION OF THE OPTIMUM CONDITIONS WITH STATISTICAL METHOD FOR THE PRODUCTION OF FURFURAL FROM HAZELNUT SHELLS WITH USING TWO STEP REACTIONS AND LIQUID EXTRACTION METHOD

Hazelnut seed shells are suitable agricultural waste for furfural production because of its 25-30 percent pentosan content. In this research production of furfural from hazelnut shells by using two steps reactions with o-nitrotolene extraction method and a statistical model was developed to express the furfural production rate. In the first step of furfural production, milled and sieved hazelnut shells were hydrolysed with dilute sulphuric acid to its pentoses at boiling point of water during 4 hours. In the second step, pentoses were converted to furfural by means of a high temperature dehydration process. Produced furfural was extracted with periodic agitation to o-nitrotoluene phase. Experimental design was carried out by using Box-Wilson experimental design method for two independent varaibles, namely sulphuric acid concentration and temperature whose ranges were selected as (3-7 %) and (160-190 degrees C) respectively. Optimum conditions for the maximum furfural production rates (0.3079 g furfural / h-g xylose) were found as 177.7 degrees C and at 4.00 % (g/100 mL) sulphuric acid concentration by using developed model and maximum furfural conversion yield of hazelnut pentosans were found as 60 % at these optimum conditions.