Figure 6, Figure 7, Figure 8 and Figure 9 show the conversion percent (conv.%) of methanol dehydration and the yield percent (Y%) of DME produced using natural kaolinite (KN), chemically treated kaolinite (KT), ball milled kaolinite (KB) and ball milled kaolinite with CaSO4 (KB-Ca) respectively at reaction temperature ranged from 200 to 500 °C and different contact times (15, 30 and 45 min).