Effect of Steam Activation on Oil Shale Semi-coke Surface Properties

Broadening applications of waste materials is of great importance. One such underused material is semi-coke waste from oil shale industry, which is the subject of this study. In this paper, different steam activation conditions were tested to investigate their effect on the change of surface area and pore volume of oil shale semi-coke. For steam activation, water was added to the reactor with flow rates from 1 to 6 mL/h for different time periods - from 30 to 180 minutes. The highest surface area of 60 m2/g was achieved when oil shale was heated to 700 °C at a heating rate of 7.5 °C/min in a pure N2 environment and activated with steam at a flow rate of 1 mL/h for 90 minutes. The results indicated that longer activation times promoted the development of larger meso- and macropores, resulting in the increase of total pore volume.