Utilization of petroleum residues under microwave irradiation

• Applied porous carbon sorbents possess high value of microwave irradiation adsorption.
• Breakdown processes occur initially on the surface of carbon sorbent and then in the bulk of the material.
• Microwave irradiation energy enough for active C–H bond cracking.
• Hydrogen is a main gas product of tar conversion under MWI.

This paper presents the results of tar conversion under microwave irradiation (MWI). It is established that carbon adsorbents produced from natural mineral row possess by high microwave energy absorption coefficients; which characterized by high value of dielectric losses. Non-liner dynamics of carbon adsorbents heating at different current density from 80 till 200 μA/cm2 indicates that plasma generation occurs during microwave irradiation. It is found that the mechanism of tar conversion which preliminary adsorbed in the pores of the carbon sorbents under microwave irradiation and convective heating is different. The C–H bond is mainly activated and decomposed under microwave treatment with predominant formation of hydrogen. In case of C–C bonds, they are mainly subjected to thermolysis under convective heating and methane is the main product of degradation. To confirm the difference in the mechanism of tar destruction under microwave influence and convective heating the experiments with individual hydrocarbons adsorbed in the pores of hydrophobic sorbents were carried out.