Investigation of Light Tar Cracking in a Gliding Arc Plasma System

Utilization of biomass gasification technology is not widely adopted due largely to tars contained in the product gas that pose serious problems, especially in engine use. In this paper, a laboratory scale plasma system for light tar cracking was developed. The system was based on non-equilibrium plasmas generated from two gliding arc plasma in series. Light tar components were represented by naphthalene in nitrogen flow, generated at constant rates between 130 – 690 mg/m3. Destruction efficiency and specific energy use were evaluated. It was found that destruction efficiency in the range of 70 – 95% could be achieved with a simple, single stage reactor. Plasma assisted tar decomposition was found to increase with applied electrical energy. Complete destruction (>99%) of light tars was obtained with the two-stage, gliding arc plasma system with applied electrical energy of about 1.8 – 2.9 kWh/m3.