Theoretical and experimental approach of fuel gas and carbon black production from coal tar pitch by thermal plasma process.

Coal tar pitch (CTP) processing for the production of clean fuel gas and carbon black (CB) was studied in plasma reactor equipped with a DC plasma torch. The composition of gas produced and energy costs were estimated theoretically for the CTP pyrolysis and gasification processes with two oxidant: oxygen and water vapor. We have found that the main gaseous compounds obtained in the pyrolysis and gasification processes are hydrogen (H2), carbon monoxide (CO), and very often carbon dioxide (CO2). For the pyrolysis case, the mean value of the synthesis gas concentration reaches major value of 98 vol. % (H2 - 81 vol. %, CO - 17. vol. %). However, only 23% of initial CTP is transformed into gas phase at 1100 K and its content increases up to 37.4% at temperature 3000 K. For oxygen gasification the syngas quantity is little less than for pyrolysis case and attain 96.6 vol. % (H2 - 26.5 vol. %, CO - 70.1 vol. %) for T > 1100 K. An intermediate case is syngas content for the water steam gasification 97.8 vol. % (with H2 - 55.8 vol. % and CO - 42.0 vol. %). The CB produced was composed of well-defined spherical particles of the size of about 30 nm, furthermore, is composed of carbon (98.2%), and followed by oxygen (1.8%) with a surface area of 97 m2 g-1. The thermal plasma system shows high efficiency in conversion CTP into high-value-added products.