A two-step gasification process and apparatus for the conversion of
solid or liquid organic waste into clean fuel, suitable for use in a
gas engine or a
gas burner, is described. The waste is fed initially into a primary gasifier, which is a
graphite arc furnace. Within the primary gasifier, the organic components of the waste are mixed with a predetermined amount of air,
oxygen or steam, and converted into
volatiles and
soot. The
volatiles consist mainly of
carbon monoxide and
hydrogen, and may include a variety of other hydrocarbons and some
fly ash. The gas exiting the primary gasifier first passes through a hot
cyclone, where some of the
soot and most of the
fly ash is collected and returned to the primary gasifier. The remaining
soot along with the volatile organic compounds is further treated in a secondary gasifier where the soot and the volatile compounds mix with a high temperature
plasma jet and a metered amount of air,
oxygen or steam, and are converted into a synthesis gas consisting primarily of
carbon monoxide and
hydrogen. The synthesis gas is then quenched and cleaned to form a clean
fuel gas suitable for use in a
gas engine or a
gas burner. This offers higher
thermal efficiency than conventional technology and produces a cleaner fuel than other known alternatives.