A technique for pyrolyzing biomass materials is disclosed wherein a hot surface is provided having a predetermined temperature which is sufficient to pyrolyze only the surface strata of the biomass material without substantially heating the interior of the biomass material thereby providing a large temperature gradient from the surface strata inwardly of the relatively cool biomass materials. Relative motion and physical contact is produced between the surface strata and the hot surface for a sufficient period of time for ablative pyrolyzation by heat conduction to occur with minimum generation of char.

Inductive storage pulse circuit device is disclosed which is capable of delivering a series of electrical pulses to a load in a sequential manner. Silicon controlled rectifiers as well as spark gap switches can be utilized in accordance with the present invention. A commutation switching array is utilized to produce a reverse current to turn-off the main opening switch. A commutation capacitor produces the reverse current and is initially charged to a predetermined voltage and subsequently charged in alternating directions by the inductive storage current.