TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The cold arc discharge is generated by a pulsating high voltage (HV) discharge imparted through a capacitor to a high voltage electrode placed in the reaction zone, to an electrode in series with a capacitor connected to ground. The cold arc discharges are generated within the reaction zone. The reactor has a tubular shape with a rotatable cylindrical ground electrode in the middle and with a cylindrical outer wall of dielectric material through which a plurality of HV electrodes extend into the reaction zone, each of the HV electrodes is provided with a capacitor in series and is connected, through the capacitor, to a pulsating high voltage source such as to produce a high frequency cold arc discharge between each HV electrode and the ground electrode. The apparatus provided several rows of HV electrodes over the reactor's vertical length, with HV electrodes in each row. The HV electrodes in one row are staggered with relation to the HV electrodes in the next row. The apparatus further comprises: an enclosure between the outer wall and the ground electrode with an opening to the reaction zone and means are provided for feeding natural gas or methane into the enclosure and through the enclosure into the reaction zone, and to maintain a positive pressure in the enclosure with reference to the reaction zone; a rectifier between each capacitor and HV electrode for producing a unipolar positive or negative cold arc discharge in the reaction zone; a means for creating an inert atmosphere around the reactor; and a high frequency particle arrester for separating the solid carbon particles exiting from the reactor from the gaseous constituents. The reactor has a tubular shape with a rotatable cylindrical shaft in the middle made of dielectric material and a tubular HV electrode surrounding the shaft, the reaction zone being formed between the shaft and the HV electrode; electrodes embedded in the rotatable cylindrical shaft and project outwardly in the reaction zone, where each of the electrodes is connected to a capacitor and then to common ground; and a pulsating high voltage source is connected to the HV electrode such as to generate a cold arc discharge between each capacitor-connected electrode and the common HV electrode in the reaction zone. The several rows of capacitor connected electrodes are mounted on the shaft. Preferred Components: The gaseous constituents consist of hydrogen and acetylene, mixed with unreacted natural gas or methane. The pulsating high voltage discharge is unipolar or bi-polar. The outer wall of dielectric material is made of plastic or ceramic. The shaft of dielectric material is made of plastic or ceramic. EXAMPLE - The natural gas/methane was fed in to a reactor at a flow rate of 17 l/minutes. Then nitrogen was fed into the reactor to provide an inert atmosphere around the reactor. In the reactor the ground electrode made of aluminum was rotated by motor at 200 rotationperminute to supply the electric current that was passed through the high voltage (HV) electrodes during the operation, where each HV electrode was adjusted to have a gap of 5 mm between the tip of the HV electrode and the surface of the ground electrode. A 100 pico-farad capacitor was connected in series to each electrode and in turn connected to a central bus bar. A voltage of 22 kV at a frequency of 8 kHz was then applied to the capacitors and the resulting power of 800 W produced a cold arc discharge in the gap between each HV electrode and the rotating ground electrode. Then the cold arc discharge decomposed the natural gas or methane into hydrogen. Then the resulting gas was then passed from the bottom part of the reactor via line through a high efficiency particle arrester to collect the solid carbon particles.