Abstract: A relatively lower value carbonaceous feedstock can be converted into a relatively higher value chemical product, by introducing the relatively lower value carbonaceous feedstock into an inductively coupled plasma (ICP) torch under conditions selected to generate a synthetic gas mixture having a tailored composition, and then introducing the synthetic gas mixture into a microbial digester configured to convert the synthetic gas mixture into the product. Significantly, the composition of the synthetic gas mixture produced by the ICP torch can be quickly modified to correspond to an optimal quality and quantity required by the digester, such that if the quantity of composition of the synthetic gas mixture being provided does not meet the needs of the digester, the quantity and stoichiometric ratio can be quickly varied. This enables greater efficiency to be achieved as compared to systems where the quality and quantity of the synthetic gas mixture cannot be easily changed.