This article shows the relevance of designing a mobile-but-new reactor for the utilization of associated petroleum gas, as associated petroleum gas flaring causes irreparable environmental damage. Yet for the processing of associated gas extracted from small fields to be economically profitable, the resulting products must have a large added value. Such products can be nanomaterials, such as carbon nanofiber. Based on the review of published reactor designs, the satisfaction criteria are formulated. The results show no reactors satisfying all the necessary conditions, so the option closest to solving the problem was chosen. A suitable system of equations for the chemical kinetics of the processing associated petroleum gas into nanostructured fiber has been formulated. Further work has been outlined, which includes a) the study on the possibilities of increasing the yield of target products by optimizing the selection of thermodynamic properties; b) the development of a mathematical model of the reactor which considers mass and heat transfer, as well as changing the composition of the starting material; c) determining the optimal conditions of the carbon nanofiber synthesis process and developing practical recommendations for achieving and maintaining these conditions.