Mathematical modeling of nicotinic acid synthesis process by means of beta-picoline air oxidation in multitubular reactor was carried out. Factors that impact the process efficiency were studied. Special attention was focused on the role of recycling. The analysis was based on a two-dimensional quasi-homogeneous mathematical model of a tubular reactor and proprietary kinetic model of beta-picoline oxidation over V2O5-TiO2 catalyst. (C) 2011 Elsevier B.V. All rights reserved.