The paper is devoted to complex technical and economic studies of the large-scale combined production of methanol and electricity based on brown coal. The proposed solution is based on coal gasification in a fluidized bed gasifier with steam-oxygen as a gasification agent, three-stage catalytic synthesis of methanol, and a combined cycle. Detailed, effective mathematical models of combined methanol electricity production plant (CMEPP) and its components are developed. Optimization studies on the mathematical model of the plant are carried out, optimal flow diagrams and parameters of the CMEPP are obtained. The sensitivity of optimal variant to the change in the external economic conditions is estimated. The conditions for the CMEPP competitiveness are shown. (C) 2018 Elsevier Ltd. All rights reserved.