Hydrogen consumed in large quantities in the chemical industry. The most common industrial process for hydrogen production is steam-methane reforming, which is carried out using an energy-intensive furnace. The plant energy efficiency depends strongly on the spatial temperature distribution within the furnace; the narrower the distribution, the higher the efficiency that can be achieved. However, currently available studies on plantwide optimization of hydrogen plants ignore this crucial aspect. Adequate resolution of the spatial temperature distribution is necessary to determine the furnace operating temperature, which, in turn, determines the plant efficiency. In this work, a multi-resolution model of a hydrogen plant is developed. It includes a high-resolution model of the furnace, and low-resolution models, adequate for the purpose of plantwide optimization, of other unit operations. The developed model is used to determine the optimal process conditions after furnace temperature homogenization as part of a plant start-up or setpoint changeover procedure. (C) 2017 Elsevier Ltd. All rights reserved.