A load-following reactor system and associated facilities for improved control of a reactor under varying loads. The load-following reactor may be a tube-cooled reactor for methanol synthesis. A reactant may be controlled by at least one valve element such that a portion of the reactant is fed to the reactor through the reactor tubes, and a portion of the reactant is fed to the reactor after being heated in a heat exchanger. The heated portion of the reactant may be fed to the reactor after the tubes. The valve element may be controlled based on a temperature of the reactor and/or a flowrate of reactant feed to adapt the temperature of the reactor to the changing reactant flowrate.