Phase Equilibriums of Ammonium Chloride Systems as Model Hydrogenolysis Products of Organochlorine Compounds under Naphtha Hydrotreating Conditions

Abstract The study focuses on corrosion challenges for naphtha hydrotreating equipment (installed upstream of a reforming unit) caused by ammonium chloride deposits and the development adequate chemical engineering protection measures. Using an experimental setup, we investigated sublimation/desublimation at varying pressures temperatures in medium typical hydrogen-bearing gas streams flowing from hydrotreater. Superstoichiometric concentrations hydrogen were found to significantly decrease desublimation temperature (by 30–50°C) compared system that has stoichiometric HCl concentration. Consequently, solid-phase exists wider range pressures. Introducing surfactants (especially higher alcohols) into reduces adhesion affects crystalline structure salt deposits—despite solid phase being stabilized excess (superstoichiometric) concentration chloride—which makes suitable mitigating deposition challenge. Based data obtained, proposed effective methods use water-soluble inhibitors combination with online automated organochlorine control.