The refractory drying of the reactor feed heater can be conducted simultaneously with the drying of the reaction section. If this is the case, then the procedure for refractory drying will control the rate of temperature rise and the duration of the drying step. The Axens start-up representative will consult with the heater manufacturer's representative to agree on an acceptable procedure. Drying can be carried out under air or nitrogen, depending on availability, using the recycle compressor.