The experimental set-up consists of a fixed-bed reactor made of steel with an internal diameter of1.4 cm and a length of 80 cm. The catalyst was positioned in the middle of the tube and diluted with(inactive) quartz sand in a ratio of 1:2 by mass in order to keep the catalyst temperature constant andto prevent hot spots. The reactor was thermostated by an oil heating system, guaranteeing isothermalconditions.