Under a Creative Commons Attribution 4.0 International license., Experimental set-up: The gas-feeding system consists of a central supply of Air, N2, He and H₂ and gas cylinders carrying C.O. and CO₂. Bronkhorst mass flow controllers and pressure controllers control feed flow rates and pressure, respectively, at the inlet and outlet of the reactor. The mass flow controllers are linked to a computer-controlled central device that controls the set points of the mass flow controller. When the flow rate through a mass flow controller was zero, the valve as the outlet had to be shut off since the flow controllers cannot function as on/off valves. Before the gas exiting the reactor was analysed, it was cooled to condense any H₂O, ensuring the outlet gas composition was measured dry. The reactor arrangement, the Carbolite ® furnace and the liquid-feeding system are located in Fume Cupboard 2 (FC-2). A picture of the reactor system is presented in Figure 1.-- Model development: Grid points are compared, 32 vs. 104. The model shows little difference between the temperature profile, allowing the use of 32 grid points and quicker computational time.-- TGA conversion curve.
Figure 5 and Figure 6 shows the solid conversion curves, during reduction in H2 and CO between 700-900 °C at 50°C intervals.-- Air oxidation model vs experimental: Breakthrough comparison between experiment (orange solid line) and the 1-D model (dotted line), flow rate is a total of 10 NLPM, 6.5 NLPM N2, 2.5 NLPM O2, and 1 He at a bed temperature of 600°C bed temperature and 1 bar pressure.-- Glycerol reforming dry outlet gas composition:
Glycerol reforming 9:1 steam to glycerol composition profiles for the experiment (solid lines) and the 1-D model (dotted lines). Glycerol reforming 12:1 steam to glycerol composition profiles for the experiment (bars) and the 1-D model (dots). Combined Glycerol reforming 9:1 and 12:1 steam to glycerol composition profiles for the experiment (bars) and the 1-D model (dots).-- Temperature profile during glycerol reforming:
The temperature profile can be reasonably stable if the furnace maintains the set-point temperature. However, an axial temperature gradient exists in the reactor, with the inlet of the bed being cooler than the outlet. This is due to the furnace being situated downstream of the inlet. As a result, the set-point temperature for the reforming stage refers to the temperature reading of TC6, which is in the middle of the bed. It is noted from the temperature profile that TC1-3 experiences the most significant fluctuation in temperature, indicating that most of the reforming takes place nearer the bed inlet. This is important to recognise because the lower portion of the bed is cooler. Therefore, the temperature at which reforming occurs is much lower than the set-point temperature. Even after glycerol reforming at the bottom of the bed, as the gas must pass over the hotbed afterwards, W.G.S. reactions will still occur. To an extent, this explains the minor inconsistencies between the experimental and modelling outlet gas composition values., The authors would like to acknowledge EU Horizon 2020 research and innovation programme under grant agreement no. 884197 (GLAMOUR project)., Peer reviewed