This work reports the development of a test bench facility for ethanol processing, H2 upgrading, purification and demonstration of fuel cell integration feasibility.
This system is composed by one allothermal steam-reforming reactor heated by an electronically controlled electrical furnace, a low temperature shift reactor for CO depletion, and purification step. Ethanol and water mixtures are pumped by a manually controlled electrical pump. Many sampling points are located in the overall system in order to make possible to analyze the efficiency of all components in any part of the system.
The apparatus scheme is presented in Fig. 1.
Fig. 1. Test bench for ethanol processing system evaluation.
The purification step begins with a one-pass water cooled heat exchanger, followed by a trap to retain the liquid phase (produced or non-processed) after ethanol and CO processing.
The partially dried syn-gas goes to the 2-bed З-segment treatment for chemical water drying, C02 and CH4 separation. Finally, CO separation occurs exclusively in the second purification bed.
There are several sampling points in the system to collect gas samples to be analyzed. Determining the gas composition is useful to verify theoretical approaches for catalyst and purification elements and also to define the lifetime of the purification beds in order to implement an automated gas purifier based on PSA (Pressure Swing Adsorption) and TSA (Temperature Swing Adsorption) hybrid cycle.
The integration of the prototype to a PEM fuel cell is only intended to demonstrate the technical feasibility. Since the system is based on an electrical furnace and considering the energy losses involved, the assertion that this assembly corresponds to an electrical generator based on ethanol fuel using a thermo-electrochemical route, is not
true. But this system makes it possible to find many necessary parameters to develop an autothermal ethanol processor, whose project is under way.
This new processor is illustrated in Fig. 2.
The first evaluation of the assembly showed in Fig. 1 should be seen as the performance of the system rather than the catalyst performance itself. The CuNi / у – A1203 catalyst was previously studied with respect to its structure and composition for different preparations and thermal treatments [4-6].
In this work, the catalyst was evaluated at higher temperatures (400-700°C) and atmospheric pressure. The results are presented ahead.