On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications
The objective of the project was to develop a new on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. The Florida Solar Energy Center's responsibilities included building, operating and validating the performance of a diesel pre-reformer as well as developing and demonstrating a small scale desulfurization unit. Chevron Technology Ventures provided catalysts and know-how for the design and fabrication of the pre-reforming reactor. The pre-reformer was coupled with a regenerable Fe2+/Fe3+ redox/electrolysis system used for hydrogen sulfite removal from the pre-reformer effluent. Results from laboratory tests showed that electrolysis of acidic FeSO4 aqueous solution was highly efficient with a coulumbic efficiency of 100% at a cell potential of 1.0 V and that the electrolytic process can be made to operate with a Pt-free anode to oxidize ferrous to ferric ions, thereby reducing the cost of the electrolytic scrubber. FSEC researchers have also developed a robust bi-functional catalyst for accomplishing the pre-reformation of the high-sulfur fuels (sulfur content as high as 5,240 ppmw) to short chain hydrocarbons (C1-C4, mostly propane) at an average yield of about 97%. Furthermore, results showed that after100 hours of continuous operation, the combined Fe2+/Fe3+ redox/electrolyzer H2S scrubber and pre-reformer could achieve desulfurization efficiencies greater than 95% and removed sulfur down to less than 5 ppmv in the pre-reformer effluent.
Florida Solar Energy Center and Block, David, "On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications" (2010). FSEC Energy Research Center®. 311.