Catalytic Steam and Partial Oxidation Reforming of Liquid Fuels for Application in Improving the Efficiency of Internal Combustion Engines

Abstract

This study investigated the potential for catalytically reforming liquid fuels in a simulated exhaust gas recirculation (EGR) mixture loop for the purpose of generating reformate that could be used to increase stoichiometric combustion engine efficiency. The experiments were performed on a simulated exhaust flow reactor using a Rh/Al2O3 reformer catalyst, and the fuels evaluated included iso-octane, ethanol, and gasoline. Both steam reforming and partial oxidation reforming were examined as routes for the production of reformate. Steam reforming was determined to be an ineffective option for reforming in an EGR loop, because of the high exhaust temperatures (in excess of 700 °C) required to produce adequate concentrations of reformate, regardless of fuel. However, partial oxidation reforming is capable of producing hydrogen concentrations as high as 10%–16%, depending on fuel and operating conditions in the simulated EGR gas mixture. Meanwhile, measurements of total fuel enthalpy retention were shown to have favorable energetics under a range of conditions, although a tradeoff between fuel enthalpy retention and reformate production was observed. Of the three fuels evaluated, iso-octane exhibited the best overall performance, followed by ethanol and then gasoline. Overall, it was found that partial oxidation reforming of liquid fuels in a simulated EGR mixture over the Rh/Al2O3 catalyst demonstrated sufficiently high reformate yields and favorable energetics to warrant further evaluation in the EGR system of a stoichiometric combustion engine.

Catalytic Exhaust Gas Recirculation-Loop Reforming for High Efficiency in a Stoichiometric Spark-Ignited Engine through Thermochemical Recuperation and Dilution Limit Extension, Part 2: Engine Performance

“…However, because all of the cylinder 4 exhaust is used to feed the reforming catalyst and is recirculated to the other three cylinders, it is not necessary to maintain stoichiometric conditions in cylinder 4 to have a stoichiometric exhaust. In fact, to provide the catalyst with the proper feed for good performance, cylinder 4 is intentionally operated under nonstoichiometric conditions …”

“…To achieve high fuel conversion and robust operation of the catalyst, we operated cylinder 4 so that it provided the catalyst with a fuel-rich mixture that also contained oxygen, as our previous studies indicated was necessary . This was accomplished by operating the main combustion event in cylinder 4 fuel-lean and providing a post-injection of fuel at a constant timing of 150°CA ATDC, which is near the exhaust valve opening timing.…”

Overview on the Vital Step toward Addressing Platinum Catalyst Poisoning Mechanisms in Acid Media of Direct Ethanol Fuel Cells (DEFCs)

“…Their combustion significantly contributes to global warming by introducing a huge amount of greenhouse gases. For this reason, the increasing interest in alternative future energy source technologies has generated an urgent need to develop clean and renewable energy sources with less greenhouse gas emissions. − Electrooxidation of renewable fuels such as bioethanol in fuel cells could be recognized as attractive alternative energy generation technologies. − …”

Catalytic Exhaust Gas Recirculation-Loop Reforming for High Efficiency in a Stoichiometric Spark-Ignited Engine through Thermochemical Recuperation and Dilution Limit Extension, Part 1: Catalyst Performance

“…In this manuscript, we characterize reformer catalyst performance over a range of Φ catalyst conditions in an effort to find a balance between the POx reactions required for sustained catalyst activity and durability and the endothermic steam reforming reactions required to minimize energy losses or to achieve TCR during reforming. This experimental study was conducted using a full-sized catalyst on a multicylinder engine but builds on previous bench flow reactor experiments conducted by Brookshear et al 48 This paper characterizes reformer performance and energetics using iso-octane with the EGR-loop reforming catalyst under a variety of operating conditions while a companion paper 49 focuses on whole-engine performance, including EGR dilution tolerance, emissions, and brake thermal efficiency.…”