The discovery of abundant natural gas resources has greatly increased the study of using methane as a feedstock to produce transportation fuels. Biogas (primarily containing methane and CO2), which is generated from waste biomass via anaerobic digestion or landfills, is regarded as a renewable source of methane, and has the potential to achieve sustainable production of transportation fuels. Since biogas also contains a significant amount of impurities (e.g., H2S, NH3, and siloxane), a cleaning procedure is generally required prior to conversion to transportation fuels. Physical approaches, mainly compression and liquefaction, have been commercially applied to upgrade biogas to bio-compressed natural gas (CNG) and liquefied biogas (LBG). For chemical approaches, catalytic reforming is the dominant method for converting methane to syngas, followed by Fischer–Tropsch synthesis (FTS) or fermentation of syngas to a variety of alcohols (e.g., methanol, ethanol, and butanol) and liquid hydrocarbon fuels (e.g., gasoline, diesel, and jet fuels). High purity hydrogen, a clean fuel, can also be produced via reforming. Methanol can be produced by direct oxidation of methane, while interest in the biological conversion of methane to methanol has grown recently due to its mild operating conditions, high conversion efficiency, and potential for using raw biogas. The derived methanol can be further converted to gasoline via a methanol to gasoline (MTG) process. This paper provides a comprehensive review of major research progress on technologies for converting biogas/methane into transportation fuels, and discusses the principles, kinetics, operating conditions, and performance of each technology. Efficient direct conversion of biogas into ethanol and higher alcohol fuels (e.g. butanol), which is envisaged to be the focus of research pursuits in the near future, is also discussed, with emphasis on the development of methane-utilizing microbes through genetic engineering.

Progress and perspectives in converting biogas to transportation fuels

Steady state and dynamic performance of proton exchange membrane fuel cells (PEMFCs) under various operating conditions and load changes

Fuel cell coupled with biomass-derived fuel processor can convert renewable energy into a useful form in an environmental-friendly and CO2-neutral manner. It is considered as one of the most promising energy supply systems in the future. Biomass-derived fuels, such as ethanol, methanol, biodiesel, glycerol, and biogas, can be fed to a fuel processor as a raw fuel for reforming by autothermal reforming, steam reforming, partial oxidation, or other reforming methods. Catalysts play an important role in the fuel processor to convert biomass fuels with high hydrogen selectivity. The processor configuration is another crucial factor determining the application and the performance of a biomass fuel processing system. The newly developed monolithic reactor, micro-reactor, and internal reforming technologies have demonstrated that they are robust in converting a wide range of biomass fuels with high efficiency. This paper provides a review of the biomass-derived fuel processing technologies from various perspectives including the feedstock, reforming mechanisms, catalysts, and processor configurations. The research challenges and future development of biomass fuel processor are also discussed.

A review of biomass-derived fuel processors for fuel cell systems

Reversible physical absorption of SO2 by ionic liquids

Room temperature ionic liquids (RTILs), ether-functionalized imidazolium methanesulfonates, exhibit extremely high SO2 solubility, at least 2 moles of SO2 per mole of RTIL at 30 °C and at atmospheric pressure. The solubility of SO2 in these RTILs increases with increasing number of tethered ether oxygen atoms and also with the pressure rise. FT-IR spectroscopic and quantum mechanical calculation results show that such high SO2 solubility is originated from the combined interactions of SO2 with methanesulfonate anion and ether oxygen atom or atoms on the imidazolium ring. The absorbed SO2 gas can be readily and completely desorbed from the RTILs by heating at 100 °C in a N2 flow, thereby allowing the RTILs to be reused up to 5 cycles without loss of their initial capacity.

Ether-functionalized ionic liquids as highly efficient SO2 absorbents

Use of limestone for SO2 removal from flue gas in the semidry FGD process with a powder-particle spouted bed

Process development of hydrogenous gas production for PEFC from biogas

PROBLEM TO BE SOLVED: To provide a drive of vehicles where an inverter is integrated in short wiring length, and space can be ensured for arranging a current sensor detecting a motor drive current. SOLUTION: The drive of vehicles comprises a dynamo-electric machine; a power control unit for performing the drive control of the dynamo-electric machine; a connection member for connecting the dynamo-electric machine to the power control unit electrically; and a case for storing the dynamo-electric machine and the power control unit. The connection member includes a terminal block 116 that is provided integrally with the case and connects a power line from the power control unit to the dynamo-electric machine; and a current sensor integrated with the terminal block 116 to detect the drive current. The terminal block 116 includes a conductive member whose one end is connected to a bus bar from the power line and the other end is connected to a bus bar from the stator coil of the dynamo-electric machine; and a sealing member for sealing the conductive member. The current sensor is integrated with the conductive member for sealing, and detects the drive current flowing in the conductive member. COPYRIGHT: (C)2007,JPO&INPIT

Drive of vehicle

PROBLEM TO BE SOLVED: To provide a method for simultaneously producing hydrogen and aromatic hydrocarbons including benzene and naphthalene from lower hydrocarbons including methane without causing the detereoration of catalytic activity. SOLUTION: This method simultaneously produces hydrogen and aromatic hydrocarbons consisting mainly of benzene and naphthalene from lower hydrocarbon(s) including >=60 mol% methane in the presence of a catalyst; wherein the feedstock lower hydrocarbon and a hydrogen or a hydrogen- containing gas for maintaining the activity of the catalyst or regenerating the catalyst detereoration in activity are contacted with the catalyst periodically and alternately.

Method for producing aromatic hydrocarbon and hydrogen from lower hydrocarbon

PROBLEM TO BE SOLVED: To provide a semiconductor device cooling structure that is high in cooling efficiency. SOLUTION: The semiconductor device cooling structure is provided with a semiconductor device 1 including semiconductor devices 11, 12, a heat sink 2 having a mounting face 2A onto which the semiconductor device 1 is mounted and formed with a coolant channel 20 and in which a coolant for cooling the semiconductor device 1 flows in its inside, and each protruding part 3 that is provided at a part located on the side opposite to the mounting face 2A in the heat sink 2 and protrudes toward the inside of the coolant channel 20 from the bottom face 20A of the cooling channel 20 while extending in a direction intersecting with the coolant flow direction (an arrow DR1 direction). The semiconductor devices 11, 12 are arranged side by side in the arrow DR1 direction so that the semiconductor device 11 is located on the upper-stream side than the semiconductor device 12. A protruding part 32 for the semiconductor device 12 is provided so as to be located on the further downstream side than the semiconductor device 11 and on the upper-stream side than the center in the arrow DR1 direction of the semiconductor device 12. COPYRIGHT: (C)2008,JPO&INPIT

Tadashi Yoshida

Papers

Use of limestone for SO2 removal from flue gas in the semidry FGD process with a powder-particle spouted bed

Process development of hydrogenous gas production for PEFC from biogas

Drive of vehicle

Method for producing aromatic hydrocarbon and hydrogen from lower hydrocarbon

Semiconductor device cooling structure