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and BRUNO SOLARI 1NTEVEP, S.A.The jet bubble column consists of a conical entrance section which expands to a cylindrical column. Gas and liquid are co-currently introduced at the bottom of the column by a small diameter inlet pipe which acts like an ejector. The kinetic energy of the gas and liquid jet together with the conical geometry at the lower section of the column cause the formation and dispersion of small bubbles, Gas-liquid mass transfer in the jet bubble column (61 cm diameter) was measured by a dynamic response technique, in which a step change was made in the gas phase oxygen concentration and the aqueous dissolved oxygen concentration response was measured at various axial and radial locations. It was found that a continuous stirred tank reactor model could be used to evaluate experimental results. The volumetric mass transfer coefficient in this type of system was found to increase with increasing gas flow rate and was about 1.5 times larger than the values obtained at similar conditions in conventional bubble columns. Preliminary measurements and calculations indicate negligible effects of liquid velocity and bed height on the mass transfer coefficient. KEYWORDS Gas-liquid Mass transfer Jet bubble column Multiphase Bubble column and interphase mass transfer.

Environmental and energy security concerns are driving federal agencies to evaluate alternative domestically produced energy. Among the various technologies studied, the U.S. Department of Energy (DOE) launched a five-year demonstration project named “Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project” to investigate the feasibility of hydrogen as a transportation fuel. To achieve the objective, the DOE selected a team of industry leaders to design, construct and operate a system consisting of various hydrogen fueling stations and fleet of fuel cell electric vehicles. One of the selected teams consists of Chevron Technology Ventures Inc., Hyundai American Motor Co., UTC Fuel Cells, and Southern California-Edison (SCE). Each team member is responsible for a key task: Chevron — design and build the hydrogen fueling station, Hyundai and UTC — build the Fuel Cell Electric Vehicles, and SCE — site-owner, characterize and operate the system in a real world setting.The hydrogen fueling station was built at the corporate offices of SCE in Rosemead, California. This station is capable of maintaining a minimum storage capacity of 60 kg, a daily production and dispensing capacity of 40kg, a fueling pressure of 5,000PSI, and a maximum vehicle fueling time of five minutes. As an electric utility company, SCE will perform a detailed power analysis of the station and determined key functions, such as system power demand, efficiency, and reliability. Prior to fleet assessment, SCE characterized the performance of three fuel cell electric vehicles at its EV Technical Center in Pomona, California. This characterization included both freeway and urban drive-range testing. In addition, the vehicles will be deployed to various sites throughout the SCE service territory for fleet assessments. Among the various test sites will be Palm Springs, designated as the hot-climate site.This project demonstrates the ability of hydrogen to be a possible source of sustainable domestic transportation energy. The lessons learned in this project provide valuable knowledge to the partners by conducting project tasks, such as permitting, code compliance, vehicle characterizations, fleet assessment, and infrastructure installation.