Abstract: The present invention relates to a process for purifying a gas stream comprising hydrogen sulfide or mercaptans, or mixtures thereof. The gas stream can be a sour natural gas stream, a landfill gas or an industrial gas stream. The process comprises contacting the gas stream at effective absorption conditions including an absorption temperature less than about 300° C. with a solid absorbent effective to absorb the hydrogen sulfide, or mercaptans or mixtures thereof to provide a purified gas stream. Method is useful for treating gas streams having up to 90 vol-% hydrogen sulfide, or treating highly pure hydrogen streams. The invention is useful as a guard bed for fuel cells and sensitive laboratory instruments. The invention can also be employed to treat steam reformer product hydrogen streams without the need for further compression of the product hydrogen streams.

Abstract: The present invention relates to a process for purifying a gas stream comprising hydrogen sulfide or mercaptans, or mixtures thereof. The gas stream can be a sour natural gas stream, a landfill gas or an industrial gas stream. The process comprises contacting the gas stream at effective absorption conditions including an absorption temperature less than about 300° C. with a solid absorbent effective to absorb the hydrogen sulfide, or mercaptans or mixtures thereof to provide a purified gas stream. Method is useful for treating gas streams having up to 90 vol-% hydrogen sulfide, or treating highly pure hydrogen streams. The invention is useful as a guard bed for fuel cells and sensitive laboratory instruments. The invention can also be employed to treat steam reformer product hydrogen streams without the need for further compression of the product hydrogen streams.

Abstract: A combustion system includes a catalytic oxidizer for oxidizing a mixture of air and fuel vapor. The amount of air provided for mixing with the fuel vapors is determined in accordance with the temperature of the oxidation reaction as measured by a temperature sensor. Controlling the dilution level in this manner provides an efficient vent processing design. The system is used to process vapor emissions emanating from a vehicle fuel tank during refueling.

Abstract: A vapor recovery system employs a sensor apparatus for determining the actual content of hydrocarbon in the effluent vapor stream. The vapor flow of the hydrocarbon effluents is regulated by controlling an adjustable valve configured at the intake or outtake side of the vapor pump in accordance with the measured hydrocarbon content. The vapor flow rate is effectively varied without requiring any change in the pump operating speed. Sensor apparatus for performing the hydrocarbon measurements include a fiber-optic sensor, an oxygen sensor, and a crystal oscillation sensor. A solenoid assembly is provided to suitably activate the valve in response to the sensor measurement data.

Abstract: A vapor recovery system is disclosed that utilizes a crystal oscillator for sensing the presence of hydrocarbon in the vapor emissions emanating from a fuel tank during refueling. The crystal oscillator is coated with a layer of material having a sensitivity for hydrocarbon. In response to any interaction between the coating layer and hydrocarbon, the crystal oscillator experiences a shift in its oscillation frequency relative to the fundamental resonance frequency. The frequency shift is representative of the hydrocarbon concentration in the vapor emissions. A control signal based on the frequency shift is generated and then used to adjust the operating speed of the vapor pump.

Abstract: A method and apparatus is disclosed for sensing hydrocarbon in the vapor path of fuel dispensers using a fiber-optic sensor. The sensor includes an absorber-expander sensing structure mechanically coupled to the fiber body and responsive to the presence of effluent fuel components for absorbing the hydrocarbon therein and expanding in response thereto. The expansion activity has the effect of generating a microbend deformation in the fiber, producing detectable changes in the optical throughput representing the concentration of hydrocarbon that is sensed by the absorber-expander element. The fiber-optic sensor is particularly useful in a vapor recovery system by providing an optical signal that is representative of the ambient hydrocarbon concentration.

Abstract: A vapor recovery system is disclosed that provides direct measurements of the oxygen concentration within fugitive vapor emissions displaced from a fuel tank during refueling activity. The hydrocarbon concentration is derived from the oxygen concentration and used to adjust the operating speed of a vapor pump so as to minimize the presence of oxygen in the vapor recovery line.

Abstract: A Stage II Vapor Recovery System is provided with a special array of storage tanks, dispensers, fuel pumps, vapor assist pumps, and flow control nozzles, to capture hydrocarbon emissions, prevent condensate from blocking vapor return lines, and dispense gasoline or other liquid fuel and condensate to customer tanks.

Abstract: A user friendly vapor recovery nozzle with special signaling devices to signal and assure the customer of proper delivery of fuel and return flow of hydrocarbon vapors. In the preferred embodiment, the signaling devices include both a fuel flow indicator and a vapor flow indicator. The flow indicators can comprise one or more fuel and vapor driven balls, paddle wheels, propellers, spinners, blades, or vanes. In the preferred form, the vapor recovery nozzle has an inner fuel spout to discharge gasoline into a customer's tank and has an outer spout which cooperates with the inner spout to provide a vapor return passageway to return vapors emitted during fueling to a vapor return hose. The nozzle has a liquid sensing tube in the vapor return passageway to sense when the customer's tank is filled. An automatic shutoff valve cooperates with the liquid sensing tube to shutoff the supply of gasoline when the customer's tank is filled.

Abstract: A vapor recovery process signals to customers the presence of flow of gasoline or other liquid fuel and the return flow of vapors. In the preferred process, a customer's tank is fueled with a vapor recovery nozzle. Vapors emitted during fueling are collected by the nozzle and passed to a vapor return hose and then into a storage tank. A vapor flow indicator on the nozzle signals flow of vapors passing through the nozzle. A separate fuel flow indicator in the nozzle signals fueling, i.e., passing a fuel through the nozzle into the customer's tank.

Abstract: A Stage II Vapor Recovery System is provided with a special array of storage tanks, dispensers, fuel pumps, vapor assist pumps, and flow control nozzles, to capture hydrocarbon emissions, prevent condensate from blocking vapor return lines, and dispense gasoline or other liquid fuel and condensate to customer tanks. Specifically, fuel lines connect storage tank to flow control nozzles via dispensers and are assisted by fuel pumps to pump gasoline into customers' tanks. The nozzles have vapor passageways to capture hydrocarbon vapors emitted during fueling. The captured vapors are pumped by vapor assist pumps from the vapor passageways through vapor return lines into the storage tanks. The nozzles are equipped with condensate liquid pickup tubes to remove condensed vapors blocking the vapor return lines. The condensate liquid tubes communicate with condensate venturi ports adjacent venturi sleeves in the nozzles.

Abstract: In the process, fuel is pumped from a storage tank through a dispenser and nozzle into a customer's tank. Hydrocarbon vapors emitted during fueling are collected through a vapor recovery passageway between the inner and outer spouts of the nozzle and conveyed by a vapor pump through vapor return lines into the storage tank. A portion of the vapors in the vapor return lines condense and are removed with the nozzle's condensate pickup tube. The removed condensate is dispensed into the customer's tank.