Occidental Petroleum

Other

Occidental Research Corporation

Edward F Wahl, Iii

Frederic B Boucher

Method and apparatus for transmitting a two-phase fluid of water and steam from a geothermal well head to a thermal energy use plant. A pipeline with substantially no flow restrictions and a decoupling tank, with the pipeline directly feeding the tank, and the tank feeding the energy use plant. Several embodiments of a decoupling tank including one with separate steam and water outlets, one with an outlet tube within the tank and an outlet slot in the tube at the water level of the tank, and one with a dumbbell-shaped outlet slot with a narrow central portion at the water level.

Process and apparatus for control of two-phase flow to geothermal power

Process for recovery of energy from geothermal fluids such as geothermal brine in a geothermal formation by injecting a water immiscible working fluid, preferably organic, typically a hydrocarbon, e.g. isobutane, into the geothermal formation containing a geothermal fluid such as hot brine, wherein the hydrocarbon working fluid is heated by direct heat exchange contact with the hot geothermal fluid in the formation, and employing the hot working fluid to drive a heat engine or turbine to produce work or electrical energy or to provide heat energy to a chemical process (e.g., alcohol manufacture). The cooled working fluid discharged from the turbine is reinjected into the geothermal formation. The working fluid preferably has a density which changes substantially with temperature to provide a substantial pressure difference for causing flow of heated working fluid up the production well. The density difference can be due to phase transfer from liquid to gas.

Geothermal energy production

A process for removing carbon dioxide in geothermal power generating processes employing a geothermal fluid such as geothermal brine containing carbon dioxide, to improve the efficiency of geothermal power generation, comprises introducing an aqueous alkaline solution, preferably an aqueous calcium hydroxide solution, into a vapor stream obtained from the brine during power generation, to remove carbon dioxide from the stream. In the case, for example, of power generation by direct contact heat exchange between geothermal brine and a working fluid such as isobutane, where the working fluid is expanded to generate power, aqueous calcium hydroxide can be introduced into a direct contact condenser into contact with the working fluid therein to remove CO.sub.2 present in the working fluid, thereby aiding in reducing loss of working fluid from the system and aiding in reducing pump power. The aqueous alkaline, e.g., calcium hydroxide, solution alternatively can be contacted with the geothermal fluid prior to flashing or prior to direct contact heat exchange with a working fluid, to remove CO.sub.2 from uncondensible gas contained in the fluid.

Removal of carbon dioxide in geothermal power systems

Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g. with respect to the design of such plates, number of plates employed, spacing between plates, area thereof, column diameter, and the like, are designed to achieve maximum throughput of brine or hot water and reduction in temperature differential at the respective stages or plates between the brine or hot water and the working fluid, and so minimize lost work and maximize efficiency, and minimize scale deposition from hot water containing fluid including salts, such as brine. Maximum throughput approximates minimum cost of electricity which can be produced by conversion of the recovered thermal energy to electrical energy.

Recovery of energy from geothermal brine and other hot water sources

In the recovery of energy from geothermal brines and other water containing or hot water sources, such brine or hot water under pressure is introduced into direct heat exchange contact with a working fluid such as isobutane, the resulting hot isobutane is expanded in a turbine to produce work, the turbine discharge is condensed and returned to the heat exchanger and the cooled brine is withdrawn from the column. The present invention is directed to recovery of working fluid dissolved and/or entrained in the spent geothermal brine or water withdrawn from the direct contact heat exchanger, including the steps of settling the brine in a settling tank to recover some of the isobutane, flashing the remaining brine to flash off additional isobutane and steam stripping the spent brine to drive off further isobutane, the recovered isobutane in each of the steps being recycled to the direct contact heat exchanger.

Process and system for recovery of working fluid for direct contact heat

Recovery of energy from geothermal brines and other hot water sources by direct contact heat exchange with a working fluid, such as a hydrocarbon working fluid, e.g. isobutane. The process and system consists of a plurality of stages, each stage including mixing and settling units. In the first stage, hot brine and arm working fluid are intimately mixed and passed into a settler wherein the brine settles to the bottom of the settler and the hot working fluid rises to the top. The hot working fluid is passed to a heat engine or turbine to produce work and the working fluid is then recycled back into the system. The system is comprised of a series of stages each containing a settler and mixer, and wherein the working fluid and the brine flow in a countercurrent manner through the stages to recover the heat from the brine in increments and raise the temperature of the working fluid in increments.

Countercurrent direct contact heat exchange process and system

Apparatus to convert the internal energy of hot fluids to mechanical work comprising a pair of nozzles, e.g. convergent-divergent nozzles, mounted oppositely on hollow support arms which are in turn mounted on a rotating hollow shaft which is coupled to a conventional electric generator or other device requiring mechanical power. The hot liquid, e.g. hot brine, flows through the hollow shaft and the hollow support arms to the nozzles, where the hot fluid expands and creates a thrust and torque on the shaft, causing it to rotate and create shaft power. The nozzles and rotating shaft are mounted in a closed container from which the exhaust fluid, gases and liquid are removed by conventional means so as to maintain a reduced pressure within the container.

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Claremont, CA, United States of America

Edward F Wahl, Iii