A thermal storage subsystem may include at least a first storage reservoir configured to contain a thermal storage liquid at a storage pressure that is greater than atmospheric pressure. A liquid passage may have an inlet connectable to a thermal storage liquid source and configured to convey the thermal storage liquid to the liquid reservoir. A first heat exchanger may be provided in the liquid inlet passage and may be in fluid communication between the first compression stage and the accumulator, whereby thermal energy can be transferred from a compressed gas stream exiting a gas compressor/expander subsystem to the thermal storage liquid.

A hydraulic compressed air energy storage system includes air and liquid tanks, each of which includes interdependent volumes of liquid and air. Each tank includes dedicated passages through which incoming air may be fed, forcing outflow of liquid, or incoming liquid may be fed, forcing outflow of air. Compressed air tanks are connected to a first group of the air and liquid tanks. The system further includes a pump and a liquid turbine, the liquid turbine being electrically connected to a generator for generating electric power. During charging of the system, liquid is pumped through the first group of air and liquid tanks, and air is expelled from the first group of air and liquid tanks and compressed in the compressed air tanks. During discharging of the system, compressed air is released from the compressed air tanks, and said compressed air pumps liquid through the liquid turbine, thereby generating electricity.

A compressed gas energy storage system may include an accumulator for containing a layer of compressed gas atop a layer of liquid. A gas conduit may have an upper end in communication with a gas compressor/expander subsystem and a lower end in communication with accumulator interior for conveying compressed gas into the compressed gas layer of the accumulator when in use. A shaft may have an interior for containing a quantity of a liquid and may be fluidly connectable to a liquid source/sink via a liquid supply conduit. A partition may cover may separate the accumulator interior from the shaft interior. An internal accumulator force may act on the inner surface of the partition and the liquid within the shaft may exert an external counter force on the outer surface of the partition, whereby a net force acting on the partition is less than the accumulator force.

This invention provides a means of loading, processing and conditioning raw production gas, production of CGL, storage, transport, and delivery of pipeline quality natural gas or fractionated products to market. The CGL transport vessel utilizes a pipe based containment system to hold more densely packed constituents of natural gas held within a light hydrocarbon solvent than it is possible to attain for natural gas alone under such conditions. The containment system is supported by process systems for loading and transporting the natural gas as a liquid and unloading the CGL from the containment system and then offloading it in the gaseous state. The system can also be utilized for the selective storage and transport of NGLs to provide a total service package for the movement of natural gas and associated gas production. The mode of storage is suited for both marine and land transportation and configured in modular form to suit a particular application and/or scale of operation.

A method and apparatus for cooling a compressed fuel gas during transfer of the gas from a source vessel to a receiving vessel. The method includes receiving a portion of the fuel gas from the source vessel in an intermediate vessel. Then, fluidly isolating the intermediate vessel from the source vessel. Work is then extracted from the fuel gas by causing or allowing expansion of the fuel gas, thereby cooling the fuel gas. Finally, the cooled portion of fuel gas is released from the intermediate vessel to the receiving vessel.

A compressed gas energy storage system may include an accumulator for containing a layer of compressed gas atop a layer of liquid. A gas conduit may have an upper end in communication with a gas compressor/expander subsystem and a lower end in communication with accumulator interior for conveying compressed gas into the compressed gas layer of the accumulator when in use. A shaft may have an interior for containing a quantity of a liquid and may be fluidly connectable to a liquid source/sink via a liquid supply conduit. A partition may cover may separate the accumulator interior from the shaft interior. An internal accumulator force may act on the inner surface of the partition and the liquid within the shaft may exert an external counter force on the outer surface of the partition, whereby a net force acting on the partition is less than the accumulator force.

A thermal storage subsystem may include at least a first storage reservoir configured to contain a thermal storage liquid at a storage pressure that is greater than atmospheric pressure. A liquid passage may have an inlet connectable to a thermal storage liquid source and configured to convey the thermal storage liquid to the liquid reservoir. A first heat exchanger may be provided in the liquid inlet passage and may be in fluid communication between the first compression stage and the accumulator, whereby thermal energy can be transferred from a compressed gas stream exiting a gas compressor/expander subsystem to the thermal storage liquid.

A fueling station can include an outer housing comprising a housing volume, a first fluid bladder positioned within the housing volume and configured to hold a first fluid, a second fluid bladder positioned within the housing volume and configured to hold a second fluid, a first fluid conduit in fluid communication with the first fluid bladder, a second fluid conduit in fluid communication with the second bladder, a first hose positioned at least partially outside the outer housing and in fluid communication with both the first and second fluid conduits, and a bi-directional first nozzle connected to an end of the first hose opposite the first and second fluid conduits. The bi-directional first nozzle can be configured to simultaneously release fluid from the first hose and to collect fluid into the first hose. The first fluid bladder can be configured to release fluid through the first conduit in response to introduction of fluid into the second fluid bladder via the second conduit. The second fluid bladder can be configured to release fluid through the second conduit in response to introduction of fluid into the first fluid bladder via the first conduit.

A method of compressing gas includes maintaining a volume of gas at a first pressure within a first chamber. Pressurized liquid is forced into the first chamber through a nozzle having a curved profile. Based on the Coanda effect, the liquid compresses the volume of gas to a second pressure greater than the first pressure. The liquid is separated from the gas in a second chamber while maintaining the gas at the second pressure to provide compressed, dry gas.

A pressure vessel refueling system enables fast refueling of Compressed Natural Gas (CNG) fuel tanks. The system includes a pressure vessel having a gas inlet/outlet port and a liquid inlet/outlet port; a first liquid at least partially filling the pressure vessel; a liquid layer of a second liquid floating on top of the first liquid, wherein the second liquid is immiscible with the first liquid; a gas at least partially filling the pressure vessel above the liquid layer of the second liquid, the gas in fluid communication with the gas inlet/outlet; and a pump in fluid communication with the liquid inlet/outlet of the pressure vessel, whereby the first liquid can be pumped or returned to/from storage into or out of the pressure vessel.