Certain aspects of natural gas liquid fractionation plant waste heat conversion to simultaneous power, cooling and potable water using integrated mono-refrigerant triple cycle and modified MED system can be implemented as a system that includes two heating fluid circuits thermally coupled to multiple heat sources of a NGL fractionation plant. An integrated triple cycle system, which includes an organic Rankine cycle (ORC), a refrigeration cycle and an ejector refrigeration cycle, is thermally coupled to the first heating fluid circuit. A MED system, configured to produce potable water, thermally coupled to the second heating fluid circuit. The system includes a control system configured to actuate control valves to selectively thermally couple the heating fluid circuits to portions of the heat sources of the NGL fractionation plant.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

A carbon dioxide capturing apparatus using cold heat of liquefied natural gas (LNG) includes a heat exchanger to cool primary coolant using heat exchange between the primary coolant and the LNG; a chiller connected to the heat exchanger and configured to discharge capturing coolant colder than the primary coolant by performing a heat exchange between the capturing coolant and a cooling material; and a capturing cooler configured to capture carbon dioxide contained in flue gas by performing a heat exchange between the capturing coolant discharged from the chiller and the flue gas. A power generation system includes an LNG storage facility; a power generation facility discharging flue gas; a unit for heat exchange between the LNG and a coolant to regasify the LNG and cool the coolant; and a unit for capturing carbon dioxide contained in the flue gas by heat exchange between the discharged flue gas and the coolant.

Methods and systems for producing a product natural gas employing a natural gas liquids (NGL) recovery unit followed by removing nitrogen in a nitrogen rejection unit (NRU) operatively connected with the NGL recovery unit by a pressure management sub-system (PMSS). In one embodiment, the PMSS includes a first conduit fluidly connecting the top of a demethanizer column (or an existing conduit connected to the top of the demethanizer) to a separator, a second conduit fluidly connecting the separator to a pump, the pump connected to a distillation column in the NRU by a third conduit, in another embodiment, the PMSS includes a first conduit fluidly connecting an NGL expander to a separator, allowing natural gas vapors and nitrogen to be fed to the NRU column through a second conduit. Alternatively, the PMSS allows mixture from the NGL recovery unit expander to be fed directly via the first conduit to the NRU distillation column.

A main heat exchanger receives and partially condenses an effluent fluid stream so that a mixed phase effluent stream is formed. A primary separation device receives and separates the mixed phase effluent stream into a primary vapor stream including hydrogen and a primary liquid stream including an olefinic hydrocarbon. The main heat exchanger receives and warms at least a portion of the primary vapor stream to provide refrigeration for partially condensing the effluent fluid stream. The main heat exchanger also receives, warms and partially vaporizes the primary liquid stream. A mixed refrigerant compression system also provides refrigeration in the main heat exchanger.

A system includes a waste heat recovery heat exchanger configured to heat a heating fluid stream by exchange with a heat source in a crude oil associated gas processing plant. The system includes an Organic Rankine cycle energy conversion system including a pump, an energy conversion heat exchanger configured to heat the working fluid by exchange with the heated heating fluid stream, a turbine and a generator configured to generate power by expansion of the heated working fluid, a cooling element configured to cool the expanded working fluid after power generation, and an accumulation tank. The heating fluid flows from the accumulation tank, through the waste heat recovery heat exchanger, through the Organic Rankine cycle energy conversion system, and back to the accumulation tank.

A method of recovering heat from a Natural Gas Liquid (NGL) fractionation plant for production of potable water. The method includes heating a buffer fluid via a heat exchanger in the NGL fractionation plant to transfer heat from the NGL fractionation plant to the buffer fluid. The method includes heating feed water with the buffer fluid discharged from the heat exchanger for production of potable water via a multi-effect-distillation (MED) system. The method may include producing potable water with heat from the buffer fluid in the MED system.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

A natural gas liquid recovery system includes a cold box and a refrigeration system. The refrigeration system includes a primary refrigerant loop in fluid communication with the cold box. The primary refrigerant loop includes a primary refrigerant including a first mixture of hydrocarbons. The refrigeration system includes a secondary refrigerant loop. The secondary refrigerant loop includes a secondary refrigerant including i-butane. The refrigeration system includes a first subcooler configured to transfer heat between the primary refrigerant of the primary refrigerant loop and the secondary refrigerant of the secondary refrigerant loop. The refrigeration system includes a second subcooler downstream of the first subcooler. The second subcooler is configured to transfer heat between the primary refrigerant and a vapor phase of the primary refrigerant. The cold box is configured to receive the primary refrigerant from the second subcooler.

The present invention relates to a method for liquefying hydrogen, the method comprises the steps of: cooling a feed gas stream comprising hydrogen with a pressure of at least 15 bar(a) to a temperature below the critical temperature of hydrogen in a first cooling step yielding a liquid product stream. According to the invention, the feed gas stream is cooled by a closed first cooling cycle with a high pressure first refrigerant stream comprising hydrogen, wherein the high pressure first refrigerant stream is separated into at least two partial streams, a first partial stream is expanded to low pressure, thereby producing cold to cool the precooled feed gas below the critical pressure of hydrogen, and compressed to a medium pressure, and wherein a second partial stream is expanded at least close to the medium pressure and guided into the medium pressure first partial stream.