A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A hydrogen feed stream comprising oxygen and one or more impurities selected from the group consisting of nitrogen, argon, methane, carbon monoxide, carbon dioxide, and water, is purified by first removing oxygen using a copper oxide and/or manganese oxide getter, then using a cryogenic temperature swing adsorption (CTSA) process with high overall recovery of hydrogen. The oxygen getter prevents an explosive mixture of hydrogen and oxygen from occurring in the CTSA during regeneration.

A hydrogen feed stream comprising one or more impurities selected from the group consisting of nitrogen, argon, methane, carbon monoxide, carbon dioxide, oxygen, and water, is purified using a cryogenic temperature swing adsorption (CTSA) process with high overall recovery of hydrogen. The waste gas from regenerating the CTSA may be used to improve the performance of upstream hydrogen processing steps.

Disclosed herein are systems and processes for removing heavies during the liquefaction of a natural gas. The processes include dissolving the heavies in the natural gas by adding external natural gas liquid (NGL), followed by a staged removal of the natural gas liquid (NGL) and dissolved heavies.

Certain aspects of natural gas liquid fractionation plant waste heat conversion to simultaneous power and potable water using organic Rankine cycle and modified multi-effect distillation systems can be implemented as a system that includes two heating fluid circuits thermally coupled to two sets of heat sources of a NGL fractionation plant. The system includes a power generation system that comprises an organic Rankine cycle (ORC), which includes (i) a working fluid that is thermally coupled to the first heating fluid circuit to heat the working fluid, and (ii) a first expander configured to generate electrical power from the heated working fluid. The system includes a MED system thermally coupled to the second heating fluid circuit and configured to produce potable water using at least a portion of heat from the second heating fluid circuit. A control system actuates control valves to selectively thermally couple the heating fluid circuit to a portion of the heat sources of the NGL fractionation plant.

A method for production of liquid natural gas (LNG) at natural gas liquids (NGLs) recovery plants that maximizes NGLs recovery by producing LNG and using the produced LNG as an external cooling source to control the operation of a de-methanizer column at the NLG recovery facility. In at least one embodiment, LNG is added from an LNG overhead receiver by direct mixing to control the temperature profile in the NGL de-methanizer column. The temperature in an overhead product of the de-methanizer column is controlled by controlling addition of LNG as a reflux stream. The temperature in an expanded feed gas to the de-methanizer column is controlled by controlling addition of LNG as a tempering gas, while stripping of carbon dioxide from an NGL product stream is controlled by controlling the addition of LNG as stripping gas.

Methods and systems for reducing the pressure of a hydrocarbon-containing stream so as to provide a cooled, reduced-pressure hydrocarbon-containing stream are provided. Facilities as described herein utilize a single closed-loop mixed refrigeration system in order to facilitate transportation, loading, and/or storage of a liquefied hydrocarbon-containing material at or near atmospheric pressure. In some aspects, the facilities can include at least one separation device for removing lighter components from the feed stream, which may separately be recovered as a vapor product for subsequent processing and/or use.

Disclosed herein are systems and processes for removing heavies during the liquefaction of a natural gas. The processes include dissolving the heavies in the natural gas by adding external natural gas liquid (NGL), followed by a staged removal of the natural gas liquid (NGL) and dissolved heavies.

Certain aspects of natural gas liquid fractionation plant waste heat conversion to simultaneous power and potable water using organic Rankine cycle and modified multi-effect distillation systems can be implemented as a system that includes two heating fluid circuits thermally coupled to two sets of heat sources of a NGL fractionation plant. The system includes a power generation system that comprises an organic Rankine cycle (ORC), which includes (i) a working fluid that is thermally coupled to the first heating fluid circuit to heat the working fluid, and (ii) a first expander configured to generate electrical power from the heated working fluid. The system includes a MED system thermally coupled to the second heating fluid circuit and configured to produce potable water using at least a portion of heat from the second heating fluid circuit. A control system actuates control valves to selectively thermally couple the heating fluid circuit to a portion of the heat sources of the NGL fractionation plant.