An automated control loop for dynamically adjusting a temperature of wet steam is provided. This leads to increased heat transfer and decreased fouling in a reboiler of a distillation column used for distilling a petrochemical. The control loop includes controlling the combining of condensed water with dry steam to produce the wet steam. The produced wet steam is input to the reboiler in order to transfer heat to the petrochemical while being converted to the condensed water. The control loop further includes monitoring a pressure of the produced wet steam, and setting a target temperature for the produced wet steam based on the monitored pressure. In addition, the control loop includes monitoring the temperature of the produced wet steam, and adjusting a proportion of the condensed water in the produced wet steam in response to the monitored temperature deviating from the set target temperature by at least a threshold value.

A heat exchanger unit that comprises a heat exchanger vessel comprising a plurality of process stream conduits to receive the gaseous process stream and discharge a cooled process stream, and a plurality of refrigerant conduits to receive a pre-cooled mixed refrigerant stream and discharge a cooled mixed refrigerant stream; an expansion device to receive the cooled mixed refrigerant stream and discharge a further cooled mixed refrigerant stream, which is connected to a third and/or fourth refrigerant inlets to provide cooling to the process stream conduits and the refrigerant conduits; a refrigerant bleed vessel to receive a first refrigerant split-off stream from the cooled mixed refrigerant stream and a second refrigerant split-off stream from the pre-cooled mixed refrigerant stream; the refrigerant bleed vessel comprising a bleed outlet to discharge a bleed stream and a recycle outlet fluidly connected to the third and/or fourth refrigerant inlets.

The present invention relates to the control systems of the compression refrigerating machines, namely, to the methods of control of the natural gas liquefaction process to produce liquefied natural gas (LNG), and can be used for liquefaction and cooling of natural gas on the most major technological lines and LNG production plants, working on the mixed refrigerant (MR). The method of control of the natural gas liquefaction process on the mixed refrigerant-operating LNG production plant comprises a periodic measuring of the current parameters of the said process, and controlling composition of the mixed refrigerant entering the main cryogenic heat exchanger, in order to achieve the optimal process parameters. Carnot factor is used as an optimality criterion for parameters of the process. The mixed refrigerant composition is controlled by direct calculation on the basis of the current process parameters and equation of state (for example, Peng-Robinson equation of state) of the substance amount of the mixed refrigerant components required to obtain in the main cryogenic heat exchanger the temperature profile corresponding to the optimal process parameters, and to introduce the said components into the main cryogenic heat exchanger. The invention improves efficiency of the natural gas liquefaction process and, as a result, minimizes specific compressor power required for LNG production.

The present invention relates to the control systems of the compression refrigerating machines, namely, to the methods of control of the natural gas liquefaction process to produce liquefied natural gas (LNG), and can be used for liquefaction and cooling of natural gas on the most major technological lines and LNG production plants, working on the mixed refrigerant (MR). The method of control of the natural gas liquefaction process, on the mixed refrigerant-operating LNG production plant comprises a periodic measuring of the current parameters of the said process, and controlling composition of the mixed refrigerant entering the main cryogenic heat exchanger, in order to achieve the optimal process parameters. Carnot factor is used as an optimality criterion for parameters of the process. The mixed refrigerant composition is controlled by direct calculation on the basis of the current process parameters and equation of state (for example, Peng-Robinson equation of state) of the substance amount of the mixed refrigerant components required to obtain in the main cryogenic heat exchanger the temperature profile corresponding to the optimal process parameters, and to introduce the said components into the main cryogenic heat exchanger. The invention improves efficiency of the natural gas liquefaction process and, as a result, minimizes specific compressor power required for LNG production.

A natural-gas purification apparatus includes: a compressor; a cooling unit that liquefies and separates a part of natural-gas liquid; a heating unit; first to third carbon-dioxide separation units that separate carbon dioxide through carbon-dioxide separation membranes; a detection carbon-dioxide separation unit that further separates carbon dioxide through a carbon-dioxide separation membrane; a carbon-dioxide-flow-rate sensor that detects the amount of carbon dioxide separated by the detection carbon-dioxide separation unit; an arithmetic control device that adjusts and controls at least one of the pressure to be applied by the compressor, the cooling temperature of the cooling unit, and the heating temperature of the heat unit based on information from the carbon-dioxide-flow-rate sensor such that the amount of carbon dioxide to be separated by the detection carbon-dioxide separation unit will be higher than or equal to a prescribed amount.

A natural-gas purification apparatus includes: a compressor; a cooling unit that liquefies and separates a part of natural-gas liquid; a heating unit; first to third carbon-dioxide separation units that separate carbon dioxide through carbon-dioxide separation membranes; a detection carbon-dioxide separation unit that further separates carbon dioxide through a carbon-dioxide separation membrane; a carbon-dioxide-flow-rate sensor that detects the amount of carbon dioxide separated by the detection carbon-dioxide separation unit; an arithmetic control device that adjusts and controls at least one of the pressure to be applied by the compressor, the cooling temperature of the cooling unit, and the heating temperature of the heat unit based on information from the carbon-dioxide-flow-rate sensor such that the amount of carbon dioxide to be separated by the detection carbon-dioxide separation unit will be higher than or equal to a prescribed amount.

A method for production of at least two liquid oxygen product streams from an air separation unit, wherein, the oxygen streams are cooled by heat exchange from at least one gaseous stream comprising predominantly nitrogen from the distillation column, and wherein the product liquid oxygen streams are at different temperatures.

An air separation unit comprises a first rectification column, having a top condenser and a second rectification column placed side by side, a heat exchanger, a first pump and a second pump connected in parallel, the first pump being capable of producing liquid at a first liquid pressure and the second pump being capable of producing liquid at a second liquid pressure, higher than the first pressure, each pump having an inlet connected to the second column, a first outlet of the first pump being connected to a first outlet conduit, a second outlet of the second pump being connected to a second outlet conduit, the first and second outlet conduits being connected to the condenser section

A hydrocarbon vapor capture and processing system is disclosed to reduce both carbon emissions and conventional pollution, while producing financial returns by turning waste vapors into high quality NGLs. In one embodiment, the hydrocarbon vapor is sent to a compressor for compression. Compressed vapor is then cooled via an air cooler, before being condensed by a refrigerator to form a liquid. The resulting two-phase flow is then separated into a dry gas stream and a liquid stream using a cyclonic separator. The dry gas stream may be transmitted as a light gas to sales line. The resulting liquid stream is passed to a stripping column to produce NGLs. The system offers great benefits to the environment and public health, by providing a technology that drastically cuts carbon emissions and noxious pollution, while incentivizing drillers to implement such measures through its ability to produce revenue.

A method to perform operations of a natural gas liquid (NGL) plant equipment iws disclosed. The method includes obtaining real time process condition parameters of the NGL plant equipment, calculating, using an equation of state (EOS) and based on the real time process condition parameters, a compressibility factor of inlet and outlet streams of the NGL plant equipment, calculating, based on the calculated compressibility factor, a performance measure of the NGL plant equipment, and facilitating, based on the calculated performance measure, the operations of the NGL plant equipment.