The invention relates to a process for separating a component mixture (K) comprising hydrogen, methane, hydrocarbons having two carbon atoms and hydrocarbons having three or more carbon atoms, wherein in a deethanization at least a portion of the component mixture (K) is subjected to a first partial condensation by cooling from a first temperature level to a second temperature level at a first pressure level to obtain a first gas fraction (G1) and a first liquid fraction (C1), at least a portion of the first gas fraction (G1) is subjected to a second partial condensation by cooling from the second temperature level to a third temperature level at the first pressure level to obtain a second gas fraction (G4) and a second liquid fraction (C2), and at least a portion of the first liquid fraction (C1) and at least a portion of the second liquid fraction (C2) are subjected to a rectification to obtain a third gas fraction (G3) and a third liquid fraction (C3+). The first liquid fraction (C1) or its part subjected to the rectification and the second liquid fraction (C2) or its part subjected to the rectification are expanded to a second pressure level and the rectification is carried out at the second pressure level, the first pressure level being 25 to 35 bar and the second pressure level being 14 to 17 bar. An overhead gas formed during the rectification is cooled to −25 to −35° C. and partially condensed, wherein a condensed portion of the overhead gas is used partially or completely as a reflux in the rectification and an uncondensed portion of the overhead gas is provided partially or completely as the third gas fraction (G3). The present invention likewise provides a corresponding plant (100, 200).

The invention relates to a method (100, 200) of obtaining one or more olefins, in which, using an oxidative coupling of methane (10), a gas mixture comprising hydrogen, methane, carbon monoxide and higher-boiling hydrocarbons than methane is formed and is subjected to a low-temperature separation (1-5), characterized in that the low-temperature separation (1-5) is conducted using a rectification column (2) having a first separation region (21), a second separation region (22) arranged above the first separation region (21), and a condenser-evaporator (23), wherein the gas mixture is cooled, fed at least partly as first separation feed into the first separation region (21) and subjected to a first rectification in the first separation region (21) to form a first tops gas and a first bottoms liquid, wherein, using a first proportion of the first tops gas in the condenser-evaporator (23), a condensate which is recycled to the first separation region and, using a second proportion of the tops gas, a second separation feed which is fed into the second separation region (22) are formed, and wherein the second separation feed is subjected to a second rectification in the second separation region to form a second tops gas and a second bottoms liquid.

A process for separating a component mixture comprising essentially hydrocarbons having two or two or more carbon atoms, methane and hydrogen using a distillation apparatus (10) is proposed. Fluid (a, c, e, g, i) from the component mixture is cooled stepwise to a first pressure level, with separation of first condensates (b, d, f, h, j) out of the fluid (a, c, e, g, i) in each case. Fluid (k) from the component mixture that remains in gaseous form thereafter is expanded to a second pressure level in an expander, giving a second condensate (I). Fluid from the first condensates (b, d, f, h, j) is expanded from the first pressure level to the second pressure level and fed together with the fluid from the second condensates into the distillation apparatus (10) which is being operated at the second pressure level. The present invention likewise provides a corresponding separation apparatus.

A system used to recycle exhaust gas during olefin polymer production, comprising: a compression cooling mechanism (101); a hydrocarbon membrane separation mechanism (102) and a hydrogen membrane separation mechanism (103), both connected to a first outlet (202) of the compression cooling mechanism; and a deep cooling mechanism (104) connected to a first outlet (208) of the hydrogen membrane separation mechanism. A method used to recycle exhaust gas during olefin polymer production, comprising a compression cooling step, a hydrocarbon membrane separation step, a hydrogen membrane separation step and a deep cooling step.

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 for vaporizing liquid propane to be supplied as a raw material to a naphtha cracking ractor. The method comprises: decompressing liquid propane to lower a vaporization point and vaporize at least a portion of the liquid propane; utilizing vaporization heat, generated during vaporization of the portion of liquid propane, as a refrigerant; compressing the vaporized propane gas to increase pressure of the propane gas and produce compressed propane gas; and preheating the compressed propane gas. By using this method, it is possible to reduce pressure of liquid propane to a significantly lower pressure than the related art method so that all the vaporization latent heat or vaporization heat included in liquid propane may be utilized as a refrigerant, while also reducing heat energy consumed in a preheat process before it is supplied to the naphtha cracking reactor.

A natural gas liquids (NGL) plant, the NGL plant comprising an absorber configured to provide an absorber overhead and an absorber bottoms, a stripper configured to produce a stripper overhead and a stripper bottoms, wherein the stripper is positioned downstream from the absorber and fluidly connected therewith such that the absorber bottoms can be introduced into the stripper, and a multi-pass heat exchanger configured to provide at least one reflux stream to the absorber, wherein the absorber and stripper are configured, in an ethane rejection arrangement, to provide the stripper overhead to a top of the absorber, and wherein the absorber and stripper are configured, in an ethane recovery arrangement, to provide the stripper overhead to a bottom of the absorber.

In an aspect, the present disclosure provides a method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C.sub.2+ compounds). The method can include mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen and performing an oxidative coupling of methane (OCM) reaction using the third gas stream to produce a product stream comprising one or more C.sub.2+ compounds.

Methods and systems for operating and NGL recovery process are provided. In an exemplary method, an absorber column upstream of a fractionator column is operated at a higher pressure than a pressure in the fractionator column. An NGL (C.sub.3 plus) stream is taken from the bottom of a fractionator column and then ethylene/ethane stream is taken from the top of the fractionator column. A differential pressure between the absorber column and the fraction are column is controlled based, at least in part, on a flow rate of the fractionator feed stream from the absorber column to the fractionator column.

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.