One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.

A method to recover hydrocarbonfractions from refineries gas streams involves a pre-cooled heat refinery fuel gas stream mixed with a pre-cooled and expanded supply of natural gas stream in an inline mixer to condense and recover at least C.sub.3.sup.+ fractions upstream of a fractionator. The temperature of the gas stream entering the fractionator may be monitored downstream of the in-line mixer. The pre-cooled stream of high pressure natural gas is sufficiently cooled by flowing through a gas expander that, when mixed with the pre-cooled refinery fuel gas, the resulting temperature causes condensation of heavier hydrocarbon fractions before entering the fractionator. A further cooled, pressure expanded natural gas reflux stream is temperature controlled to maintain fractionator overhead temperature. The fractionator bottoms temperature may be controlled by a circulating reboiler stream.

A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.

A method of cooling a boil off gas stream (01) from a liquefied cargo having a boiling point of greater than −110° C. when measured at 1 atmosphere in a liquefied cargo tank (50) in a floating transportation vessel, said method comprising at least the steps of: compressing a boil off gas stream (01) from said liquefied cargo in two or more stages of compression comprising at least a first compression stage (65) and a final compression stage (75) to provide a compressed BOG discharge stream (06), wherein said first compression stage (65) has a first stage suction pressure and said final compression stage (75) has a final stage suction pressure; cooling the compressed BOG discharge stream (06) against one or more first coolant streams (202, 302) to provide a first cooled compressed BOG stream (08); providing a gaseous vent stream (51) from the first cooled compressed BOG stream (08); cooling the first cooled compressed BOG stream (08) against a second coolant stream (33) to provide a second cooled compressed BOG stream (35); expanding a portion of the second cooled compressed BOG stream (35) to the first stage suction pressure or below to provide a first expanded cooled BOG stream (33); using the first expanded cooled BOG stream (33) as the second coolant stream to provide a first expanded heated BOG stream (38); and cooling the gaseous vent stream (51) against the second coolant stream (33) to provide a cooled vent stream (53), wherein cooling of the first cooled compressed BOG stream (08) and cooling of the gaseous vent stream (51) occurs in a heat exchanger located adjacent to the liquefied cargo tank (50).

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.

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 process and apparatus reboil a propylene splitter bottoms by heat exchange and/or a deethanizer bottoms stream with a compressed propylene splitter overhead stream. Use of single splitter compressor and operation of the propane-propylene splitter column at lower pressure are enabled, whereas conventionally two splitter compressors and higher splitter pressure were necessary to provide a propylene product stream and a propane recycle stream of equivalent quality.

The invention essentially concerns a method for storing a biogas in a tank, said method comprising the following steps:

direct contacting of the biogas with a hydrocarbon of the C.sub.3 to C.sub.7 family under conditions allowing at least partial liquefaction of the biogas to obtain a biogas-hydrocarbon mixture that is at least partly liquid, and

storing (S260) the biogas-hydrocarbon mixture in the tank.

Systems and processes for detecting leaks into a refrigeration system having a heat exchanger where the process side is configured to operate at a higher pressure than the refrigerant side. The system includes a refrigerant circulation system including a refrigerant feed pipe fluidly connected to and configured to provide a refrigerant to an inlet of the refrigerant side of the heat exchanger, as well as a refrigerant effluent pipe fluidly connected to and configured to receive a refrigerant from an outlet of the refrigerant side of the heat exchanger. One or more sensors are provided, the sensors being configured to measure a property of the refrigerant, such as temperature, pressure, or flow rate, for example. Additionally, the system for detecting leaks includes a digital control system configured to provide an alert when a signal from at least one of the one or more sensors is indicative of a leak from the process side of the heat exchanger to the refrigerant side of the heat exchanger.