Abstract: Disclosed is a system in which saturated mercury adsorbent in a gas mercury removal unit is dehydrated in a LNG, LPG or cryogenic gas plant using a regeneration gas stream. Spent regeneration gas stream is then condensed and the water is removed therefrom to form a renewed regeneration gas stream in a closed loop. The regeneration gas stream is compressed and recycled to a location in the plant upstream of an acid gas removal unit or upstream of a regeneration gas dehydration unit such that the regeneration gas stream is not sent to a flare. A dehydration unit having a pair of dehydration vessels, arranged in parallel, alternating between absorption and regeneration modes, receives gas from the compressor. Conventional plants can be retrofitted to achieve improved process efficiencies, cost savings and environmental benefits.

Abstract: Disclosed is a system in which saturated mercury adsorbent in a gas mercury removal unit is dehydrated in a LNG, LPG or cryogenic gas plant using a regeneration gas stream. Spent regeneration gas stream is then condensed and the water is removed therefrom to form a renewed regeneration gas stream in a closed loop. The regeneration gas stream is compressed and recycled to a location in the plant upstream of an acid gas removal unit or upstream of a regeneration gas dehydration unit such that the regeneration gas stream is not sent to a flare. A dehydration unit having a pair of dehydration vessels, arranged in parallel, alternating between absorption and regeneration modes, receives gas from the compressor. Conventional plants can be retrofitted to achieve improved process efficiencies, cost savings and environmental benefits.

Abstract: Saturated mercury adsorbent in a gas mercury removal unit is dehydrated in a LNG, LPG or cryogenic gas plant using a regeneration gas stream. Spent regeneration gas stream is then condensed and the water is removed therefrom to form a renewed regeneration gas stream in a closed loop. The regeneration gas stream is compressed and recycled to a location in the plant upstream of an acid gas removal unit or upstream of a regeneration gas dehydration unit such that the regeneration gas stream is not sent to a flare. Conventional plants can be retrofitted to achieve improved process efficiencies, cost savings and environmental benefits.

Abstract: Saturated mercury adsorbent in a gas mercury removal unit is dehydrated in a LNG, LPG or cryogenic gas plant using a regeneration gas stream. Spent regeneration gas stream is then condensed and the water is removed therefrom to form a renewed regeneration gas stream in a closed loop. The regeneration gas stream is compressed and recycled to a location in the plant upstream of an acid gas removal unit or upstream of a regeneration gas dehydration unit such that the regeneration gas stream is not sent to a flare. Conventional plants can be retrofitted to achieve improved process efficiencies, cost savings and environmental benefits.

Abstract: A system is disclosed in which water-saturated desiccant in a dehydration unit, having previously been used to dehydrate natural gas, is regenerated in a closed loop process using liquid petroleum gas (LPG). LPG is pumped from a storage tank, vaporized and superheated. The superheated LPG gas enters the dehydration unit such that the hot gas passes over the desiccant thereby regenerating the desiccant. An overhead stream from the dehydration unit passes to a condenser where the temperature of the hot gas from the dehydration unit is dropped to form a fluid stream containing LPG, water and non-condensable gases. The fluid stream passes to a three phase separator for separating the fluid stream into a gas stream, a water stream, and a liquid stream containing LPG which is then returned to the storage tank for reuse in the closed loop process.

Abstract: A system is disclosed in which water-saturated desiccant in a dehydration unit, having previously been used to dehydrate natural gas, is regenerated in a closed loop process using liquid petroleum gas (LPG). LPG is pumped from a storage tank, vaporized and superheated. The superheated LPG gas enters the dehydration unit such that the hot gas passes over the desiccant thereby regenerating the desiccant. An overhead stream from the dehydration unit passes to a condenser where the temperature of the hot gas from the dehydration unit is dropped to form a fluid stream containing LPG, water and non-condensable gases. The fluid stream passes to a three phase separator for separating the fluid stream into a gas stream, a water stream, and a liquid stream containing LPG which is then returned to the storage tank for reuse in the closed loop process.

Abstract: Water-saturated desiccant in a dehydration unit, having previously been used to dehydrate natural gas, is regenerated in a closed loop process using liquid petroleum gas (LPG). LPG is pumped from a storage tank, vaporized and superheated. The superheated LPG gas enters the dehydration unit such that the hot gas passes over the desiccant thereby regenerating the desiccant. An overhead stream from the dehydration unit passes to a condenser where the temperature of the hot gas from the dehydration unit is dropped to form a fluid stream containing LPG, water and non-condensable gases. The fluid stream passes to a three phase separator for separating the fluid stream into a gas stream, a water stream, and a liquid stream containing LPG which is then returned to the storage tank for reuse in the closed loop process.

Abstract: Water saturated molecular sieve in a gas dehydration unit is regenerated. A short loop is used in which regeneration gas is recycled to a heater upstream of a vessel in regeneration mode. The regeneration gas passes over the molecular sieve in the vessel to desorb water thereby regenerating the molecular sieve. The short loop also includes a condenser, a water separator and a compressor. The regeneration gas is not recycled to the AGRU at the front-end of the plant, thus the regeneration gas flow rate can be increased, as it is not limited by the front-end capacity of the plant. Moreover, the pressure of the system during regeneration can be reduced within the limits of system hydraulics. By using the short loop, the total time required for regeneration can also be reduced. The embodiments disclosed can de-bottleneck molecular sieve regeneration constraints in LNG, LPG or cryogenic gas plants.

Abstract: Water-saturated desiccant in a dehydration unit, having previously been used to dehydrate natural gas, is regenerated in a closed loop process using liquid petroleum gas (LPG). LPG is pumped from a storage tank, vaporized and superheated. The superheated LPG gas enters the dehydration unit such that the hot gas passes over the desiccant thereby regenerating the desiccant. An overhead stream from the dehydration unit passes to a condenser where the temperature of the hot gas from the dehydration unit is dropped to form a fluid stream containing LPG, water and non-condensable gases. The fluid stream passes to a three phase separator for separating the fluid stream into a gas stream, a water stream, and a liquid stream containing LPG which is then returned to the storage tank for reuse in the closed loop process.

Abstract: Water saturated molecular sieve in a gas dehydration unit is regenerated. A short loop is used in which regeneration gas is recycled to a heater upstream of a vessel in regeneration mode. The regeneration gas passes over the molecular sieve in the vessel to desorb water thereby regenerating the molecular sieve. The short loop also includes a condenser, a water separator and a compressor. The regeneration gas is not recycled to the AGRU at the front-end of the plant, thus the regeneration gas flow rate can be increased, as it is not limited by the front-end capacity of the plant. Moreover, the pressure of the system during regeneration can be reduced within the limits of system hydraulics. By using the short loop, the total time required for regeneration can also be reduced. The embodiments disclosed can de-bottleneck molecular sieve regeneration constraints in LNG, LPG or cryogenic gas plants.

Abstract: Disclosed are processes in which the pressure of a dense phase fluid stream containing hydrocarbons is reduced to produce a two-phase fluid stream, and energy is recovered. The process includes passing the dense phase fluid stream at a pressure greater than the cricondenbar pressure of the dense phase fluid stream through an expander where the dense phase fluid stream is expanded isentropically such that a two phase fluid stream having a pressure lower than the pressure of the dense phase fluid stream leaves the expander. The expander is coupled to a rotating mechanical power user, such that the expander drives the rotating mechanical power user. The process further includes passing the two phase fluid stream leaving the expander to a separator such that the two phase fluid stream is separated into a vapor phase stream and a liquid phase stream. The composition or quantity of liquid formed can be adjusted to control the dew point of the gas produced from the dense-phase fluid.