Fluor’s Cryo-Gas Process portfolio of patented propane and ethane recovery technologies is applicable to both conventional and unconventional natural gas sources. For leaner conventional gas, the process configurations utilize turboexpanders to efficiently recover propane and ethane from a variety of feed gas compositions and inlet pressures. For richer unconventional gases, the process can be configured without a turboexpander, recovering 99% of the propane while rejecting ethane to the residue gas. The processes can also be configured to be flexible and allow for adjusting from ethane rejection to moderate levels of ethane recovery (40-70%) without a turboexpander and up to 95% with a turboexpander.

The natural gas liquids (NGL) recovery units can be designed as modular units for expedient deployment to the site at small to moderate scales, depending on the logistics constraints of the specific site. Small modular plants have been executed with capacities down to 60 million standard cubic feet per day (mmscfd). Single train capacities up to 1,500 mmscfd are possible.

Deep Dewpointing Process (DDP):
DDP is a standard module designed for shale gas applications, with ethane liquid contents of 6 to 12 gallons per mmscf (GPM), and a feed pressure ranging from 500 psig to 900 psig. The process can achieve 95% propane recovery in full ethane rejection mode and can recover 60% ethane in ethane recovery mode. The process has a high turndown capability, similar to conventional mechanical refrigeration unit plants, and does not require the use of a turboexpander.

In 2019, Fluor's DDP technology won Best Gas Processing/LNG Technology at the Hydrocarbon Processing 2019 Awards gala event.

Twin-Reflux Absorption Process (TRAP):
TRAP is an integrated ethane and propane recovery design utilizing deethanizer overhead for refluxing during propane recovery and ethane reabsorption during ethane recovery. When used in retrofitting for ethane recovery, only piping modification is required without the need for re-wheeling of the turboexpander. TRAP can achieve over 90% ethane recovery with 99% propane recovery and is ideal for revamping existing NGL plants for ethane recovery.

Enhanced Residue Gas Recycle (ERGR):
This process is designed to recover 99% propane during propane recovery and 95% ethane during ethane recovery using equipment of the propane recovery process. The design is switchable from propane recovery to ethane recovery by an enhanced by residue gas recycle configuration, which has been demonstrated suitable for variable nitrogen content feed gases.

Fluor offers a flexible recovery configuration that incorporates either two or three of the prior technologies into a single facility, where ethane recovery can be adjusted based on market-based price signals and switching between DDP and TRAP operation can happen in a single shift.

Vapor Reflux Absorption Process (VRAP):
VRAP has a low capital cost, weight and footprint. It is ideal for offshore applications with relatively lean gas available at high inlet pressures requiring propane recovery of over 99% without external refrigeration.

Two-Column, High-Pressure Absorber Process (TCHAP):
TCHAP is a high-pressure absorber operation that avoids CO₂ freezing issues and can produce high pressure residue gas suitable for pipeline operation and feed gas to LNG liquefaction plants. It can be designed to fully reject ethane without loss in propane recovery and can achieve less than 500 ppmv CO₂ in the ethane product. TCHAP is suitable for high­ pressure feed gas over 1,000 psig and ethane recovery of more than 80% with propane recovery of 99%.

Sub-cooled Absorption Reflux Process (SARP):
SARP is a sub-cooled lean absorption configuration that can avoid CO₂ freezing during high ethane recovery. It is designed for feed gases with a high CO₂ content and is capable of achieving ethane recovery in excess of 90% with propane recovery of more than 99%.