Gas Dehydration & Purification

Drizo®

As the exclusive licensor of the Drizo® technology, Axens Solutions provides operators with the most efficient and environment-friendly dehydration solution.

Thanks to its specific Drizo® loop for optimum TEG stripping, Drizo® enables higher dehydration efficiency while minimizing BTEX/CO₂ emissions, making it the best available glycol-based dehydration process. Glycol dehydration performances rely on final glycol purity achieved by glycol regeneration. With Drizo®, up to 99.995 wt% of glycol purity is achieved instead of the typical 99.95 wt% of conventional glycol units, enabling down to 1 ppm vol. residual water in treated gas. With minimum additional equipment compared to conventional glycol units, Drizo® features higher dehydration performances for a marginal increase in investment cost. The simplicity of the Drizo® loop implementation makes it a perfect candidate to easily upgrade the performances and the environmental footprint of existing TEG units.

TriEthylene Glycol (TEG)

Water absorption with TriEthylene Glycol (TEG) is a very well known and proven technology. It is the most common process used for gas dehydration.

Lean TEG in a gas/glycol contactor absorbs the water contained in the gas to be treated counter-currently. At the bottom of the contactor, the rich TEG (containing the absorbed water) is sent to the regeneration section where water is vaporized in a Reboiler at low pressure (close to atmospheric pressure).

Depending on the requested lean TEG purity, the lean TEG produced in the reboiler can be either:

• Pumped directly to the gas/glycol contactor (low TEG purity required)
• Stripped with stripping gas before being pumped to the gas/glycol contactor (high TEG purity required)

IFPEXOL™

IFPEXOL™ is a simple, highly flexible and environmentally friendly process that uses recoverable methanol to allow water and HC dewpointing in a single cooling step. This technology virtually removes the complete dehydration unit from the processing plant. It provides CAPEX and OPEX savings while eliminating the on-site atmospheric emissions (CO₂, BTEX) associated with TEG Unit off-gas disposal.

IFPEXOL™ consists in using a portion of the water-saturated feed gas to recover the methanol contained in the methanol-water aqueous mixture collected in the cold process.

The methanol is stripped off and recovered as vapor in the overhead gas stream leaving the stripper, while nearly pure liquid water is drawn off from this column. The wet feed gas, containing the recovered methanol, is chilled to the required dewpoint temperature by any appropriate means (JT expansion, turbo-expander or external refrigeration).

A dry and HC-dewpointed sales gas and a HC liquid stream (NGL) are produced while the methanol-water mixture is collected separately and recycled to the IFPEXOL™ stripper.

No flash gas or low pressure off-gases are generated. Any freezing issues are avoided in the cold process thanks to the presence of the methanol that is recirculated into the cold process to inhibit the formation of hydrates or ice. A small amount of pure methanol is injected under automatic control to maintain the correct methanol concentration in the process.