Not All H2S Treating Solutions are Equal

A Potentially Lethal Hazard

Hydrogen sulfide (H₂S) is a poisonous contaminant found in some crude oil and natural gas that must be removed before the produced hydrocarbons reach the market.

Concentrations as low as 4 parts per million (ppm) classify the gas as “sour” and requiring treatment to remove the H₂S.

The permissible exposure limit at a work site is 10 ppm.  Concentrations above 100 ppm are considered immediately dangerous for life or health (IDLH).

H₂S Treatment Solutions

Most of the H₂S produced at a well site is found in the gas phase.

Treatment of the contaminated gas typically involves contact with either liquid triazine or a solid media scavenger.

An ideal H₂S removal system provides a rapid adsorptive reaction while making efficient use of the scavenging media.

Triazine treatment is widely used for higher concentrations and larger gas volumes since the scale of the treatment justifies the more complex process equipment that is required.

Solid scavenger, on the other hand, is effective and more economic when treating lower H₂S concentrations and smaller gas volumes, where infrequent media changes are needed.

Solid media systems have other inherent advantages over liquid treating, such as:

1. No downstream effects, such as scaling or fouling of piping and equipment that can occur when excessive liquid scavenger is introduced.
2. No need for additional equipment to collect and dispose of spent scavenger.
3. Simpler operation – no pumps, mixers, and related maintenance.
4. Reduced media consumption – media is only used when H₂S is present, avoiding the need to continuously treat for maximum expected contamination levels, which frequently leads to over-treating and the downstream issues described above.

An Opportunity to Improve

As a leader in vapor recovery and treatment, EcoVapor recognized an opportunity to design an innovative solid scavenger solution for the H₂S levels and flow rates our systems routinely handle.

From the outset, we wanted to deploy newly available improvements in solid media treating, as well as providing a turnkey solution that not only includes the vessel and media but also condition monitoring, routine servicing, media changeout, and spent media disposal.

New manufacturers of solid media have recently made important improvements to iron oxide-based adsorbents.

We identified a scavenger that is highly adsorptive, available in a variety of grades and shapes to optimize performance while minimizing pressure drop, is easily removed, and can be disposed of as non-hazardous waste once spent.

With that material in mind, we designed the equipment to work within both the desired range of site conditions and the capabilities of the media.

The vessel design ensures effective diffusion of the gas stream across the diameter of the solid media bed and optimal contact with the media by sizing for the appropriate gas velocity.

It also provides multiple sample ports for monitoring sulfur loading within the bed so that media usage can be maximized while ensuring media changeout is completed before sulfur break-through.

Please contact us at info@ecovaporrs.com or give us a call to discuss your application.