How to Size an H2S Scrubber for Your Battery Site

One of the most common questions Rheton receives from operators is some version of: "How big a scrubber do I need?" It is a reasonable question, and the answer depends on a handful of site-specific variables. Getting the sizing right matters — an undersized unit will be overwhelmed during peak production, and an oversized unit wastes capital and scavenger fluid.

This post walks through the key factors in the sizing process for a typical battery site application.

Start With Your H₂S Concentration

The first variable is the H₂S concentration in the gas stream you are treating. This is typically expressed in parts per million (ppm) or as a percentage by volume.

At most battery sites, H₂S concentrations in the tank vapour space range from a few hundred ppm to several thousand ppm, depending on the formation and production stage. If you have recent well test data or gas analysis results, those numbers are your starting point. If you do not, a conservative estimate based on your formation's known H₂S profile is a reasonable approach while you gather better data.

Higher H₂S concentrations mean the scavenger fluid saturates faster, which affects both the required vessel capacity and your fluid change interval.

Estimate Your Gas Flow Rate

The second variable is how much gas the scrubber needs to handle. At a battery site, this is primarily the vapour displaced from the tanks during filling operations, plus any continuous venting from the vapour space.

A rough estimate can be derived from your daily fluid production volumes and your tank geometry. For a more precise number, a flow meter on the tank vent line will give you actual data. If you are in the planning stage and do not yet have production data, your drilling and completions team should be able to provide estimated production rates.

Gas flow rate, combined with H₂S concentration, determines the H₂S load your scrubber needs to handle — typically expressed in grams per hour or kilograms per day.

Match the Load to a Vessel Size

Rheton's onsite mini scrubbers are available from 200 to 1,000 litres. As a general guide:

• 200–300 litres — suitable for single-tank installations with moderate H₂S concentrations and lower gas flow rates. Common on smaller battery sites or during early production phases.
• 400–600 litres — the most common range for mid-sized battery sites with multiple tanks or elevated H₂S concentrations.
• 700–1,000 litres — appropriate for larger battery sites, high-production wells, or applications where H₂S concentrations are consistently high.

These are starting points, not hard rules. The right size for your site depends on the specific combination of flow rate and H₂S concentration. Rheton works through this calculation with operators directly — bring your production data and we can recommend the right unit.

Account for Peak Conditions

Sizing for average conditions is not enough. Your scrubber needs to handle peak gas flow rates, which typically occur during rapid tank filling or during temperature swings that drive increased vapour generation.

A unit that is correctly sized for average conditions but undersized for peak conditions will allow H₂S to pass through untreated during exactly the periods when your site is most active. Build in a reasonable margin — typically 20 to 30 percent above your estimated peak load.

Consider Whether You Need Trailer-Mounted Flexibility

For operators managing multiple sites, or for sites where production volumes are expected to change significantly over time, a trailer-mounted scrubber offers flexibility that a fixed installation does not. The unit can be relocated as production profiles evolve, or moved to a higher-priority site during peak periods.

Trailer-mounted units are available across Rheton's full capacity range. If relocation flexibility is a priority, mention it early in the sizing conversation — it affects the mounting and connection design.

When Your Site Outgrows a Single Unit

Some battery sites — particularly those with multiple high-production wells or very high H₂S concentrations — exceed what a single onsite mini scrubber can handle. In those cases, Rheton's mobile tri-axle system is worth considering. It provides significantly higher treatment capacity and is designed for sites where the H₂S load is too large for a standard vessel-based scrubber.

The tri-axle system uses a four-stage treatment process and is trailer-mounted for site-to-site flexibility. It is a different class of equipment than the onsite mini scrubbers, and the sizing conversation is correspondingly more involved — but the starting point is the same: H₂S concentration, gas flow rate, and peak load.

Getting a Quote

The sizing process does not need to be complicated. If you can provide your estimated H₂S concentration, your approximate gas flow rate, and the number of tanks you are treating, Rheton can recommend the right unit and provide a quote.

Contact us to start the conversation. We manufacture in Western Canada and work directly with operators — no distributor markup, no guesswork.