The Truth About Electric RTOs

‍Why an “all-electric” RTO isn’t always the simpler, more cost-effective option

Electric regenerative thermal oxidizers (RTOs) are often positioned as the next step in sustainable air pollution control. With no direct natural gas combustion and point source greenhouse gas reduction, they can appear to be a cleaner, easier alternative.

But the full picture is more complex.

Utility costs still drive operating expense

Electric RTOs eliminate natural gas burners, but they do not eliminate energy consumption. Instead, they shift the energy demand entirely to electricity.

In many regions, industrial electricity rates are significantly higher than natural gas on a BTU-equivalent basis. That difference can dramatically impact long-term operating costs—especially for facilities running continuous or high-volume processes. However, if VOC levels are high enough to offset the need for added fuel, both gas and electric systems effectively stop generating heat and operate the same way, using energy only for fans.  

Additionally, peak demand charges can add substantial cost if the system requires high electrical loads during startup or process fluctuations.

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Infrastructure requirements can be significant

Converting to an electric RTO may require:

• Upgraded transformer
• Increased service capacity
• New switchgear
• Utility coordination & permitting
• Dramatically larger wire sizes, even for small RTOs

These upgrades can add unexpected capital costs and extend project timelines. In some cases, facilities must wait months for utility infrastructure improvements before installation can proceed.

Future process changes can also affect an existing control device. To upgrade or change the electric heat source is a significant cost and downtime investment. If the heat source was not originally designed for the new process, adding extra power is way more complicated than re-tuning a burner for higher output.

In terms of capital cost, the equipment to replace a burner with an equivalent electric source is easily 3-4 times more. The combustion chamber gets significantly larger as well, adding to fabrication, installation, and shipping costs.

Heat recovery still matters

Regardless of fuel source, RTO efficiency depends on effective heat recovery. Ceramic media performance, airflow balance, and system design remain critical.

An electric heat source does not automatically improve thermal efficiency. Poorly designed or undersized systems will still struggle with performance and operating costs—just with electricity instead of gas.

Maintenance is different, not eliminated

Electric heating elements introduce their own service considerations. Some electric heaters are not meant to withstand being in the environment they produce. Being constantly subjected to combustion chamber temperatures means they need to be replaced more often than gas burners.

Electric RTO maintenance considerations may include:

• Element degradation and replacement
• Electrical component stress
• Control system complexity
• High-amperage safety requirements

Electric does not mean maintenance-free. It simply changes the type of maintenance required and the required skills of the maintenance personnel.

Sustainability depends on the power grid

Electric RTOs are often marketed as a carbon-reduction solution. However, the actual environmental impact depends heavily on the source of the electricity. In regions where power generation relies on fossil fuels, emissions may simply shift upstream rather than disappear.

NOx considerations

Electric or flameless combustion significantly reduces NOx output (nitrogen oxidizes, harmful air pollutants), which can be a big advantage in some locations with stricter emissions guidelines.

However, you don’t necessarily have to go fully electric to get low NOx. Some traditional gas-fired RTO systems use natural gas injection (NGI). With NGI, the CO2 generation component of natural gas combustion will still be present, but NOx generation is virtually eliminated while still using a traditional gas system. If NOx is a major consideration in choosing an electric or flameless RTO, a regular RTO with NGI can also be an option.

• Electric RTO systems: Very low NOx, little to no combustion emissions
• NGI gas RTO systems: Very low NOx, but still produce CO2

Electric RTO systems: the bottom line

Electric RTOs can be the right solution in specific applications—particularly where natural gas access is limited or electrification incentives are strong. Industries where they tend to make the most sense include pharmaceutical manufacturing, chemical processing, petrochemical facilities, tank terminals, and oil & gas plants. This is especially true when open flames present safety concerns in classified locations.

But electric RTO systems are not automatically more cost-effective, simpler to manage, or universally “greener.”

The right oxidizer solution depends on process conditions, utility costs, facility infrastructure, and long-term operating goals. Not sure which configuration fits your application? Explore the main RTO types to compare your options, or learn how to purchase an RTO and what to evaluate before you buy.

Careful evaluation—not marketing headlines—should drive your decision.

Ready to evaluate your options?

KKI's team has decades of experience helping facilities in practically every industry around the world select the right oxidizer for their process while avoiding costly mismatches between system type and site conditions. Contact us for expert guidance.