Factors to be considered in assessing overall lifetime cost include initial installed capital cost, ongoing operating cost, maintenance, and reliability.
The initial capital cost for the equipment is generally similar and is dependent on the flow of the exhaust to be treated. Installation cost for electric catalytic oxidizers is typically lower than RTOs as RTOs tend to be much larger and heavier than similarly sized catalytic oxidizers. This potentially limits where the RTO may be placed and require additional foundation support. However, very large electric catalytic oxidizers require access to high electric loads at the site.
Ongoing operating cost depends on several factors including the pollutant to be treated, the required destruction efficiency, the amount of potential energy in the stream, and the cost of electricity compared to gas at the site. Each application should be evaluated to understand the estimated operating cost.
Maintenance and reliability are difficult to predict but very important considerations. When properly designed for industrial use, both types of oxidizers have good on-stream time and are capable of operating 24/7 for long periods of time. Electric catalytic oxidizers have much fewer moving parts compared to an RTO. Both systems have fans that operate continuously. However, an RTO has diverter valves, which shift frequently to alter the direction of flow through the system. These valves and drives create continuous pressure and temperature fluctuation and are subject to significant wear and tear. Additionally, RTOs operate at much higher temperatures which stresses the materials of construction and may lead to hot spots. Both systems are subject to fouling or plugging if placed in the wrong application.