Arkansas Boiler Operator Practice Exam

Which of the following is one of the three most common fuels used in boilers?

1. Wood

2. Coal

3. Propane

4. Biodiesel

The correct answer is: Coal

One of the three most common fuels used in boilers is coal. This is primarily due to its historical abundance and high energy content, which provides effective combustion for generating steam and heat. Coal has been a traditional fuel source for power generation and process heat for many industrial applications. While other answers such as wood, propane, and biodiesel are also used in certain applications, coal maintains a prominent position due to its practicality and the efficiency with which it generates heat in large-scale boiler systems. Wood is typically used in lower-capacity or specialized systems, propane serves as more of a niche fuel in specific scenarios, and biodiesel is often associated with renewable energy applications which, while growing, do not match the widespread use of coal in traditional boiler operation.