Chemistry Quiz: Fuel Analysis and Boiler Water

Total Acid Number (TAN)

• TAN of marine distillates and residual fuels is expressed in KOH, an alkaline or base
• It indicates the amount of base required to neutralize the acid present in the oil

Implications of Out-of-Limit Conditions

• If pH of boiler water is out-of-limit (low), it may lead to: • Scale formation • Corrosion and iron deposits • Reduced heat transfer
• If HFO viscosity is out-of-limit, the main implication is poor atomization, and the remedy is to increase fuel oil temperature
• If HFO flashpoint is out-of-limit, the main implication is safety concerns (fire and explosion), and the remedy is to use flashpoint-increasing additives or temperature control
• If HFO pour point is out-of-limit, the immediate implication is pumping issues, and the remedy is temperature control or blending with lower pour point fuels

Fuel Oil Service System

• The volume of fuel oil that flows through the flowmeter is the same volume that is not flowing through the pressure control valves
• When engine speed increases, the flow through the circulating pump reduces, but the flow through the supply pump increases

Fuel Oil Properties

• If CCAI of HFO is out-of-limit, the primary concern is ignition delay, and the remedy is to use ignition improver additives
• If ash is out-of-limit in HFO, the primary implication is equipment wear and maintenance, and the remedy is fuel filtration and treatment

Electrical Safety

• To confirm the absence of power supply after switching off the circuit breaker, use a voltmeter
• Current is the flow of electrons around a circuit
• Voltage is the pressure that pushes an electric current to conduct more power from an electric circuit