Blend Compatibility (SPOT / CCAI)

Predict compatibility of two marine residual fuels before co-mingling. Uses the Spot test index and CCAI to flag asphaltene incompatibility risk and combustion-ignition mismatch.

VoyageBunkersBlend

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\text{CCAI} = \rho_{15} - 81 - 141 \log_{10}(\log_{10}(\nu_{50} + 0.85))

Symbol	Meaning	Unit
$\rho_{15}$	Density at 15 °C	kg / m³
$\nu_{50}$	Kinematic viscosity at 50 °C	cSt
$\text{CCAI}$	Calculated Carbon Aromaticity Index
$m_A, m_B$	Mass of fuels A and B to blend	t
$\text{CCAI}_\text{mix}$	Mass-weighted blend CCAI

Source: ASTM D4740 - standard test for compatibility of residual fuels; ISO 8217 Annex F - stability & compatibility guidance

In short

Predict compatibility of two marine residual fuels using density, viscosity, CCAI and a Spot-test proxy before co-mingling on board.

Learn the theory Bunker Quality and ISO 8217 Marine Fuel Standards