Loading Plan for MEA: ISO Tank, IBC and Drum Payload Math

Loading plan for monoethanolamine (MEA; CAS 141-43-5) is based on three load-bearing variables: the temperature-corrected fill degree, the marked capacity of the transport unit, and the density of MEA at the fill temperature. The product is transported as UN 2491, Class 8, Packing Group III, with the proper shipping name “Ethanolamine” or “Ethanolamine solution” depending on grade. A reference density of 1.017 kg/L at 20 °C and a volumetric thermal expansion coefficient of 0.00075 K⁻¹ are used for logistics calculations. Because the atmospheric boiling point is 171 °C at 101.3 kPa, the loading plan is dominated by liquid ullage rather than vapour pressure; the mass capacities of standard packages are normally not exhausted before the thermal-expansion limit is reached.

Thermal Expansion, Ullage and the Fill-Degree Expression

The temperature-corrected maximum filling degree for non-viscous liquid dangerous goods is expressed as DF = 100 / (1 + α(T_ref − T_fill)). For MEA with α = 0.00075 K⁻¹, T_fill = 15 °C, and T_ref = 50 °C, the calculation gives 97.44 %. Applying that to a 24,000 L containment volume reserves 614 L of headspace for thermal expansion between 15 °C and 50 °C. If the fill temperature is 25 °C, the fill degree becomes 98.16 %, because the expected temperature rise is only 25 K. The permitted volume increases, but the density at 25 °C falls to approximately 1.013 kg/L; the resulting net mass remains nearly constant. A load plan should therefore quote both fill temperature and net mass, not volume alone.

What Does the ISO Tank T11 Calculation Return at 15 °C and 25 °C?

For a 20 ft ISO tank container certified to T11 and a data-plate capacity of 24,000 L, common plate values are 36,000 kg maximum gross mass and 3,600 kg tare. At 15 °C, the allowable volume is 23,386 L. The density correction yields 1.021 kg/L, so the MEA net payload is 23,873 kg; gross mass is 27,473 kg. At 25 °C, the allowable volume is 23,558 L with a density of 1.013 kg/L, giving 23,869 kg net and 27,469 kg gross. The volume difference of 172 L is real, but the mass difference is only 4 kg because the density coefficient offsets the volume correction. The tank is volume-limited, not mass-limited; the gross mass remains 8,527 kg below the 36,000 kg limit at the 15 °C condition. Any residual heel must be subtracted from the data-plate capacity before applying the fill-degree multiplier; a heel of 50–300 L can otherwise consume part of the required ullage. Where a particular ISO tank has a water capacity of 21,000 L or 26,000 L, the same fill-degree multiplier is applied to the actual data-plate value before multiplying by the fill-temperature density.

IBC loading applies the same thermal-ullage logic to a 1,000 L composite unit. A UN 31HA1/Y1.5/1000 IBC has a rated density of 1.5, which is substantially above the MEA specific gravity of 1.021 at 15 °C. At 15 °C, the 97.44 % fill degree permits 974 L, and the net mass is 995 kg. With an IBC tare of 65 kg, the gross unit mass is 1,060 kg, below the typical 1,800 kg maximum gross mass for that IBC class. At 25 °C, the permitted volume rises to 982 L but the density falls to 1.013 kg/L, so the net mass remains 995 kg. In a 20-IBC truckload, the net payload is approximately 19,900 kg and the gross package mass is approximately 21,200 kg, excluding the vehicle and any palletised ancillary equipment. The IBC filling head should stop the transfer at the temperature-corrected mass setpoint, not at a fixed volume. The filling nozzle should terminate below the liquid surface to reduce hygroscopic uptake and static charge; although MEA is not a flammable liquid under transport classification, its flash point of 93 °C by ASTM D93 makes bonding of conductive IBC cages and transfer lines a standard operating requirement.

If Drum Supply Replaces ISO Tank Deliveries

A standard 55 US gal closed-head steel drum has a brimful capacity of 208.2 L. The common fill target for MEA is 200 L, which is 96.0 % of brimful and provides an 8.2 L headspace. At 15 °C and a density of 1.021 kg/L, the net mass per drum is 204.2 kg. A steel drum tare of 24 kg places the gross at 228.2 kg. If the drum were filled strictly to the temperature-corrected 97.44 % of brimful, the fill would be 202.9 L and the net 207.2 kg; the difference is 3.0 kg per drum. The conservative 200 L fill is maintained because it simplifies drum closures and reduces liquid hold-up in the neck. In a 20-ft general container with 80 drums on 20 pallets, the net MEA payload is 16,336 kg; gross drum mass is 18,256 kg before pallet and container tare. When lower drums are double-stacked, the pallet and lower drum must withstand the vertical load of the upper tier; the gross block mass for 4 drums is approximately 910 kg excluding the pallet.

Compliance Standards and Density Determination

The shipment documentation must align the fill-degree calculation with the applicable regulatory code. For IBCs and drums, the packaging fill requirement is checked against ADR 4.1.1.9; for tank containers, the tank fill degree is checked against ADR 4.2.1.9. The ISO tank container itself is certified under ISO 1496-3, while density for commercial payload reconciliation is commonly determined by ASTM D4052 or ISO 12185. The product is classed as UN 2491, Class 8, PG III. All entries on the dangerous goods note must match the package markings, and the declared net mass should be the temperature-corrected mass derived from the loading measurement.

Mass-based measurement is preferred for final reconciliation. A Coriolis meter calibrated to ±0.1 % of rate yields an uncertainty of ±24 kg on a 23,873 kg ISO tank load. A volumetric meter with a separate density loop can introduce an additional combined uncertainty of ±0.5 %. For IBC top-fill skids, the stop-at-mass interlock must be recalculated from the batch tank temperature immediately before transfer; a fixed volume setpoint will over-deliver mass in winter and under-deliver in summer by the density error alone. Operational boundaries for MEA loading extend beyond payload arithmetic. The material is hygroscopic and absorbs carbon dioxide; prolonged exposure to ambient air can increase water content and form carbamate species. Loading hoses, gaskets, and seals should be selected from compatibility tables for alkanolamines, with PTFE or EPDM used as wetted seal materials for ambient transfer. Copper and aluminium alloys are not recommended for transfer lines. Final weighbridge reconciliation should verify the taré mass against the data plate before loading; the loaded ISO tank gross of 27,473 kg is well below the 36,000 kg maximum gross mass, but the same tolerance analysis should be applied to smaller IBC and drum batches to avoid overloaded pallet configurations.