BT-627 Oxidation Inhibitor Treatment For International Coal Shipment

Situation

A coal-fired utility in the UK is importing coal from the western United States for a test burn.  Benetech is treating a shipment of 75,000 tons of PRB Low CV Coal with an oxidation inhibitor. So, to make sure the coal arrived safely and was easy to handle upon delivery. The shipments are treated and loaded to river barges in St. Louis (USA) and shipped via the Mississippi River to offshore barge/ocean vessels outside New Orleans (USA). During travel, the shipments experienced a great deal of rain and humidity. Hot spots and the threat of spontaneous combustion were a genuine concern, as was the expectation of handling wet, sticky coal.

Benetech Solution

Benetech treated the PRB Coal with BT-627 Oxidation Inhibitor, which coats the surface of the coal, inhibiting moisture absorption from rain and humidity. During the shipment, the material was subject to a great deal of humidity and rain, including:

  •  St. Louis to Mississippi open barges-12”-25” Rain
  •  Lower Mississippi to New Orleans-open barges- 5”-13” Rain
  •  New Orleans transfer from open barges to closed holds in MV Topaz freighter – Hot, Humid, 0.6” rain

Moisture Levels
Approximately 700 tons of water were pumped off from the holds indicating that the coal shed excess water during travel. During the unloading process, coal moisture equaled “as mined” levels.

Temperature (5 Days after arrival)
Average: 87°F (31°C) – Minimum: 64°F (18°C) The maximum temperatures measured for the coal remained constant. The minimum temperatures decreased over time, and the average temperature approached the average air temperature with no evidence of spontaneous combustion.

Conclusion
The BT-627 treated coal did not experience spontaneous combustion during travel from the United States to the United Kingdom. In stack out, the coal was dry and easy to handle. After stack out, the BT-627 showed a positive self–heating profile to reduce the oxidation/spontaneous combustion process. In addition, BT-627 was also highly effective as a dust suppressant.