Tank Cleaning – High Wax Content Sludge

Project Overview

 Tank Size  200 ft. (60 m) diameter
Tank Design External roof
Service Heavy crude
Sludge Volume 18,500 barrels (2,941 m3)
 % Oil Removed >98%
Time Required 6 weeks

Results Achieved

98% of the sludge volume was salvaged as recoverable hydrocarbon

Recovered oil value was over $400,000 resulting in a net profit to the refinery over the cost of the job

Chemical profiles


Created for the dissolution and recovery of asphaltenes in process equipment, pipelines and storage tanks.

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A large refinery in the United States had a large, floating roof tank that required cleaning of high wax content sludge.


The sludge was solid at ambient temperatures, and the company had routinely cleaned these types of vessels by mechanical means. The removed sludge is typically centrifuged with over 50% of the volume being disposed as a hazardous material. The client was interested in recovering more oil and limiting their disposal volume to control the disposal expense.


Sludge removal was done by using manway-mounted cannons and a proprietary chemical product FQE™ Solvent-H and cutter stock to facilitate the dissolution of the recoverable solids and oil. As the sludge volume was above the manway covers, the chemical solution was circulated through the side entry port to the water intake and pumped overhead to a roof access. Over 98% of the sludge volume, approximately 18,000 bbl (2,861 m3)) was salvaged as recoverable hydrocarbon and reprocessed through the crude distillation unit.


The recovered oils (including diluent stock) were quoted as having a value to the refinery of over $400,000 and resulted in profit to the refinery over the cost of the job.

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