Tank Cleaning Odor and Waste Water Abatement

Project No 103

The Challenge

A small tank cleaning facility needed to control odorous emissions from its cleaning operation. Additionally, The facility was spending as much as 13.5¢/gallon for wastewater disposal and $4.25/1000ft3 of operating natural gas, they also wanted to find a more economical and efficient solution. Steam used for cleaning the interior of these tanks would push the aromatic compounds (Benzene, Toluene, Ethylene etc.) into the atmosphere resulting in an odorous nuisance to the neighbouring community.

The Solution

An engineering team was formed to complete analysis of the existing process and hazzardous compounds and re-designed a complete economical, safe and reliable system. The tank cleaning process was modelled as a batch process for wastewater and a dynamic process for the VOC concentration in the gas phase. The greatest challenge was to design a system that can handle the changes in concentration and assure safe operation even at 1407% of the LEL.The final system consists of a duct network that feeds diluted process gases into the thermal oxidizer, pipe networks that feeds wastewater and sludge into the thermal oxidizer, and a waste heat boiler.

The Results

The facility went from spending 13.5¢/gallon of wastewater, only producing 2,800 lb steam/hr, and an odor problem,  to having a complete system that produced more steam/hr, eliminated their odor problem, reduced wastewater disposal by 6¢/gallon, while also meeting the most stringent EPA regulations.

EPCON’s system safely dilutes the VOCs to 50% of LEL, destroying 99.9% of VOC and as much as 5000 gallons/day saving an estimated $81,000 per year in wastewater treatment alone.