Case Study: Odour Control for Creosote Wood Preservation
Byline: A major manufacturer of railway ties has odour issues solved by CharTech.
CharTech Solutions was retained by a company specializing in the manufacture of railway ties to solve an odour problem at one of its facilities in the United States.
The company, which manufactures railway ties, received numerous complaints from neighbours and a Notice to reduce odour emissions from environmental enforcement officers.
The source of the odour was from the creosote used as a preservative for the wood that comprised the railway ties. Creosote vapours are emitted within the plant when the access doors to the creosote-containing vessels are opened to either insert or extract the railway ties. The creosote vapour was vented to the atmosphere and its odour was picked up by the neighbours.
The company needed to control the odours emitted from the facility, or face environmental fines and possibly be forced to shut down.
Figure 1: Railway ties are coated with creosote to extend their use
The company retained CharTech Solutions to develop an odour control system to reduce the emission of creosote vapor and subsequent odour. The goal was to design an air treatment system that could efficiently treat creosote vapours.
A preliminary study conducted by CharTech found that the vapour treatment system would need to handle an air flow of 6,500 cubic feet per minute (CFM) when the access doors to the creosote-containing vessels were opened and 1,000 CFM when the access doors are closed.
CharTech Solutions engineered a solution that consisted of a patented REITHER® wet scrubber, instrument control system, two induction fans, VFD controls and an actuator. The system worked by drawing in the creosote vapour and destroying it in the REITHER® wet scrubber.
What is unique about the odour control system was that the REITHER® scrubber has adjustable throat to accommodate variable gas flows. Also, the utilization of two induction fans greatly reduces electricity costs at the facility. When the doors to the creosote vessels are closed, the lower power 1,000 CFM induction fan is in operation. When the doors to the vessels are open, the higher capacity fan automatically turns on to accommodate the higher odour air flows.
Figure 2: Schematic of Venturi Scrubber system to control creosote odours, including schematic of unique adjustable throat that allows for a wide range of gas flows
The odour control system is in full operation and preforming to design specifications. Since it was installed there have been no odour complaints and no issues with local environmental officers. The successful operation at the facility along with the dedicated field service support given by CharTech Solutions resulted in the client arranging for the installation of the same system at six more of its operations across the U.S.
Alex Keen, Founder, Altech Technology Systems (now CharTech Solutions Inc.)
For more information or advice, contact CharTech Solutions at 416.467.5555 or info@CharTechSolutions.com