Gulf Construction Online - Innovative systems help control pollution

Industrial Construction

Europe Environment’s gas and odour control systems ... cost-effective and high quality.

Innovative systems help control pollution

01 January 2009

EUROPE Environment, a leader in corrosive, toxic and odorous gas treatment market, is set to demonstrate innovative solutions at the Environment 2009 trade fair in Abu Dhabi, UAE, this month (January 19 to 21).

The French firm engineers a wide range of industrial air pollution control systems, from biological treatment to chemical scrubbing and carbon adsorption units, which ensure that gas emissions comply with current environment regulations.
“Drawing on a competitive R&D department and an advanced production facility, which uses the latest CAD/CAM technology, we retain control of all our facilities in-house, from initial design to manufacturing, testing, installation, commissioning and training,” says a company spokesman.
Specifically, Europe Environment’s services include the design of the fume capture and extraction system, chemical and mechanical engineering of the fume scrubbing unit and the installation and commissioning of the plant to an agreed discharge concentration. Its systems are applicable in a host of industrial sectors, including chemicals, metal surface plating, metal processing, sewage treatment works, as well as the aeronautical, micro-electronics, pharmaceutical, and food processing industries.
Describing the operating principle behind its gas scrubbers, which will be displayed during the exhibition, the spokesman says: “The principle applied in our fume scrubbing systems for odour and industrial acid gases, involves making the pollutants — be they acid, ammonia or sulphur dioxide, among others — soluble in a washing liquid (water or water with added reagents). A packing, generally made from polypropylene (PP), allows process optimisation. Once the pollutants have been made soluble, they are degraded and neutralised by reagents.”
Its gas scrubbing range comprises systems for wet chemical scrubbing, including packed towers, spraying gas scrubbers and venturi scrubbers, and covers a wide range of duties. The process can accommodate high airflows (up to 100,000 cu m per hour can be treated in a single unit), and both constant and intermittent contaminant loads. Applications range from surface treatment, odour treatment, wastewater treatment, to use in composting centres and chemical industries, among others.
The collection and processing of sewage and industrial waste water poses a poses a major challenge when it comes to treating unpleasant odours.
“Industrial waste water contains dissolved organic material and particles, nitrogenous compounds (including ammonia) and phosphorous whose purification by-products (sludge and grease) may directly or indirectly cause unpleasant odours due to the biological process of fermentation which occurs in oxygen-deprived media,” the spokesman points out. “These odours are very strong, but once air is extracted from the various critical points, scrubbing technology enables very effective deodorising.”
The different types of compounds are treated using separate packed towers or horizontal crossflow scrubbers. During the process, the first scrubbing tower removes ammonia and amines using sulphuric acid, while the second scrubbing tower removes hydrogen sulphide and mercaptans using sodium hypochlorite and caustic soda. The last scrubbing tower (optional) is a polishing tower to complete the removal of hydrogen sulphide and mercaptans using caustic soda only. A final polishing stage using activated carbon may be used.
For metal surface treatment, the company offers fume capture and extraction systems such as single-side lip extraction, two-side lip extraction, and push/pull extraction.
For the chemical industry, Europe Environment offers a complete range of thermoplastic fume scrubbing units, including packed columns, spray scrubbers venturi scrubbers, and horizontal cross flow scrubbers.
“Processes for the chemical industry involve the use of absorption towers with reactants such as sodium hydroxide, potassium, hydrogen peroxide or combined reactants such as caustic soda and bleach.”

Biofilters
The advantage of using the biofilter method for odour removal is that it completely degrades the pollutants without using any chemicals, says the company. Biofilters are particularly suited to odour removal in sewage treatment works where there are constant contaminant loads. They are also often used in many industries for VOC (volatile organic compounds) removal. Europe Environment uses an incompressible filter media with a low pressure drop, which allows it to design and fabricate tall filters with a reduced footprint area, according to the spokesman.

Active carbon tower
The active carbon tower is a technique that combines simplicity with effectiveness, achieving a flow rate of up to 6,000 cu m treated per hour. The air to be treated is blown into the bottom of a tower containing active carbon, and the pollutants are adsorbed to the porous carbon. This process is aimed at water treatment facilities, as well as chemical, petrochemical, food processing and pharmaceutical industries. The company offers two versions: The ‘outdoor unit’, which combines a loading door and a gas outlet, and an ‘indoor unit’, which has an outlet for transported gases to which discharge ducts can be connected.
Meanwhile, regenerative carbon filtration is used for larger quantities of pollutants. Two parallel towers are used in this system, wherein the air is blown into a tower of activated carbon while the other one is characterised by a regeneration process using steam. In this system, it is possible to recover the gas (solvent) in liquid form, and thus to re-use it after reconditioning.