The PLASMACAT Exhaust Air Decontamination Process

PLASMACAT is the registred trade name of a new and extremely efficient method of decontaminating the exhaust air containing small concentrations of noxious matter. It is intended for the most diverse applications. Apart from the very low operating costs the main advantage is the high level of purity which can be achieved.

 

Description of process

In an excitation device, which is of a very innovative design and uses special materials, the gases are exposed to electrical discharges. These discharges are of the silent, (dark) Townsend, corona or glow types. The gas molecules flowing through this electrical field are displaced by electron collisions into a state with amplified oscillations which produces a strongly increased readiness to react (cold plasma, nonthermal plasma).

In the electric alternating field the electrons accelerate according to the voltage. When they meet the gas molecules the electrons release their kinetic energy and thereby cause the molecules to oscillate in a similar way to what would happen if the temperature was raised by some thousands of degrees. This collision excitement process proceeds with no measurable loss and only causes a very slight heat build-up. An electron is split (ionization) if the energy supply is so great that it can no longer be stored in a stable excited state in the molecule. The energy transmitted is stored in the molecules until the excited particles are converted into other molecules or even ions. This can be initialised by collisions or take place spontaneously with the emission of light and heat. The heat thus created is lost as an energy source, however the light is reabsorbed by gas molecules and can then be used for photochemical reactions.

The products formed in the electrical field depend upon the composition of the entry gases, their concentration and the field strength. The separation, particularly in the case of larger molecules, is a chain reaction and is often induced by hydroxyl radicals and peroxide compounds. The life of the intermediate products is usually very short. Complete separation is achieved through the use of contact catalysts, which are effective at ambient temperature and have a very long service life.

Properties

• Universal: The applicational range includes organic and many inorganic, gaseous compounds.
• For any volumetric flow rates: Thanks to the simple modular design of the plant it can be used efficiently by small, medium and large companies.
• Reliability : The process is not sensitive to variations in concentration and changes in the composition of the exhaust air. The highest level of safety is provided due to the low-maintenance plant technology and simple operation. In addition remote control and remote monitoring can be provided.
• No disposal of unwanted by-products: The noxious matter in the exhaust air is converted into non-toxic, odourless substances, which can normally be released either directly into the atmosphere or the sewage system.
• Low maintenance and operating costs: The plants require only minimum expenditure on maintenance and energy consumption is very low.
• Tried and tested: There are several plants operating in various different branches of industry. They have proved the efficiency and the high commercial benefits of the process. Demonstrations can be arranged at any time to evaluate the treatment of different exhaust gases.

 

APPLICATIONS:

• Odour-elimination
• Elimination of solvents (low concentrations) in exhaust gases
• Elimination of halogenated solvents (low concentrations) in exhaust gases
• Detoxification of toxic substances
• Purification of feed air

 

EXAMPLE APPLICATIONS

• Odour-elimination in the food processing industry through the oxidation of amines, aldehydes, fatty acids and hydrogen sulphide.
• Elimination of odoursome materials from sewage treatment works (sludge treatment) as well as from composting plants. (Butyric acid, caproic acid, mercaptan, indole and skatole).
• Elimination of odours from the transport, storage and processing of meat, fish and carcasses.
• Oxidative separation of solvents into carbon dioxide and water, e.g. hydrocarbons, aldehydes, ketones, esters, ether etc. in the varnish, paint and printing industries.
• Treatment of exhaust airs from the processing of water-based paints and varnishes. (butyl-glycol, phenoxy-propanol, butanol, dimethyl-methanol-amine, propyl-glycol, propylene-glycol).
• Generation of pure air for measurement stations, buildings and special applications.
• Disinfection of air.

Call us if your own area of application is not listed here, we will be happy to test the applicability of the PLASMACAT process.

 

Advantages over competitive processes:

In many cases thermal or catalytic incineration is not economic because of the low calorific value of the exhaust air, particularly if the heat energy cannot be reused. Moreover in the case of incineration there is additional contamination of the atmosphere by the combustion gases from the fuel (plus large amounts of CO2 as well as CO and nitric oxide according to the process).

The use of activated carbon or other types of adsorbents brings with it the problem of removing the adsorbed materials or considerable costs for decontamination. In all adsorption processes there is also the difficult problem of monitoring the free capacity which is left.

Biofilters are not universally applicable. A relatively lengthy period of adaptation is necessary with a change in the composition and/or the concentration of the exhaust air. To ensure successful operation it is necessary to continuously feed the system, and toxic materials (biocides) must be totally excluded. Formaldehydes or small-molecular hydrocarbons (e.g. methane), amines and general solvents in higher concentrations are problematical. Apart from these disadvantages or limitations the biofilter also requires a large amount of space. Moreover the service life of the biomass is often only short and requires a large amount of work and gives disposal problems when it has to be changed.

Oxidants such as peroxide, permanganate, dichromate, chlorine or ozone are very expensive because large amounts are required. In addition certain oxidation products (e.g. manganese and chrome) have to be disposed of. Sometimes the oxidants can only be used in the liquid phase and/or require additional activation, e.g. UV or Ultrasonics.

Technical Data

Concentration range

Dependens on the type of noxious matter. Generally speaking suited for low and very low concentrations.

 

Operating requirements

3 x 400 Volt, 50 Hz supply for volumetric flows above 500 cu.m/h. 220 Volt, 50 Hz supply for lower volumetric flows.

 

Energy Consumption

For the excitation 0.5 to 2.5 Wh per cu.m gas is needed. Therefore a PLASMACAT system for 3000 cu.m/h does have a power consumption of 1.5 to 7.5 kWh.

 

Achievable purity

According to the type of noxious matter a purity level below the detection limit can be achieved.

 

Scope of Supply

• PLASMACAT waste air and odour treatment systems
• Catalytic incineration (oxidation) plants
• VOC concentrators
• Engineering, planning, construction and commissioning (also for other type of equipment)
• Consulting for any type of waste air problem
• Servicing and maintenance
• Site trials (several mobile test units are available)
• Analysis, laboratory trials and special developments

 

Information

You can obtain more information from:

Up-To-Date Environmental Engineering AG

Linthlistrasse 9

CH-8868 Oberurnen, Switzerland

Tel. +41 55 / 617 20 30  Fax. +41 55 / 617 20 39  

http://www.plasmacat.com   info@up-to-date.ch

 

Up-To-Date Umwelttechnik AG    Linthlistr. 9   CH-8868 Oberurnen
Tel +41 55 617 20 30    Fax +41 55 617 20 39
Email: info@up-to-date.ch     http://www.up-to-date.ch/umwelttechnik