voc scrubber

Hybrid scrubber reduces SOx emissions to meet the environmental regulations at coastal region. The main source of SOx emissions is burning of fossil fuel which contains high sulphur component in diesel engine. The high sulphur content fuel is used for marine applications because of its less Hybrid expensive. Switching to low price fuel to high price fuel causes burden to ship owners. This causes the SOx emissions in marine environment, thus disturbs marine eco systems, harms human health and violate the regulations.  In order to control the SOx emissions from ship engines, Apzem designed and developed a hybrid wet scrubber.

Working Principle of Wet Scrubber

It works based on the absorption with chemical reaction, involved to remove pollutants from exhaust gas by dissolving into the liquid. A central piece of equipment, called packed bed column, in which the polluted gas is fed from the bottom and pass upward through packing material. At the same time, solvent is sprayed from the top to wash the pollutants. The down come liquid is again recirculated back using pump. SOx scrubber includes packed bed column, scrubber tank, re-circulation pipe connected with solvent spray nozzle. Recirculation pump, Instrumentations, Suction blower and Control panel. All the parts involved in the scrubber unit is designed and selected based on the standard design criteria. Packed column helps to achieve heat transfer and mass transfer. The exhaust gas contains SOx mostly has high temperature than atm. The packed column is utilized in cooling of hot gases and dissolving acid gases into the solvent. Water will be used as solvent for the physical absorption. However, Alkali solution will be used for continuous effective scrubbing. Packing material with high surface area is used to increase intimate contact between gas and liquid.

Generally, there are 3 type of Scrubber for this applications.

• Open loop scrubber
• Closed loop scrubber
• Hybrid Scrubber

Open loop Scrubber

There is no re-circulation of used water. The water is used as single pass through the column. Once the water is passed through column by single pass, it is discharged directly into the sea. The seawater will be used as fresh liquid for each time to scrub the pollutants. This type of scrubber is mostly used currently.

Closed loop Scrubber

The scrubbing liquid (sea water) used in this process is re-circulated continuously until it reaches discharge point based on conductivity.

Hybrid Scrubber

The hybrid scrubber can be run in both open loop and closed loop mode. The scrubbing liquid can be directly discharged into the sea or recirculated back based on use. This scrubber can be installed on all vessels type, tanker, cruise ships, cargo carriers etc.  It is important to select the material of construction. The material used for fabricating scrubber will be exposed to sulphur from the exhaust gases and also seawater causes wet corrosion. These parameters will cause corrosion to the materials used for scrubber system. So, life span of the scrubber system depends on material used and its corrosion resistance.

catalytic scrubber

Catalytic scrubber is important to remove toxic gases and make the pollutants into simple non-hazardous components. Apzem developed a catalytic dry scrubber for this purpose. The catalytic scrubber works on principle of chemisorption process. Chemisorption is an adsorption process which involves chemical reaction between the toxic pollutants and chemical present on the surface of adsorbents. This type of scrubber consist of catalyst which adsorbs the gaseous pollutants and reacts with them to make into simple components. Unlike normal adsorption dry scrubber, the catalytic scrubber will not be affected by contact time and inlet pollutant concentration. When the catalyst is saturated with pollutants, this can be easily taken back and replace with new catalyst. This type of scrubber is suggested for exhaust with low concentration of toxic gases, because of life time of catalyst. It can also be used for exhaust with high concentration. However, the catalyst will be saturated within a short period of time. It can also be used for emergency applications, where there is higher pollutant contamination risk.

voc dry scrubber

Improving the process reliability is important for manufacturing large volume of goods. Industries have adopted various chemicals methods to ensure the process go smoothly. Dry gas scrubbing process remain important stage in ensuring the environmental regulations. Dry scrubbing of VOCs from exhaust gas is becoming a feasible alternative technology to the wet scrubbing process. Unlike wet scrubber, dry scrubber does not saturate with moisture. It is an important part of gas filtration and plays significant role in not only maintaining environmental standards but also in maintaining some processes. Various industries handle and use highly volatile solvents. The solvents are emitted as vapour form because of its volatile properties and affect the human health and environment. Apzem developed a dry scrubber to capture and treat solvent emissions. It is designed especially for source capturing of fumes directly without having duct connections. This avoid spreading of vapor to nearby areas. It is capable of removing fumes up to 99 % before releasing into the air. The dry scrubber has pre-filter and carbon filter, which are easily removable for maintenance or renewal when it is saturated.

Carbon filter

Activated carbon filter is used to adsorb solvents, inorganic and organic vapors. It has large number of pores, provide high surface area to trap/adsorb odor and chemical fumes. The filters will become saturated with pollutants and should be replaced to get efficiency. The efficiency of filter depends on pollutants characteristics and adsorption capacity, usually 99 %. Effectiveness of carbon is not based on carbon quantity but the adsorption isotherm. The higher the adsorption capacity, the more pollutants will be adsorbed on carbon. We use variety of carbon grades in portable dry scrubber depending on chemicals.

wet voc scrubber

Volatile Organic Compounds (VOCs) are the toxic chemicals which are very harmful to humans and the environment. There is need of feasible method to remove these VOCs. Various methods including physical, chemical and biological treatments are available to remove VOCs either by destruction or recovery. Water scrubbing of VOC’s are highly efficient depending on its solubility and vapour pressure. The absorption of VOCs in water are most practical for water scrubber. Wet scrubber will be suitable for treating exhaust gases with high concentration VOCs.

Working principle

VOC wet scrubber works on principle of absorption technology. A column in which gas is passed at bottom and liquid is sprayed at opposite direction. Packing material is filled to bring the intimate contact between gas and liquid. There are two things happening here, providing cooling for exhaust gas and removing solvent vapour from exhaust.

Apzem provides complete packages from start to end including water level controller using automated solenoid valve, pH controller with dosing system.