VOCZero's
Thermally Regenerated Activated
Carbon System, TRAC™

VOCZero offers a range of Vapor Recovery Systems (VRUs) designed for the recovery of volatile organic compounds from vapors at relatively low concentrations. These systems are particularly suitable for applications such as petrochemical facilities where extremely low VOC emissions at ppb–ppm levels are required.

The process is based on the adsorption of VOCs onto activated carbon, followed by steam regeneration of the carbon. This technology is among the most effective solutions available for applications such as storage terminals and loading operations.

The design and selection of components are carried out to achieve a durable, safe, and efficient processing facility and are based on internationally recognized standards in the oil and gas industry, including ASME VIII, ASME B31.3, EN 60079, and EN 1127.

 

Typical vapors to be treated:

- Gasoline

- Diesel

- E5–E100 Gasohol (Ethanol)

- Methanol

- Benzene

- Toluene

- Xylene

- MTBE

- ETBE

- Naphtha

- Crude Oil

- Gas Condensate

 

VRUs are designed to meet the stringent health and safety requirements specified by the European ATEX and Machinery Directives.

VOC Emission Standards

- 1 ppm

- 150 mg/Nm³

- 100 ppm

- 300 ppm

- Application-specific emission standard

 

Key Features

- Modular Design

- Energy Efficient

- Prefabricated piping and steel structures simplify installation

 

PROCESS DESCRIPTION

Low-concentration VOC vapor from storage tanks or other VOC handling facilities, typically containing VOC concentrations between 1% and 4%, is collected in a closed vapor header and directed to one of the two activated carbon filters in the VRU.

As the VOC vapor flows downward through the activated carbon bed, VOC molecules are adsorbed onto the surface of the activated carbon, while inert gas/air exits from the bottom of the filter vessel.

When the activated carbon reaches saturation, the regeneration process is initiated.

 

The activated carbon is thermally regenerated using steam. Since activated carbon has a significantly higher affinity for VOCs than for water molecules, it readily releases VOC molecules when 100°C steam is passed through the activated carbon bed. Steam regeneration continues until the activated carbon and vessel are heated, and a temperature breakthrough is detected at the top of the activated carbon filter vessel.

The released VOCs and steam then flow into an air-cooled condenser where the steam condenses and is subsequently discharged in a separator. From the separator, the pure VOC vapor is directed to the bottom of a packed absorber column, where the VOC vapor is partially condensed and partially absorbed into a suitable absorbent stream taken from a nearby storage tank. The absorbent containing the recovered VOC is collected at the bottom of the absorber and pumped back to the storage tank.

After regeneration, the activated carbon must be dried and subsequently cooled before the carbon bed is ready for another adsorption cycle.