Vapour Recovery System

Context

• Green concern: Fuel stations are a major source of emission, according to the National Green Tribunal.

Committee’s recommendation

• A joint committee appointed by the National Green Tribunal (NGT) to study air pollution in Kerala has recommended the installation of a vapour recovery system at fuelling stations and retrofitting of diesel vehicles with particulate filters to improve air quality.
• The report pointed out that petrol refuelling stations were a major source of benzene emissions, volatile organic compounds, and particulate matter 2.5 concentration.
  • Therefore, the installation of a vapour recovery system is an important step in improving air quality.
  • This is to be implemented in coordination with the Petroleum and Explosives Safety Organization [PESO] shortly.

District-wise analysis

• The committee was directed to assess the ambient air quality levels in the State, especially in Thiruvananthapuram, Kollam, Kochi, Alappuzha, Kozhikode, Thrissur, Kasaragod, and Kannur.
• The panel recommended stringent action against industrial units that do not comply with emission norms.

Diesel generators

• The Pollution Control Board has already suggested retrofitting of emission control devices of generators and replacing diesel generators with gas-based ones.
• Other recommendations include promoting battery-operated vehicles and banning old diesel vehicles in a phased manner, greening of open areas, and creation of green buffers along traffic corridors.
• Introduction of wet/mechanised vacuum sweeping of roads, controlling dust pollution at construction sites, and ensuring the transport of construction materials in covered vehicles.

Benzene:

• Benzene is an organic chemical compound with the molecular formula C6H6.
  • The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each.
• Benzene is a natural constituent of crude oil and is one of the elementary petrochemicals.
• Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon.
• Benzene is a colourless and highly flammable liquid with a sweet smell and is partially responsible for the aroma around petrol (gasoline) stations.

Health impacts of Benzene:

• Benzene works by causing cells not to work correctly.
  • For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anaemia.
  • Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells.
• Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries.
• Animal studies have shown low birth weights, delayed bone formation, and bone marrow damage when pregnant animals breathed benzene.

What is a vapour recovery system?

• A vapour recovery system helps to collect petrol vapour released during unloading and refueling back to the petrol tanker and underground storage tank, respectively.
• A Vapor Recovery Unit (VRU) is a set-up designed to remove unwanted vapors present in crude oil or distillate tanks allowing operators to comply with prevailing emission regulations.
• VRU systems can be employed in a wide range of chemical industries with several variants available.
  • For example, a vapor recovery system for storage tanks can be used to recover vent gas from crude oil and distillate tanks at storage facilities.