Bharat Stage Emission Standards are regulations introduced by the Indian Government to restrict the pollutant levels emitted by internal combustion engines, including those of automobiles. These standards are designed based on European regulations and are numbered as BS3, BS4, BS5, BS6, respectively; the higher the number, the more rigid the standard.
Let us now answer the questions, “what is Bharat Stage 4?” and “what is Bharat Stage 6?” Bharat Stage 4 showed greater hope than its previous norms by significantly reducing the atmospheric sulphur levels. But, it still failed in terms of reducing Particulate Matter (PM) and Nitric Oxide (NOx). Bharat Stage 6, on the other hand, is not only expected to reduce NOx and PM levels dramatically but will further bring down sulphur traces.
Need to Move From BS4 to BS6 Norms
India is a vast country. Despite our great cultural heritage, we have at least ten highly populated cities whose pollutant levels are such that make the shift from Bharat Stage 4 to Bharat Stage 6 emission norms imperative. For instance - The PM2.5 or Particulate Matter 2.5 levels of the country’s capital, Delhi are six times worse than the permissible levels allowed by the WHO. No wonder such poisonous volumes of vehicular emissions have started taking a toll on the citizens’ health.
Moreover, India signed the Paris Climate Agreement in 2016 wherein the country has taken the responsibility to cut down its carbon footprint by a whopping 35 to 55%. This step has further compelled the nation to jump directly to BS6 norms from its current BS4.
As per the BS6 rules, the NOx (Nitrogen Oxide) emissions are to be brought down by 25% in petrol engines and 68% in diesel engines. Similarly, PM emissions are expected to see a fall of 80% in diesel engines.
Technological Changes Demanded by BS6
Complying with the Bharat Stage 6 norms will demand complex technological changes. Original Equipment Manufacturers (OEMs) cannot merely add extra components to their vehicles to bring this to pass. For example - Diesel Particulate Filters or DPFs will need to be fitted to expel PM, whereas, for reducing the emission of NOx, Selective Catalytic Reduction (SCR) and Exhaust Gas Recirculation (EGR) technology need implementation. Now, if a BS6-compliant DPF has to be installed in a compact diesel car, the bonnet size will also have to be increased. Though challenging, the same is possible.
A BS6 engine works as follows - the SCR unit converts NOx into two harmless particles (diatomic nitrogen and water) using AdBlue (diesel exhaust fluid). Now, when the pollutants from the engine come in contact with the AdBlue, the urea present in the diesel fluid gets converted to Ammonia and carbon dioxide, which further break down into gases like nitrogen and water vapour. This is how BS6-compliant engines reduce emissions.
4 окт 2024