Question

Write answers on here and NOT on paper.

1. Provide information on other emission control.

•Thermostat Air cleaner systems

•Air injection reaction systems

•Fuel evaporation control systems

•Spark control systems

•Others

•How has the Trump administration changed auto emission standards?

Answer 1

The engine emissions are

1. Unburned hydro carbons

2. Oxides of carbon

3.Oxides of sulphur

4.oxides of nitrogen

5. Smoke

All emissions are harmful except carbon dioxide emission.

Causes for the formation of Nitrogen oxides: For the formation of oxides of Nitrogen, the temperature should be high and there should be sufficient availability of oxygen. The first requirement for the formation of oxides of Nitrogen is high temperature. At high temperatures, nitrogen (N2) converted into N and this nitrogen when reacts with oxygen form oxides of nitrogen. This pollutant causes for photo-chemical smog.

Methods of controlling oxides of nitrogen:

(1) Retarding the spark

(2) Exhaust gas re-circulation

(3) Use of catalyst to reduce temperature

(4) Water injection.

The visible part of combustion products is known as smoke. There are two types of smokes,

(1)Bluish white smoke (2)Black smoke

Bluish white smoke is due to lubricating oil getting contaminated with charge and this is basically due to worn out piston rings. Black smoke is due to carbon particles suspended on exhaust gas.

The another method for reducing the emission is catalytic converter:

The main pollutants are unburned hydro-carbons, oxides of Nitrogen and carbon monoxide. Catalytic convertor converts all this pollutants into in-harmful products. It consists of platinum, Palladium and rhodium elements. Platinum helps for converting hydro-carbons into hydrogen dioxide and carbon dioxide. Palladium converts carbon monoxide into carbon dioxide. Rhodium helps for converting nitrous oxides into nitrogen and oxygen.

Drawbacks of catalytic converter:

1. The exhaust temperatures are more due to exothermic reaction

2.If sulphur is present in the fuel with catalytic converter, oxides of sulphur are formed and this may results in acid rain.