In previous article Emission Control Device and Measures-I, we have seen Catalytic Converter and Exhaust Gas Recirculation methods to control the emissions. Here I am going to present some other emission control measures which are quite uncommon.

1. Plasma Exhaust Treatment:

Non-thermal plasma technologies are being developed to reduce NOx emissions from gasoline and diesel exhaust. Since oxidation reactions dominate during plasma discharges in lean exhaust, the plasma alone is ineffective in reducing NOx. Combined plasma-catalyst systems, however, have been shown to enhance the catalyst selectivity and NOx removal efficiency. Non-thermal plasma reactors can be also designed as diesel particulate matter reducing devices. Plasma technologies still require a significant improvement in their consumption of electrical energy and in other areas.

2. Ammonia Injection:

As a fuel, ammonia does not hold much promise, but if used as an exhaust additives it can give excellent control for NOx emission . Ammonia and nitric oxide interact to form nitrogen and water. Ford motor co. has been doing investigation with injecting ammonia water in the exhaust manifold, downstream from the port. For an effective utilization of ammonia injection, the exhaust gas temperature has to be kept within strict limits and the injecting device has to be put sufficiently down to bring the gas temperature to 165ºc.This also demands a very close tolerance in air fuel ratio supplied by the carburettor . The present carburettors are incapable of this and it might be necessary to adopt electronic injection system to keep close control over fuel-air ratios.

3. Electronic Injection:

It is possible to develop an electronic injection system with sensors for air temperature,manifold pressure and speed which will precisely regulate the fuel supply giving only such air-fuel ratio as will give no HC or CO emissions. The emissions on deceleration can be completely removed by shutting off the fuel supply when the throttle is closed.But this system will still not be able to control the NOx emission .Combination of electronic injection and ammonia as an exhaust additives has an attractive future .

4. Using Alternative Fuels:

This is different and creative way of reducing emissions. If we have problem with petrol and diesel combustion, then why use them? Use something else which does not make that kinda pollution. This theme seems to be simple. But, finding out alternate fuel and designing machines according to them is quite unusual task. But, using alternate fuel is good idea.

Biodiesel is oxigenated fuel. So, it reduces the problem of Carbon Monoxide and Hydrocarbons and it boosts up the NOX. Similarly, different results are obtained by using CNG (Compressed Natural Gas) or LPG (Liquefied Petroleum Gas). Some properties are desirable and some are vice versa.

That’s All About Emissions.

For More Information check below

[1] Emission Control In Petrol Engine.

[2] Emission Control In Diesel Engine.

[3] Exhaust Gas Recirculation.

Related posts:

1. Emission Control Devices and Measures-I
2. Emission Control in C.I.Engine
3. Emission Control in S.I.Engine

In my article, Emissions we have studied about emissions, types, contents of emission gases and their major sources viz. C.I. Engines and S.I. Engines.

We have also discussed about emission control in Petrol Engines and Diesel Engines particularly. The reason behind discussing these both sources is that, they are the sources which contribute highest in total Worlds’ Emissions. Here We will see some more kind of Emission Control Devices.

For Automobile Tuning Information and Parts, please check out ppe tuner.

Emission Control Devices:

1. Catalytic Converter:

Catalytic converter is the device which is fitted on the way of outgoing gases from the engine to atmosphere. Catalytic converter compromises of some chemicals or active chemicals which reacts with content of outgoing gases like CO and NOX. Moreover, they take part in reaction as catalyst which causes their presence unchanged at the end of reaction. After reaction reactants like CO are converted into acceptable emissions like Carbon Di Oxide. Depending upon fuel quality, catalyst material, working temperature etc. life of catalytic converter varies. But generally they have good life and produce effective results.

Some of Major Kinds of Catalytic Converters are As Below:

a. Fast Light off Catalyst:

Allows the catalytic converter to work sooner by decreasing the exhaust temperature required for operation. Untreated exhaust emitted at the start of the legislated emissions test and on short journeys in the real world is curtailed. Changes to the thermal capacity of substrates and type and composition of the active precious metal catalyst have together affected big improvements.

b. Hydrocarbon Adsorber System:

They incorporate special materials, such as zeolites, into or ahead of the catalyst. Hydrocarbon emissions are collected when exhaust temperatures are too low for effective catalyst operation. The hydrocarbons are then desorbed at higher temperatures when the catalyst has reached its operating temperature and is ready to receive and destroy the hydrocarbons.

c. Electrically Heated Catalyst System:

As name suggest, it is provided with electrical heater for heating the catalyst material. At higher temperature, rate of reaction grows and hence electrical heating encourages the catalyst work better.

d. Lean Combustion:

Lean combustion is essential to limit carbon dioxide emissions and to reduce fuel consumption. New diesel technologies with greater use of electronic management and direct injection with unit injectors or common rail injection, can achieve further fuel consumption improvements. The conventional three-way catalyst technology used on petrol engines needs a richer environment with lower air:fuel ratios to reduce NOx, so a radical new approach is required.

e. DeNOx (or Lean NOx) Catalysts:

f. NOx adsorbers (NOx traps):

g. Thermally Durable Catalyst:

So, these are various methods of emission control by using Catalytic Converter. There is one more method for Controlling of NOX from engine.

Exhaust Gas Recirculation:

Exhaust gas recirculation is one of the popular methods now a days. This method mainly controls the NOX emissions. NOX is generated due to very high engine temperature which ranges from 1000 to 1100 degree Celsius. Engine runs at such high temperature due to rich mixtures provided for combustion. In EGR method on the part of outgoing (exhaust) gases is redirected to the input of engine. This suppresses the richness of mixtures. This causes to lower down the temperature of engine which in turn lowers the NOX percentage in exhaust.

More Emission Control Measures are provided in next article.

Related posts:

1. Emission Control in C.I.Engine
2. Emission Control in S.I.Engine
3. Emissions

Emission:

Whenever, any fuel is burnt, we receive energy as main product and many other products. In general we will call them as”Emissions”. So, Emission is product of combustion of fuels which may contain, smoke, carbon monoxide, sulphur compounds, particulates, nitrogen compounds (popularly known as NOX) fumes etc.

Need For Emission Control:

In 20th century, growing technology have handed us with great machines and gadgets. One of them is Internal Combustion Engine (I.C. Engine). Growing technology demanded for more use of energy which we extracted from burning of fuels. This have lead us to the most horrible problem today “Air Pollution”. Air pollution is simply the presence of undesirable gases in undesirable quantities in the air.  This have lead to more serious phenomenon of Global Warming. These are just main problems but there are so many local problems which may differ place to place.

Main source of emission is fuel burnt in the I.C. Engine (about 42% of overall emissions).

Emission Details:

1. Emissions from Spark Ignition Engine:

Major emission from S.I. Engine are listed below.

• Carbon Monoxide (CO).
• Hydrocarbons (HC).
• Oxides of Nitrogen (NOX).

2. Emissions from Compression Ignition Engine:

Major emissions from C.I. Engine are listed below.

• Carbon Monoxide (CO).
• Unburnt Hydrocarbons (HC).
• Oxides of Nitrogen (NOX).
• Sulphur Di Oxide.
• Invisible Emissions.
• Metallic Particulates.
• Visible Emissions.
• Smoke.

So, from these lists we can say that diesel engines are more harmful to environment than that of petrol one.

This is the brief information of emission sources and emissions. We will see in detail about emission control in next article.

References:

[1] http://en.wikipedia.org/wiki/Air_pollution

[2] http://www.naturalnews.com/emissions.html

No related posts.