GENERAL IDEAS IN GENERAL IDEAS IN AIR POLLUTION CONTROLAIR POLLUTION CONTROL

Dr. Wesam Al MadhounDr. Wesam Al Madhoun

If we have an air pollution problem there are three If we have an air pollution problem there are three control options available:control options available:

Improve dispersionImprove dispersion *Tall stacks*Tall stacks *Intermittent control scheme*Intermittent control scheme *Relocate the plant*Relocate the plant

Reduce Emissions by Process Change, Pollution Reduce Emissions by Process Change, Pollution PreventionPrevention

Use a Downstream Pollution Control DeviceUse a Downstream Pollution Control Device

1.1.1.1.Tall StackTall Stack

50 years ago:50 years ago:

Tall stacks to dilute the pollutants before they Tall stacks to dilute the pollutants before they came to groundcame to ground

““Dilution is the solution to pollution”Dilution is the solution to pollution”

1.1.Tall Stack1.1.Tall Stack

Today, it is still a measure, but not the only oneToday, it is still a measure, but not the only one

There are limitations for the minimum stack heights There are limitations for the minimum stack heights allowedallowed

A high stack will also affect the effect area of a certain A high stack will also affect the effect area of a certain facilityfacility

A tall stack will decrease ground concentrations only A tall stack will decrease ground concentrations only close enough to the emission sourceclose enough to the emission source

1.2.1.2. Intermittent control schemesIntermittent control schemes

Intermittent control schemes areIntermittent control schemes are *predictive, *predictive, *observational*observational *combined predictive-observational*combined predictive-observational

To reduce emissions then, allowing emissions to return to normal To reduce emissions then, allowing emissions to return to normal rates at other, less critical timesrates at other, less critical times

Short-term emission reduction is brought about by Short-term emission reduction is brought about by *a plant shutdown, *a plant shutdown,

*fuel switching, *fuel switching, *production curtailment during the period of control.*production curtailment during the period of control.

1.3.1.3. Relocate the plantsRelocate the plants

It is hard to remove an existing plant, but a

new plant can be located where it is emissions

will have their greatest impact in non

populated areas.

2.Reduce Emissions by Process Change, 2.Reduce Emissions by Process Change, Pollution PreventionPollution Prevention

Water base paints for some of their oil based Water base paints for some of their oil based paints and greatly reduce their emissionspaints and greatly reduce their emissions..

Copper smelters have replaced furnaces, which Copper smelters have replaced furnaces, which produce low concentration SOproduce low concentration SO22

Pollution Prevention StrategiesPollution Prevention Strategies

• Pollution prevention [vs. control] offers important economic benefits and at the same time allows continued protection of the environment.

• While most pollution control strategies cost money, pollution prevention has saved many firms thousands of dollars in treatment and disposal costs.

• More importantly, pollution prevention should be viewed as a means to increase company productivity.

• By reducing the amount of raw materials that are wasted and disposed of; manufacturing processes become more efficient, resulting in cost savings to the company.

Pollution prevention should be the first consideration in planning Pollution prevention should be the first consideration in planning

for processes that emit air contaminants. for processes that emit air contaminants.

Undertaking pollution prevention practices may reduce air Undertaking pollution prevention practices may reduce air

emissions enough to allow a business or industry to avoid emissions enough to allow a business or industry to avoid

classification as a major air emission source. classification as a major air emission source.

What is Pollution Prevention?What is Pollution Prevention?

• Pollution prevention is the elimination or prevention of wastes (air

emissions, water discharges, or solid/hazardous waste) at the source.

• In other words, pollution prevention is eliminating wastes before they are

generated.

• Pollution prevention approaches can be applied to all pollution generating

activity: hazardous and nonhazardous, regulated and unregulated.

• Pollution prevention does not include practices that create new risks of

concern.

SOURCE REDUCTIONSOURCE REDUCTION

Product Changes

• Designing and producing a product that has less environmental impact

• Changing the composition of a product so that less hazardous

chemicals are used in, and result from, production

• Using recycled materials in the product

Reusing the generated scrap and excess raw materials back in Reusing the generated scrap and excess raw materials back in

the process.the process.

Minimizing product filler and packaging.Minimizing product filler and packaging.

Producing goods and packaging reusable by the consumer.Producing goods and packaging reusable by the consumer.

Producing more durable productsProducing more durable products

Input Material Changes

• Material substitution Using a less hazardous or toxic solvent

for cleaning or as coating

• Purchasing raw materials that are free of trace quantities of

hazardous or toxic impurities

Equipment and Process Modifications

•Changing the production process or flow of materials through

the process.

•Replacing or modifying the process equipment, piping or layout.

•Using automation.

•Changing process operating conditions such as flow rates,

temperatures, pressures and residence times.

•Implementing new technologies

Good Operating Practices

• Instituting management and personnel programs such as employee training or employee incentive programs that encourage employees to reduce waste.

• Performing good material handling and inventory control practices that reduce loss of materials due to mishandling, expired shelf life, or improper storage.

• Preventing loss of materials from equipment leaks and spills.

• Segregating hazardous waste from non-hazardous waste to reduce the volume of hazardous waste disposed.

Using standard operating procedures for process operation and Using standard operating procedures for process operation and maintenance tasksmaintenance tasks

Performing preventative maintenance checks to avoid Performing preventative maintenance checks to avoid unexpected problems with equipment.unexpected problems with equipment.

Turning off equipment when not in use.Turning off equipment when not in use.

Improving or increasing insulation on heating or cooling lines.Improving or increasing insulation on heating or cooling lines.

Environmentally Sound Reuse and RecyclingEnvironmentally Sound Reuse and Recycling

3.Use Downstream Pollution Control Devices (Tailpipe Control Devices)

Treat the Treat the contaminated gas streamcontaminated gas stream,to ,to remove or remove or

destrodestroyy the contaminant to make the stream the contaminant to make the stream

acceptable for discharge into the ambient air.acceptable for discharge into the ambient air.

In this courseIn this course

We will focus more on two of these headlines

2.Reduce Emissions by Process Change, Pollution Prevention

3.Use Downstream Pollution Control Devices (Tailpipe Control Devices)

Resource Recovery

If the pollutant is a valuable material or a fuel, it If the pollutant is a valuable material or a fuel, it

may be more economical to collect and use it may be more economical to collect and use it

than to discard it.than to discard it.

Air Pollution Control Strategies

Pollution formation prevention (before)Pollution formation prevention (before)

Pollutant formation control by the process (during the Pollutant formation control by the process (during the

process)process)

Pollutant reduction after the formation (after)Pollutant reduction after the formation (after)

The Ultimate Fate of Pollutants

If possible, we prevent the formation of

pollutants.

If we can not do that, we hope to capture them

and put to some good use

CHALLENGES IN AIR POLLUTION CONTROL (technical)

Heterogenous chemistry needed frequentlyHeterogenous chemistry needed frequently..

Area sourcesArea sources..

Tailpipe devices applicable only to industrial Tailpipe devices applicable only to industrial applicationsapplications..

Sampling and measurement difficultiesSampling and measurement difficulties

CHALLENGES IN AIR POLLUTION CHALLENGES IN AIR POLLUTION CONTROL (administrative)CONTROL (administrative)

Transboundary pollution more difficult to handleTransboundary pollution more difficult to handle

Lack of adequate staffLack of adequate staff

Defined future targets and how to accomplishDefined future targets and how to accomplish..