Presentation on theme: "Chemistry Project Methods of reducing air pollution."— Presentation transcript:
Chemistry Project Methods of reducing air pollution
Methods of reducing air pollution of motor cars
Catalytic Converters ( 催化轉化器 )
Catalytic converters -For cars using unleaded petrol( 無鉛汽油 ) -Convert toxic air pollutants (e.g. CO, NO) in the exhaust to harmless substances (e.g. CO 2, water) -Contain catalysts( 催化劑 ) to speed up the reactions
Catalytic converters - Become ineffective when poisoning or heat deactivation occur Poisoning causes by –lead, sulphur, zinc, manganese, silicon or phosphorus Heat deactivation causes by –Lubricating oil –Engine misfire or ignition failure –A cracked exhaust valve
Reducing Pollutants From Motor Cars By Using Environmental Fuels
Using Unleaded Petrol unleaded petrol comes in combination with the use of a catalytic converter. transform noxious exhaust gases into less undesirable gases. The Hong Kong government banned the sale of leaded petrol in 1999 **Car exhaust gas contains a mixture of lead compounds which may cause serious lung diseases!
Reducing Pollutants From Motor Cars By Using Environmental Fuels Liquefied Petroleum Gas Pollution from motor vehicles is controlled through fuel and emission control.Pollution from motor vehicles is controlled through fuel and emission control. The Hong Kong government tried to encourage taxi operators to replace diesel taxi with those operated on LPGThe Hong Kong government tried to encourage taxi operators to replace diesel taxi with those operated on LPG A LPG taxi
By regulation Control excessive emissions of smoke from car
Air Pollution Control Ordinance At 1990 Prohibits the use of high sulphur content solid and liquid fuel for commercial and industrial appliances. At1994 Prohibits the sale of leaded petrol At 2003 Requires pre-Euro light diesel vehicles to have emission reduction devices. Duringpublicconsultation Proposal to Ban Idling Vehicles with Running Engine
Individual method to reduce air pollutants Using low sulphur content petrol or diesel oil Using unleaded petrol Installation of catalytic converters in car exhaust systems Switching off the engines of idling vehicles Taking public transport
Government strategies More stringent fuel and vehicle emission standards. Encouragement to adopt cleaner alternatives to diesel vehicles, such as the use of Liquefied Petroleum Gas for taxis and light buses. Installation of old diesel vehicles with devices that, reduce emissions such as particulate traps or catalytic converters. Promotion of better vehicle maintenance and eco-driving habits.
Results of strategies
Ways to reduce air pollution of industries
Scrubber ( 裝置滌氣器 )
Use of Scrubber : ． can remove up to 95% of SO 2 ( 二氧化硫 ). ． Scrubbers mainly use in power plants( 發電廠 ), factories( 工廠 ) and incinerators( 焚化爐 ). Scrubber is used to remove substances from the exhaust gas stream, or to neutralize those substances.
． Scrubber can be divided into dry and wet scrubber. Scrubber dry scrubber wet scrubber Dry and wet scrubber can be used separately, and also used together. Scrubber ( 裝置滌氣器 )
1 2 3
Electrostatic precipitation removing fine particulates( 細小的微粒 ) from airstreams( 氣流 ), gases of combustion(( 燃燒 ) of fossil-fuel ( 化石燃料 ) Dirty gases pass through a strong electric field( 電場 ) dirty gases particulates become charged( 帶 電荷 ) charged particulates are collected by opposite charge’s plants
What can the government do to reduce air pollution caused by the mobile? Vehicles: sponsorsponsor to use LPG ( 液化石油氣 ) PromotePromote good driving habits Set up monitoring stations( 空氣監測站 )Set up monitoring stations( 空氣監測站 )
What can the government do to reduce air pollution caused by the stationary ? Factory: Town planningTown planning Estate should be away from industry Implement ordinancesImplement ordinances Eg: install scrubbers, filters and electrostatic precipitates Power plants ( 發電廠 ): Implement ordinancesImplement ordinances natural gas use natural gas Incinerators( 焚化爐 ): Replaced by transfer stations Factory Refuse transfer station
Recent measures from the Policy Address 2007-2008 Regulation: VOC ． to limits the VOC content of products ． requiring power station to use natural gas *note: voc causes smog Mr Donald Tsang
The Present Situation Vehicle Kilometres Travelled and Emission Trend Emissions of nitrogen oxides and particulates from vehicles have been dropping despite an increase in kilometres travelled.
Comparison of New Vehicle Exhaust Emission Standards Using petrol is better than using diesel !