Exhaust Aftertreatment Technology for Emission Control of Diesel Engines
Background One of the major air pollution sources in Hong Kong is emissions from diesel engines that mainly includes: Mobile Facilities/vehicles on road motor vehicles non-road mobile machineries Stationary Facilities emergency diesel generator sets for buildings / establishments 2
Background 3
Background The Environment Bureau released "A Clean Air Plan for Hong Kong" in March 2013, which outlines the challenges Hong Kong is facing with regard to air quality as well as the relevant policies, measures to tackle the problem. The Plan also gives a detailed improvement measures undertaken to tackle air pollution from land and sea transport, power plants and non-road mobile machinery (NRMM) 4
On-road Motor Vehicles Hong Kong Government has been implementing a comprehensive motor vehicle emission control programme in order to tackle emissions from on-road motor vehicles (diesel engines) such as: phasing out pre-euro IV diesel commercial vehicles progressively subsidizing the replacement of catalytic converters and oxygen sensors of LPG taxis and light buses subsidizing the franchised bus companies to retrofit some Euro II and Euro III franchised buses to upgrade their emission performance to Euro IV or above level subsidizing the franchised bus companies to procure some hybrid buses and electric buses for trial; and subsidizing the testing of green and innovative transport technologies (public transport sector and goods vehicles) through the $300 million Pilot Green Transport Fund, etc. 5
Non-Road Mobile Machinery (NRMM) Hong Kong Government will also focus on controlling the emissions from non-road mobile machinery (NRMM) in order to solve the air pollution problem generated from diesel engines of NRMM There are about 13,500 units of NRMM operating in Hong Kong, among which 11,300 units are operating at construction sites. They contribute 6% NO X and 8% PM10 to Hong Kong s total air pollution 6
Legislation Timeframe for NRMM Environment Protection Department (EPD) of the Hong Kong Government proposes to mandate the control of NRMM s emission, and among them generator set, air compressor, crane and excavator are 4 major types of major polluting NRMMs The control proposal was recently submitted to LegCo and once the legislation is completed, it will be effective in Apr 2015 tentatively. 7
Proposed Legislation Requirements The proposed regulation will include the following key elements: 1. All NRMMs to be sold or leased for local use will have to meet specified standards, which are broadly in line with the standards of the EU, the US and Japan (e.g. EU Stage IIIA standard) 2. Existing NRMMs which are already in use before the Regulation takes effect will be exempted from the emission compliance requirements 3. NRMM owner will have to properly affix a label prescribed by EPD on his approved NRMM or exempted NRMM 4. Only approved or exempted NRMMs with proper labels shall be used in specified activates such as construction sites, airport, waste disposal facilities, etc. 8
Emission Control Standard & Requirement Source: EPD, HK 9
Potential Administrative Measures for Government Projects Although, under the new ordinance, those existing NRMMs in HK will be granted with an exemption label for continual use However, it is expected Development Bureau will require the NRMMs working for the governmental projects to comply with the new emission requirement by phases. This requirement for new and existing NRMMs to be complied with the requirement will be stipulated in the tender of governmental projects by phases As such, the existing NRMM needs retro-fitting of exhaust control equipment to meet the new requirements, or the contractors have to use new equipment that comply with the new emission requirements 10
Emergency Diesel Generator Set for Building Unless the owners of the emergency diesel generators received the complaints, generally, owners do not active to solve the air pollution problem generated from the emergency diesel generators. 11
How the existing NRMM can meet the new emission requirements? How the emission problem from the emergency diesel generator set can be solved? 12
Exhaust Aftertreatment Technology for Emission Control of Diesel Engines Exhaust Aftertreatment (AFT) System is one of the reliable and economic technology to control the emission from diesel engines It mainly includes two parts: 1) Diesel Oxidation Catalyst (DOC) unit and 2) Catalyzed Diesel Particular Filter (CDPF) 13
Wall Flow Honeycomb Ceramic Catalyzed Diesel Particulate Filter (CDPF) Characteristics of CDPF Performance is better than Cordierite and Sintered Metal DPF Cost effectiveness is higher than Silicium Carbide DPF 14
Technical Specification of CDPF 30% 34.2% Percentage 4.6% 16.5% 14.7% Photographs of CDPF Structure Pore-Size Distribution 15
Exhaust Aftertreatment Technology By using the AFT Technology, we developed a system and targeted to solve the emission problem from the emergency diesel generator 16
System Characteristics Effective reduction of smoke and harmful gases Silicon carbide ceramic wall flow filter, durable and low operating cost Control system enables effective regeneration control of CDPF (Selfcleaning function) Fully automatic and simple system operation Easy installation due to system modular structure Automatic by-pass valve guarantees normal operation of emergency generator set under all circumstances No secondary pollution induced due to no spray chamber Robust system structure due to stainless steel cartridge 17
Trial Testing of Technology Testing location: A shopping mall of a local large-sized property management company (300 KW diesel generator set) 18
Trial Installation 19
Exhaust Measurement 20
Particulate Matter (PM): 85-98% Carbon Monoxide (CO): 75-90% Hydrocarbons (HC): 75-90% Testing Result According to our application of the technology to different generator sets of power rating, results of consecutive testing revealed that the averaged removal efficiency of pollutants and air quality of exhausted gas can both be maintained at same level of results. It demonstrated that the technology can be maintained at high operating level. 廚餘管理 Results revealed that the AFT technology can reduce the pollutants at exhaust of diesel generator set effectively Before After Treatment Treatment Averaged Removal Efficiency 21
Hardware of Technology 3 modules of COD and CDPF 22
Case Study 1 Problem: Black smoke and harmful pollutants was emitted by 2 sets of emergency diesel generator sets in a serviced apartment during monthly testing that caused disturbance to the renters of the apartment 23
Case Study 1 Solution: 2 sets of DOC and CDPF were installed in the exhaust pipes of the generator sets to remove the particulate matter and harmful pollutions 24
Case Study 2 Problem: Black smoke and harmful pollutants was emitted by an emergency diesel generator set in a multi-purpose building during monthly testing that caused disturbance to the passengers of nearby railway station 25
Case Study 2 Solution: 1 set of DOC and CDPF were installed in the exhaust pipes of the generator sets to remove the particulate matter and harmful pollutions 26
Case Study 3 Problem: Black smoke was emitted by 2 sets of emergency diesel generator sets in a commercial building during monthly testing that caused disturbance to the tenants of the building Solution: 2 sets of DOC and CDPF were installed in the exhaust pipes of the generator sets to remove the particulate matter and harmful pollutions 27
Case Study 4 Problem: Avoid the air pollution problem caused to the nearby residential buildings by 4 sets of newly diesel generator sets installed for a data center for backup power supply Solution: 4 sets of DOC and CDPF were installed in the exhaust pipes of the generator sets to remove the particulate matter and harmful pollutions 28
Application of Technology on NRMM 29
Trial Installation and Testing A construction company has agreed to collaborate with HKPC for conducting the trial testing of the aftertreatment technology on a generator set in a construction site Aftertreatment technology deployed in trial testing for the generator set include: DOC CDPF HKPC will conduct performance evaluation of the technology for a period of 4 months Measure the removal efficiency of major exhaust emission CO, CO 2, HC, O 2 & PM 30
Trial for Different Types of NRMM
Standard for on-site NRMM Emission Measurement We are currently liaising with a specialist on exhaust measurement to see whether a standard testing method can be formulated (ISO8178-2 ) to evaluate the performance of the technology on NRMM which can comply with the emission standards as required to grant for the approval label ISO8178-2 (Measurement of gaseous and particulate exhaust emission under field conditions) Main Exhaust Components CO, CO 2, HC, NO x, O 2 (Using PEMS*) Other Gaseous Components CH 4, NMHC, NH 3, CH 3 OH (Using PEMS*) Particulates (PT sampling filter by Partial Flow Dilution System) Exhaust Gas Flowrate Engine Loading (Torque Measurement) Engine Output (Speed Measurement) Engine Power Air Consumption Other engine operational parameters * PEMS = Portable Emission Measurement System Testing condition 1) Steady State Testing & 2) Transient Testing (with Standardized Test Cycles) 32
Challenge Apply the technology on different types of mobile NRMM Overcome the difficulties on conducting the emission measurement Qualify the measuring instrument in accordance to the ISO8178 standard Recognize the testing methodology by Authorities (e.g. EPD) Achieve the stringent emission control standards 33
Goal By successfully applying the exhaust aftertreatment technology to the diesel engine of NRMM, the retrofitted NRMM can comply with the emission control standards in order to obtain the grant for Approval Label under the subsidiary regulation of the Air Pollution Control Ordinance (Cap. 311) for controlling the air pollutant emissions of NRMM when the regulation takes effect 34
Thank You! 35