MOTORCYCLE EMISSION FACTOR DEVELOPMENT FOR EMISION INVENTORY IN INDONESIA

• Main Author: Pradini Yudison (NIM: 35312006), Adyati
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25063
• Institution: Institut Teknologi Bandung

One of the Sustainable Development Goals Program is to conduct sustainable urban and residential management that supports healthy life and is in line with climate change mitigation. To achieve these objectives, a good air quality management is required to support sustainable cities. Emissions inventory is one of the basic and important steps for air quality management. The results will be of important inputs for setting management objectives and strategies. Emission inventory describes the amount of pollutant emissions released from an activity in a given time. In the calculation of emission load, often actual emission measurement data is not available, thus, the average emission value taken from statistical analysis of similar process and source, referred to as emission factor (EF), is used. Based on current regulations and guidelines, vehicles EF in Indonesia are divided into EFs for motorcycles, gasoline-fueled cars, diesel-fueled cars, buses and trucks. Emission factors used is VKT method and classified on Tier 1 emission inventory method, which is the simplest method. There are two things that become the main challenge of VKT method utilization in Indonesia, which are the determination of driving cycle as the base of EF and the collection of activity data that is affected by behavioral pattern of society. Therefore it is necessary to develop a new FE that can overcome both challenges. At present based on national statistics, the number of motorcycles reaches +80% of the total number of vehicles, so its contribution to transportation emission loads needs to be observed. The main objective of this research is to develop the emission factor of motor cycle. This is done to fill in the existing gap, since the first set of emission inventory method in Indonesia in 1991, when the existing emission factor has not represented the actual field condition. The emission factor in this study was determined based on the measured emissions with sample specifications designed to represent the characteristics of motorcycle population in the field. These characteristics were obtained through a survey conducted in the Bandung City, as well as 10 other large cities and 1 megapolitan area. The number of respondents in the survey were 812 for Bandung City (96.4% sample confidence level) and 2101 respondents for other cities (90% confidence level). The results of the questionnaire survey show that the dominant motorcycle engine type in Indonesian urban area is EURO II and EURO III, with the average number of both types is 89.4%. Engine capacity of less than 150 cc dominates the motorcycle proportion with average value of 80.7%, while the fuel used were RON 92 (39.7%), RON 90 (35.2%) and RON 88 (21.5%). Motorcycles are generally operated at the speeds of 30-45 km/h in a duration of 1-2 hours/day. The characteristics of motorcycle usage obtained from questionaire were used as the basis to determine sample proportion using stratified random sampling methodology. The strata used is motorcycle technology of EURO II and EURO III, and the engine capacity of <150 cc and >150 cc. The emission value obtanied from this study were classified into idle condition and mobile condition (10-60 km/h). . The mean idle emission values for CO2 were 63.51 mg/sec, CO of 8.02 mg/sec, HC of 0.51 mg/sec, and NOx of 0.03 mg/sec. It was found that in general emissions were lower with increasing speedIn addition, the value of speed emissions obtained were; CO2 within the range of 7.35-22.85 g/km; CO within the range 0.99-5.49 g/km; HC within the range 0.02-0.17 g/km; and NOx within the range 0.02-0.03 g/km. In this study, the effect of technological factors is more visible than the influence of fuel, possibly because the dominant fuel characteristics used (RON 90 and RON 92) did not differ significantly. However, when interaction between engine technology and fuel were analysed, the use of RON 92 fuel showed clear advantages on the EURO II motorcycle. On the other hand, for EURO III motorcycles, the use of RON 90 and RON 92 fuel did not show a noticeable difference, might be due to TWC's role in reducing exhaust emissions. In this research, the speed-related emission determination were done for CO2, CO and HC emission factors that showed significant correlation to the speed changes. No significant correlation was found between NOx emissions and speed after a variance test was conducted, likely because NOx in exhaust gas comes from various forming processes. Instead of a model, NOx emission factor then were presented as the mean value at each speed. This research comes up with EFs suitable for different Tier methodology, according to its complexity. Emission factors for IE Tier I are general values that are not separated based on motorcycle type; Tier II EFs are separated based on motorcycle technology; and Tier III EFs are separated based on motorcycle technology and motorcycle capacity. The higher the Tier level, the more complex the data required. This study demonstrates the need for an integrated and complete database, for supporting the use of methods with high Tier that would reduce uncertainty. The development and use of emission factors in emissions inventories should be sustainable as changes occur in motorcycle use patterns. The method of emission factors development in this study can fulfill that aspect.