Optimization of the Vehicular Emissions of Public Transportation System of a Metro City Some Strategies

Abstract

Today, the capital city of India, Delhi is one of the most polluted cities in the world, which has been caused by phenomenal vehicular growth primarily during the past two-three decades. Incidentally, only a few decades earlier Delhi was acclaimed as one of the greenest capital in the world. In order to restore the air quality and refurbish its image, a number of plans have been prepared and implemented in Delhi during the past few years. The related externalities like traffic congestion, quality of available fuel quality, extent of overloading or over speeding, and maintenance, have a definite impact on the environmental degradation. Although the statistical data for the vehicular pollution of Delhi is available, a comprehensive planning and optimization strategy to overcome the above problem is yet to be formulated. The present research highlights the severity of the issues related to vehicular exhaust emissions and suggests techniques for efficient planning and management of the Public Transportation System for the city of Delhi. In this study, a frame work of an optimization model for solving the transportation problems of the capital city of India, has been proposed. This study therefore, is an attempt to: • Suggest a model to manage the complexities of the transport system of Delhi. • To examine the compatibility and potential of the alternative fuels and improvement in the quality of fuel with a view to reduce the vehicular exhaust emissions. • To incorporate feedback and expectations of the people in planning a Public Transportation System for the city of Delhi. • To map what is the likely future scenario over a span of 20-22 years with different control action plans suggestive of mitigating the problem of pollution. • To develop models to alter these future scenarios ensuring a clean and efficient transport system for Delhi. In this work, a comprehensive experimental work has been performed on different single cylinder, twin cylinder and four cylinder Spark Ignition (S.I.) and Compression Ignition (C.I.) engines to assess the impact of several alternative fuels like Ethanol, Compressed Natural Gas (CNG), Liquefied Petroleum Gas (LPG) and Bio-Diesel on the vehicular exhaust emissions and to ascertain the viability of these alternative fuels for the internal combustion engines that are being used currently. The emission levels of these alternative fuels were found to be highly encouraging and these have been used in proposing the emission modification factors for several alternative fuels and advanced engine technologies. A Delphi study was commissioned to obtain the feedback and suggestions of the experts, having technical backgrounds, such as industrial, scientific, transport administration, engineering academics and engineering studies. The questionnaire designed included a wide spectrum of different modes of transportation, beginning with bicycles and cycle rickshaws, encompassing all the prevalent modes of automobiles being used and including up to electric and solar powered vehicles. The data collected were analysed using the MATLAB software and the results have been used to estimate and then propose future emission modification factors. An estimate of the current vehicular exhaust emissions in the metro city of Delhi has been worked out by considering different characteristics of vehicles, based on their age, engine technology, type of fuel used and average kilometers travelled. These estimated emissions were incorporated in the proposed emission modification factors to obtain the projected future emissions. These emission modification factors are based on our experimental results, literature review and survey analysis. The projected future vehicle emission levels cater to various possibilities of the proposed control actions. Other than Business As Usual (BAU) scenario, eight different control scenarios have also been construed for the years 2010, 2020 and 2030. The vehicular emissions are observed to rise very rapidly- e.g. for BAU scenario the vehicular emissions in Delhi may rise approximately by 15%, 150%, and 400% respectively for the years 2010, 2020 and 2030, with reference to 2007 levels. However by incorporating certain proposed strategies, it is anticipated that about 20% to 70% emissions of the BAU scenario projections can be reduced, depending upon which proposed integrated approach is implemented faithfully. Further, it is worth mentioning here that letting the BAU continue may be very disastrous to the overall health of our people, and its overall impact may prove to be an expensive affair taking into account of the expenses to be incurred on health services, fuel expenses on inefficient vehicles, unnecessary use of personal vehicles, wastage of valuable time in slow moving traffic etc. Hence a sincere and wholehearted action to arrest the vehicular emission levels is the need of the hour. The strategies that have been contemplated include the following: i. Improvement of public transport system, by making it cheaper, comfortable, reliable, efficient and available within walk-able distances. ii. Optimization of traffic flow, improvement in traffic management (e.g., area traffic control system, no motorized-traffic zones, green corridors, removal of encroachment on roads, regulation of construction activities and digging of roads, etc.) iii. Comprehensive inspection and certification system for I & M (Inspection and Maintenance) of on-road vehicles; emission warranty by manufacturers/authorized service providers, which should be for the entire legally usable life of the vehicle. iv. Phasing out of grossly polluting units or mandatory technological up-gradation. v. Improvements in quality of Fuels (e.g., reduction of benzene and aromatics in petrol, reformulated gasoline with oxygenates/additives, reduction of sulfur in diesel etc.) vi. Accelerating the research on environment friendly alternative fuels such as ethanol, bio- diesel, hydrogen etc. and laying their quality standards and ensuring their availability in the market with satisfactory quality at affordable price and to suggest necessary subsidy wherever necessary. vii. Tightening of emission norms regularly with the advancement of the technology for newer vehicles. viii. Improvement in vehicle technology. (e.g., restriction on the two-stroke engines, provision for of on-board diagnostic system, commencement of the Gasoline Direct Injection Systems, Electric and Common Rail Diesel Injection, Hybrid vehicles, Fuel cell etc.) ix. Checking adulteration of fuel and training the volunteers from the non government organizations (NGOs) /general public to do so and devising advanced technologies to check adulteration of fuels automatically. x. Checking evaporative emissions from storage tanks and the fuel distribution systems.