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CNG vehicle growth in Pakistan. Fig. 2. Growth of CNG filling Station in Pakistan.
CNG vehicle growth in Pakistan. Fig. 2. Growth of CNG filling Station in Pakistan.
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Stepper online in Pakistan CNG vehicle growth in Pakistan. Fig. 2. Growth of CNG filling Station in Pakistan.
CNG vehicle growth in Pakistan. Fig. 2. Growth of CNG filling Station in Pakistan.
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Decline in the transport emission due to CNG program.
Decline in the transport emission due to CNG program.
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Stepper online in Pakistan Natural gas consumption by transport sector.+10
Stepper online in PakistanNatural gas consumption by transport sector.
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This article appeared in a journal published by Elsevier. The attachedcopy is furnished to the author for internal non-commercial researchand Stepper online in Pakistanher uses, including reproduction and distribution, or selling orlicensing copies, or posting to personal, institutional or third partywebsites are prohibited.In most cases authors are permitted to post their version of thearticle (e.g. in Word or Tex form) to their personal website orinstitutional repository. Authors requiring further informationregarding Elsevier’s archiving and manuscript policies areencouraged to visit:http://www.elsevier.com/authorsrights
Author's personal copyDevelopment of natural gas as a vehicular fuel in Pakistan: Issues andprospectsMuhammad Imran Khana,*, Tabassum Yasminb,1aMari Petroleum Company Ltd., G10/4, 3rd Road, Islamabad 44000, PakistanbMechanical Engineering Department, University of Engineering & Technology, Peshawar, Pakistanarticle infoArticle history:Received 28 June 2013Received in revised form15 January 2014Accepted 16 January 2014Available online 5 February 2014Keywords:CNGEmissionsVehicleFuelPakistanNatural gasabstractIn a step towards adopting environment friendly fuel and to save foreign exchange, Compressed NaturalGas (CNG) was introduced by the Government of Pakistan in the country in 1992. Due to available pricedifferential between CNG and gasoline/diesel and investor friendly policy and regulatory framework,CNG sector has shown tremendous growth over the last ten year in the country. This growing demand ofnatural gas by CNG sector, results in gas shortages in the country. This paper describes the key steps inthe development of CNG as transportation fuel in Pakistan. The present scenario of the CNG industryincluding the natural gas vehicles (NGVs) population growth and the expansion of CNG refilling stationsare discussed. Various aspects of the CNG program in Pakistan, for example environmental benefits,economic benefits and problems associated with CNG industry of Pakistan are illustrated.Ó2014 Elsevier B.V. All rights reserved.1. IntroductionThe word is turning to replace gasoline and petroleum basedenergy, which is showing a rising trend in price. Around the world awidespread research is carried out to investigate that CNG is goodfor the customer and kind to the environment, while making thecountry into more fuel sovereign state. A growing number ofcountries around the world are jumping on the moving train tomake use of CNG, because of various advantages. The entire creditfor this goes to New Zealand, which in 1980s launched CNG pro-grams on a commercial scale successfully. It seen that CNG is theanswer to the world, in the hunt for alternative transportation fuel.Today CNG programs are being pursued in more than 86 countriesand Pakistan stands 2nd in the world tally in terms of NGVs (1stIran) & fillings stations (1st China) (Statistics and Europe, 2013).2. Background CNG program in PakistanThe foundation-stone of CNG program in Pakistan was laiddown by HDIP (Hydrocarbon Development Institute of Pakistan)through the establishment of CNG refilling stations at Karachi in1982. In 1992, Ministry of Petroleum and Natural Resources ofPakistan, announced the CNG Rules of 1992, which commercial-ized CNG as a transportation fuel in the country. The programreally picked up in 1998 when the government declared a twoyear goal of establishing 150 CNG stations and conversion of100,000 vehicles.Keeping in view the lack of domestic fuels, a large space alwaysexisted in the country for the development of alternative trans-portation fuels, particularly natural gas, which is locally available ata low cost, while a widespread infrastructure for transmission anddistribution of natural gas is already in position.3. Statistics of Pakistan’s CNG industryDue to Government’s consumer friendly policy, ample regu-latory framework and extensive efforts, CNG industry hasdeveloped significantly at an unprecedented rate of around 52.5%per annum during the last few years. Currently the country has6.167 million total number of register vehicles (Pakistan National,2010), out of which there are 3,100,167 (89%) vehicle has beenrunning on CNG while the rest, which includes buses, trucks, andtwo wheelers, three wheelers etc, are using gasoline and diesel.Table 1 depicts the statistical highlight of natural gas vehicles eNGVs in Pakistan.*Corresponding author. Tel.: þ92 3469261649.E-mail addresses: imran.khan@mpcl.com.pk (M.I. Khan), tabassum@nwfpuet.edu.pk (T. Yasmin).1Tel.: þ92 3459218769.Contents lists available at ScienceDirectJournal of Natural Gas Science and Engineeringjournal homepage: www.elsevier.com/locate/jngse1875-5100/$ esee front matter Ó2014 Elsevier B.V. All rights reserved.http://dx.doi.org/10.1016/j.jngse.2014.01.006Journal of Natural Gas Science and Engineering 17 (2014) 99e109
Author's personal copy4. Prevailing status of CNG in PakistanBecause of higher priority and the insatiable demand for naturalgas by power plants and industry, the government has to rationnatural gas for CNG sector. It often announces “gas holidays”wheregas supply to CNG stations is cut off for several days a week,conducing to widespread dissatisfaction among CNG consumers.Owing to these gas shortage problems, the government is not infavor of further expansion of CNG sector in the country. The officialsare struggling with the difficult task of trying to turn back thestrategy and to ablactate vehicles back onto gasoline to divert thenatural gas to industry and power plants. Recently the government,without consulting the stake holders, imposed ban on import ofCNG Kits and CNG Cylinders and has restricted the OEM companiesi.e. Pak Suzuki Motor Company, Indus Motors Company (Toyota)and also after-market installers to stop conversion of vehicles toCNG.To rationalize the gas consumption, a load plan in October 2010has been implemented. Under the plan, gas feeding to the CNGstations was curtailed to five days a week in certain regions of thecountry. The main reason behind failure of gas energy plans andpolicies in Pakistan is political disability, as a result of which pol-icies of previous governments have been destabilized by precedinggovernments.5. Stepper online in PakistanGrowth of CNG in the countryThe CNG industry in Pakistan has witnessed a tremendousgrowth in Stepper online in Pakistanthe last decade, by virtue of friendly government policiesand the key role played by CNG station/vehicle owners. At present,it is stands 1st in the world. Figs. 1 and 2reflect the continuousincrease in Stepper online in Pakistanthe number CNG stations and CNG vehicles respectively.A significant increase has also been seen in the consumption ofnatural gas by CNG sector as shown Fig. 3. Over the past ten Stepper online in Pakistanyears(2001e2010) there is more than 11, 000 percent raise in gasconsumption by this sector. Currently CNG industry consumes 325MMSCFD (million standard cubic feet per day) natural gas (9% ofcountry gas production) (Pakistan Energy, 2013).6. Government policy & supportPakistan has sought ways to raise awareness, investment,technology and institutional framework, while pursuing fast trackdevelopment of the CNG industry. Government’s interest to boostnational economy by reducing oil import bill and improving theenvironment has led to the provision of incentives for investors inCNG sector. Some of them are highlighted below:Exemption from import duty and GST for CNG station andvehicle conversion equipment for a period of five yearsPermit import of used and reconditioned CNG compressor.Loans on soft terms to setup a CNG stationStrong commitment by the government to promote the use ofCNGLiberal procedures for issuance of license for setup a CNGstations.Deregulated market price for CNG consumersNatural gas tariff for CNG coupled to gasolineGas connection priority to CNG stations7. Natural gas scenario in PakistanPakistan is an energy deficit country. The country primary en-ergy supply during the financial year 2011e12 was recorded as 64.7MTOE (million tons of oil equivalent) (Pakistan Energy, 2013) and itis majorly depends upon imported petroleum products, as a resultof which the country’s annual oil import crossed the limit ofTable: 1Statistics of Pakistan’s CNG industry (Statistics and Europe, 2013).Total NGV population (other than ships, trains and aircraft) CNG stations DateTotal NGVs LD þMD þHD Vehicles LD Vehicles MD þHD Buses Other % of total vehiclesin the country% of total NGVsworldwideTotal % of total CNG stationsworldwide3,100,167 2,920,167 2,919,500 667 180,000 89.14% 19.12% 3330 15.84% March, 2012Fig. 1. CNG vehicle growth in Pakistan. Fig. 2. Growth of CNG filling Station in Pakistan.M.I. Khan, T. Yasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109100
Author's personal copyfourteen billion US dolor, which is a big load on economy. Totalenergy consumption of the country in fiscal year 2011e12 remained40.03 MTOE (Pakistan Energy, 2013). The contribution of naturalgas was remained highest equal to 43.3% of the total energy con-sumption of the country, followed by oil (29%) (Fig. 4).In Pakistan oil and gas are the two sources of energy used astransportation fuel. Transport is the largest consumer of oil in thecountry as more than 50% of oil is consumed by this sector (Habib-ur-Rehman et al., 2009-10). However, over the past 10 years therehas been loss of more than 20% in the consumption of oil throughthe transport sector. This decrease is due to the growing trend to-wards the use of compressed natural gas as transportation fuel(Fig. 5).Pakistan has a good potential for the production of natural gas.Current recoverable reserves of natural gas in the country are 28.9TCF (trillion cubic feet) (Pakistan Energy, 2013). The daily produc-tion of natural gas during the fiscal year 2011e2012 was remained4002 MMSCFD, a bulk of which is utilized as fuel for power gen-eration (27.2%), followed by industrial sector (23.5%). To support itsCNG sector, the country has a widespread infrastructure of naturalgas distribution pipeline network spreading in major part of thecountry (Fig. 6). In recent years a phenomenal growth has beenwitnessed in the transmission and distribution networks of naturalgas pipeline due to rapid increase of natural gas as a transportationfuel.8. Supply and demand gapThe annual growth rate for the demand of natural gas in thecountry is expected at an average rate of 2% from the year 2012. Fig7illustrates the future of gas demand and supply projections in thecountry. Keeping in view the current supply projections, indige-nous gas production is expected to reach its peak value of 3680MMSCFD in 2014 and will decline thereafter. With passage of timenatural depletion of gas reservoirs will make sure that committedsupplies fall well short of demand, which is expected to reach 5980MMSCFD in year 2016. Moreover, since the local production ofnatural gas will no longer be ample to meet growing demands,dependence on imports will raise.To meet the growing demand of CNG by transport sector, thegovernment is promulgating a new strategy to import natural gasfrom neighboring countries. The TurkmenistaneAfghanistanePakistaneIndia (TAPI) and IranePakistan (IP) gas pipeline projectsare the key elements of this strategy. The IranePakistan (IP) gaspipeline project is projected to bring natural gas to Pakistan at theend of 2014. In this context, an agreement has already been signedbetween the two countries. The volume of gas supply is expected tobe 7.52 BSCFD (billion standard cubic feet per day) for the first yearand 13.98 BSCFD for the second year and 21.5 BSCFD from the thirdyear onward until the expiry of IP GSPA (Iran Pakistan gas salespurchase agreement), 25 years from the effective date. If theseprojects to import natural gas have not completed in time, gasshortages could worsen considerably. This will drastically affect thecountry’s CNG industry.9. Economic benefitsThe growth of CNG vehicles is mainly due to the cost benefits ofCNG over gasoline/diesel fuel. In Pakistan CNG is much cheapercompared to petrol and diesel. The cost for the operation of CNGvehicles vis-a-vis its operation on gasoline/diesel has been carriedout at the current fuel prices in the country. The results arereproduced in the form of a bar Stepper online in Pakistangraph as shown in Fig. 8. Thecomparison is illustrated using the following calculations:Current Price of CNG ¼Rs. 65/kgCurrent Price of Gasoline ¼Rs. 105/LitCurrent Price of Diesel ¼Rs. 104/LitFig. Stepper online in Pakistan3. NaturalStepper online in Pakistan gas consumption by transport sector.Commercial4.0%Domestic23.4%Industrial37.6%Other Govt.1.9%Transport31.4%Agriculture1.8%Fig. 4. Energy Consumption by Sector (Excluding fuel Stepper online in Pakistanconsumed in thermal powergeneration).Fig. 5. Fuel consumption by transport sector.M.I. Khan, T. Stepper online in PakistanYasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109 101
Author's personal copyNow on the basis of energy equivalent1 kg of CNG ¼1.4 L of Gasoline And on the basis of enginecompression ratio1 L of Diesel ¼1.4 L of GasolineConsider the case of Honda Civic 1.8 L Car in Pakistan, in generalthStepper online in Pakistanis car with a fuel consumption rate of 17.5 km per literof gasolineon the highway. If the said car traveled a distance of 1000 km, it willconsume 57 L of gasoline or 41 kg of CNG. Therefore keeping inview the current maStepper online in Pakistanrket prices, CNG allows significant fuel savingsof about 50% compared to gasoline or diesel. Fig. 9 shows the retailfuel price advantage of CNG over gasoline/diesel for the last 12years in the country.In addition, the CNG has substituting at least 6.2 billion gallonsof gasoline each year and save foreign exchange amounting tobillions of dollars. The CNG industry pays 24% GST (general salestax) and 4% withholding tax to the government. The CNG sector ofthe country has so far attracted more than Rs. 89 billion investment(Annual Report, 2011-12). The activities in this industry havecreated more than 121,000 cumulative (direct and indirect) jobopportunities. Figs. 10 and 11 illustrate the investment trend andemployment opportunities produced by CNG sector respectively.Fig. 6. Pakistan natural gas infrastructure (Petroleum Exploration, 2012).Fig. 7. Gas demand & supply projections (Inter State Gas Systems, 2013). Fig. 8. Cost comparison of CNG vs other fuel.M.I. Khan, T. Yasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109102
Author's personal copy10. CNG technology in PakistanIn Pakistan almost the entire fleet of NGVs is usually bi-fuelvehicle, burning one fuel at time. Their engine is a standard gaso-line Internal Combustion Engine. For converting the gasoline en-gine into CNG engine, a CNG conversion kit and a cylinder isrequired. CNG conversion kit is basically a set of components andtools that are installed in a vehicle so it can operate using bothgasoline and CNG. The driver can select what fuel to burn by simplyflipping a switch on the dashboard. CNG conversion kits usuallycome with parts such as regulator, high pressure tubing and fit-tings, pressure gauge, filling nozzle, hoses, refueling valve, poweradjuster, closed loop fitting system, emulator, timing advanceprocessor, fuel change over switch as well as the necessary wiring,straps and screws.Fig. 9. Pakistan retail fuel prices.Fig. 10. Employment in CNG sector. Fig. 11. Investment in CNG sector.M.I. Khan, T. Yasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109 103
Author's personal copyIn Pakistan there are 9 approved brands of CNG conversion kitand 11approved brands of CNG cylinder, which has generally beenused for converting gasoline vehicle to natural gas vehicles. Of the 9approved brands of CNG conversion kits, five has been manufac-tured locally. Landi Renzo, one of the renowned Italian CNG kitmanufacturers has setup a plant at Karachi with complete tech-nology transfer to Pakistan. Over 90 percent market share of CNGkits in Pakistan has captured by local companies. These localcompanies has a broad based engineering design, development,testing and hi-tech manufacturing setup that are geared towardsthe production and constant improvement of CNG kits.The country has now started regular export of CNG kits to China,Brazil, Far Eastern and European countries. The CNG cylinders areusually imported from India. There is only one local companyengaged in the manufacturing of CNG cylinder. To setup a CNGrefilling station one needs CNG compressor and dispenser. CNGcompressors are imported from UK, USA, CanadaStepper online in Pakistan, Germany, Chinaand Italy while major share of dispenser are produced locally by M/s Tesla Tech.11. Environmental aspect of CNG programDue to rapid industrial growth, urbanization and hence increasein traffic volume over the last fewStepper online in Pakistan decades under developedcountries like Pakistan have undergone substantial increases interms of emission sources of air pollutants (Majid et al., 2012). InPakistan, as in many other countries, traffic is a major cause of highlevels of pollution in the cities (Ali and Athar, 2008). There are nosystematicStepper online in Pakistan obligations for controlling the vehicle emissions inPakistan, which caused more than 90% of the ambient pollution(Faruqee, 1996). Pakistan’s National Conservation Strategy Reportstates that the average Pakistani automobile, releases 20 timesmore hydrocarbons, 25 times more carbon monoxide and 3.5 timemore NOxin grams per kilometer than the average vehicles in theUnited States (Pakistan Strategic, 2006). The report states that ur-ban air pollution cause around 22,700 premature deaths per yStepper online in Pakistanear inthe country (Pakistan Strategic, 2006). Most of the Pakistani citiesare reeling under critical levels of NOxand particulate matterpollution. There are serious public anxiety about health effects ofdiesel associated fine particulate matter, and other air pollutants.These worries are supported by the dissemination of studies inIndia and epidemiological studies conducted in various othercountries that have highlighted variety of health risks associatedwith particulate matter in vulnerable populations, including pre-mature death, hospital admissions, respiratory diseases andchanges in pulmonary function.The emission of air pollutants is directly related to fuel con-sumption. Consumption of petroleum products in Pakistan isgrowing at an annual rate of about 6%, almost half of themconsumed in the transport sector. The major agents of the vehicleemission in Pakistan are: CO2,CO,NOxand PM.11.1. Carbon dioxide CO2Carbon Dioxide eCO2is the major source of emission associatedto transport, because it is the natural outcome of combustion ofcarbon based fuels such as diesel and gasoline (both of which havehigh carbon contents compared to CNG). In Pakistan transportsector makes up 70% of CO2emissions (IEA Statistics, 2012; Imtiazet al., 2008). CNG has the lowest carbon-to-hydrogen ratio thaneither gasoline or diesel fuel (McTaggart et al., 2008). This led to thelower emission of CO2for the CNG than the gasoline or diesel fuel(McTaggart et al., 2008). Additionally, the emissions of CO2from aCNG engine can be decreased by more than 20% compared to that ofa petrol engine with the same load due to the high hydrogencontent of natural gas fuel (Kato et al., 2001; Weaver, 1989).The CO2emissions of a CNG vehicle can even be lower than thatof a diesel vehicle with the same air -fuel ratio and nearly the samethermal efficiency under very lean conditions (Tilagone et al.,1996).The conclusion of recent studies, like those conducted by CaliforniaAir Resources Board (CARB), is that CNG can reduce CO2emissionsby 20%e30% compared to diesel and gasoline.11.2. Carbon monoxide eCOOne of the other hazardous vehicle emissions is carbon mon-oxide eCO. In Pakistan the road traffic contributes 70% to the na-tional CO-emission and totally dominates the CO-pollution in mostof the cities (IEA Statistics, 2012). Carbon monoxide is produced byincomplete combustion of carbon-based fuels. Incomplete com-bustion takes place when there is not enough oxygen available forthe fuel to burn completely or when burning is extinguished nearthe cold surface of combustion cylinder.Carbon monoxide is a toxic gas, which causes nausea, headache,fatigue, breathlessness and in high concentrations it may causedeath. It is responsible for more than 50% of all poisoning deathsreported worldwide each year (Raub et al., 2000). Due to excellentlean flammability limit of CNG, it produces lean burning operationwhich conduces to the reduction of carbon monoxide and NOxproduction in exhaust emission (Nine et al., 1997). As per NGVAmerica, CNG vehicle can reduce the production of CO in theexhaust emissions by 70 percent (NGV, 2013).11.3. Nitrogen oxides eNOxNOxare by-products of all carbon based fuel combustion pro-cesses and national transport sector contributes Stepper online in Pakistanabout 35% of totalNOxemissions (Ali and Athar, 2008). In the respiratory system NO2is transformed Stepper online in Pakistaninto secondary pollutant such as nitrates and nitricacid (HNO3) which act as respiratoryStepper online in Pakistan irritants. Exposures to NOxforlonger duration may affect the lungs structure, lungs immunesystem,Stepper online in Pakistan lungs metabolism, and impair the lungs function. Ascombustion of CNG takes Stepper online in Pakistanplace at a lower flame temperature thangasoline/diesel fuel, which results in low NOxemissions (Tilagoneet al., 1996).11.4. Hazardous additives in liquid hydrocarbon Stepper online in PakistanfuelIn Pakistan the other major hazardous vehicle emission is causedby the high concentration of sulfur in High Speed Diesel (HSD). Thecountry maximum allowable value of Sulfur in High Speed Diesel eHSD is 1 percent (10,000 ppm), while the Stepper online in Pakistanneighbor countries Chinaand India have set the limit of 50 ppm for the same. The sulfurcontent of diesel fuel has direct correlation with the production ofparticulate matter-PM in combustion. Stepper online in PakistanReducing sulfur content offuels will lower the cStepper online in Pakistanoncentration of sulfur dioxide (SO2) and sulfatePM in exhaust emission (Saiyasitpanich et al., 2005; Bielaczyc et al.,2002) As CNG does not consist of any sulfur content thus lower theemission of sulfate PM from all vehicles, and decreases maintenancecosts, as high sulfur levels cause corrosion of Stepper online in Pakistanfuel injector and pistonrings, oil acidification and overall engine wear.Unlike gasoline or diesel, CNG is Stepper online in Pakistandirectly utilized in vehiclewithout any refinery processing i.e. no chemical agents are addedto CNG fStepper online in Pakistanuel. While many hazardous additives such as olefins andaromatic compounds are added to gasoline to improve its octanenumber. These olefins and aromatic additives affects the perfor-mance of the engine and by lowering their concentration will resultto lower octane number. These octane enhancing additives are notenStepper online in Pakistanvironmentally friendly because aromatics produce more smokeM.I. Khan, T. Yasmin / Journal of Natural Gas Science and EnStepper online in Pakistangineering 17 (2014) 99e109104
Author's personal copyand smog and increase the NOxemission. Maximum allowableEuropean requirements for olefins and aromatics are 18 %v/v and42% v/v respectively. Once again the quality of Pakistani gasoline isvery poor as compared to European Union standards for examplecurrently there are no high limits for the concentration of olefinsand aromatics for gasoline imported to or produced in Pakistan(Yasin et al., 2008).11.5. Particulate matter ePMIn order to avoid more costly methods of boosting octane numberof gasoline, petroleum refiners inPakistan have ads tetraethyllead eTEL to gasoline blends. However, the costs to society in form ofadverse health effects from lead are comprehensive and well-documented. These include but not limited to immune deficiency,kidney function impairment, coronary artery disease,prematuredeath, reproductive and developmental problems in children.Owning to this poor quality of gasoline and HSD, road traffichasbeenidentified as major source of lead and nitrous oxide, and an impor-tant contributor of particulate matter (PM-10), carbon monoxide eCO and sulfur dioxide eSO2in Pakistan (Brandon, 2010).In a recent study by Alam et al. (Majid et al., 2012) using anoptical particle counter documented 24 h average PM10 concen-trations of 461mg/m3,198mg/m3,448mg/m3, and 540mg/m3forKarachi, Lahore, Rawalpindi and Peshawar respectively which ismuch higher than comparable 150 ppm WHO standards. Exposureto traffic-related particulate matter in most of the urban area ofPakistan has been shown to increase the risk of various healthproblems. CNG vehicle releases very small amounts of particulatematter because CNG does not contain aromatic compounds such asbenzene (Cho et al., 2007).Natural gas majorly comprises of methane which does notpossess carbonecarbon molecular bonding and as result combus-tion of natural gas leads to a significantly lower possibility ofbenzene rings formation, which subsequently conduce to decreasein formation of polycyclic aromatic hydrocarbons (PAHs) withvarious carcinogenic potencies (Warnatz et al., 1999). ThereforeCNG eliminates the risk to the health of consumers who mayreceive direct exposure of the carcinogenic substance.The rising concern about the potential health impacts of tradi-tional Pakistani gasoline & HSD exhaust emissions, have made CNGa very appealing alternative fuel for road transport with advantagesof being environmentally friendly fuel. Although specific studieshave not been carried out to assess the environmental & healthbenefits of the CNG program in Pakistani cities, however it isassumed based on the global research findings and experiencesthat in contrast to the gasoline/diesel, the natural gas vehicles offergreater advantage of reducing exhaust emissions due to the lowcarbon content. For example, the U.S. Environmental ProtectionAgency calculated the environment friendly potential of CNG ve-hicles vis-à-vis gasoline fueled vehicles and summarized the resultsas following (Clean Alternative Fuels, 2012):Reduces CO exhaust emissions by 90%e97%Reduces NOxexhaust emissions by 35%e60%Reduces CO2 exhaust emissions by 25%Significantly reduces non-methane hydrocarbon exhaust emis-sions by 50%e75%Releases minute or no PMEradicate evaporative exhaust emissionsReleases less toxic and carcinogenic pollutantsNGV America, Encana estimate and Environmental ProtectionAgency conducted a comparative analysis of CNG vs Diesel vehicleemissions as shown in Fig. 12Analysis of ambient pollutant levels before and after theexecution of CNG program in the country shows significant re-ductions in PM, CO, CO2, TSP, NOx&SO2.On general for over 3.2 NGVs in the country, there is corre-sponding decline in the transport emission as highlighted in Table 2(RazaNasreen, 2008).Few years ago therewas no nationalAuto Fuel Policy in Pakistan.To control vehicular pollution resulting from the dramatic growthin vehicular traffic in the country, Pakistan Environmental Protec-tion Agency (Pak-EPA) launched National Environmental QualityStandards (NEQS) for exhaust emissions of vehicles in 2009. Table 2depicts the emission limits for passenger car according to thispolicy. As can be seen the limits are very similar to Euro II emissionfor same category vehicles. The implementation of this policy willfurther boost the growth of CNG program in the country.12. ProblemsBesides several advantages of CNG, there are some negativeeffects which CNG introduce in the energy sector of Pakistan.1. Pakistan present gas consumption growth rate shows that ourgas needs will increase from 5400 mmscfd in 2012e8400mmscfd in 2020.2. Due to the rapid replacement of diesel and gasoline vehicle withCNG powered vehicles, the prices of natural gas are rising upvery sharply. As evident from Fig. 9, the prices of CNG raisednearly 8 times in the last 13 years due towhich domestic naturalgas prices are also raised very sharply and this increasing shareof transport in the gas consumption has made it a contender forFig. 12. CNG vs Diesel vehicle emissions (Natural Gas and Transport, 2012).Table 2Decline in the transport emission due to CNG program.S. no. Emissions Kg/Km01 Carbon dioxide eCO235502 Carbon monoxide eCO 768003 Oxides of Nitrogen eNOx608004 Hydrocarbons eHC 89605 Particulate matter ePM 7616M.I. Khan, T. Yasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109 105
Author's personal copythe domestic/household sector. The questions such as either tosupply natural gas for ‘cooking meal for poor on costly fuel’or‘fueling vehicles of the wealthy people on inexpensive fuel’arebecoming increasingly prominent in the country.3. Due to gas curtailment to CNG sector, CNG station are now openonly four days a week, Owing to this, whenever CNG suppliesresumed motorists have to wait for hours in long queues to gettheir tanks filled (Fig. 13), clogging traffic and car drivers waitingfor CNG filling cannot serve passengers. Many taxi drivers arereluctant to use petrol; those who do charge higher fares thantheir CNG-burning counterparts.4. Increasing CNG cylinder accidents are a major threat to life inPakistan. Although CNG is much safer fuel as compare to gaso-line & diesel, but owning to low quality CNG system material e.g.CNG cylinder, CNG design & installation, maintenance systemetc. and lack of strict government CNG vehicle safety regula-tions, every year several CNG vehicles accidents took place inthe country. Table 3 summarizes the major CNG accidentshappened in the country during the period 2003e2012. Table 4Fig. 14 highlight some of the above mentioned CNG vehiclesaccidents. Analyzing the causes responsible for the above reflectedCNG vehicle accidents, following technical deficiencies can bederived.Leakage of gas from high pressure piping and cylinder valve dueto various reasons.The use of non-certified gas cylinder.Stepper online in PakistanPulling out of high pressure gas pipes from fittings.Bursting of unapproved cylinders, weldedStepper online in Pakistan cylinders and thecylinder not made for CNG.Short circuit in Stepper online in Pakistanelectrical wiring creating sparks.Bursting of unapproved valve.Generally, the conversions were found to have much lowerquality than the OEM vehicles.Clamping of gas pipes was not sufficient Stepper online in Pakistanin several locationsIn order to prevent CNG-related accidents, ministry of petro-leum has formed a task force to draft a lawStepper online in Pakistan in consultation withstake holders. Following measures are being taken under task forceto make safe usage of CNG:1. More than 100 workshops all over the country duly approved byChief Inspector of ExplosivesStepper online in Pakistan (CIE) and certified by HydrocarbonDevelopment Institute of Pakistan (HDIP), have started certi-fying vehicles, in this campaign all un-approved CNG Stepper online in Pakistanequipmentincluding unapproved CNG Cylinders shall be replaced.2. HDIP and CIE being the Stepper online in Pakistanstatutory bodies for the purpose aredeveloping detailed criteria for installation of CNG system in thevehicles, especially Public Service Vehicles.3. Allowing only approved brands CNG cylinders manufactured asper NZS 5454-Stepper online in Pakistan1989 standard and the installed CNG cylindershall be pressure tested Stepper online in Pakistanafter every five year.4. Un-certified Vehicles shall not be given fitness certificate/routepermits by relevant transport authorities.5. Uncertified vehicles shall not be allowed to be filled by Stepper online in PakistanCNGStations.6. Massive media campaign is also launched for awareness ofsafety aspects associated with usage of CNG.13. ConclusionFrom the above details we may draw conclusions as follows:Natural gas is clearly a powerful weapon for Pakistan in thebattle to replace oil in the transportation sector, to reduce airpollution and to Stepper online in Pakistanaddress the challenge posed by climate change.To quantify the environmental benefit of the Stepper online in Pakistancountry CNG pro-gram, there is a need for qualitative and quantitative assessmentof ambient aiStepper online in Pakistanr of quality in major cities of Pakistan.CNG is going to witness a phenomenal growth with growth oftransmission pipeline network and implementation of city gasdistribution netwoStepper online in Pakistanrk in various cities of the country. In Pakistan,from the vehicle owner’s prospective the attraction for CNG isnot its environment impact, but its cost viz-a-viz petrol anddiesel. It is this differentialStepper online in Pakistan in the operating cost of a vehicle thatis the driving force to opt for CNG.The country has extremely efficient gas transmission and dis-tribution networks for utilization of natural Stepper online in PakistanStepper online in Pakistangas transportationfuel. However, in order to meet the shortfall of gas for CNG in-dustry, it is essential that natural gas must be imported on fast-track basis either through Stepper online in PakistanTurkmenistan-Afghanistan-Pakistan(TAP) or IranePakistan gas pipeline project or LNG. There is avital need for improvement in exploration activities and to in-crease domestic gas production.Discontinuing the use of CNG aStepper online in Pakistans a transportation fuel will add tothe economic woes of the government that will have to spend 5- 6 billion dollars more to import additional quantities of petroland diesel.The decision by the government to curtail the gas supply to CNGsector will adversely affect hundreds of thousands of workersFig. 13. Long queues of vehicles waiting for filling of CNG at refilling station.Table 3NEQS vehicles emission standard, 2009, (g/Km).Type of vehicle Category Tiers Fuel CO HC þNOxPM ApplicabilityPassenger Cars RW <2500 Kg Pak-II Diesel 1 0.7 0.08 1st July, 2012Gasoline 2.2 0.5 e1st July, 2009 (new car)1st July, 2012 (older than 2009 car)VsPassenger Cars Euro II DieselStepper online in Pakistan1 0.6 1 1996Gasoline 2.2 0.5 eM.I. Khan, T. Yasmin / Journal of Natural Gas Science and Engineering 17 (2014) 99e109106Stepper online in Pakistan
