LPG has been used as Auto Gas for a number of years in many countries around the world. In most countries the Government has played an instrumental role in legalizing its usage as an auto fuel and has primarily been driven by the following factors:

• Its clean burning properties with very low amounts of pollutant
• Its relatively lower price to Petrol and other fuels and
• Its relative ease, with which it can be transported.

Pakistan has witnessed an increase in the production of LPG by over 60% in the last 12 months. This has enabled LPG to become available in all those areas where previously due to a shortage of supply the product was not available. Unlike most countries, Pakistan has an extensive natural gas pipeline network covering most of the major cities.

However there are still a number of cities and villages that do not have access to natural gas and therefore resort to using other fuels. These include bio mass, wood, kerosene and LPG.

The current producer price of LPG coupled with the marketing companies’ and distributors’ profit margins make it unaffordable to the common man living in the village. This is not to say that the increased production has not benefited these people. More LPG is being consumed today in areas where there is no natural gas, than was the case a year ago.

However; due to its relative inexpensiveness to petrol, more and more LPG is being consumed by the auto sector in Pakistan. The primary users in this sector are the rickshaws and taxis. This paper will present a detailed comparison of fuel costs, but suffice it to say that a user of LPG can travel the same distance as that of a user of Petrol in about less than half the cost.

With the increase in production of LPG and the recent hike in petrol prices the auto sector accounts for more than half the consumption of LPG in Pakistan. Attempts by the authorities to curb its usage have always been met with severe resistance from its users and to date have not been successful. This fact is not surprising because the common man driving a rickshaw or taxi can no longer afford petrol at the current prices. And with the petrol prices set to rise, this trend will only increase.

An alternative to LPG in the auto sector which the Government has been promoting is CNG. As compared to LPG, a CNG kit is three times more expensive that an LPG kit. The former costs Rs. 30,000 whereas the latter about Rs. 10,000. Secondly, in terms of mileage and engine performance CNG is inferior to LPG. (A detailed comparison follows). Most importantly, its availability is limited to the availably of natural gas pipeline.

Let me clarify at the outset that this paper is not promoting LPG in favor of CNG. The latter has been of great economical and environmental benefits to both the Government and the masses. This paper is only recommending that LPG should be used in conjunction with CNG and the choice of fuel should be left to the consumer. This is the case in many countries; including India and China.

Pakistan is a country well endowed with natural gas reserves and in order to reduce dependence on imported crude it is necessary for the Government to promote fuels such as CNG. But since its availability is limited and it is more expensive than LPG; not everyone has access to it.

Major Air pollutants in Fuels

Each fuel has different emission characteristics, with consequently different impacts on public health. The key regulated pollutants, and their impacts on human health, are summarized below:

Oxides of Nitrogen (NOx) include several gaseous compounds made of nitrogen and oxygen emitted by both spark-ignition and diesel vehicles. Oxides of Nitrogen are lung irritants and can increase susceptibility to respiratory illness (especially asthma) and pulmonary infection.

In addition, NOx contributes to the formation of ground level ozone, which is a major constituent of smog. Smog severely irritates the mucous membranes of the nose and throat, which can lead to coughing and even choking. It also impairs normal functioning of the lungs and long-term exposure may cause permanent damage.

Volatile Organic Compounds (VOCs) or Hydrocarbons (HC) are gaseous organic chemical compounds derived from diesel, gasoline and most alternative fuels which also contribute to the formation of ground level ozone.

As well as being emitted from the tailpipe of motor vehicles, these compounds are also released to the atmosphere by vehicles during refueling, through evaporation via leaks in fuel filler caps, hot engine parts or failures in a vehicle’s on-board vapor recovery systems.

Fine Particulate Matter (PM) is emitted by both diesel and spark ignition engines, though diesel sources tend to dominate. In 2002, after much research, the US EPA concluded that PM in diesel exhaust causes acute throat and bronchial irritation, poses a chronic respiratory hazard to humans, and is a likely carcinogen. Particles may also absorb potentially health-threatening organic "air toxics" found in engine exhaust.

LPG Compared to:

Table 1, above, summarizes LPG emissions compared with both ultra-low sulphur petrol and ultra-low sulphur diesel. Of particular note is the huge gap between diesel and LPG emissions of oxides of nitrogen (NOx) and fine particulate matter (PM).

NOx impairs the lung function in humans and is strongly linked to increases in asthma attacks. PM is a known carcinogen and intense efforts are underway to limit human exposure to this pollutant.

Over the coming decade and beyond, petrol, diesel, CNG and LPG will continue to be the most viable fuel types available to the motoring public and transport fleets.

Rational decisions on fuel selection are strongly influenced by availability, cost (operating and capital) and suitability for any particular application. Using these criteria, it is highly unlikely that any single fuel will be the optimal choice for all transport needs, at least in the foreseeable future. However LPG as Autogas does have several advantages over other fuels:

Advantages over other fuels

• The combustion of Autogas is smoother as a result of the higher octane content. Unlike other fuels, no additives are required to guarantee high quality.
• Autogas contains no lead and is therefore cleaner and leaves no residue.
• It is actually better than petrol because it reaches the engine in pure gas form with improved combustion resulting in fewer knocking.
• With modern technology, there is very little discharge of carbon monoxide, and compared to petrol and diesel, the exhaust fumes contain less harmful substances.
• The life of the engine is extended as a result of the absence of acids and carbon deposits. One can safely state that engines on LPG last almost twice than that on Petrol.
• Less carbon means less fouling of spark plugs and points i.e. less wear and tear.
• The engine oil does not become diluted with a consequential reduction in servicing costs.
• Unlike diesel, one does not have to adjust their driving style. Cold starting is no problem; engine performance is almost exactly the same as with petrol. There is no spilling when filling the tank and no possibility of theft or pilfering. Engine noise is low and one will be driving in a more environment-friendly way.

The environmental advantages of Autogas for automotive use are indisputable.

The practical, operational and environmental characteristics of all four commercially available fuels are summarized in the following Table.

For passenger cars, the low initial purchase price of petrol and LPG vehicles, together with their relatively low pollutant emissions, make these fuels well suited to mainstream private and business use. Significantly lower greenhouse emissions and generally lower pollution levels from current-technology LPG cars tip the balance in favor of this fuel.

Categories of Vehicles:

Light Commercial Vehicles (LCVs) are used very extensively in urban areas. These include rickshaws, taxis and private vehicles. Hence, although they can operate satisfactorily on any of the commercially available fuels, the deciding factor for the majority is the cost of the fuel and convenience of availability.

Medium Trucks, such as those widely used for urban delivery and freight carriage,
currently operate almost on petrol and diesel. However LPG engines for mini buses and trucks are now available and these deliver measurable economic benefits, both in direct fuel costs and through extended access hours due to their lower noise levels.

Heavy-Duty Trucks, particularly those on long-haul operations, are effectively restricted to diesel operation, due to fuel availability considerations coupled with the ruggedness and fuel efficiency of heavy-duty diesel engines.

Dual fuel diesel/LPG or diesel/CNG trucks, in which a virtually standard diesel engine burns both fuels together, have demonstrated their ability to reduce PM and greenhouse emissions but to date have achieved only very minor penetration into the trucking market. Further work is needed to achieve satisfactory levels of reliability and consistency from these conversions, and to gain the confidence of the trucking industry.

Buses have traditionally used diesel, but the low cost of CNG, coupled with its reduced noise levels and "clean" image, has led to the recent ideas about converting them to CNG. Adoption of CNG involves significant investment in a fuel compression, storage and dispensing facility, as well as a large premium on the vehicle purchase price to cover the cost of installing and structurally supporting multiple high-pressure on-board fuel cylinders.

An alternative to this would be to convert buses on to LPG. These engines share with CNG the same low noise and emission levels, but do not require high-cost fuelling facilities, nor extensive vehicle modifications to accommodate the fuel tanks.

In summary, it can be seen that there is a continuing role for all the currently available fuels, over the foreseeable future. There is, however, considerable scope to improve air quality, reduce community health problems and lower greenhouse emissions through the increased uptake of both LPG and CNG.

What about CNG?

CNG shares many of the positive environmental advantages of LPG, such as lower NOx than petrol or diesel, and much lower particle emissions than diesel. As such, there is little to differentiate between LPG and CNG in respect of noxious emissions affecting local or regional pollution levels.

CNG is also often heralded as a very greenhouse "friendly" fuel because of its low carbon content and hence low CO2 emission levels. Although CO2 is certainly the dominant greenhouse influence, it is often overlooked that natural gas (CNG) is composed almost entirely of methane, which has a greenhouse effect 21 times greater than that of CO2.

Extensive testing has shown that residual unburnt methane in the exhaust of some natural gas vehicles can completely outweigh any greenhouse benefits that CNG engines theoretically offer through reduced CO2 levels. LPG contains only negligible amounts of methane, so there is no potential for this gas to compromise LPG’s inherently low CO2 emissions.

LPG vs. CNG

A comparative study of the two gas-based fuels vis-a-vis diesel and petrol shows that LPG gains over CNG on several counts. The impact on greenhouse emissions is considerably less than other fossil fuels when measured through the total fuel cycle. Moreover, for the same volume, LPG requires a tank that is one-third the size of a CNG tank.

LPG is a clean burning, high octane, environment friendly fuel. It generates no smoke or fumes and emits extremely low levels of Carbon Monoxide, Hydrocarbons and Nitrogen Oxides. It emits virtually no sulphur oxides and no particulate matter.

Vehicles that run on CNG experience a reduction in engine power by up to 20 percent, primarily due to gas carburetors. On the other hand, LPG can be used in a way similar to diesel, with liquid sequential multi point fuel injection (MPFI). In a normal CNG tank, with the reduction of quantity, engine power comes down significantly. So, to maintain engine power at optimum levels, pressure-creating systems are installed, which leads to the increase in conversion cost.

LPG on the other hand, doesn’t have such complications. The heavy tanks that CNG requires are not required for LPG applications. This fuel also does not face the problem of power reduction. A case in point is the LPG used in a kitchen, where LPG burns with the same intensity throughout, irrespective of the level of the product in the cylinder.

However, the greatest advantage of LPG is that it can be easily made available through out the country. While CNG dispensing requires special equipments, dispensing Auto LPG is much easier. Again, transportation and distribution of CNG needs pipeline networks, but LPG can be made available right at the consumers’ doorstep. This very fact has helped authorities decide on taking up the cause of Auto LPG at a much larger scale.

Cost Comparison of LPG Vs CNG and Petrol

1 Kilogram of LPG = 1.79 liters (Water Capacity)

Average retail price of LPG per kilo is Rs. 35.

1 kg = Rs. 35

Therefore it is fair to say that 1.79 liters of LPG is for Rs. 35.

1 Liter of LPG is therefore equal to Rs. 19.55.

Compare this to the Average price of Petrol for the current year; Rs. 45 per liter.

It is safe to say that in Rs 100, a vehicle running on LPG can travel almost 2.5 times the distance as that of a vehicle running on petrol. Compared to CNG as well, a vehicle running on LPG gives better mileage plus there is no reduction in engine power.

Legalizing the use of LPG in the auto sector would cause the import of the product to increase. Currently there is a $100 per tonne differential between the price of local and imported LPG. This fact alone makes import of LPG unattractive to most marketing companies. However this would no longer be the case if it was allowed to be used as Autogas, since as I have demonstrated above that as long as the overall cost of LPG consumed per Rs. 100 remains lower than that of petrol there will always be an incentive to use it.

We may assume that the average cost of imported LPG for the whole year may be Rs. 50 per kilogram.

That would translate into Rs. 28 per liter.

Even at this high end price, LPG would compete most favorably with both Petrol and CNG.

Autogas: Safety Record

From the safety perspective in automobiles, LPG is considered as safe as any conventional fuel. Authorities worldwide have successfully carried out several crash and fire tests on auto LPG. The pressure at which CNG (at 200 bars) and LPG (at 5-7 bars) is stored also makes LPG a better and safer option. Experts also say that owing to the strength and integrity of the fuel tank, LPG is safer than petrol and is on par with diesel.

All tanks are fitted with relief valves that provide an escape for the gas should the tank come in contact with extreme heat. Tanks are not filled with more than 80% of total capacity. This ensures there is sufficient room for the liquid to expand when heated or the temperature being high. Moreover, in any eventuality of a leakage the gas escapes in the air and does not remain in the engine like petrol to catch fire.

Infact the use of Autogas is safer than Petrol as cylinders/tanks are kept horizontally in a car and the adapter allows the liquid to flow all the way to magnetic valves before converting to gas. An odorant is added to LPG so leaks can be detected by the distinctive smell. Autogas is a non-poisonous, non-toxic gas, so inhaling the fumes will not do any harm.

SUMMARY

Transport fuel choice has a major impact on the health and wellbeing of people living in Pakistani towns and cities. LPG is a naturally occurring and inherently low polluting automotive fuel that offers a number of social and economic benefits when compared with other commercially available fuels, including:

• Greatly reduced emissions of the two most harmful vehicle pollutants (PM and NOx), compared with emissions of these pollutants from diesel vehicles;
• Net hydrocarbon emissions ten times lower than comparable petrol vehicles;
• Much lower health cost impacts than diesel and petrol;
• 12% to 14% lower greenhouse gas emissions than petrol cars, and arguably lower life-cycle greenhouse emissions than diesel;
• Easily transportable; like petrol and is not dependent on a pipeline network.
• It is both more economical and efficient as compared to CNG and Petrol
  

Worldwide Autogas Activity

TOP TEN
AUTO FUEL MARKETS

LPG has been used as Autogas since the 1970’s. The increase in production coupled with its environmental benefits has driven the developed countries to adopt it as an alternative to conventional fuels.

France
The reduction in January 1996, of the tax on Autogas by 70%, and the increase in tax on diesel, has greatly stimulated the growth of Autogas as a road fuel.

Netherlands
A small country with a huge oil refining capacity, where the Government has accepted Autogas as a clean motor fuel for over 40 years Consequently the maturest Autogas market in the world has developed here, and around 8% of the country’s passenger cars run on Autogas. The Autogas industry is well organized and maintains a good working relationship with the Government.

Australia
Autogas, or "Go Gas" as they call it, is the main alternative motor fuel in Australia and currently represents 6% of passenger and light duty commercial vehicle demand. More importantly from the viewpoint of urban air quality, Autogas represents nearly 10% of vehicle fuel demand in the major cities There are now more than 300,000 vehicles running on Autogas in Australia. 15,000 being taxis (over 90% of local taxi fleet). The balance of the market comes mainly from the high mileage users. The driving force behind the growth in Autogas demand has been the Australian government’s policy of exempting Autogas from excise duty and state taxes. Consequently, Autogas enjoys a substantial price advantage over petrol and diesel.

South Korea
It is the largest consumer of LPG as a vehicle fuel and is the second largest taxi market for Autogas (their Autogas is 100% butane), and is still growing rapidly. Due to a shortage of LPG, the use of Autogas in other vehicles is prohibited. The same argument can be used for the Pakistani market.

Japan
The second largest consumer of LPG, as a vehicle fuel, is Japan, which uses over 1.8 million tonnes annually. Over 90% of all the taxis in Japan run on Autogas. Stringent, (Nitrogen oxides) limitations in designated areas of major cites are promoting the use of alternative fuels. It is interesting to note that the Japanese government has given no tax incentive for vehicle users to convert to Autogas and in fact taxes it. The Japanese consumer also pays the highest price for LPG consumed, compared to the rest of the world.

Thailand
The Autogas taxi market is mainly concentrated in the city of Bangkok, where many of the three wheeled Rickshaws are fuelled by Autogas.

Taiwan
Currently over 15000 vehicles on the road and the number is expected to rise to 20,000 by 2007. The Taiwan Government is actively supporting and encouraging the use of Autogas in the country because of its clean burning properties. Furthermore currently there is a subsidy of T $3/liter of Autogas consumed and the Government has recently allocated T $7 million for the construction of Autogas Dispensing stations.

New Entrants to the Auto Gas Market

Philippines
Semi-state owned Petron Corporation has recently begun marketing of LPG as Autogas to the taxi fleet only. Till date there are 78 taxi units in Manila that have converted to Autogas.

India
The Government of India has legalized the use of LPG as Autogas since 2001. Prior to that, LPG in the auto sector was being used in the same unsafe manner as it is being presently used in Pakistan.

With the legalization of its use in the auto sector, the country witnessed a rapid growth in the number of Autogas Dispensing stations. Currently over a 100 of these are in operation with another 70 to be set up by the end of this year serving some 75,000 vehicles and accounting for 30,000 MT consumption per year.

The interesting fact is that in Pakistan, where LPG usage for the auto sector is still illegal; over 300,000 MT per year is consumed in the auto sector. Consider the benefits that the country could gain in terms of safety, economy and environment if it was to legalize its usage.

Unlike Pakistan, India does not have an extensive natural gas pipeline network stretching across the country. Therefore LPG is the primary cooking and heating fuel for the domestic sector and is highly subsidized whereas that consumed for commercial/ industrial/auto sector is sold at the international market price.

In an attempt to control the pollution level, the Government of India has made it mandatory for all auto rickshaws to convert to LPG. Furthermore as mentioned above Autogas is priced at the international market price and is also taxed by the Government.

Conclusion

It is evident that both developed and developing countries around the world have legalized the use of LPG as Autogas for two basic reasons:

• To control the level of pollution
• To provide relief to the common man who can no longer afford to pay for petrol

As mentioned above, most countries have offered some sort of subsidy to Autogas to encourage its use. In Hong Kong, where scarcity of land is a problem, the Government is offering land free of all costs to those who want to set up a petrol station; provided they supply Autogas from the same station.

At a time when most countries are offering subsidies to encourage the use of Autogas, which adds to their woes of budget deficits, in Pakistan its use is widespread with no formal subsidy in place.

It is the recommendation of this paper that the Government should allow the use of LPG as Autogas in order to

• Provide relief to the taxi and rickshaw drivers,
• To lower the level of pollution to a sustainable level and
• In order to ensure that all unsafe usage of LPG by the auto sector comes to a complete halt.

This is the only solution to the menace of decanting by distributors. Furthermore as opposed to subsidizing it, the Government could actually impose a tax on Autogas (currently non existent). For example, the South Korean Government has imposed a flat tax on Autogas; 50% of existing tax on petrol.

By legalizing its use, the Government could reduce its oil import bill and also its dependence on imported oil. Furthermore with more gas fields coming up in the future (mostly rich in LPG content), the domestic production of LPG will continue to rise. One option would be to legalize its use in the public transport sector alone. An example in point is South Korea again, which has legalized its use in the taxi fleet only. Alternatively the Government could allow LPG dispensing stations to be initially set up in those areas where there is no natural gas pipeline.