Alternate fuels

In this country, it is believed that crude oils and petroleum products will be come very scarce and costly. Day to day fuel economy of engines is getting improved and will continue to improve. However enormous increase in number of vehicles has started dictating the demand of fuels. Gasoline and diesel will become scarce and most costly in the new future. With increased used and the depletion of fossil fuels alternative fuels Technology will become more common in the coming decades.

 

    All these years there have always been some IC engines fuelled with non gasoline or diesel oil fuels. However their numbers have been relatively very small. Because of the high cost of Petroleum products some developing countries are trying to use alternative fuels for their vehicles. 

    Another reason motivating the the development of alternative fuels for the IC engine is the concern over the imitation problems of gasoline and diesel engines. Combined with other polluting systems the large number of automobiles is a major contributor to the ear quality problem of the world. Quite a lot of improvements have been made in reducing emissions from automobile engines. If 35% improvement it made over a period of years it is to be noted that during the same time the number of automobiles in the world increases by 40% their why nullifying the improvements. Lot of efforts has gone into for achieving the net improvement in cleaning up automobile exhaust. however more improvements are needed to bring down the ever increasing air pollution due to automobile population. 

    A third reason for alternate fuel development is the fact that a large percentage of crude oil must be imported from other countries which control the largest oil fields. As of now many alternate fuels have been used in Limited quantities in automobile. Quite often fleet vehicles have been used for testing like taxis, delivery vans utility, company trucks. This paves way for comparison with similar gasoline fuelled vehicles and simplifies fuelling of these vehicles. 

   The engines used for alternative fuels are modified engines which were originally designed for gasoline fuelling. They are therefore not the optimum design for the other fuels. Only when extensive research and development is done over a period of years maximum performance and efficiency can be realised from these engines. However the research and development is difficult to justify until the fuels are accepted as viable for large number of engines.

   Some diesel engines have started appearing on the market they use methanol or natural gas and small amount of diesel fuel that is injected at the proper time to Ignite both fuels. most ultimate fuels are very costly at present since the quantity used is very less.

    Many of these fuels will cost much less If the amount of their usage get to same order of magnitude as gasoline. the cost of manufacturing distribution and marketing would be less. another problem with alternate fuels is the lack of distribution points like service stations where the fuel is available to the public. the public will be reluctant to purchase in automobile unless there is a large scale network of service stations available where fuel for that automobile can be purchased. on the other hand it is difficult to justify building a network of these service stations until there are enough automobiles to make them profitable. some cities have started a few distribution points for some of these fuels like propane natural gas LPG and methanol. the transfer from one major fuel type to another will be a slow costly, and sometimes painful process. In the following sections we will discuss the various alternative fuels. into three forms solid liquid and gaseous. Present day automobiles used mainly liquid fuels of Petroleum origin. However some use gaseous fuels like CNG and LPG. It is interesting to note that during early days even solid fuels like coal, slurry and charcoal have been tried. In the following sections the various alternative fuels for IC engine are discussed.

1. SOLID FUELS

Solid fuels are obsolete for IC engines. In order to have historical perspective some of the earlier attempts are described in this section.

             In the latter half of the the 1800 before petroleum based fuels were perfected many other fuels were tested and used in IC engines. When Rudolf diesel developing his engine one of the fuel he used was a coal dust mixed with water. Fine particles of coal were dispersed in water and injected and burned in Ali diesel engines. Although this never became a common fuel, a number of experimental engines using this fuel have been built over the last hundred years even today some work continuous on this fuel Technology. The major improvement in this type of fuel has been the reduction of the average coal particle size. Coal is an attractive fuel because of the availability in large quantity however as an engine fuel other methods of use simo feasible. These include liquefaction for gasification of the coal.

Liquid fuels are preferred for IC engines because they are easy to store and have reasonably good calorific value full stop in the liquid fuel category the main alternative is the alcohol. The examples of the alternate liquid fuels are,

    2.1 ALCOHOL

    2.2 METHANOL

    2.3 ETHANOL

    2.4 REFORMULATED GASOLINE FOR SI ENGINE

    2.5 WATER GASOLINE MIXTURE FOR SI ENGINES

    2.6 SPARK ASSISTED DIESEL

    2.7 VEGETABLE OIL

    2.8 BIODIESEL

3. GASEOUS FUELS

      gaseous fuels are best sweet for IC engines since physical delay is almost zero. However as fuel displaces equal amount of air the engine may have poor volumetric efficiency. There are quite a few gaseous fuels that can be used as alternative fuels. Some of the alternative gaseous fuels are these,

    3.1 HYDROGEN

    3.2 NATURAL GAS

    3.3 COMPRESSED NATURAL GAS (CNG)

    3.4 LPG

4. OTHER POSSIBLE FUELS

     attempts to use many other type of fuel have been tried throughout the history of IC engines. Orphan this was done out of necessity or to promote financial gain by some group. At present a number of biomass fuels are being evaluated mainly in Europe. These include fuels oil made from wood, barley, soya beans, rape seed, and even beef tallow. Advantages of these fuels generally include availability and low cost, low sulphur, low emission. Some of the the other alternative possible fuels are these,

    4.1 BIOGAS

    4.2 PRODUCER GAS

    4.3 BLAST FURNACE GAS

    4.4 COKE OVEN GAS 

    4.5 BENZOL

    4.6 ACETONE

    4.7 DIETHYL ETHER