Article contributed by Mr. Hitendra Bankoti, Assistant Professor, Faculty of Technology and Computer Applications.
Do you know which fuel is used abundantly worldwide in automobiles and machines?
The obvious answer is petroleum fuels. You could have known the importance of gasoline fuel in world economy. Its uncontrolled exertion depletes the deposit of fossil fuels. It’s estimated that if the use continues as fast as what we do now would cause to deplete all fossil fuels in another 20 to 25 years. Apart from petroleum, there are a couple of fuels and energy sources which are renewable in nature and could be utilized in vehicles. We can have a glance at such alternative fuels for automobiles.
Need alternative fuels in cars?
Why would we need to invest tons to seek out alternate or surrogate energy resources and fuels in automobiles? There are maturedand proven ways by which technologies assist in extraction of energy from fossil fuels and IC engines had utilized this in vehicles for an extended period of time in the past. Petroleum fuels are common in automotive industry. Technologies to extract petroleum and obtaining power through its combustion are well established. Then, why do we need to seek for alternative fuels or energy resources?
Global warming has already had observable effects on environment. Emissions of gases (Nitrogen Dioxide, Carbon Dioxide, Carbon Monoxide etc.)From automobiles, environmental pollution, depletion of fossil fuels etc. make alternative fuels in vehicles very important. According to statistics 1 litre of Petrol emits 2.3 Kg of Carbon dioxide when it is burnt. 2.3 Kg of Carbon dioxide is not a low value!! How does it impact the environment? As per WHO “Transport accounted for about 23% of global carbon dioxide emissions in 2010 and 27% of end-use energy emissions with urban transport accounting for about 40% of end-use energy consumption. Carbon dioxide persists in the atmosphere for over a century, with long-term warming effects (IPCC, 2014).” Greenhouse gases increases the temperature and therefore the increased temperature disturbs the balance of environment. Desertification, melting of ice bergs, water level rise etc. are a few negative impacts of global warming.
Disadvantages of fossil fuels
- Fossil fuels are non-renewable source of energy which depletes and aren’t produced as quick as the rate of depletion
- Rate of generation of Fossil fuel is very long as compared to rate of depletion
- Fossil fuels emit air pollutants – Combustion of fossil fuels emits green-house gases which causes pollution.
- Global warming – as a results of green-house gas emission, atmospheric temperature increases.
Benefits of alternative fuels
Upon discussing a bunch of disadvantages of fossil fuels let’s check a couple of benefits of Alternative fuels.
- Alternative fuels are replacement for conventional fuels.
- They cause less pollution.
- They are renewable sources of energy.
- Alternative fuels increases energy security by providing opportunity to supply it in every country.
Alternative fuels have disadvantages also, Alternative fuels are costly, technology isn’t matured, comparatively and competitively, low energy density etc.)
Alternative fuels for cars
Alternative fuels that could have used in vehicles are listed below. A short explanation of every fuels is additionally presented. These alternative fuels for vehicles are already tested and proven technology in automotive industry. Here may be a list of top alternative energy sources for a vehicles:
Biodiesel may be a renewable source of energy that produced from vegetable oil, animalfat, restaurant and household grease etc. They are produced by chemically reacting lipids with an alcohol producing carboxylic acid esters. Since it is made from organic matter it is biodegradable & renewable source of energy. Diesel engines can use biodiesel alone or blended with conventional petro-diesel fuels. It works with existing engines with very little or no modifications. Moreover its applications are beyond transportation, it can be used for heating homes, generating electricity, producing hydrogen for use in hydrogen fuel cells, degreasing tools and engine parts etc. Biodiesel combustion Produces 74% less net carbon dioxide emissions than conventional diesel.
Methanol is an alternate fuel that’s less costly to supply for combustion engine vehicles. Methanol is used as a fuel alternative in race cars by rule because of the fact that it does not produces any opaque cloud of smoke in the event of an accident. Similar to biodiesel, methanol also can be used alone and blended with conventional petroleum fuels.Using methanol as a fuel in spark-ignition engines can offer an increased thermal efficiency and increased power output (as compared to gasoline) due to its high octane rating and high heat of vaporization. Besides, it is also being used as a cooking fuel in many countries like China , India etc.
Ethanol or ethyl alcohol is an alternate fuel for cars that made up from sugarcane or corn. With relatively high energy density, ethanol fuel may be a successful replacement for fossil fuels. It’s the oldest known source of renewable energy for automobiles: Henry Ford’s Model-T ran on a mix of a gas and grain alcohol as fuel. Gasoline gallon equivalency of ethanol is approximately 1.5. That means 1.5 unit by volume of ethanol can replace 1 unit by volume of gasoline in terms of energy.Ethanol blended fuels are widely utilized in USA,Brazil, and Europe. Bio-ethanol is being produced by converting carbon based agricultural feedstock like sugar cane, bagasse, grain, barley, potatoes.
- Compressed air
Another source of energy for automobiles is compressed air. Energy density of compressed gas is low and its pressure falls as air is taken from the tank. A pneumatic motor which works on expanding compressed gas is employed to convert the energy to work in form of either linear motion or a rotary one. Even though compressed gas results no pollution, its inefficiency in conversion and low energy density make it less competitive. Regenerative braking are often utilized in compressed gas vehicle to utilize the energy that might have dissipated as heat during braking. Various companies like MDI, Tata, Engineair pty ltd, Peugeot etc. are researching in development of compressed air cars.
Hydrogen as a fuel can be utilized in two ways during the operation of a vehicle. Hydrogen is often burned in combustion engine to power the car to maneuver or it is often used with oxygen in fuel cell to run electric vehicle. Honda Calrity, Toyota Mirai are a couple of samples of hydrogen powered vehicles. Hydrogen fuel is expensive and highly inflammable. So they are not popular in automotive industry.
Electric energy is another sort of energy that is being currently utilized in vehicles. Is electricity a fuel? Can we consider it as a choice of fuels for cars? Yes. We can. Electricity is considered as an alternate fuel in 1992 under energy polity act. Electric vehicle has zero or very low exhaust emission. An electric vehicle may be a vehicle that uses one or more electric motors for propulsion. An Electric battery stores energy to propel the vehicle. An electric vehicle converts electric energystored within the battery to energize the vehicle using electric motors. As we know, they EVs aren’t limited to road transportation, Electric aircraft Impulse 2 revolved round the earth using electric energy
.Electric vehicles are classified into Battery Electric Vehicle (BEV), Plug-in Hybrid Electric Vehicle (PHEV) & Hybrid Electric Vehicle (HEV).
Pure battery electric vehicle uses only electricity because the source of energy and that they don’t emit any gases. Battery Electric Vehicles are environmental friendly.
Hybrid Electric Vehicles uses one or more sources of energy in conjunction with electricity. The popular combination is electrical motor plus conventional combustion Engine.
Battery capacity, Lack of power, reduced range, charging time etc. are some of the drawbacks of electric vehicle. Tesla motors manufacture high end and affordable electric cars with largest range. Since electric cars are being manufactured world-wide by automotive manufactures like Volkswagen, BMW etc., they have started gaining popularity and that makes them acceptable. You can read the list of world top electric manufactures, electric vehicles aren’t rare. Almostover two million electric cars were sold in the year 2017.
- Natural gas
Compressed Natural Gas (CNG), Synthetic Natural Gas (SNG) and Liquefied Petroleum gas (LPG) are one of the alternative fuels utilized in a vehicle. Natural gas is mixture of gases which are rich in hydro-carbons and usually occurs underground in association with petroleum and may be utilized in vehicle as fuel. Existing gasoline powered vehicles could also be converted to gas vehicle or they will be used as bi-fuel (petrol and CNG) vehicle. Due to less emission of environmental polluting gases, CNG vehicles are popular in cities like Delhi, Mumbai etc.
Liquefied Petroleum Gas (LPG) is a mixture of Propane and Butane. Some variants of gas are primarily propane. So they are called propane fuel. Liquefied petroleum gas which is usually called Autogas is that the third largest used automotive fuel in the world. It is one among the choice of fuels for cars. Carbon dioxide emission of autogas is around 15% but that is primarily of petrol.
- Fuel cell
Fuel cell is an electrochemical cell that converts energy from fuel into electricity through an electrochemical reaction of hydrogen fuel with oxygen or another oxidant.There are many renewable sources we could use to get the hydrogen used in fuel cells. These include electrolysis, fermentation and even biodiesel.A continuous supply of fuel is important in cell to get electricity. Generated electricity is used for vehicle propulsion.As alternative fuel for cars there biggest benefit is they produce water vapour as exhaust emission.
Hyundai, Honda and Toyota all offer fuel cell vehicles, and many other brands are working on their own models. And according to Jennifer Gangi of the Fuel Cell and Hydrogen Energy Association (FCHEA), fuel cells are gaining traction in forklifts and other equipment in warehouses and distribution centres across the country. “Customers are finding value in improved operational efficiency and cost savings using fuel cells in vehicles over battery units.”
Moreover it may also be used for powering any devices that use batteries, producing clean energy for building, fuelling booster rockets for space shuttles etc.