When discussing the automotive industry, diesel has long had a negative image. Many people hear the words "diesel engine" and automatically have visions of loud clattering noises and belching clouds of blueish-black smoke depositing a layer of soot on everything nearby. Most of this is based on a consumer's limited knowledge of the transport trucks chugging along the highways and interstates.
Even among those who are not in diesel's fan camp, there is no argument that diesel engines are far more efficient than their gasoline counterparts, especially if the vehicle has an EGR engine. As advances are made that work toward making vehicles running on diesel cleaner and quieter, the trend toward replacing gas engines is starting to take an upward turn.
With the global concern for protecting the environment now in the forefront of product research and development, diesel engine technology is not sitting idle. New claims promise that when it comes to environmental-friendliness, making a non-gasoline purchase is the way to go. So, what exactly is it that makes the diesel engine superior when it comes to environmental concerns?
Gas Engines vs. Diesel – What's the Difference?
Theoretically, the two engine types are similar. They both operate with the use of internal combustion engines that convert the available chemical energy from a fuel into usable mechanical energy. The mechanical energy then takes over and forces the pistons inside the cylinders, which are connected to the crankshaft, to move up and down. The vehicle moves forward, thanks to this linear motion creating rotary motion to turn the wheels.
Combustions are small explosions the engine uses to get its energy out of the fuel. How this process happens differs between gas and diesel, and it is the main difference between the two. For vehicle engines running on gas, the fuel mixes with air, gets compressed by the pistons, and ignition happens when sparks are released from the spark plugs.
Diesels work the opposite way. Compression of the air occurs before the injection of fuel. Compressed air then heats up, igniting the fuel. Now that you understand the difference, let's explore why diesels are just plain better than gas engines.
1. The Fuel
Crude oil is the base for all petroleum fuel. Naturally found beneath Earth's surface, the refining process separates fuel types, among them diesel, kerosene, jet fuel, and traditional gasoline. If you have ever seen or smelled diesel fuel, then you will know it is radically different from gasoline.
Being both oilier and heavier than regular gas, often you may hear diesel referred to as "diesel oil." It has a boiling point higher than water, meaning that it evaporates at a much slower rate. Chemically, diesel contains longer chains of carbon atoms. It has a higher density of energy and requires less refining to produce, making it less expensive and more efficient.
The environmental impact of diesel has both pros and cons, although great strides are being made to reduce or eliminate the negative aspects. On the positive side, global-warming-causing emissions such as carbon dioxide, hydrocarbons, and carbon monoxide are emitted in smaller amounts when burning diesel. This is a huge contributor to making the air we breathe safer.
Negatively, diesel releases higher amounts of particulates and nitrogen compounds when it burns, and these are said to lead to smog, acid rain, and other related conditions. However, in the last several decades, there has been a real push to improve the cleanliness of diesel fuel when it burns and to improve engine performance.
2. Sustainably Clean Options
Advances such as ultra-low sulfur diesel (ULSD), an improved refining option, are lowering the output of harmful emissions, and the process of developing upgraded engines with cleaner fuel options is becoming easier. One such cleaner fuel is biodiesel—chemically altered animal fat or plant oils instead of petroleum. The advantage to biodiesel is that little or no modifications are needed for most engines to run on it, and it can either be used on its own or added into regular diesel fuel. The inventor of the diesel engine, Rudolph Diesel, had considered fueling his invention with vegetable seed oil back when he patented it in 1898!
3. Quicker Refining Process
Since diesel does not require the long refining process time of gasoline, it is both less expensive and easier to produce. Gasoline is so expensive to produce in the United States because of the stringent restrictions and regulations attached to the refining process. As diesel fuel becomes the choice option, there is a decreased need for gas production. As refining gas emits greenhouse gases, this impact will be reduced by producing less.
4. Lower Volatility
Due to the lack of additives as compared to gas, diesel is a far more stable fuel. Even when working with it in confined spaces, diesel is far safer to breathe. Lower volatility means it is more difficult for it to start a fire, as evidenced by the fact that you can burn colored diesel in an oil tank to heat a home.
5. EGR Engine System
Although both types of engines can use the exhaust gas recirculation system (ERG), 99% of the manufacturers of diesel vehicles install these diesel engine systems. They are key components for decreasing the working temperature of the engine, lowering emissions from C02 and carbon, and increasing gas mileage.
The operating process is simple. Instead of the exhaust pipe releasing the fumes like it usually would, they get sent back to the engine for re-burning a second time. Theoretically, the environment receives only 50% of the fumes it would have if they were not re-used.
6. Enhanced Performance Parts
To further increase the standards manufacturers are trying to adhere to concerning burning cleaner fuels, advanced technologies such as catalytic converters and CRT particulate filters can be found under the hood. Although catalytic converters have been around since 1975, they were first released to the marketplace to convert destructive pollutants into less damaging emissions.
CRT or Continuous Regenerating Technology particulate filters are passive two-stage systems that use nitrogen dioxide (N02) to oxidize the soot from burning diesel. With both parts installed on a vehicle, upward of 90% of hydrocarbons, C02, and other particulate matter is reduced.
Protecting the environment is a collective effort. From recycling to reducing water usage, to choosing to lower our carbon footprint, we are each responsible for doing our part.
Diesel engine manufacturers are taking a huge step for us by providing us with the opportunity to help save our planet by choosing their more environmentally friendly options, and it is a step that we shouldn't be wasting.