Diesel engines: environmental impact and control.

Diesel engines are the most effective prime movers currently in use. Diesel engines can drive most of the world's cargo, power most of the world's equipment, and generate electricity more economically than other size ranges. However, diesel is one of the biggest causes of the global environmental pollution problem, it will be in the future, and the population of the automobile and the fuel efficiency (VMT) of the car greatly increase, the global emissions are It is expected to increase. Diesel emissions contribute to the development of cancer, cardiovascular and respiratory health affects air, water, soil pollution, pollution, loss of vision, and global climate change. In the case of implementation, the management plan is effective for reducing emissions of diesel vehicles. Fuel changes such as sulfur and aromatics reduction promptly improve the entire diesel and off road vehicle and promise to be further improved under future control. For example, in the United States, overseas diesel in 49 states (other than California) contains ten times the sulfur of national highway diesel fuel. Significantly reducing this sulfur content will reduce the formation of secondary particulate matter (PM) and enable the use of control technology proven to be effective on the road surface. It is expected that the use of substantially zero sulfur fuel, such as natural gas in heavy duty applications, will continue to be used. Due to the slow speed of the vehicle, it takes time to fully implement technical changes (engine remodeling, exhaust gas recirculation, catalyst aftertreatment, etc.). However, they will ultimately lead to significant emission reductions and will continue to expand in the US and worldwide. New technologies such as hybrids and fuel cells are showing great potential for diesel to reduce current mainstream sources of emissions. Finally, the turnover of trucks, especially off-road equipment is low, pollution prevention agencies need to deal with existing emissions issues through the use procedures such as remodeling of exhaust valves and inspection of smoke. Such a plan is in progress in California. These and other steps that can be continuously improved will greatly reduce their adverse environmental and health hazards and their use of diesel engines with excellent fuel consumption will continue to benefit society . The next decade may be "Clean Diesel 10 Years", and it must be.

Regarding gas and diesel engine bus, both types of engines and fuels have advantages and disadvantages. When it becomes environmental impact, this is a draw. Historically, diesel engines have struggled to produce higher emissions than gasoline engines, but due to the regulations of the Environmental Protection Agency (EPA), today's natural gas and diesel emissions are negligible. Since EPA implemented the new diesel engine exhaust gas regulation in 2010, these two types of exhaust gas are almost the same.

The disadvantage of using diesel fuel is related to environmental impact. Engines that use diesel will tend to emit more particles, such as soot and nitrogen oxides. According to the US Environmental Protection Agency (EPA), due to the high carbon content of diesel, more carbon dioxide is consumed per gallon of fuel compared to gasoline. However, the higher fuel economy of diesel reduces greenhouse gas emissions over the life of the car. There are also fuel additives such as smoke suppressants and detergent additives developed to reduce the environmental impact of diesel fuel. Smoke suppressants are organic compounds that reduce the amount of soot emitted from diesel engines, but instead increase the amount of ultrafine particles released into the atmosphere and the overall sulfate release.

Air pollution and global climate change are caused by internal combustion engines. Contamination adversely affects our health and the environment. Despite the environmental benefits of diesel engines such as low greenhouse gas emissions, these are offset by concerns about emissions of nitrogen oxides and diesel particulates. Diesel exhaust gas, commonly referred to as "diesel smoke", consists of thousands of chemical substances, mixtures of complex gases, and fine substances. Particles and air pollutants Diesel exhaust gases in the gas phase are water vapor, oxygen, nitrogen, carbon dioxide, carbon monoxide, nitrogen oxides, sulfur compounds, volatile organic compounds and low molecular weight hydrocarbons. Toxic gases in the gas phase include aldehydes (formaldehyde, acetaldehyde, acrolein), benzene, nitrosamine and polycyclic aromatic hydrocarbons. The content of carbon particles and soot varies between 60% and 80% depending on the type of fuel and engine used.