Diesel Emissions, Kerosene and Air Pollution
As of June 1, 2007, it was mandated that refiners begin producing low-sulfur diesel fuel for use in locomotives, ships and non-road equipment (those used in industries such as agriculture and construction). Low-sulfur diesel fuel was mandated to meet a 500 parts per million (ppm) sulfur maximum.
This was the first step of EPA’s Non-road Diesel Rule. They eventually had a goal of reducing the sulfur level of fuel for these engines to meet an ultra-low standard (15 ppm) to enable new advanced emission-control technologies for engines used in locomotives, ships and other non-road equipment.
Non-road diesel engines contribute greatly to air pollution in many communities. The US EPA has set emission standards for engines used in most construction, agricultural and industrial equipment. They also adopted non-road diesel fuel requirements to decrease the allowable levels of sulfur, which damage the new advanced emission control technologies. With the new technologies, it is anticipated that exhaust emissions from newer engines will decrease by more than 90 percent.
Non-road diesel engines are used in machines that perform a wide range of jobs.
Examples of land-based non-road applications using diesel engines include:
*Construction equipment such as backhoes,
*Ships such as barges and cargo ships,
*Agricultural equipment such as tractors,
*Material handling equipment such as heavy forklifts,
*Industrial equipment such as airport service vehicles and
*Utility equipment such as generators and pumps.
Non-road engines being produced today must meet relatively modest emission requirements and therefore continue to emit large amounts of nitrogen oxides (NOx) and particulate matter (PM), both of which contribute to serious public health problems.
Recent data has shown that nearly 160 million people live in non-attainment areas for smog, which is formed by NOx and other pollutants. About 65 million people live in areas that violate air quality standards for PM. The Fairbanks area is now in a non-attainment area for particulate matter. Helping to reduce non-road emissions is a critical part of the effort by tribal governments to reduce the adverse health impacts of air pollution.
In May 2004, as part of its Clean Diesel Programs, US EPA finalized a comprehensive rule to reduce emissions from non-road diesel engines by integrating engine and fuel controls as a system to gain the greatest emission reductions. The new engine standards will reduce PM and NOx emissions by 90 percent.
The latest emission standards and diesel fuel sulfur reductions complement the program reducing emissions and fuel sulfur for highway diesel engines and fuel in 2007. The engine manufacturing industry had made great technical strides in adapting efficient emission controls from highway diesel to non-road applications. At the same time, the manufacturers of this equipment that use these engines have responded by creatively incorporating the new engines and emission controls into their machines. These improvements will continue as stringent new emission standards come into effect in the coming years, coupled with the elimination of most of the sulfur from the diesel fuel used in non-road equipment.
In March 2008, EPA finalized a three part program that will dramatically reduce emissions from diesel locomotives of all types -- line-haul, switch, and passenger rail. The rule will cut PM emissions from these engines by as much as 90 percent and NOx emissions by as much as 80 percent when fully implemented. The final rule for this program sets new emission standards for existing locomotives when they are remanufactured--to take effect as soon as certified systems are available. Emission standards for existing locomotives began in 2008.
Diesel Fuel
There are chemical characteristics and natural impurities in diesel fuel that can affect exhaust emissions from diesel engines, can damage or impede the operation of emission control devices and can increase secondary pollutant formation in the atmosphere.In the hierarchy of refined petroleum products from highest to lowest (from a gaseous state, then liquid, to solid) are:
*Natural gas;
*"Wet" Natural gas;
*High-octane Aviation Gasoline;
*Automotive Gasoline;
*Finished Kerosene;
*Home Heating oil;
*Diesel Fuel;
*Industrial Fuel Oil;
*Finished Lubricating Oils;
*waxes and Paraffin's;
*Gas;
*Oil;
*Coke;
*and finally Asphalt.
Also moving from highest to lowest, the viscosity or stiffness, of the refined product increases. For example, at room temperature, automotive gasoline flows much more freely than finished lubricating oils.
Diesel fuel lies in the middle of the refined petroleum hierarchy and is considered one of the middle distillates -- slightly heavier than kerosene and slightly lighter than industrial (bunker) fuel oil.
Like automotive gasoline, diesel fuel is refined into several sub-categories or grades. From highest to lowest viscosity are:
Number 1 Diesel Fuel (1-D)
Number 2 Diesel Fuel (2-D)
Number 4 Fuel Diesel (4-D)
There used to be a Number 3 Diesel Fuel (3-D), but it is no longer refined.
Numbers 1 and 2 Diesel Fuel are the primary fuel for mobile diesel engine applications. Number 1 Diesel Fuel is commonly labeled at the pump as Premium Diesel. It is not as thick as Number 2 Diesel Fuel and for this reason is the choice for motorists during the cold winter months. The disadvantage of Number 1 Diesel Fuel is that it does not have the lubricating qualities associated with Number 2 Diesel Fuel.
While Number 2 Diesel Fuel has a higher lubricating quality than Number 1 Diesel, its thickness can cause rough starting in a cold engine and rough-running in cold weather.
Number 4 Fuel Diesel Fuel is slightly lighter than industrial fuel oil and is used in low and medium speed engines that operate at a constant or near-constant speed, such as stationary power plants or railroad locomotives. Even though Number 4 Fuel Diesel Fuel has an ignition quality similar to Numbers 1 and 2 Diesel Fuel, it is too thick to work well in a truck engine where the load on the engine is constantly changing and requires varying amounts of fuel to be injected into the cylinders.
Kerosene
Just above Diesel fuel in the middle distillate category is Kerosene. Like Number 4 Fuel Diesel Fuel, Kerosene has an ignition quality similar to Numbers 1 and 2 Diesel Fuel.Unlike Number 4 Fuel Diesel Fuel, which is too thick, Kerosene is too thin to work well as an engine fuel. The thickness of the diesel fuel itself acts as a lubricant to prevent wear of the engine's fuel injectors. This lubricating quality of diesel fuel is why some still refer to it as "Diesel Oil." Adding a common lubricant to Kerosene usually decreases its ignition quality.
Kerosene can be used in fuel for jet engines (more technically Avtur, Jet A, Jet A-1, Jet B, JP-4, JP-5, JP-7 or JP-8). One form of the fuel known as RP-1 is burned with liquid oxygen as rocket fuel. These fuel grade kerosenes meet specifications for smoke points and freeze points.
Kerosene is sometimes used as an additive in diesel fuel to prevent gelling or waxing in cold temperatures.
Home Heating Oil
Home Heating Oil is closest to Number 2 Diesel Fuel in ignition quality and lubricating ability. Home Heating Oil is not intended to be used in an internal combustion engine and the furnace fuel that is sitting in your basement tank may or may not have the smoke suppressants, ignition accelerators and biocides to kill fungi and bacteria that we generally assume to be present in the diesel fuel.DIESEL EXHAUST AND AIR POLLUTION
Diesel exhaust is a mixture containing over 450 different components, including vapors and fine particles. Over 40 chemicals in diesel exhaust are considered toxic air contaminants. Exposure to this mixture may result in cancer, exacerbation of asthma and other health problems.For the same load and engine conditions, diesel engines spew out 100 times more sooty particles than gasoline engines. As a result, diesel engines produce higher levels of particulate pollution (PM10) and nitrogen oxides (NOx) than do the gasoline engines.
Marine Diesel Engines
Marine diesel engines used on a variety of different types of vessels ranging in size and application from small recreational runabouts to large ocean-going vessels are significant contributors to air pollution in many of our nation’s cities and coastal areas.
Marine diesel engines produced today must meet emissions requirements, but the current standards are relatively modest and these engines continue to emit significant amounts of nitrogen oxides (NOx) and particulate matter (PM), both of which contribute to serious public health problems. EPA is addressing emissions from marine engines in two ways, through their fuels and through their emission limits.
In the March 2008 three part program that was finalized by the EPA there were calls for dramatic reductions in emissions from marine diesel engines below 30 liters per cylinder displacement.
These include marine propulsion engines used on vessels from recreational and small fishing boats to towboats, tugboats and freighters, and marine auxiliary engines ranging from small generator sets to large generator sets on ocean-going vessels.
The rule was planned to will cut PM emission from these engines by as much as 90 percent and NOx emissions by as much as 80 percent when fully implemented. The final rule also includes the first-ever national emission standards for existing marine diesel engines, applying to engines larger than 600kW when they are remanufactured.
Diesel Generators
A diesel generator is the combination of a diesel engine with an electrical generator (often called an alternator) to generate electric energy. Diesel generators are used in places without connection to the power grid or as emergency power-supply if the grid fails as occurs in many Tribal Communities of Alaska.Small portable diesel generators range from about 1kVA to 10kVA, while the larger industrial generators can range from 8kVA - 30kVA and up to 2000kVA used for community generators, factories and power stations. These generators are widely used not only for emergency power, but also many have a secondary function for providing back-up power to utility grids.
Marine vessels often employ diesel generators, sometimes not only to provide energy for electric systems, but also for propulsion. The use of diesel generators for propulsion is actually becoming more common, because in this arrangement the generators do not need to be positioned close to the propeller and instead they can be placed in better positions, usually allowing more cargo to be carried.
Electric drives for ships were developed prior to WW I. Electric drives were specified in many warships built during WW II because manufacturing capacity for large reduction gears was in short supply, compared to capacity for manufacture of electrical equipment. Such a diesel-electric arrangement is also used in some very large land vehicles.
Fairbanks Case Study of Diesel Use in Cold Climates
Demonstration of Fischer-Tropsch Diesel Fuel in Cold Climates.
http://www.fta.dot.gov/documents/Fischer_Tropsch_Synthetic_Diesel_Demonstration_Project.pdf
Health Effects of Diesel
Diesel exhaust has been linked in numerous scientific studies to cancer, the exacerbation of asthma and other respiratory diseases. A draft report released by the EPA in February 1998 indicated that exposure to even low levels of diesel exhaust is likely to pose a risk of lung cancer and respiratory impairment.Because diesel exhaust is an important source of atmospheric soot and fine particles it is implicated in human heart and lung damage. Diesel exhaust has been found to contain nanoparticles which have been found to damage the cardiovascular system.
The study of nanotoxicology is still in its infancy, and the extent of health and societal effects caused by diesel combustion is unknown. Biodiesel and biodiesel blends result in greatly decreased pollution levels.
In August 1998, the State of California found that there was enough evidence to list the particulate matter in diesel exhaust as a toxic air contaminant - a probable carcinogen requiring action to reduce public exposure and risk.
There are dozens of studies linking airborne fine particle, such as those in diesel exhaust, to increased hospital admissions for respiratory diseases, chronic obstructive lung disease, pneumonia, heart disease and up to 60,000 premature deaths annually in the United States.
The health risks from diesel exposure are greatest for children, the elderly, people with respiratory problems or who smoke, people who regularly exercise in diesel-polluted areas and people who work or live near diesel exhaust sources.
Studies have shown that the proximity of a child's residence to major roads is linked to hospital admissions for asthma and there is a positive relationship between school proximity to areas of heavy diesel traffic and asthma occurrence. Truck and traffic intensity and exhaust measured in schools were significantly associated with chronic respiratory symptoms.
During the comments on the new diesel rules, local cities and Tribal communities raised an important question that could not be answered according to the ADEC and EPA question and answers from the rule making comment period: What is the health impact of higher sulfur diesel on Tribal communities of Alaska? Many scientific studies show significant health impact with adequate exposure to diesel exhaust. This is of great concern to people living in dense, highly trafficked cities. Indeed, the high probability of existing health impacts from heavy duty vehicle diesel emissions is the driving force behind the national rule.
The national rule only applies to heavy duty trucks and buses. However, trucks and buses are rarely the primary source of diesel exposure in Tribal Communities of Alaska. The biggest source for exposure may be power generation. The method of power generation in Tribal Communities of Alaska is unique, with most communities serviced by a central diesel generator rather than being connected to an electrical grid. The potential health impact of this situation has not been studied.
To address this, ADEC is developing a study and seeking funds to determine health impacts of diesel air pollution in Tribal Communities of Alaska. Communities can use the results to help decide how to transition to ultra-low sulfur diesel fuel. The state may use the results in permit decisions on stationary diesel sources.