Emissions trading is a market-based approach to controlling pollution by providing economic incentives for reducing the emissions of pollutants. The concept is also known as cap and trade (CAT) or emissions trading scheme (ETS). One prominent example is carbon emission trading for CO2 and other greenhouse gases which is a tool for climate change mitigation. Other schemes include sulfur dioxide and other pollutants.
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. The exhaust gas displaces atmospheric air and reduces O2 in the combustion chamber. Reducing the amount of oxygen reduces the amount of fuel that can burn in the cylinder thereby reducing peak in-cylinder temperatures. The actual amount of recirculated exhaust gas varies with the engine operating parameters.
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricultural, domestic or industrial biowaste. Biofuels are mostly used for transportation, but can also be used for heating and electricity. Biofuels are regarded as a renewable energy source. The use of biofuel has been subject to criticism regarding the "food vs fuel" debate, varied assessments of their sustainability, and possible deforestation and biodiversity loss as a result of biofuel production.
Biodiesel is a renewable biofuel, a form of diesel fuel, derived from biological sources like vegetable oils, animal fats, or recycled greases, and consisting of long-chain fatty acid esters. It is typically made from fats.
A catalytic converter is an exhaust emission control device which converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. Catalytic converters are usually used with internal combustion engines fueled by gasoline or diesel, including lean-burn engines, and sometimes on kerosene heaters and stoves.
Alternative fuels, also known as non-conventional and advanced fuels, are fuels derived from sources other than petroleum. Alternative fuels include gaseous fossil fuels like propane, natural gas, methane, and ammonia; biofuels like biodiesel, bioalcohol, and refuse-derived fuel; and other renewable fuels like hydrogen and electricity.
Vehicle emissions control is the study of reducing the emissions produced by motor vehicles, especially internal combustion engines. The primary emissions studied include hydrocarbons, volatile organic compounds, carbon monoxide, carbon dioxide, nitrogen oxides, particulate matter, and sulfur oxides. Starting in the 1950s and 1960s, various regulatory agencies were formed with a primary focus on studying the vehicle emissions and their effects on human health and the environment. As the worlds understanding of vehicle emissions improved, so did the devices used to mitigate their impacts. The regulatory requirements of the Clean Air Act, which was amended many times, greatly restricted acceptable vehicle emissions. With the restrictions, vehicles started being designed more efficiently by utilizing various emission control systems and devices which became more common in vehicles overtime.
Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life. Different regions and countries have different standards for vehicle emissions.
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.
Diesel exhaust is the gaseous exhaust produced by a diesel type of internal combustion engine, plus any contained particulates. Its composition may vary with the fuel type or rate of consumption, or speed of engine operation, and whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application.
A fossil fuel power station is a thermal power station which burns a fossil fuel, such as coal or natural gas, to produce electricity. Fossil fuel power stations have machinery to convert the heat energy of combustion into mechanical energy, which then operates an electrical generator. The prime mover may be a steam turbine, a gas turbine or, in small plants, a reciprocating gas engine. All plants use the energy extracted from the expansion of a hot gas, either steam or combustion gases. Although different energy conversion methods exist, all thermal power station conversion methods have their efficiency limited by the Carnot efficiency and therefore produce waste heat.
Selective catalytic reduction (SCR) means of converting nitrogen oxides, also referred to as NO
x with the aid of a catalyst into diatomic nitrogen, and water. A reductant, typically anhydrous ammonia, aqueous ammonia, or a urea solution, is added to a stream of flue or exhaust gas and is reacted onto a catalyst. As the reaction drives toward completion, nitrogen, and carbon dioxide, in the case of urea use, are produced.
In atmospheric chemistry, NOx is shorthand for nitric oxide and nitrogen dioxide, the nitrogen oxides that are most relevant for air pollution. These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone.
BlueTEC is Mercedes-Benz Group's marketing name for engines equipped with advanced NOx reducing technology for vehicle emissions control in diesel-powered vehicles. The technology in BlueTec vehicles includes a selective catalytic reduction (SCR) system that uses diesel exhaust fluid, and a system of NOx adsorbers the automaker calls DeNOx, which uses an oxidizing catalytic converter and diesel particulate filter combined with other NOx reducing systems.
Chemically, black carbon (BC) is a component of fine particulate matter. Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is one of the main types of particle in both anthropogenic and naturally occurring soot. Black carbon causes human morbidity and premature mortality. Because of these human health impacts, many countries have worked to reduce their emissions, making it an easy pollutant to abate in anthropogenic sources.
A portable emissions measurement system (PEMS) is a vehicle emissions testing device that is small and light enough to be carried inside or moved with a motor vehicle that is being driven during testing, rather than on the stationary rollers of a dynamometer that only simulates real-world driving.
Continuous emission monitoring systems (CEMS) are used as a tool to monitor the effluent gas streams resulting from combustion in industrial processes. CEMS can measure flue gas for oxygen, carbon monoxide and carbon dioxide to provide information for combustion control in industrial settings. They are also used as a means to comply with air emission standards such as the United States Environmental Protection Agency's (EPA) Acid Rain Program, other US federal emission programs, or state permitted emission standards. CEMS typically consist of analyzers to measure gas concentrations within the stream, equipment to direct a sample of that gas stream to the analyzers if they are remote, equipment to condition the sample gas by removing water and other components that could interfere with the reading, pneumatic plumbing with valves that can be controlled by a PLC to route the sample gas to and away from the analyzers, a calibration and maintenance system that allows for the injection of calibration gases into the sample line, and a Data Acquisition and Handling System (DAHS) that collects and stores each data point and can perform necessary calculations required to get total mass emissions. A CEMS operates at all times even if the process it measures is not on. They can continuously collect, record and report emissions data for process monitoring and/or for compliance purposes.
Bharat stage emission standards (BSES) are emission standards instituted by the Government of India to regulate the output of air pollutants from compression ignition engines and Spark-ignition engines equipment, including motor vehicles. The standards and the timeline for implementation are set by the Central Pollution Control Board under the Ministry of Environment, Forest and Climate Change.
The California Statewide Truck and Bus Rule was initially adopted in December 2008 by the California Air Resources Board (CARB) and requires all heavy-duty diesel trucks and buses that operate in California to retrofit or replace engines in order to reduce diesel emissions. All privately and federally owned diesel-fueled trucks and buses, and privately and publicly owned school buses with a gross vehicle weight rating (GVWR) greater than 14,000 pounds, are covered by the regulation.
The Cummins X-series engine is an Inline (Straight)-6 diesel engine produced by Cummins for heavy duty trucks and motorcoaches, replacing the N14 in 2001 when emissions regulations passed by the EPA made the engine obsolete. Originally called the "Signature" series engine, the ISX uses the "Intellect System" to further improve the engine. This engine is widely used in on highway and vocational trucks and is available in power ranging from 430 hp all the way to 620 hp 2050 lb-ft. The QSX is the off-highway version of the ISX with the Q standing for Quantum. The QSX is used for industrial, marine, oil & gas and other off-highway applications. Cummins also produced a 650 hp and 1950 lb-ft version for the RV market.
