Vehicles fuel combustion products

A great attraction of hydrogen is pollution-free combustion while a host of undesirable compounds are emitted from gasoline and diesel fuel vehicles, or formed from their emissions. The main combustion product of hydrogen is water ... 

Primary organics are emitted to the atmosphere by industrial sources (oil refineries, chemical plants, producers and users of solvents and plasticizers), vehicles (as a result of incomplete fuel combustion, oxygenated degradation products of lubricating oil, polymers from tires), and agricultural activities (use of pesticides). An exhaustive literature survey is beyond the scope of this section, but can be found in Air Quaiity Criteria for Particulate Matter many useful references are also available. 

Boron particles are incorporated into GAP pyrolants in order to increase their specific impulse.[8-i2] xhe adiabatic flame temperature and specific impulse of GAP pyrolants are shown as a function of air-to-fuel ratio in Fig. 15.10 and Fig. 15.11, respectively. In the performance calculation, a mixture of the combustion products of the pyrolant with air is assumed as the reactant. The enthalpy of the air varies according to the velocity of the vehicle (or the relative velocity of the air) and the flight altitude. The flight conditions are assumed to be a velocity of Mach 2.0 at sea level. An air enthalpy of 218.2 kj kg is then assumed. 

Uses/Sources. Intermediate in nitric and sulfuric acid production nitration of organic compounds and explosives found in vehicle emissions and fossil fuel combustion... 

Ihe specific information used to provide estimates of activity levels varies with the emission source sector being examined. For utilities, fuel use is desired. For the industrial sector, information on fuel use alone is not adequate since many industrial process emissions do not result from fuel combustion. Usually, some approximation for product output, such as estimates of value added or earnings, is often used. For motor vehicle emissions, estimates of vehicle miles traveled is more useful than fuel use because most emissions are unrelated to vehicle efficiency, i.e., a small car emits about the same amount of pollution per mile as a larger car. 

Large amounts of nitrosamines leak into the environment from the pharmaceutical and food industries, plastics industry, textile industry, waste transport (motor vehicles), industrial effluents (dyes, lubricants, mbber), and the production of solvents. Fuel manufacturing plants and oil refineries are also important emitters of nitrosamines, as well as landfills and fossil fuel combustion processes (to produce heat and power). These compounds naturally penetrate the environment through animal droppings. 

Particulate emissions are by-products of fuel combustion, industrial processes, and motor vehicles and are believed to have a significant potential for causing adverse health effects. Carbonaceous material present in atmospheric aerosols is a combination of elemental carbon and organic and inorganic compounds. Particulate matter may also consist of fly ash, minerals, or road dust and contain traces of a number of heavy metals. Population-based studies have consistently found that the association between adverse respiratory effects and particulate concentrations occurs in a number of regions throughout the United States. This association is strongest for PM]o and PM2.5 indices (particulate matter less than 10 and 2.5 pm in diameter, respectively). The observed adverse effects include increases in total mortality, mortality due to respiratory and cardiovascular causes, chronic bronchitis, and hospital visits and admissions for asthma. Elderly or unhealthy individuals and infants appear to comprise subpopulations that are most sensitive to the adverse health effects of PM. 

The transport sector is almost entirely fueled by oil products as it has been for almost a century. The technological development in fuels, vehicles and related infrastructures are locked in to the specific configuration of oil products and combustion engines. Basing transport exclusively on crude oil is, however, unsustainable (lEA, 2007). The reserves are limited and the competition for them is increasing. The environment suffers from the emissions of fossil fuel combustion. The power that it confers on whoever controls the remaining reserves is undesirable for Europe. 

Fossil fuel combustion Vehicle emissions Non-ferrous metal production Iron and steel production Cement production Waste disposal Total emissions (1995) Emissions (1983) ... 

Sources of CO2 associated with Portland cement manufacture include (i) the decarbonization of limestone (ii) the exhausts of kiln fuel combustion and (iii) the exhausts of the vehicles used in cement plants and distribution. Of these sources, the first produces a minimum of about 0.47 kg CO2 kg cement, whilst production via the second source varies with the plant efficiency. For example, an efficient precalciner plant will produce 0.24kg CO2 kg cement, while a low-efficiency wet process may produce up to 0.65 kg CO2 kg . The production of CO2 via the third source is almost insignificant (0.002-0.005 kg CO2 kg cement). Hence, the typical total CO2 footprint is around 0.80 kg CO2 kg finished cement This leaves aside the CO2 associated with electric power consumption, which varies according to the local generation type and efficiency. Typical electrical energy consumption is of the order of 90-150 kWh per metric ton of cement this is equivalent to 0.09-0.15 kg CO2 kg finished cement if the electricity is coalgenerated. All of this amounts to about 7% of the total CO2 generated worldwide (Malhotra, 1999). 

The scope of this LCA study considers the provision of the product biodiesel from tallow (TME) and biodiesel from used vegetable oil (UVO) from raw material extraction to the usage of the finished product (resulting in vehicle emissions caused by fuel combustion). The scope here is therefore a cradle-to-wheel LCA. The production of energy, raw materials and auxiliary materials is included as is the waste disposal and the treatment of liquid and gaseous emissions during all steps of the life cycle. The production and operation of die infrastructure needed in the provision of the function is excluded from the LCA as it has turned out to be of minor influence (see Figure 1). 

As a chemical intermediate and solvent, highly pure synthetic methanol has been an article of commerce for several decades its properties and distribution modes are familiar and well understood in this context. In the role of transportation fuel, however, considerations are so radically different that fuel methanol must be treated almost as a new product. This is so partly because the general public is exposed to contact when fueling vehicles and partly because engine combustion products and fuel distribution systems raise a host of new technological questions that have never been addressed by conventional chemical industry. 

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