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Energy Use and Environmental Impact
Published in B K Bala, Energy Systems Modeling and Policy Analysis, 2022
Nitrogen oxides (NOx) can contribute to environmental problems in several ways. Short-term exposure to elevated NO2 concentrations (0.2 to 0.5 ppm) can cause respiratory symptoms among asthmatics. Indoor fuel combustion, particularly from gas stoves or traditional fuel use, can lead to elevated indoor levels that have been associated with increased respiratory illness and decreased resistance among children. Nitrogen oxides contribute to the formation of atmospheric ozone and nitrate aerosols. NOx species may also have a role in global warming, but the extent of this role is still a subject of debate.
Air pollutants and their sources
Published in John K. Pearson, Richard G. Derwent, Air Pollution and Climate Change, 2022
John K. Pearson, Richard G. Derwent
Nitric oxide (NO) and nitrogen dioxide (NO2) are always found together in the atmosphere and classed as Nitrogen Oxides (NOx = NO + NO2). In developed countries, the largest source of NOx comes from the automotive sector, accounting for about 50%, with power stations contributing about 20%. In previous years, the diesel engine has made the greatest NOx contribution in the automotive sector, but advances in diesel engine technology (for example: de-NOx catalysts) have started to reduce this considerably. Further reductions continue as the diesel engine gives way to electric and hybrid engine technologies. Most pollutant sources emit their NOx as NO which is converted in the atmosphere to the much more harmful NO2 by chemical reactions involving ozone. High levels of NO2 are a major concern in our cities because of health effects, particularly their contribution to excess deaths. These issues are addressed in Chapter 4.
The biodiesel' industry and policies
Published in Walter Amedzro St-Hilaire, Agribusiness Economics, 2022
However, it should be pointed out that this indicator, constructed from modelling based on the analysis of the entire life cycle of biofuels, is less ‘robust' than those constructed on the energy balance and greenhouse gas emissions, the results of which have already been set out above. In other more recent studies of a different nature, based on direct observation of pollutant emissions, the effect of biofuels on air pollution varies greatly depending on the type of pollutants, fuels, age of vehicles and conditions of use or traffic. A possible positive effect appears to be more noticeable in older vehicles than in newer ones. Furthermore, it should be noted that ethanol-rich fuels and hydrotreated vegetable oils have stable or lower nitrogen oxide emissions than fossil fuels.
Selective catalytic reduction of NO by NH3 using Mn-based catalysts supported by Ukrainian clinoptiolite and lightweight expanded clay aggregate
Published in Environmental Technology, 2022
Pranas Baltrėnas, Davyd Urbanas, Zita Sukackienė, Irena Stalnionienė, Loreta Tamašauskaitė-Tamašiūnaitė, Aldona Balčiūnaitė, Vitalija Jasulaitienė
Nitrogen oxides (NOx) are attributed to the most harmful air pollutants in terms of damage to ecosystems. Moreover, NO2 is one of the most serious pollutants in Europe considering its negative influence on human health [1]. NOx emitted into the atmosphere cause serious environmental problems like photochemical smog, acid rains, acidification of soil, acidification and eutrophication of rivers and lakes [1,2]. In 2016, about 62% of the area of the European ecosystems was exposed to NOx concentrations that exceed a critical level for eutrophication. Additionally, a critical level for acidification was exceeded on about 5% of the European ecosystems area as a result of nitrogen and sulphur compounds released into the atmosphere [1]. Nitrogen oxides are mainly generated as a result of fuel combustion by both stationary and mobile sources. During a common combustion process two nitrogen oxide species (NO and NO2) are generated. These two compounds are combined in a one general group of pollutants – nitrogen oxides (NOx). However, as a result of a common combustion process NOx generated mainly consists of NO (90–95%) [3–5]. Therefore, usually only the NO compound is used in scientific investigations of NOx removal when gas cylinders with synthetic gas mixtures are used as a source of pollutants.
The critical techno-economic aspects for production of B10 biodiesel from second generation feedstocks: a review
Published in International Journal of Sustainable Energy, 2022
Timothy Tibesigwa, Peter Wilberforce Olupot, John Baptist Kirabira
Biodiesel is a fuel that has gained a lot of public attention because it is environmentally friendly, renewable, agriculturally oriented, and its development could generate employment opportunities in developing countries (Basosi et al. 2013). It has a high cetane number, low sulphur content, and low volatility (Wu, Ge, and Choi 2020) and can be blended with petroleum-based diesel (Rodríguez-Fernández et al. 2019). Some of the problems encountered when using biodiesel include the increase in nitrogen oxides emissions and lower energy output as compared to petro-diesel. Nitrogen oxide emissions can result in the formation of smog and acid rain. In addition, the use of valuable cropland to grow biodiesel crops could lead to food scarcity and cause a rise in the cost of food (Atabani et al. 2013).
Convex nonparametric least squares and stochastic semi-nonparametric frontier to estimate the shadow prices of PM2.5 and NOx for Taiwan’s transportation modes
Published in International Journal of Sustainable Transportation, 2021
Huey-Kuo Chen, Yi-Hsiu Lin, Chia-Yen Lee
The World Health Organization (WHO, 2018) has indicated that air pollution is the leading cause of early death such as heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections. Particulate matter with diameters less than 10 and 2.5 microns (PM10 and PM2.5) can penetrate deep into lung passageways and enter the bloodstream to impact cardiovascular, cerebrovascular and respiratory systems. WHO has also noted that nitrogen oxides (NOx) consist mainly of two molecules, nitric oxide (NO) and nitrogen dioxide (NO2). NOx causes acid rain and damage our environment. In particular, NO2 mainly emitted by power generation, industrial, and traffic sources, can increase symptoms of bronchitis and asthma, hence leading to respiratory infections and reduced lung functions. These findings imply that may be responsible for a large number of contemporary diseases.