getty
Clean hydrogen is vital to help curb carbon emissions from dirty industrial processes like making steel and fertilizer. So in 2022, the Biden Administration created a valuable new credit for hydrogen that’s made without generating lots of additional greenhouse gases, worth up to $3 a kilogram. But it’s taken a long time to determine exactly what form of hydrogen is clean enough to receive the credit. With just a couple of weeks left until the start of Trump 2.0, the Treasury Department finally unveiled its guidelines for the so-called 45V credit on Jan. 3…….Continue reading…
By: Alan Ohnsman
Source: Forbes
.
Critics:
Air pollutant emission factors are reported representative values that aim to link the quantity of a pollutant released into the ambient air to an activity connected with that pollutant’s release. The weight of the pollutant divided by a unit weight, volume, distance, or time of the activity generating the pollutant is how these factors are commonly stated (e.g., kilograms of particulate emitted per tonne of coal burned).
These criteria make estimating emissions from diverse sources of pollution easier. Most of the time, these components are just averages of all available data of acceptable quality, and they are thought to be typical of long-term averages. The Stockholm Convention on Persistent Organic Pollutants identified pesticides and other persistent organic pollutants of concern. These include dioxins and furans which are unintentionally created by combustion of organics, like open burning of plastics, and are endocrine disruptors and mutagens.
Ewaste processing in Agbogbloshie, Ghana, using open-burning of electronics to access valuable metals like copper. Open burning of plastics is common in many parts of the world without the capacity for processing. Especially without proper protections, heavy metals and other contaminates can seep into the soil, and create water pollution and air pollution. The United States Environmental Protection Agency has published a compilation of air pollutant emission factors for a wide range of industrial sources.
The United Kingdom, Australia, Canada, and many other countries have published similar compilations, as well as the European Environment Agency. An air pollutant is a material in the air that can have many effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases, and often takes the form of an aerosol (solid particles or liquid droplets dispersed and carried by a gas). A pollutant can be of human or natural origin.
Pollutants are classified as primary or secondary. Primary pollutants are produced directly by a source and remain in the same chemical form after they have been emitted into the atmosphere. Examples include ash from a volcanic eruption, carbon monoxide gas from motor vehicle exhausts, and sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact.
Ground-level ozone is a prominent example of a secondary pollutant. Some pollutants may be both primary and secondary: they are both emitted directly and formed from other primary pollutants. Ammonia (NH3) is emitted mainly by agricultural waste. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Although in wide use, ammonia is both caustic and hazardous.
In the atmosphere, ammonia reacts with oxides of nitrogen and sulfur to form secondary particles. Carbon dioxide (CO2): Carbon dioxide is a natural component of the atmosphere, essential for plant life and given off by the human respiratory system. It is potentially lethal at very high concentrations (typically 100 times “normal” atmospheric levels). Although the World Health Organization recognizes CO2 as a climate pollutant, it does not include the gas in its Air Quality Guidelines or set recommended targets for it.
Because of its role as a greenhouse gas, CO2 has been described as “the worst climate pollutant”. Statements such as this refer to its long-term atmospheric effects rather than shorter-term effects on such things as human health, food crops, and buildings. This question of terminology has practical consequences, for example, in determining whether the U.S. Clean Air Act (which is designed to improve air quality) is deemed to regulate CO2 emissions.
That issue was resolved in the United States by the Inflation Reduction Act of 2022, which specifically amended the Clean Air Act “to define the carbon dioxide produced by the burning of fossil fuels as an ‘air pollutant.’” CO2 currently forms about 425 parts per million (ppm) of Earth’s atmosphere, compared to about 280 ppm in pre-industrial times, and billions of metric tons of CO2 are emitted annually by burning of fossil fuels. CO2 increase in Earth’s atmosphere has been accelerating.
CO2 is an asphyxiant gas and not classified as toxic or harmful in general. Workplace exposure limits exist in places like UK (5,000 ppm for long-term exposure and 15,000 ppm for short-term exposure). Natural disasters like the limnic eruption at Lake Nyos can result in a sudden release of huge amount of CO2 as well. Carbon monoxide (CO): CO is a colorless, odorless, toxic gas.
It is a product of combustion of fuel such as natural gas, coal or wood. Vehicular exhaust contributes to the majority of carbon monoxide let into the atmosphere. It creates a smog type formation in the air that has been linked to many lung diseases and disruptions to the natural environment and animals. Nitrogen oxides (NOx), particularly nitrogen dioxide, are expelled from high temperature combustion, and are also produced during thunderstorms by electric discharge.
They can be seen as a brown haze dome above or a plume downwind of cities. Nitrogen dioxide is a chemical compound with the formula NO2. It is one of several nitrogen oxides. One of the most prominent air pollutants, this reddish-brown toxic gas has a characteristic sharp, biting odor. Particulate matter (PM), also known as particulates, atmospheric particulate matter (APM), or fine particles, are microscopic solid or liquid particles suspended in a gas. Aerosol is a mixture of particles and gas.
Volcanoes, dust storms, forest and grassland fires, living plants, and sea spray are all sources of particles. Aerosols are produced by human activities such as the combustion of fossil fuels in cars, power plants, and industrial processes. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer. Particulates are related to respiratory infections and can be particularly harmful to those with conditions like asthma.
Sulfur dioxide (SO2) is produced by volcanoes and in various industrial processes. Coal and petroleum often contain sulfur compounds, and their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain is formed. This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.
Ground-level ozone (O3): Ozone is created when NOx and VOCs mix. Photochemical and chemical reactions involving it fuel many of the chemical activities that occur in the atmosphere during the day and night. It is a pollutant and a component of smog that is produced in large quantities as a result of human activities (mostly the combustion of fossil fuels).
O3 is largely produced by chemical reactions involving NOx gases (nitrogen oxides, especially from combustion) and volatile organic compounds in the presence of sunlight. Due to the influence of temperature and sunlight on this reaction, high ozone levels are most common on hot summer afternoons. Volatile organic compounds (VOC): VOCs are both indoor and outdoor air pollutants. They are categorized as either methane (CH4) or non-methane (NMVOCs).
Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases because of their role in creating ozone and prolonging the life of methane in the atmosphere. This effect varies depending on local air quality. The aromatic NMVOCs benzene, toluene and xylene are suspected carcinogens and may lead to leukemia with prolonged exposure. 1,3-butadiene is another dangerous compound often associated with industrial use.
Leave a Reply