Missing Chart What do CFCs do? CFCs are commonly used as refrigerants, solvents in industrial cleaning applications, and as aerosol propellants. Why are CFCs being replaced? When CFCs work their way up into the stratosphere, UV radiation from the Sun can break the molecule down, and release a chlorine atom. This chlorine atom then interacts with an ozone molecule (ozone is vital to the Earth's system in that it protects the surface from harmful UV rays). This interaction results in the destruction of ozone and the eventual release of the chlorine atom to break apart another ozone. It has been estimated that one chlorine atom can dismantle about 100,000 ozone molecules. Ozone's importance and the direct threat to it by CFCs, are the reasons behind the replacement of the chemicals. One thing to notice from the chart is the extremely high ODP for the Halon compounds. These compunds (as can be seen from their formulas) contain a bromine atom that can destroy more ozone when compared to a chlorine. This occurs because it takes longer for a bromine atom to be taken out of the stratusphere. Halons were used in foam blowing apparatuses for fire-retarding systems, but were phased out along with CFCs. Innovative chemical companies With the advent of the Montreal Protocol and other legislation to reduce the production and use of CFCs, companies have increased research and development of replacement system and/or chemicals. The companies that have produced proven products for cleaning, refrigeration, and propellant use are 3M and Dupont. Their products Dupont is a world renowned company whose major contributions include chemicals. On the order of CFC replacement, Dupont has developed hydrofluo... ... middle of paper ... ...iverging nozzle where it is accelerated to supersonic speeds. The supersonic gas-liquid stream is directed onto components that require cleaning or cleanliness verification. The velocity imparted to the water by the gas flow gives it sufficient momentum at impact to remove contaminants on the surface of the component being cleaned or verified while simultaneously dissolving the contaminant into the water, which can be captured for cleanliness verification. The flow parameters for the gas-liquid nozzle can be set so virtually any gas and liquid can be used for a desired flow and mixing ratio. In addition, the size and number of nozzles are adjustable. This adjustability makes it possible to create sizes ranging from small handheld cleaning nozzles to very large multiple-nozzle configurations. Unfortunately, the cost and maintenance required for such a system is high.
This fluid is made up of 32.5% urea in 67.5% de-ionized water. This mixture is then injected into the exhaust stream using an advanced catalyst system. When DEF is released into the exhaust stream the hot exhaust causes the fluid to release ammonia which then breaks down the greenhouse harming gas of NOx into nitrogen and water. This fluid must be refilled at approximately every 10,000 miles (Voelcker).
Life on this planet Earth is the product of a delicate balancing act provided by nature. Mankind's very existence is totally dependent on this fragile ecosystem's ability to maintain itself. A valuable player in the balance of the environment, the ozone layer, is facing a very serious threat by man. Chloroflourocarbons (CFCs), are chemical agents commonly found in refrigerants, aerosol sprays, and in the manufacturing of Styrofoam and industrial solvents. With the rate of more than a half-million tons of CFCs being spewed into the atmosphere yearly, the rate of ozone depletion is rising at an alarming rate. If a global effort is not made to end the unnecessary use of CFCs, the inhabitants of this planet face an extremely difficult and frightening future.
U.S. Chemical Safety and Hazard Investigation Board. (March 20, 2007). Final Investigation Report. Retrieved July 26, 2010, from U.S. Chemical and Safety Board: http://www.csb.gov/assets/document/CSBFinalReportBP.pdf
The current main issues concerning the next purchasing contracts for Marconil are that it is an input material on which we are very dependent and that if a shortage takes place, it can bring serious risks for our business in terms of reputation, sales revenues and customer loyalty. Last year, Sabor’s sales for air filtration systems accounted for $72 million dollars. With a profit margin of 72% (the manufacturing cost is 28%), Marconil enjoys a considerable importance in
Hairspray. Refrigerators. Air conditioners. These everyday luxuries, while making human life more comfortable, are taxing our health seriously. Clorofluorocarbons, or CFCs, are anthropogenic chemicals used in refrigerants and as propellants in aerosols. CFCs, also known as freons, are also the primary culprit behind the depletion of stratospheric ozone, which allows harmful ultraviolet rays to reach the Earth and its inhabitants.
The article states experimental data has the potential to “shatter” the current belief system regarding ozone depletion (Schiermeier, 2007). The shattering may go all the way up to how scientists and ultimately the laymen understands the ozone hole formation occurs and the connection to changes in climate. The Montreal Protocol has been a big plus in how the hole may be managed, but the effects of those years freely using CFCs will still linger in the atmosphere for decades to come (Schiermeier, 2007). Interaction of CFCs and the sun rays are complex, but chemists at NASA’s Jet Propulsion Laboratory in Pasadena, California are relying on the new measurements to cast doubt on how the understanding of ozone holes are flawed. After experiments with a new photolysis rate applied to a chemical model of ozone depletion they found that 60% of ozone destruction at the poles has to do with anything else, but CFCs. The new finding is being tested by other researchers, but the possibility of the idea held for so long that ...
...ces in the long term. Many people have become more concerned with the environment and have become eco friendly or as newer terms put it “green”. “The technology is already in use by many plants in Europe, has enabled the plants to operate in a ‘closed cycle’ that not only protected the environment but reclaimed waste material, which was then sold to chemical producers” (Brooks, 2007, p. 372).
The Olefins II Unit makes hydrocarbons from naphtha or natural gas using furnaces. After distillation, the p...
From the day-to-day use of CFC’s (Chloro fluoro carbons) and other depletion substances the ozone wears off more and more. These substances are referred to as ozone-depleting substances (ODS). They are usually found in chemicals and as a result of causing depletion in the ozone layer, cause skin cancer and disorder in humans and animals as well. CFC’s are used as coolers in refrigerators, and air conditioners. They used to be used in car air conditioners until 1995, when it was discovered the CFS’s were depleting the ozone. Industrially, they are found in solvents and sometimes in dry cleaning agents. Furthermore, cleaning agents, foam insulation and packaging materials are also known to aid in the ozone depletion.
Even though the process had not been used in several years, everything worked very well. The flow meter used to measure the water flow rate had a small leak which was easily remedied using a bucket. One of the storage tanks still had approximately 400 liters of kerosene with a benzoic acid concentration of 0.00208 (gm/mL). Using this as a feed for the process, concentrations of benzoic acid in the aqueous extract were found to be 0.00109 (gm/mL) and 0.000783 (gm/mL) for two separate steady state experimental runs. The flow rates of the kerosene feed for the two steady states were 0.361 (gal/min) and 0.157 (gal/min) respectively. The number of theoretical stages for a flow rates of 0.361 (gal/min) and 0.157 (gal/min) were determined to be 1.76 and 0.87 stages respectively. With the height of the column equal to 48.9 inches the HETS for the two steady state conditions were 27.71 inches and 56.42 inches respectively.
follows: (How do CFCs Destroy the Ozone) Cl + O3 -----> ClO + O2 ClO + O
Chemicals are used in a wide variety of products and play an important role in the world economy. They are constituents of materials, are used in preparations and products and are embedded in complex physical systems. While chemicals are a significant contributor to national economies, sound chemical management across the life cycle - from extraction to disposal - is essential to avoid significant risks to human health and the environment, along with their associated economic costs, and to maximize benefits for human well-being. Growth in chemical production and use has slowed in many of the developed countries that previously dominated the market, while it has accelerated rapidly in a number of developing countries and countries with economies in transition. These countries are, increasingly, the drivers of global expansion in production and use of these chemicals.
Willis Haviland Carrier invented the first air conditioner in 1902. This was designed to boost the working process control in a printing plant. Carrier’s invention controlled temperature and humidity. The low heat and humidity helped keep the paper dimensions and ink alignment the same. Later his invention was used to populate productivity in the workplace. The Carrier Air Conditioning Company of America developed for the increasing demands. Gradually, air conditioning was used to help increase comfort in homes and cars. Residential sales increased rapidly in the 1950's.
La producción de cloro-fluoro-carbonos [CFCs] contribuye con aproximadamente el 14% del efecto invernadero. Los CFCs son sustancias químicas sintéticas, formadas por cloro, flúor y carbono. Las moléculas de CFC tienen una larga vida activa. El CFC-1 1 es activo durante unos 65 años y el CFC-12 durante unos 110 arios. Cada molécula de CFC-11 y de CFC-12 contribuye 3.500 y 7.300 veces más, respectivamente, al efecto invernadero que cada molécula de C02.
... temperature of 112 0C also and a pressure 2.5 bar. Cooling water is used to condense the vapor exiting column. Remaining methane and hydrogen are separated in reflux drum where the vapor stream is combined with other gases streams. The overhead of first and second separator are combined to form fuel gas. The liquid stream exiting in the bottoms of the reflux drum is pumped at pressure of 3.3 bar for discharging pressure. The pump stream is separated in two streams. One stream is to feed to tray one of the column and the other one stream is cooled down to 38 0C in heat exchanger. Then, the cooled product stream is sent to storage.