Production
The complete process of coal tar production is shown in Figure 1. The coal tar is produced by carbonization of coal. In this process, the coal is heated at 900-1100 ºC and the evolved vapors are condensed to form liquid, from which ammonia is removed to obtain a black viscous crude coal tar. The composition of tar so obtained depends upon the origin and composition of starting material used viz. bituminous (soft) coal, anthracite (hard) (Arnold 1997, Thami 2002).
Crude coal tar can be further purified using various techniques viz. solvent extraction, fractional distillation or coloum chromatography. The extraction of crude coal tar with alcohol containing 5% w/w Tween 80 produces Liquor carbonis detergens (LCD). Similarly, the distillate and residue obtained after fractional distillation of CCT are known as coal tar creosotes and coal tar pitch respectively. The creosotes consist of light oils (2-8%), middle oils (8-10%), heavy oils (8-10%) and anthracene oils (16-20%) (Gosselin et al. 1984). Pitch is mostly made up of highly condensed aromatic hydrocarbons (Kershaw 1993). Medical pix lithantracis is a mixture of pitch (66.67%) and tar oils (33.33%) (Roelofzen 2007).
Physical and chemical characteristics
Crude coal tar is a black and viscous liquid. It has obnoxious naphthalene like odor and a prickly burning taste (Gennaro1990). It is heavier than water. It is “practically insoluble” in water, whereas “all or almost all” dissolves in benzene or nitrobenzene (Budavari 1989).
According to EPA 1994 & IARC 1985, CCT contains approximately 10,000 compounds which consist of 48% hydrocarbons, 42% carbon and 10% water. The chemical composition of coal tar depends upon the temperature of distillation (IARC Monogr Eval C...
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...rmulation in mice (Bhatia 2009, 2011).
The therapeutic benefits of coal tar are the results of synergistic or additive effects of its more than thousand chemical constituents whose concentrations vary depending upon the source and distillation conditions. There is also not any compendial requirement which any coal tar sample must meet. There is not any specific analytical technique which can detect these variations in constituents. The disadvantages which are associated with currently used techniques viz. HPLC, GC aggregate the problem. Hence, the development of low cost, highly sensitive analytical method which can detect the minute alterations in the composition of coal tar will be helpful in product control, ensuring uniform safety and efficacy of drug product.
Conclusion
The safety and efficacy of coal tar in mild to moderate psoriasis is well documented.
hydrocarbons that forms during the extraction of natural gas and is used as a thinning
The physical effect of exposure to dioxin was first seen in skin diseases developed by chemical plant workers in 1895. The exposure to dioxin results in a type of skin disease like acne called "chloroacne," since its cause was initially and incorrectly linked to chlorine gas. In 1957, in Germany, Dr. Karl Schulz of the University of Hamburg identified chloroacne in several workers from a Boehringer chemical plant. The disease in its mildest form resembles teen-age acne but differs in that the blackheads and cyst cluster in two locations: appearing in a crescent shape outside of and under the eyes and ears. In more pronounced cases, pus-containing spots erupt and spread across the rest of the face, neck, shoulder and down to the rest of the body.
The reason for this report is to increase the reader’s knowledge on the Alberta Tar Sands, which will allow them to create their own opinions on the situation. It is a very pertinent issue in politics and will have a very large effect on the carbon emissions of Canada. Also, I wanted to further my understanding of the Alberta tar sands and learn the side effects of the tar sands. How the tar sands are different from other oil and energy procurement methods and which method is more energy efficient? Would the construction of the Keystone XL pipeline in the United States be an intelligent way for the US to involve itself in the tar sands? I wanted to answer these questions by knowing the real facts about the tar sands versus what the oil companies are telling the consumers. The ability to assess the entire situation will allow both the reader and I to formulate our own opinions about the tar sands and whether the extraction of oil at the tar sands should continue.
Fossil fuels, such as coal and oil, are Carbon rich compounds, the combustion of which produces Carbon Dioxide, a pollutant and a greenhouse gas. A large amount of energy is released during this process, which is why the pollutants off products are tolerated. This process occurs constantly throughout the world, in power stations, vehicles and cooking ovens, leading to an immense volume of CO2 being released every second, 50% of which is absorbed by oceans (Oce...
"The Toll from Coal." Catf.us. Clean Air Task Force, Sept. 2010. Web. 25 Nov. 2013.
Psoriasis is a disease that has been associated with humans since the beginning of time. It is a type of autoimmune disease that produces red, slivery, and scaly patches to appear on the skin. Autoimmune disease is a type of disease that occurs when the body’s immune system mistaken the body’s organs as foreign substance. Psoriasis is chronic and can affect people of all ages but it is not contagious. There are currently about 125 million people around the world suffering from psoriasis or about 3% of the world’s total population. This essay will discuss the importance, biochemistry, and the potential treatment options of psoriasis.
Psoriasis is an autoimmune disease that affects 125 million people world wide according to the World Psoriasis Day consortium. The origin of psoriasis is unknown, but many doctors and researches believe that genetics, along with environmental factors, trigger a hyperactive reaction of the immune system that leads to the relatively harmless, yet uncomfortable skin disease. The response of the immune system induces skin cells to multiply and mature rapidly, causing the skin cells to accumulate on top of each other and as a result, the skin becomes red, scaly, itchy, and forms thick patches on the skin. Despite that this disease is the most frequent auto-immune disease in the world, there is no cure for it. Not only is there no cure for psoriasis, but this disease can lead to other problems depending on the severeness of the disorder for example: psoriatic arthritis. However, this chronic disease has several treatment options that if used correctly and in a timely manner, will reduce and lessen the symptoms.( Although there is no cure for psoriasis, understanding how it begins, recognizing the symptoms, and learning about treatment options can enhance the quality of life for a person diagnosed with psoriasis.)
Storm water runoff is the biggest polluter of streams, creeks, rivers and ocean water systems. “Nationwide, storm water is a leading source of water pollution. About thirteen percent of U.S. rivers, eighteen percent of lakes and thirty-two percent of estuaries are classified as impaired by storm water, which means they are rendered unsafe for swimming or fishing. It also contributes to the degradation of many other waterways” (Coefield, 2010, p.1). The improperly disposed coal waste from Duke Energy easily percolates through t...
Coal is one of the world’s most abundant fossil fuels. Coal was formed during the Carboniferous Period when dead plant material was buried and subjected to high pressure and heat. Coal is classified by moisture content and composition. There are four d...
Coal has a very negative impact on the environment, one of the main impacts on the environment is the actual process of extracting the coal from the ground. The two ways that coal is mined, underground and surface, both have different effects on the environment. The first way that coal is mined is by digging tunnels and creating mineshafts underground and then removing the coal from th...
Psoriasis is a chronic skin disorder, easily identified by its symptoms of white, scaly skin and red lesions, though not so easily cured or understood. In psoriasis, skin cells mature faster than the body can shed them, causing a buildup. Although there are many theories as to what the cause of such a disease might be – genetics, stress, or other triggers – no one is quite sure why the disease occurs, or what could be a possible way to fully cure it. In this essay we will explore the symptoms, types, and effects of this condition, and also some of the known treatments.
The sample was subjected to steam distillation as illustrated in Figure 1. A total of 50ml of distillate was collected while recording the temperature for every 5.0 ml of distillate. The distillate was transferred into a 250ml Erlenmeyer flask and 3.0 g of NaCl was added. The flask was cooled and the content was transferred into a 250-ml separatory funnel. Then 25.0ml of hexane was added and the mixture was shaken for 5 minutes with occasional venting. The aqueous layer was discarded and the organic layer was left inside. About 25.0ml of 10% NaOH was then added and the mixture was shaken as before. The aqueous layer was collected and then cooled in an ice bath. It was then acidified with enough 6.00 M HCl while the pH is being monitored with red litmus paper. Another 25.0 ml of hexane was added and the mixture was shaken as before. The hexane extract was saved and a small amount of anhydrous sodium sulfate was added. The mixture was then swirled for a couple of minutes then filtered. A small amount of the final extracted was tested separately with 1% FeCl3 and Bayer’s reagent.
“Coal Tar Hair Dyes: Hair Care Cautions” (2011): Hairfinder: Hair Styles, Hair Care & Fashion. Web. 2 Feb. 2015.
Environmental Health & Engineering, Inc. EMISSIONS OF HAZERDOUS AIR POLLUTANTS FROM COAL- FIRED POWER PLANTS. Environmental Report. Needham, 2011. Print. 18 November 2014.
All different kinds of secondary products are discussed in these section such as particulate matter (section 2.3.1), Tar compound (section 2.3.2), Sulphur compound (2.2.4). Although not much literature is available, section 2.3.3 briefly introduces the importance of Alkaline, heavy metals and halides compounds as secondary products. It is worth mentioning that secondary products come out from the gasification process concentrations of which in the gas depend on the biomass composition and the technology used.