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Carbon Dioxide and Global WarmingAbstractCarbon dioxide plays a very important role in the process of global warming. In order to reduce the level of CO in the atmosphere, two main measures can be taken, carbon dioxide emission reduction and utilization of CO. IntroductionSince 1985, scientists Villach meeting on global warming and its consequent climate change, great efforts have been taken to study global warming (Houghton, 1990). According to their researches, global warming is unequivocal, as is manifested in three internationally global temperature records with the global average temperature rising at a rate of 0.70-0.75 per 100 years during 1910-2009(Wen et al., 2011). Global temperature increase will cause a series of negative effects on natural systems, including snow and ice melting, sea-level rising and intermingle in the hydrological cycle. At the same time the increase in COconcentrations will lead to the acidification of sea water. Such effects will directly or indirectly threaten terrestrial and marine ecosystems and social systems (FANG Jing-Yun et al, 2011).As a main greenhouse gas, carbon dioxide has attracted many countries attention since 1980. Statistics indicated, because of the burning of the fossil fuels, 185 -242billion ton COwere released into the atmosphere per year (YuTian-Jie et al., 2008). Recently, with the developmentof natural gas, the content of carbon dioxide in the natural gas is also increasing year by year. The large number of CO emissions, not only causes waste of carbon resource, but also contributes to the global warming. In order to improve the situation, Kyoto Protocol was put forward to limit developed countries to reduce the emission of CO. Therefore, American, Britain and Germany all researched to make a reduction system. Meanwhile, Japan started to increase the speed of study of CO, planed to build an independent industry system to take CO as the chemical material (Yu Tian-Jie et al, 2008).Carbon dioxideis closely related to globalwarming, its emission reduction and utilization are no delay.The relationship of carbon dioxide and global warmingCarbon dioxide is an important reactor of global warming. In 2008, Shi Guang-Yu worked in ChineseAcademy of Sciences Institute of Physics summarized that if double the amount of carbon dioxide in the atmosphere, the density will increase about 3.75Wm(Shi Guang-Yu, 2008.) . Carbon dioxide affects global warming in many ways, for example it can make the solar short wave radiation passed freely and absorbs the long wave from the surface of earth. However carbon dioxide is not the only reason resulting in global warming. Cao Gen-Hua and his partners put forward two evidences to prove that global warming was not entirely caused by COin their literature “Discussion on the Carbon Dioxideand Greenhouse effect”. Firstly, basing on the long research of climate change, scientists discovered that the records of temperature were not entirely consistent with the content change of carbon dioxide in the atmosphere. Although the carbon dioxide is increasing, the trend was stopped three times by cold period while the increasing of temperature was not stopped. Secondly, ifexcessive carbon dioxide emissionsentirely causeglobal warming, the cloud cover will also increase and temperature rising will be offset by reducing the earths surface heat from the sun. (Cao Hua-Gen et al, 2008)The utilization technologies of carbon dioxideTechnologies of physics utilizationCarbon dioxide is widely used in psychics, such fire extinguishing agent, refrigerant and cleaningagent. In mid May,2004,Chinas firstliquidcarbon dioxide dry cleaningmachinelocated in Beijing. As a new cleaning agent, carbon dioxide has a great effect on cleaning textiles. Compared with traditional methods, it has four main advantages： 1. Using carbon dioxide as the solvent,dry cleaningequipmentcan realize true green dry cleaning ; 2. The use ofliquidcarbon dioxide can help dry cleaningmachinereduce operating costs and saveenergy; 3.Liquid carbon dioxide has good washingeffect; 4. Themechanical property of liquid carbon dioxide dry cleaningmachine is superior. (Qi Da-Tong, 2004) Carbon dioxide also has many applications in the food industry. They can be summarized threecategories. 1. High densityof carbon dioxide has great effects on the sterilizationdisinfection.2. Carbon dioxide is aninert medium. For it doesnt damage thevariousrange of food components, thecarbon dioxideand carbon dioxide gasin puffed food productionare verypopular.3. Carbon dioxide can also be used to produce a king of popular drinks-sodas.Technologies of chemical utilizationExpect for physics, carbon dioxide is also used in the chemical industry as a chemical martial. For example, the synthesis of urea, urea is a very importantfertilizer, undercertainconditions. It can be synthesized from NH and CO. The chemical equation is as follows:2 NH+ CONHCOONHCO (NH) + HO based on the equation, 740 kg of carbon dioxide will be consumed to produce one ton urea. Because all of the crops growths need urea, it is in a great demand. Large amount of carbon dioxide can be consumed. Besides the synthesis of urea, many other developed technologies taking COas the material have been used in the Synthesis of salicylic acid,production of sodium carbonate,calcium carbonateand other inorganiccarbonate. In addition, as a resource rich in carbon and oxygen, people are also trying to use carbon dioxide in the productions of hydrocarbon,methanol,ethylene carbonate,diethyl carbonate and polycarbonate Etc. In addition to researching the technologies to use CO, trying to reduce the emission of COis also very helpful to govern global warming.The emission reduction of carbon dioxide in chemical engineering The utilization ofcarbon dioxide in chemical engineeringis one of the most important means in the emissions reduction of carbon dioxide,especiallyin large-scalechemical production, the largeuse of carbon dioxideplaying a decisive role on the emission reduction. Take an example: Currently, the quantity of ammonia plant probably reaches to 500. Take the medium-plant as an object. If the carbon dioxide emissions can be recycle, each plant will get 30000-50000tons carbon dioxide products and the total will reach 1.65-2.75millions ton per year.The synthesis of ureais the most successful example to fixed and use large mass of carbon dioxide. With the continuous progressof chemicalengineering utilization technologies of carbon dioxide,chemical engineering of carbon dioxide has become the mainmeans of carbon dioxide emissions reduction. Thenhow to use the developedchemicaltechnology to reducecarbon dioxide emissions and how to achieve thereliable combination ofthe technologies to deal with carbon dioxide and reduce carbon dioxide emissions,are particularly important.Adjust the process of production and reduce the emission of carbon dioxideOne of the main sourcesof carbon dioxidefrom the chemical industryis the by-product gas in the production of hydrogen. Synthetic gas with hydrogen,carbon monoxideas main component will be produced after oil, coal and natural gas vaporization at the high temperature. Then the carbon monoxide will be converted into hydrogen and carbon dioxide. In reality, with the chemical industry chain of one carbon keeps on developing, carbon monoxide, as the raw material, will have greater value be used more widely. If people adjust the process and structure of production and utilize the carbon monoxide resource appropriately, the amount of carbon monoxides conversion will reduce and the generation and emission of carbon dioxide will be under control. （Yu Tian-Jie，2008） Conclusion Global warming is a huge challenge we mankind are facing today. Reducing the content of carbon dioxide in the atmosphere is one of the important measures to improve global warming. The utilization and emission reduction of carbon dioxide are the two main ways to reduce the level of carbon dioxide in the atmosphere. Realizing the wide utilization of carbon dioxide is still far away to us.Currently, making full use of carbon monoxide and reducing the carbon dioxide conversed from carbon monoxide are the two most efficient measures to reduce the emissions of carbon dioxide in the process of chemical industry. At the same time, carbon dioxide from other chemical production can be collected to use in the synthesis of urea, soda ash and carbonates. Because the technologies to produce those chemical productions are very mature, the most important step is to combine those technologies efficiently for the realization of emission reduction and maximum utilization of carbon dioxide. Reference Fang Jing-Yun, ZHU Jiang-Ling et al, 2011 Global warming, human-induced carbon emissions and their uncertainties. Houghton, 1990. Scientific assessment of climate change. Shi Guang-Yu, 2008. Impacts of COand other factors on Global Warming.Wen Ching-Yang, 2011. Particuology and climate change Yu Tian-Jie， 2008. The Chemical Use and Emissions of Carbon Dioxide齐大同，2004. 中国洗衣业的突破性进展-浅谈液体二氧化碳干洗机在洗衣业的应用曹根华、李玉杰等, 2008. 浅谈二氧化碳对温室效应的影响
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