首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The Hydrogen Economy Problems with the fossil fuel economy Currently, the United States and most of the world is locked int
The Hydrogen Economy Problems with the fossil fuel economy Currently, the United States and most of the world is locked int
admin
2013-07-02
38
问题
The Hydrogen Economy
Problems with the fossil fuel economy
Currently, the United States and most of the world is locked into what could be called the fossil fuel economy. Our automobiles, trains and planes are fueled almost exclusively by petroleum products like gasoline and diesel. A huge percentage of our power plants use oil, natural gas and coal for their fuel.
While fossil fuels have played an important role in getting society to the point it is at today, there are four big problems that fossil fuels create.
Air pollution. When cars burn gasoline, they would ideally burn it perfectly and create nothing but carbon dioxide and water in their exhaust. Unfortunately, the internal combustion engine is not perfect. In the process of burning the gasoline, it also produces carbon monoxide(一氧化碳), a poisonous gas; nitrogen oxides, the main source of urban smog; and unburned hydrocarbons, the main source of urban ozone(臭氧). Some kind of converters can eliminate much of this pollution, but they aren’t perfect. Air pollution from cars and power plants is a real problem in big cities.
It is bad enough now that, in the summer, many cities have dangerous levels of ozone in the air.
Environmental pollution. The process of transporting and storing oil has a big impact on the environment whenever something goes wrong. An oil spill, pipeline explosion or well fire can create a huge mess.
Global warming. When you burn a gallon of gas in your car, you emit about 5 pounds(2. 3 kg)of carbon into the atmosphere. If it were solid carbon, it would be extremely noticeable. But because the 5 pounds of carbon comes out as an invisible gas, carbon dioxide, most of us are forgetful to it. The carbon dioxide coming out of every car’s tailpipe is a greenhouse gas that is slowly raising the temperature of the planet. The ultimate effects are unknown, but it is a strong possibility that, eventually, there will be dramatic climate changes that affect everyone on the planet. For example, if the ice caps melt, sea level will rise significantly, flooding and destroying all coastal cities in existence today. That’s a big side effect.
Dependence. The United States, and most other countries, cannot produce enough oil to meet demand, so they import it from oil-rich countries. That creates an economic dependence. When Middle East oil producers decide to raise the price of oil, the rest of the world has little choice but to pay the higher price.
Advantages of the hydrogen economy
It can be seen that the significant, worldwide problems are created by fossil fuels. The hydrogen economy promises to eliminate all of the problems that the fossil fuel economy creates. Therefore, the advantages of the hydrogen economy include:
The elimination of pollution caused by fossil fuels. When hydrogen is used in a fuel cell to create power, it is a completely clean technology. The only by-product is water. There are also no environmental dangers like oil spills to worry about with hydrogen.
The elimination of greenhouse gases. If the hydrogen comes from the electrolysis(电解)of water, then hydrogen adds no greenhouse gases to the environment. There is a perfect cycle — electrolysis produces hydrogen from water, and the hydrogen recombines with oxygen to create water and power in a fuel cell.
The elimination of economic dependence. The elimination of oil means no dependence on the Middle East and its oil reserves.
Distributed production. Hydrogen can be produced anywhere that you have electricity and water. People can even produce it in their homes with relatively simple technology.
The problems with the fossil fuel economy are so great, and the environmental advantages of the hydrogen economy so significant, that the push toward the hydrogen economy is very strong.
Where does the hydrogen come from?
In the hydrogen economy, there is no storehouse to tap into. We have to actually create the energy in real-time. There are two possible sources for the hydrogen:
Electrolysis of water. Using electricity, it is easy to split water molecules to create pure hydrogen and oxygen. One big advantage of this process is that you can do it anywhere. For example, you could have a box in your garage producing hydrogen from tap water, and you could fuel your car with that hydrogen.
Reforming fossil fuels. Oil and natural gas contain hydrocarbons. Using a device called a fuel processor or a reformer, you can split the hydrogen off the carbon in a hydrocarbon relatively easily and then use the hydrogen. You discard the leftover carbon to the atmosphere as carbon dioxide.
The second option is, of course, slightly perverse. You are using fossil fuel as the source of hydrogen for the hydrogen economy. This approach reduces air pollution, but it doesn’t solve either the greenhouse gas problem(because there is still carbon going into the atmosphere)or the dependence problem(you still need oil). However, it may be a good temporary step to take during the transition to the hydrogen economy. When you hear about "fuel-cell-powered vehicles" being developed by the car companies right now, almost all of them plan to get the hydrogen for the fuel cells from gasoline using a reformer. The reason is because gasoline is an easily available source of hydrogen. Until there are "hydrogen stations" on every corner like we have gas stations now, this is the easiest way to obtain hydrogen to power a vehicle’s fuel cell.
The interesting thing about the first option is that it is the core of the real hydrogen economy. To have a pure hydrogen economy, the hydrogen must be derived from renewable sources rather than fossil fuels so that we stop releasing carbon into the atmosphere. Having enough electricity to separate hydrogen from water, and generating that electricity without using fossil fuels, will be the biggest change that we see in creating the hydrogen economy.
How do you store and transport the hydrogen?
At this moment, the problem with putting pure-hydrogen vehicles on the road is the storage/transportation problem. Hydrogen is a bulky gas, and it is not nearly as easy to work with as gasoline. Compressing the gas requires energy, and compressed hydrogen contains far less energy than the same volume of gasoline. However, solutions to the hydrogen storage problem are surfacing.
For example, hydrogen can be stored in a solid form in a chemical called sodium borohydride(硼氢化钠)and this technology has appeared in the news recently because Chrysler is testing it. This chemical is created from borax(硼砂)(a common ingredient in some detergents). As sodium borohydride releases its hydrogen, it turns back into borax so it can be recycled.
Once the storage problem is solved and standardized, then a network of hydrogen stations and the transportation infrastructure will have to develop around it. The main barrier to this might be the technological sorting-out process. Stations will not develop quickly until there is a storage technology that clearly dominates the marketplace. For instance, if all hydrogen-powered cars from all manufacturers used sodium borohydride, then a station network could develop quickly; that sort of standardization is unlikely to happen rapidly, if history is any guide.
There might also be a technological breakthrough that could rapidly change the playing field. For example, if someone could develop an inexpensive rechargeable battery with high capacity and a quick recharge time, electric cars would not need fuel cells and there would be no need for hydrogen on the road. Cars would recharge using electricity directly.
Prospects for the future
You will hear more and more about the hydrogen economy in the news in the coming months, because the drumbeat is growing louder. The environmental problems of the fossil fuel economy are combining with breakthroughs in fuel-cell technology, and the pairing will allow us to take the first steps.
The most obvious step we will see is the marketing of fuel-cell-powered vehicles. Although they will be powered initially by gasoline and reformers, fuel cells embody two major improvements over the internal combustion engine: They are about twice as efficient. They can significantly reduce air pollution in cities. Gasoline-powered fuel-cell vehicles are an excellent transitional step because of those advantages.
Moving to a pure hydrogen economy will be harder. The power-generating plants will have to switch over to renewable sources of energy, and the marketplace will have to agree on ways to store and transport hydrogen. These hurdles will likely cause the transition to the hydrogen economy to be a rather long process.
To solve the transportation problem, hydrogen can be stored in a______ form.
选项
答案
solid
解析
文中说氢气是一种体积较大的气体,操作起来远不及汽油那么容易。但它可以以固态形式储存在一种化学物质中。答案为solid。
转载请注明原文地址:https://kaotiyun.com/show/krn7777K
0
大学英语六级
相关试题推荐
KarlWilhelmRontgen【B1】______peoplewiththefirstx-raysin1895;thiswas【B2】_____threeyearslaterbythediscoveryofradiu
Friendshipisbothasourceofpleasureandacomponentofgoodhealth.Peoplewhohaveclosefriendsnaturallyenjoytheir【C1】_
TheUnitedStatesDepartmentofEducationsaystherearemorethan2,400Americancollegesanduniversities.About100ofthese
TheUnitedStatesDepartmentofEducationsaystherearemorethan2,400Americancollegesanduniversities.About100ofthese
A、Tosuggestchangesinthetuitionfees.B、Toimprovethestudyskillsofuniversitystudents.C、Togivepeopletheopportunity
Unlikethescientist,theengineerisnotfreetoselecttheproblemwhichinterestshim;hemustsolvetheproblemsastheyaris
Anewstudyusesadvancedbrain-scanningtechnologytoeastlightonatopicthatpsychologistshavepuzzledoverformorethan
Formanyfamilies,figuringouthowmanyafter-schoolactivitiesaretoomanyisastruggle.Forparentswhofearthey’re"over-
Formanyfamilies,figuringouthowmanyafter-schoolactivitiesaretoomanyisastruggle.Forparentswhofearthey’re"over-
A、Hercarisbeingrepaired.B、Shewantstohelpreducepollution.C、Parkingisdifficultinthecity.D、Thecostoffuelhasin
随机试题
能适用于不同工况范围的搅拌器形式为()。
生态学的主要研究方法包括野外调查研究、实验室研究和__________。
气郁化火引起发热的辨证的要点为
患者,女,60岁。视物成双、口角歪斜伴双下肢活动障碍10小时来急诊。体查:神清,生命体征正常。瞳孔等大。双眼球上下运动不受限。双侧面瘫。不能伸舌。双上肢肌力2级,双下肢肌力0~1级。感觉障碍不明显。无颈项强直。外院脑CT检查未见异常。病变损害可能位于
根据宪法和法律,下列选项中表述错误的有:
甲公司是专营进料加工的外商投资企业,该公司设在武汉.海关经营企业分类为B类。2007年6月该投资企业委托南京某进出口公司与韩国某企业签订一批原材料的进口合同,合同金额为800万美元,该批货物属于允许加工类商品。合同中已规定,40%进口料件加工成品内销,60
下列公式中正确的有()。
根据学生的身心发展特点,小学、初中、高中不同学段的德育工作有相应的侧重点,其中,小学阶段的德育重点主要是()。
习近平在《上海联合公报》发表40周年纪念活动上致辞:“……太平洋之大、世界之广,足以包容崛起的中国与美国。”时任美国国务卿希拉里表示:“美国正试图与这个崛起中的大国合作,推动其崛起成为一个对全球安全、稳定和繁荣的积极贡献者。”美国不寻求遏制中国,并将致力推
Inafactory,machineAoperatesonacycleof20hoursofworkfollowedby4hoursofrest,andmachineBoperatesonacycleo
最新回复
(
0
)