外文翻譯---天然氣

1、.附錄一：英文原文原文：Natural gasFrom Wikipedia, the free encyclopediaJump to: navigation, search For other uses, see Natural gas (disambiguation).Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, with up to 20 percent1 concentration of other hydrocarbons (usually e

2、thane) as well as small amounts of impurities such as carbon dioxide. Natural gas is widely used and is an important energy source in many applications including heating buildings, generating electricity, providing heat and power to industry and vehicles and is also a feedstock in the manufacture of

3、 products such as fertilizers.Natural gas is found in deep underground natural rock formations or associated with other hydrocarbon reservoirs, in coal beds, and as methane clathrates. Most natural gas was created over time by two mechanisms: biogenic and thermogenic. Biogenic gas is created by meth

4、anogenic organisms in marshes, bogs, landfills, and shallow sediments. Deeper in the earth, at greater temperature and pressure, thermogenic gas is created from buried organic material.2Before natural gas can be used as a fuel, it must undergo processing to clean the gas and remove impurities includ

5、ing water in order to meet the specifications of marketable natural gas. The by-products of processing include ethane, propane, butanes, pentanes, and higher molecular weight hydrocarbons, hydrogen sulphide (which may be converted into pure sulfur), carbon dioxide, water vapor, and sometimes helium

6、and nitrogen.In the 19th century, natural gas was usually obtained as a byproduct of producing oil, since the small, light gas carbon chains came out of solution as the extracted fluids underwent pressure reduction from the reservoir to the surface, similar to uncapping a bottle of soda pop where th

7、e carbon dioxide effervesces. Unwanted natural gas was a disposal problem in the active oil fields. If there was not a market for natural gas near the wellhead it was virtually valueless since it had to be piped to the end user. In the 19th century and early 20th century, such unwanted gas was usual

8、ly burned off in the oil fields. Today, unwanted gas (or stranded gas without a market) associated with oil extraction often is returned to the reservoir with 'injection' wells while awaiting a possible future market or to repressurize the formation, which can enhance extraction rates from o

9、ther wells. In regions with a high natural gas demand (such as the US), pipelines are constructed when economically feasible to move the gas from the wellsite to the end consumer.Another possibility is to export the natural gas as a liquid. Gas-to-liquids (GTL) is a developing technology that conver

10、ts stranded natural gas into synthetic gasoline, diesel, or jet fuel through the Fischer-Tropsch process developed during World War II by Germany. Such fuel can be transported to users through conventional pipelines and tankers. Proponents claim GTL burns cleaner than comparable petroleum fuels. Mos

11、t major international oil companies are in an advanced stage of GTL production, with a world-scale (140,000 barrels (22,000 m3) a day) GTL plant in Qatar scheduled to be in production before 2010.dated infoNatural gas can be "associated" (found in oil fields) or "non-associated"

12、(isolated in natural gas fields), and is also found in coal beds (as coalbed methane). It sometimes contains significant amounts of ethane, propane, butane, and pentaneheavier hydrocarbons removed for commercial use prior to the methane being sold as a consumer fuel or chemical plant feedstock. Non-

13、hydrocarbons such as carbon dioxide, nitrogen, helium (rarely), and hydrogen sulfide must also be removed before the natural gas can be transported.3Natural gas is commercially extracted from oil fields and natural gas fields. Gas extracted from oil wells is called casinghead gas or associated gas.

14、The natural gas industry is extracting gas from increasingly more challenging resource types: sour gas, tight gas, shale gas, and coalbed methane.The world's largest proven gas reserves are located in Russia, with 4.757×1013 m³ (1.68×1015 cubic feet). With the Gazprom company, Rus

15、sia is frequently the world's largest natural gas extractor. Major proven resources (in billion cubic meters) are world 175,400 (2006), Russia 47,570 (2006), Iran 26,370 (2006), Qatar 25,790 (2007), Saudi Arabia 6,568 (2006) and United Arab Emirates 5,823 (2006).It is estimated that there are ab

16、out 900 trillion cubic meters of "unconventional" gas such as shale gas, of which 180 trillion may be recoverable.4 In turn, many studies from MIT, Black & Veatch and the DOE - see natural gas - will account for a larger portion of electricity generation and heat in the future.5The wor

17、ld's largest gas field is Qatar's offshore North Field, estimated to have 25 trillion cubic meters6 (9.0×1014cubic feet) of gas in placeenough to last more than 420 yearscitation needed at optimum extraction levels. The second largest natural gas field is the South Pars Gas Field in Ira

18、nian waters in the Persian Gulf. Located next to Qatar's North Field, it has an estimated reserve of 8 to 14 trillion cubic meters7 (2.8×1014 to 5.0×1014 cubic feet) of gas.Because natural gas is not a pure product, as the reservoir pressure drops when non-associated gas is extracted f

19、rom a field under supercritical (pressure/temperature) conditions, the higher molecular weight components may partially condense upon isothermic depressurizingan effect called retrograde condensation. The liquid thus formed may get trapped as the pores of the gas reservoir get deposited. One method

20、to deal with this problem is to re-inject dried gas free of condensate to maintain the underground pressure and to allow re-evaporation and extraction of condensates. More frequently, the liquid condenses at the surface, and one of the tasks of the gas plant to collect this condensate. The resulting

21、 liquid is called natural gas liquid (NGL) and has commercial value.Town gasTown gas, a synthetically produced mixture of methane and other gases, mainly the highly toxic carbon monoxide, is used in a similar way to natural gas and can be produced by treating coal chemically. This is a historical te

22、chnology, not usually economically competitive with other sources of fuel gas today. But there are still some specific cases where it is the best option and it may be so into the future.Most town "gashouses" located in the eastern US in the late 19th and early 20th centuries were simple by

23、-product coke ovens which heated bituminous coal in air-tight chambers. The gas driven off from the coal was collected and distributed through networks of pipes to residences and other buildings where it was used for cooking and lighting. (Gas heating did not come into widespread use until the last

24、half of the 20th century.) The coal tar (or asphalt) that collected in the bottoms of the gashouse ovens was often used for roofing and other water-proofing purposes, and when mixed with sand and gravel was used for paving streets.BiogasMain article: biogasWhen methane-rich gases are produced by the

25、 anaerobic decay of non-fossil organic matter (biomass), these are referred to as biogas (or natural biogas). Sources of biogas include swamps, marshes, and landfills (see landfill gas), as well as sewage sludge and manure8 by way of anaerobic digesters, in addition to enteric fermentation, particul

26、arly in cattle.Methanogenic archaea are responsible for all biological sources of methane, some in symbiotic relationships with other life forms, including termites, ruminants, and cultivated crops. Methane released directly into the atmosphere would be considered a pollutant. However, methane in th

27、e atmosphere is oxidized, producing carbon dioxide and water. Methane in the atmosphere has a half life of seven years, meaning that if a tonne of methane were emitted today, 500 kilograms would have broken down to carbon dioxide and water after seven years.Other sources of methane, the principal co

28、mponent of natural gas, include landfill gas, biogas, and methane hydrate. Biogas, and especially landfill gas, are already used in some areas, but their use could be greatly expanded. Landfill gas is a type of biogas, but biogas usually refers to gas produced from organic material that has not been

29、 mixed with other waste.Landfill gas is created from the decomposition of waste in landfills. If the gas is not removed, the pressure may get so high that it works its way to the surface, causing damage to the landfill structure, unpleasant odor, vegetation die-off, and an explosion hazard. The gas

30、can be vented to the atmosphere, flared or burned to produce electricity or heat. Experimental systems were being proposed for use in parts of Hertfordshire, UK, and Lyon in France.Once water vapor is removed, about half of landfill gas is methane. Almost all of the rest is carbon dioxide, but there

31、 are also small amounts of nitrogen, oxygen, and hydrogen. There are usually trace amounts of hydrogen sulfide and siloxanes, but their concentration varies widely. Landfill gas cannot be distributed through utility natural gas pipelines unless it is cleaned up to less than 3% CO2, and a few parts p

32、er million H2S, because CO2 and H2S corrode the pipelines.9 It is usually more economical to combust the gas on site or within a short distance of the landfill using a dedicated pipeline. Water vapor is often removed, even if the gas is combusted on site. If low temperatures condense water out of th

33、e gas, siloxanes can be lowered as well because they tend to condense out with the water vapor. Other non-methane components may also be removed in order to meet emission standards, to prevent fouling of the equipment or for environmental considerations. Co-firing landfill gas with natural gas impro

34、ves combustion, which lowers emissions.Gas generated in sewage treatment plants is commonly used to generate electricity. For example, the Hyperion sewage plant in Los Angeles burns 8 million cubic feet (230,000 m3) of gas per day to generate power10 New York City utilizes gas to run equipment in th

35、e sewage plants, to generate electricity, and in boilers.11 Using sewage gas to make electricity is not limited to large cities. The city of Bakersfield, California, uses cogeneration at its sewer plants.12 California has 242 sewage wastewater treatment plants, 74 of which have installed anaerobic d

36、igesters. The total biopower generation from the 74 plants is about 66 MW.13Biogas is usually produced using agricultural waste materials, such as otherwise unusable parts of plants and manure. Biogas can also be produced by separating organic materials from waste that otherwise goes to landfills. T

37、his method is more efficient than just capturing the landfill gas it produces. Using materials that would otherwise generate no income, or even cost money to get rid of, improves the profitability and energy balance of biogas production.Anaerobic lagoons produce biogas from manure, while biogas reac

38、tors can be used for manure or plant parts. Like landfill gas, biogas is mostly methane and carbon dioxide, with small amounts of nitrogen, oxygen and hydrogen. However, with the exception of pesticides, there are usually lower levels of contaminants.附錄二：中文譯文天然氣來自維基百科，自由的百科全書作其他用途,見天然氣(區(qū)別)。天然氣是一種自然產

39、生的烴類氣體的混合物，主要由甲烷組成， 1其他碳氫化合物的濃度高達20（通常乙烷）以及少量的雜質，如二氧化碳。天然氣用途廣泛并且是一個重要能源應用在許多包括采暖建筑，機組發(fā)電，提供熱和力量給產業(yè)和車并且也是一種制造產品的原料 例如肥料。 天然氣在地下深處的天然巖層中被發(fā)現(xiàn)，或在煤層中，和其他油氣藏，如甲烷水合物。生物活動所產生和熱量這兩個機制隨著時間的推移形成了大多數(shù)天然氣。生物氣是由甲烷的生物體在沼澤，沼澤，垃圾填埋場，淺層沉積物中的活動產生的。在地球的更深處，在更高溫度和壓力的條件下，被埋藏的有機材質形成了地藏天熱氣在天然氣可以使用作為燃料之前 ，它必須經過加工,清洗和清除雜質包括包括水處

40、理,讓天然氣滿足市場的需求。天然氣被加工后的產品包括乙烷，丙烷，丁烷，戊烷，和較高分子量的烴類，硫化氫（可轉換成純硫），二氧化碳，水蒸氣，偶爾會有氦氣和氮氣。天然氣經常簡單地不拘形式地被指氣體，特別是當與其他能源比較時例如石油或煤炭。 天然氣在 19 世紀，天然氣通常被作為一種石油生產而產生的副產品，自小而輕的碳鏈溶解出來，作為提取液從內到外減小儲藏器的壓力，類似于打開一瓶蘇打汽水所排放的二氧化碳那樣。在在活動中的油田中，不需要的天然氣是被作為一個問題來處理。如果在天然氣井口附近沒有市場的話，它是毫無價值的除非用管道輸送到終端用戶那里。在 19 世紀和 20 世紀初，這樣不需要的氣體在油田通常

41、被燒掉了 今天，不需要的氣體(或沒有市場的擱淺的氣體)常常與石油開采相關的經常被返回注射到油井中。在等待一個可能的未來市場的形成或者再增加壓力使其相變，可以增強從其他油井提取率。在有較高天然氣需求的地區(qū)（例如美國），當經濟上可行的話會鋪設管道把天然氣從出口井輸送到用戶手上。另外一種可能性是出口液體天然氣。氣液轉換是一種發(fā)展中的技術，可以通過開發(fā)二次世界大戰(zhàn)期間的德國的費-托合成過程把不能送出的天然氣合成汽油，柴油或者別的能源。這種燃料可以運到用戶通過傳統(tǒng)的管道和加油機，支持者聲稱 GTL 燃料比可比石油燃料干凈。主要的大多數(shù)國際石油公司進入一個GTL生產的高級階段，在卡塔爾的GTL廠2010年

42、以前預定的產量具有世界級規(guī)模的（14萬桶（22,000立方米）的一天）。天然氣可以關聯(lián)”（在石油領域）或“非”（孤立在天然氣領域），而且還發(fā)現(xiàn)在煤層（煤層氣）。天然氣有時含有大量的乙烷，丙烷，丁烷，戊烷，甲烷作為燃料消費或化工原料商業(yè)使用之前需除去更重的碳氫化合物。在天然氣運輸之前，非烴如二氧化碳，氮，氦（很少），和硫化氫也必須被處理掉。商業(yè)上天然氣是從油田和天然氣田提取出來的。從石油井中提取的天然氣被稱為油井氣或者半生氣。天然氣工業(yè)從越來越多的挑戰(zhàn)資源類型：酸氣，致密氣，頁巖氣，煤層氣等中提取天然氣。世界上已經探明儲氣量最大的氣田位于俄羅斯，儲氣量高達4.757×1013米

43、9;（1.68×1015立方英尺）。與俄羅斯天然氣工業(yè)股份公司，俄羅斯經常是世界上最大的天然氣提取者。世界上主要的已經探明的天然氣資源是175400（2006），俄羅斯47570（2006）26370（2006），伊朗，卡塔爾，沙特阿拉伯，25790（2007）6568（2006）和阿拉伯聯(lián)合酋長國5823（2006）。據(jù)估計，約有900000000000000立方米的“非常規(guī)”的天然氣頁巖氣等，其中180000000000000立方米可以持續(xù)利用。反過來，來自麻省理工學院，博萊克威奇和能源部的許多研究者看到天然氣將占據(jù)大部分的供熱能源和發(fā)電能源在不遠的將來。世界上最大的天然氣田是卡

44、塔爾海上北場，在那里估計有25000000000000立方米（9×1014cubic英尺）氣體。在最佳提取的水平上足夠用420年以上。第二最大的天然氣田南帕爾斯氣田在在波斯灣伊朗水域。位于旁邊的卡塔爾北場，估計有儲量為8至14000000000000立方米（2.8×1014至5×1014立方英尺）的氣體由于天然氣不是一個單純的產品，當伴生氣在超臨界（壓力/溫度）條件下被提取出來時就如同儲層壓力下降一樣，較高分子量的成分可能部分凝結后等溫減壓這個效果叫稱為逆行縮合，這樣形成的液體可能被作為氣體儲存器的毛孔被沉淀下來，處理這個問題的方法是重新注入干氣凝析油，以保持地下壓力并允許重新蒸發(fā)和冷凝萃取。更經常地，液體凝結在表面，并且其中一項天然氣加工廠的任務就是收集