查看“︁伯克兰-艾德法”︁的源代码

[[File:Birkeland-Eyde lysbue.JPG|thumb|应用伯克兰-艾德法的反应器，功率3000&nbsp;kW，1916-1940年用于[[留坎]]的化工厂，现展览于{{link-en|挪威科学技术博物馆|Norwegian Museum of Science and Technology}}外]]

'''伯克兰-艾德法'''（{{lang-no|Birkeland-Eyde-prosessen}}，{{lang-en|Birkeland–Eyde process}}）曾是[[化学工业]]中一种[[硝酸]]的制备方法，主要用于[[氮肥]]生产。它是一种由多个步骤组成的[[固氮]]过程：高压[[电弧]]使大气中的[[氮气]]（N<sub>2</sub>）与[[氧气]]（O<sub>2</sub>）在3000&nbsp;°C高温中结合产生[[氮氧化物]]（NO<sub>x</sub>）；二氧化氮（NO<sub>2</sub>）在水中溶解得到[[硝酸]]（HNO<sub>3</sub>）；硝酸最终作为氮肥的生产原料，是[[硝酸盐]]的来源。<ref name="remsen1906">{{cite journal|last1=Remsen|first1=I.|last2=Renoup|first2=H.|title=The Oxidation of Atmospheric Nitrogen with Reference to the Manufacture of Nitrates and Nitric Acid|journal=American Chemical Journal|date=1906|volume=35|pages=358–367|url=https://archive.org/download/americanchemical351906balt/americanchemical351906balt_bw.pdf|accessdate=2024-03-04}}</ref>

本方法由挪威科学家[[克里斯蒂安·伯克兰]]研发<ref name="lucy2007-credit">{{cite book|title=The Northern Lights|author=Lucy Jago|publisher=Knopf Doubleday Publishing Group|year=2007|url=https://www.google.com/books/edition/The_Northern_Lights/C9iVxsMjSp4C?gbpv=1&dq=deeply%20unhappy%20about%20having%20to%20share&pg=PT114&printsec=frontcover|quote=Birkeland was deeply unhappy about having to share credit with Eyde, who had no part in the technical development of the idea, but he was forced to collaborate because only Eyde had access to the  huge amounts of electric power that would be needed to run the furnaces.}}</ref>，并与工业家[[山姆·艾德]]于1903年合作投产<ref name="lucy2007-credit"/><ref>{{cite journal| title= The Manufacture of Nitrates from the Atmosphere by the Electric Arc—Birkeland-Eyde Process| first=Sam | last=Eyde | journal= Journal of the Royal Society of Arts| volume= 57| issue = 2949 | year= 1909| pages= 568–576 | accessdate=2024-03-04 | jstor=41338647}}</ref>，建立在1780年代[[亨利·卡文迪什]]发现的化学现象的基础之上。<ref>{{cite journal |last1=Cavendish |first1=Henry |title=Experiments on air |journal=Philosophical Transactions of the Royal Society of London |date=1785 |volume=75 |pages=372-384 |url=https://archive.org/details/philtrans03761202/mode/2up}}</ref><ref>{{cite book
| title = The development of modern chemistry
| url = https://archive.org/details/developmentofmod0000ihde
| author = Aaron John Ihde
| publisher = Courier Dover Publications
| year = 1984
| isbn = 0-486-64235-6
| page = [https://archive.org/details/developmentofmod0000ihde/page/678 678]
}}</ref>在[[哈伯法]]与[[奥斯特瓦尔德法]]发明后，本方法因能效低、耗电大，在1910-1920年代间逐渐淘汰。<ref name="trevor1982"/>

==反应==

[[File:Birkeland-Eyde Plasma Disc.png|thumb|装置示意图，水冷电极与电磁铁产生碟片形等离子体]]

反应装置核心是一个[[火花隙]]，因此有时也称电弧炉。它的两个[[电极]]由铜管制成，具有[[同轴]]式结构，采用[[水冷]]散热。两电极间施加[[电压]]5&nbsp;kV、[[頻率 (物理學)|频率]]50&nbsp;Hz的[[高压电|高压]]交流电，使火花隙反复快速放电<ref name="lucy2007"/>，产生[[电弧]]。在电极周围，还使用与电极方向垂直的[[电磁铁]]施加一个[[静磁场]]，它产生的[[洛伦兹力]]会将电弧拉伸为碟形薄片。

碟片形电弧是温度大于3000&nbsp;°C的[[等离子体]]。当空气吹过电弧时，在高温下，氮气[[氧化]]产生[[一氧化氮]]。在自然界中，大气中的闪电也能产生相同的化学反应，是可溶性硝酸盐的一个来源。<ref>{{cite book
| title = Nitrogen fixation at the millennium
| author1 = Karl Fisher
| author2 = William E. Newton
| editor = G. J. Leigh
| publisher = Elsevier
| year = 2002
| isbn = 0-444-50965-8
| pages = 2–3
}}</ref>此外，原则上也可以使用火焰、电热铂导线、普通电弧作为热源——但效果不佳，不适合工业上大规模生产。伯克兰-艾德的碟片形电弧不但能与空气充分接触，还大幅提升了反应器的功率上限。用这种方法产生的碟片形电弧直径可达2米，发出太阳般的耀眼光芒。<ref name="trevor1982"/><ref name="lucy2007"/>

[[File:Såheim Rjukan II.jpg|thumb|建于{{link-en|萨海姆水力发电站|Såheim Hydroelectric Power Station}}（Såheim Hydroelectric Power Station）后方的反应器二号建筑，其中曾装有35个伯克兰-艾德反应器，每个功耗达3000&nbsp;kW]]

:<chem>N2 + O2 -> 2NO</chem>

此[[反应速率]]在低温时非常缓慢，因此必须在高温下进行，降低温度会使产量下降。<ref name="Mell1918">{{cite book |title=Modern Inorganic Chemistry |last1=Mellor |first1=J. W. |publisher=Longmans, Green and Co. |year=1918 |page=[https://archive.org/details/cu31924055328623/page/n532 509] |url=https://archive.org/details/cu31924055328623}}</ref><ref name="Geof1915">{{cite book |title=Industrial Nitrogen Compounds and Explosives |author1=Martin, Geoffrey |author2=Barbour, William |publisher=Crosby Lockwood and Son |year=1915 |page=[https://archive.org/details/IndustrialNitrogenCompoundsAndExplosives/page/n24 21] |url=https://archive.org/details/IndustrialNitrogenCompoundsAndExplosives}}</ref>20世纪初实验表明，温度大于2000&nbsp;°C时，反应速率“极快”，但在1000&nbsp;°C时却会“缓慢到难以测量”。<ref name="remsen1906"/>通过精心控制电弧的能量与气流的流速，在3000&nbsp;°C时可产生4%-5%的[[一氧化氮]]。本反应能耗极高，生产一吨硝酸需要消耗15[[千瓦·時#用法|兆瓦时]]（15,000千瓦时）的电能，1kWh电能仅能生产60g硝酸。伯克兰的化工厂供电需要依靠附近的[[水力发电厂]]。<ref name="Mell1918"/><ref name="Geof1915"/>

高温一氧化氮随后冷却，与大气中的氧产生[[二氧化氮]]。此反应所需时间取决于空气中NO的浓度，浓度为1%时需要180秒，浓度为6%时需要40秒，产率为90%.<ref name="webb1923">{{cite book |title=Absorption of Nitrous Gases |first=H. W. |last=Webb |year=1923 |publisher=Edward Arnold & Co. |page=[https://archive.org/details/Absorption_of_Nitrous_Gases/page/n24 20] |url=https://archive.org/details/Absorption_of_Nitrous_Gases}}</ref>

:<chem>2 NO + O2 -> 2 NO2</chem>

接着，用水溶解二氧化氮产生硝酸。最后用[[分馏法]]进行提纯。<ref>{{cite book
| title = Industrial Chemical Process Design
| url = https://archive.org/details/industrialchemic0000erwi
| author = Douglas Erwin
| publisher = McGraw-Hill
| year = 2002
| isbn = 0-07-137621-6
| page = [https://archive.org/details/industrialchemic0000erwi/page/613 613]
}}</ref>

:<chem>3 NO2 + H2O -> 2 HNO3 + NO</chem>

[[吸收 (化学)|吸收过程]]的设计对整个系统的效率至关重要。二氧化氮要通过一系列四层楼高的填料塔或板式塔，产生40-50%的硝酸（高于此浓度时，吸收速率骤降）。第一座吸收塔让气泡状的二氧化氮穿过水与不发生反应的石英碎片。当达到最终浓度后，硝酸会转移到一个花岗岩制成的容器中，塔中液体被第二座吸收塔中更稀的酸液替代。这个移动过程如此反复，气体与液体向相反的方向转移，最后一座吸收塔需要不断补充淡水。此时约20%的氮氧化物仍未反应，因此最末尾的吸收装置中含有碱性的[[石灰]]溶液，将剩余的氮氧化物转化为[[硝酸钙]]（又称挪威硝石），但仍有约2%的氮氧化物释放到空气中。<ref name="Knox1914">{{cite book |last=Knox |first=Joseph |title=The Fixation of Atmospheric Nitrogen |publisher=D. Van Nostrand Company |year=1914 |pages=[https://archive.org/details/fixationatmosph00knoxgoog/page/n56 45]-50 |url=https://archive.org/details/fixationatmosph00knoxgoog}}</ref>

硝酸是生产氮肥所需的[[硝酸盐]]离子NO<sub>3</sub><sup>−</sup>的来源，化学式为：

:<chem display=inline>HNO3 + H2O -> H3O+ + NO3-</chem>

此反应可在[[水]]或另一种[[酸碱质子理论|质子受体]]中进行。

==历史==

1781年，英国化学家[[亨利·卡文迪什]]在过量空气中燃烧氢，发现产生的水中含有硝酸。1785年，卡文迪什用电[[火花隙]]进一步研究发现，如果能量与氧气供应充足，空气中的氮气可全部氧化为硝酸，但仍有约1/120的少量气体不反应。1894年，[[瑞利勋爵]]重复了卡文迪什的实验，最终与[[威廉·拉姆齐]]爵士合作发现了稀有气体[[氩]]，同时也研究了能量输入与硝酸产出的关系。<ref name="remsen1906"/>

为提高产量与效率，后人从大量实验中得到了一系列结论：本化学反应的本质是氮气的氧化，是需要在高温下进行的未催化[[吸热反应]]；温度应大于2000度，而且一氧化氮必须能快速冷却；原则上可以使用任何一种热源，包括火焰、铂电热丝、电弧。之所以使用电弧，是因为火焰的高温区大小有限，使空气难以充分穿过，也不能迅速开关使气体有效冷却，而铂电热丝无法在金属熔点之上工作；研究还发现使用高频交流电、高阻抗、低电流时效果最佳。低电流意味着难以提升反应器功率与产能。<ref name="remsen1906"/>

1902年，美国人查尔斯·S·布拉德利（Charles S. Bradley）与迪米特·R·洛夫乔伊（Dimmitt R. Lovejoy）发明了一种具有多组小电极的圆形旋转火花隙反应器，他们申请了专利，成立大气产品公司（Atmospheric Products Co.），在纽约州[[尼亚加拉瀑布]]附近建立了一家小型化工厂。两人希望用廉价的水电资源支持生产，然而公司在商业上并不成功，仅两年后就停止运作<ref name="remsen1906"/><ref name="tcaw">{{cite journal|title=Capturing Nitrogen Out of the Air|first=David|last=M. Kiefer|publisher=American Chemical Society|journal=Today's Chemist at Work|issn=1532-4494|url=https://pubsapp.acs.org/subscribe/archive/tcaw/10/i02/html/02chemch.html|access-date=2024-03-05|archive-date=2021-12-04|archive-url=https://web.archive.org/web/20211204040224/http://pubsapp.acs.org/subscribe/archive/tcaw/10/i02/html/02chemch.html|dead-url=no}}</ref>，主要原因是产能低。在挪威，刚创刊不久的《电化学工业》发表了两人的研究成果。伯克兰看到这篇文章后，认为自己的单一碟形大电弧方案要优于多个小电弧。<ref name="lucy2007">{{cite book|title=The Northern Lights|author=Lucy Jago|publisher=Knopf Doubleday Publishing Group|year=2007|url=https://www.google.com/books/edition/The_Northern_Lights/C9iVxsMjSp4C?gbpv=1&dq=lovejoy&pg=PT112&printsec=frontcover|quote=More recently, two Americans, Bradley and Lovejoy, had built a small factory beside Niagara Falls to produce saltpeter at the end of 1902, but  their attempt had proved too inefficient to form the basis of a new industry. A description of their furnace had been included in the  first edition of a Norwegian scientific publication, ''Electrochem Indus-tri'', launched only the previous month; Birkeland studied the drawings in the new magazine to check that his idea was different, and  therefore potentially more rewarding, than theirs. He saw that they  had made a myriad of tiny arcs in their furnace, while Birkeland was  planning one large arc, repeated at a high rate and swept sideways  by the magnetic field to make contact with as much air as possible.  It would look like a circle with the shape and heat of the sun. The following Monday Eyde and Birkeland spent the morning  together at the university, inspecting the strange-looking furnace  and weighing each other up as potential business collaborators. The  first prototype, cobbled together in a few hours, beautifully demonstrated Birkeland’s idea of using magnetism to make large electric  arcs and the tremendous noise and smell it produced were persuasive testimony to its potential.}}</ref>

碟形电弧装置最初由德国物理学家[[尤利乌斯·普吕克]]在1861年发明。在该实验中，普吕克在火花隙周围放置U型电磁铁，使电磁铁与电极两端方向互相垂直，得到了碟片形电弧。随后[[瓦尔特·能斯脱]]等人也重复了类似的实验。<ref>{{cite journal |last1=Plücker |title=Ueber die Einwirkung des Magnets auf die elektrische Entladung |journal=Annalen der Physik und Chemie |date=1861 |volume=113 |pages=249-280 |url=https://babel.hathitrust.org/cgi/pt?id=umn.31951d00326552p&view=1up&seq=264&skin=2021 |trans-title=On the effect of the magnet on the electric discharge |language=German |access-date=2024-03-03 |archive-date=2024-03-03 |archive-url=https://web.archive.org/web/20240303152312/https://babel.hathitrust.org/cgi/pt?id=umn.31951d00326552p&view=1up&seq=264&skin=2021 |dead-url=no }}  From p. 255:  ''" … die Curven, welche dieselbe durchziehen, soweit die Schätzung des Auges reicht, genau die Form von  Kreisbogen an[nehmen], die sämmtlich auf der die beiden Spitzen des Entladers verbindenden geraden Linie, als gemeinschaftlicher, senkrecht stehen."''  ( … the curves which [the luminous discharges] traverse, assume — as far as the eye can judge — exactly the form of circular arcs, all of which stand perpendicular to the same straight line that joins the two points of the electrodes.)</ref><ref name="Word1921">{{cite book |title=Technology of Cellulose Esters |last=Worden |first=Edward Chauncey |publisher=D. Van Nostrand Company |volume=1:2 |year=1921 |page=[https://archive.org/details/dli.bengal.10689.5914/page/n324 870] |url=https://archive.org/details/dli.bengal.10689.5914}}</ref>[[克里斯蒂安·伯克兰|伯克兰]]将其工业化，从而克服了电流限制，解决了反应器的功率问题，使大规模生产实用化。<ref name="remsen1906"/>使用电弧的灵感，来自他之前在实验中发生短路的[[线圈炮]]发明。<ref>{{cite book|title=The Northern Lights|author=Lucy Jago|publisher=Knopf Doubleday Publishing Group|year=2007|url=https://www.google.com/books/edition/The_Northern_Lights/C9iVxsMjSp4C?gbpv=1&dq=believed%20this%20faulty%20element%20of%20his%20gun&pg=PT111&printsec=frontcover|quote=When the ladies retired to the drawing room and the gentlemen  stood around the fire, drinking whisky and smoking cigars, Birkeland approached Eyde and said, “I have the solution.” He explained  that his cannon, of which Eyde was already aware through Knudsen, produced high-energy electric arcs if it short-circuited during  testing—arcs exactly like bolts of lightning. Birkeland believed this  faulty element of his gun design could be combined with electromagnetic furnace technology to ionize air and produce nitric acid.}}</ref>

[[File:Rjukan electric arc furnace.jpg|thumb|曾在1912-1940年安装在留坎的反应器，目前为公园展品]]

挪威的两个城镇[[留坎]]、[[诺托登]]曾建有使用此工艺的化工厂，并依靠附近的水力发电厂供电。1908年，诺托登工厂的固氮产量达7000吨；留坎的化工厂则是后来建成，年产量28000吨。<ref name="tcaw"/>相比后来的新方法，伯克兰-艾德法能效低、耗电大。在[[哈伯法]]与[[奥斯特瓦尔德法]]发明后，本方法在1910-1920年代间被挪威工业逐渐淘汰。今日，这两个城镇的工厂成为[[留坎-诺托登工业遗址]]，被[[联合国教科文组织]]收录于《[[世界遗产名录]]》。<ref name="wh">{{cite web|url=https://whc.unesco.org/en/list/1486|title=Rjukan–Notodden Industrial Heritage Site|date=2015-07-05|publisher=UNESCO|accessdate=2024-03-04|archive-date=2020-07-03|archive-url=https://web.archive.org/web/20200703130701/https://whc.unesco.org/en/list/1486/|dead-url=no}}</ref>

在现代化工中，哈伯法使[[氢气]]（H<sub>2</sub>）与大气中的氮气（N<sub>2</sub>）发生反应，转化为[[氨]]（NH<sub>3</sub>）。其中的氢气通常来自[[甲烷]]（CH<sub>4</sub>），使用[[蒸汽重整]]制备。奥斯特瓦尔德法随后将氨转化为硝酸（HNO<sub>3</sub>）。<ref name="trevor1982">{{cite book
| title = A short history of twentieth-century technology c. 1900-c. 1950
| author1 = Trevor Illtyd Williams
| author2 = Thomas Kingston Derry
| publisher = Oxford University Press
| year = 1982
| isbn = 0-19-858159-9
| pages = 134–135
}}</ref>

==参见==

* [[留坎-诺托登工业遗址]]
* [[固氮作用]]
* {{link-en|弗兰克-卡罗法|Frank–Caro process}}
* [[哈伯法]]

==参考资料==
{{reflist|2}}

[[Category:化学过程]]
[[Category:挪威科技]]
[[Category:挪威发明]]