編譯：杜銘海(退休的核工程師,dumhai@126.com)

世界最大的科學(xué)協(xié)會(huì)—美國化學(xué)協(xié)會(huì)第243屆大會(huì)暨博覽會(huì)于2012年3月25－29日在加州圣地亞哥召開。國際原子能機(jī)構(gòu)的易卜拉欣•哈米斯（Ibrahim Khamis）博士在會(huì)上致辭，描述了現(xiàn)代核電廠的熱能怎樣用于更經(jīng)濟(jì)的制氫，未來核電廠怎樣專用于制氫。據(jù)說，為使“傳說”的、以氫燃料替代汽油、柴油和其它化石燃料為基礎(chǔ)，緩解對外國石油和空氣污染擔(dān)心的“氫經(jīng)濟(jì)”時(shí)代成為可能，這種長期尋求的工藝技術(shù)經(jīng)過幾十年的發(fā)展，已經(jīng)開始應(yīng)用，而且會(huì)在十年內(nèi)開始商業(yè)制氫。

某些國家利用核電廠作為制氫熱源的興趣在快速增長。相當(dāng)大的努力專注于探索現(xiàn)代和未來核動(dòng)力堆制氫選項(xiàng)。預(yù)期現(xiàn)有的各種類型的核動(dòng)力堆是短期選項(xiàng)，利用低溫電解制氫；未來的核動(dòng)力堆則是中期選項(xiàng)，為使用高溫蒸汽電解或其它有前景的熱化學(xué)循環(huán)制氫提供高溫蒸汽。

以下是哈米斯博士在會(huì)上講演的要點(diǎn)：

“世界各地利用核電廠作為制氫熱源的興趣正在快速增長。”“利用核能制氫可減少對石油做機(jī)動(dòng)車燃料和用煤發(fā)電的依賴。這樣以來，氫對緩解全球變暖有正面的影響，因?yàn)槿紵龤錃庵会尫潘羝鴽]有二氧化碳這種主要的溫室氣體。這會(huì)使污染顯著減少。”

國際原子能機(jī)構(gòu)和世界各地的科學(xué)家和經(jīng)濟(jì)學(xué)家正在集中研究，確定全世界現(xiàn)在運(yùn)行的435臺(tái)核反應(yīng)堆和未來的動(dòng)力堆怎樣支持氫氣生產(chǎn)。

現(xiàn)在大多數(shù)氫氣產(chǎn)品來自天然氣或煤炭，并釋放出溫室氣體二氧化碳。某些制品小規(guī)模地來自清潔的電解工藝，其中電流流過水，使H2O分子分裂為氫和氧。這種稱為電解的工藝，如果首先使水加熱生成蒸汽，隨之電流通過蒸汽，效率更高，更便宜。

核電廠是理想的制氫設(shè)施，因?yàn)樗a(chǎn)的熱能把水變?yōu)檎羝娏t把蒸汽分解成氫和氧。專家們設(shè)想，現(xiàn)代核電廠采用低溫電解，可以利用電廠峰谷期間低電價(jià)的優(yōu)勢制氫。未來的、專門為制氫設(shè)計(jì)的電廠就可使用更高效的高溫電解工藝，或者聯(lián)接目前正在研究開發(fā)的熱化學(xué)工藝流程。

“水或蒸汽電解的核氫氣是目前的現(xiàn)實(shí)，但需要提高經(jīng)濟(jì)性能。”他指出，某些國家正在考慮建造新核電廠外加高溫蒸汽電解（HTSE）站，期望在不斷增長的經(jīng)濟(jì)機(jī)遇中用來大規(guī)模制氫。

哈米斯描述了IAEA的氫經(jīng)濟(jì)評估程序（HEEP）如何有幫助。IAEA設(shè)計(jì)了HEEP軟件，有助于成員國開發(fā)核能生產(chǎn)氫氣的潛力。此軟件評定各種情況下制氫的技術(shù)和經(jīng)濟(jì)可行性。

依據(jù)資料：ACS, Nuclear power plants can produce hydrogen to fuel the 'hydrogen economy', PHYSorg.com, March 26, 2012

Nuclear power plants can produce hydrogen to fuel the 'hydrogen economy'

Provided by American Chemical Society (news : web), PHYSorg.com

March 26, 2012

The long-sought technology for enabling the fabled "hydrogen economy" — an era based on hydrogen fuel that replaces gasoline, diesel and other fossil fuels, easing concerns about foreign oil and air pollution — has been available for decades and could begin commercial production of hydrogen in this decade, a scientist reported here today.

Speaking at the 243rd National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society, Ibrahim Khamis, Ph.D., described how heat from existing nuclear plants could be used in the more economical production of hydrogen, with future plants custom-built for hydrogen production. He is with the International Atomic Energy Agency (IAEA) in Vienna, Austria.

"There is rapidly growing interest around the world in hydrogen production using nuclear power plants as heat sources," Khamis said. "Hydrogen production using nuclear energy could reduce dependence on oil for fueling motor vehicles and the use of coal for generating electricity. In doing so, hydrogen could have a beneficial impact on global warming, since burning hydrogen releases only water vapor and no carbon dioxide, the main greenhouse gas. There is a dramatic reduction in pollution."

Khamis said scientists and economists at IAEA and elsewhere are working intensively to determine how current nuclear power reactors — 435 are operational worldwide — and future nuclear power reactors could be enlisted in hydrogen production.

Most hydrogen production at present comes from natural gas or coal and results in releases of the greenhouse gas carbon dioxide. On a much smaller scale, some production comes from a cleaner process called electrolysis, in which an electric current flowing through water splits the H2O molecules into hydrogen and oxygen. This process, termed electrolysis, is more efficient and less expensive if water is first heated to form steam, with the electric current passed through the steam.

Khamis said that nuclear power plants are ideal for hydrogen production because they already produce the heat for changing water into steam and the electricity for breaking the steam down into hydrogen and oxygen. Experts envision the current generation of nuclear power plants using a low-temperature electrolysis which can take advantage of low electricity prices during the plant's off-peak hours to produce hydrogen. Future plants, designed specifically for hydrogen production, would use a more efficient high-temperature electrolysis process or be coupled to thermochemical processes, which are currently under research and development.

"Nuclear hydrogen from electrolysis of water or steam is a reality now, yet the economics need to be improved," said Khamis. He noted that some countries are considering construction of new nuclear plants coupled with high-temperature steam electrolysis (HTSE) stations that would allow them to generate hydrogen gas on a large scale in anticipation of growing economic opportunities.

Khamis described how IAEA's Hydrogen Economic Evaluation Programme (HEEP) is helping. IAEA has designed its HEEP software to help its member states take advantage of nuclear energy's potential to generate hydrogen gas. The software assesses the technical and economic feasibility of hydrogen production under a wide variety of circumstances.

More information:Abstract The interest in hydrogen production using nuclear power plants as heat sources is growing rapidly in a number of nations. A considerable focus is being devoted to explore the option of current and future nuclear power reactors for hydrogen production. The use of current types of nuclear power reactors are foreseen as a short-term option for the production of hydrogen using low temperature electrolysis. Whereas the later one are seen as mid-term option as they will provide high temperature steam for the production of hydrogen using high temperature steam electrolysis or other promising thermochemical cycles.