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題 名 | 甲烷氣水包合物的研究調查回顧與展望=Review and Prospect of Methane Hydrate |
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作 者 | 鐘三雄; 張碩芳; | 書刊名 | 經濟部中央地質調查所彙刊 |
卷 期 | 14 2001.09[民90.09] |
頁 次 | 頁35-82 |
分類號 | 457.8 |
關鍵詞 | 能源資源; 甲烷氣水包合物; 籠形包合物; 海底仿擬反射; 氣候變遷; Energy resources; Methane hydrate; Climate change; |
語 文 | 中文(Chinese) |
中文摘要 | 本文旨在回顧國內外甲烷氣水包合物的研究結果,讓國內產官學各界能初步瞭解其性質與重要性,以及未來的研究與展望。 天然氣水包合物是一種非化學計量的結晶籠形包合物,是由水分子組成的籠狀構造將甲烷、乙烷、丙烷等烷氫類,或二氧化碳、氮氣、硫化氫等氣體分子包裹於結晶構造空隙中,此種以凡得瓦力鍵結形成的籠狀構造特性有別於一般水合物。目前倍受重視的甲烷氣水包合物之主成分為水和甲烷。氣水包合物有三種結晶構造--sI、sII、sH,分別代表依體心立方緊密組合、面心立方最密組合(金剛石結構)與六方最密組合等結構。 甲烷氣水包合物廣泛分布於極區永凍層及陸緣海域等處;依分布的地理位置,可分為陸域和海域甲烷氣水包合物。全球甲烷氣水包合物的甲烷蘊藏量,在標準溫壓環境下保守估計至少有20 × 10[fee4]m³,約為目前已知全球化石燃料等能源之有機碳總儲量的兩倍,極可能成為二十一世紀最重要能源資源之一。 在低溫高壓的環境下,海域甲烷氣水包合物呈準穩定固態,當平衡溫度或壓力發生改變,很容易解離產生水和甲烷氣,在地層中形成富含氣水混合流體層之弱帶,降低陸緣大陸斜坡沉積物的穩定性而衍生海床崩移或滑移等地質災害,並伴隨有大量的甲烷氣逸出海床進入水體,甚至進入大氣圈,而產生極大的溫室效應,衝擊全球的氣候變遷。 未來必須更加瞭解與掌握甲烷氣水包合物的性質與賦存特性,有系統的研發與突破現有探採技術,在能事先控制與防範海域地質災害之發生及對於全球氣候變遷提出正確評估的前提下,進行甲烷氣水包合物的開發與利用。 |
英文摘要 | This study reviews the literature on natural gas hydrates and introduces their characteristics as well as the roles the may play today and in the future. Gas hydrates are non-stoichiometric crystalline compounds which are present when water forms a cage-like structure around smaller guest gas molecules which could be either methane, ethane, propane, isobutane, normal butane, nitrogen, carbon dioxide or hydrogen. The methane hydrate in the current review, though mainly consisting of water and methane, can be identified and classified into three crystal structures of gas hydrates: structure I (sI) with a body-centered cubic structure; structure II (sII) with a diamond lattice within a cubic framework; structure H (sH) with a hexagonal closest packing structure. Methane hydrates occur widely in permafrost areas and in the deep oceans. Under standard temperature and pressure conditions, the amount of methane in global methane hydrate reservoirs can be conservatively estimated to be at least about 20 × 10[fee4] m³ or about the twice amount of the known global fossil fuel reservoirs. They are, in fact, expected to become one of the most important energy resources in the twenty-first century. Based on the geographical distribution, they may be further classified as on-shore or off-shore. Off-shore methane hydrate is stabilized within the sediments under high hydrostatic pressure and frigid bottom-temperature conditions. Any change in these conditions, either by a lowering of the sea level or an increase in bottom-water temperature, may trigger the dissociation of the hydrate at its base. The liquid gas-water mixture weakens the shear strength of the sediments, which results in not only major slumping and sliding but also the release of significant quantities of methane into the atmosphere which, in turn, enhances greenhouse warming. With a better understanding of methane hydrate and its reservoir through systematic research investigations in the near future, it may be possible to resolve most of the technological problems in exploration and production as well as accurately assessing the role of methane hydrate in slope stability and in climate change. |
本系統中英文摘要資訊取自各篇刊載內容。