An Abundance of Frozen Clean Energy from the Sea
Associate Director of Research
Naval Research Laboratory
About the Lecture
Methane hydrates occur naturally in ocean sediments as a crystalline solid under proper conditions of temperature and pressure in a water environment. The crystalline framework of water molecules capture the biogenically produced methane during crystallization and forms icy solids known as clathrates. Clathrates are stable well above the freezing point of water and typically binds 70 to 160 volumes of methane gas for one volume of liquid water. Abundant methane hydrate deposits are found along the all continental shelves of the world either on the surfaces of seabeds or shallow depths in the sediment. The total amount of concentrated methane deposits is estimated to be over twice the known amount of carbon in earth’s fossil-fuel reserves. With a rapid depletion of oil reserves, the vast hydrate deposits have the potential of becoming the major energy resource for the 21st century, similar to the coal during the 19th and oil during the 20th centuries. Nearly pure methane, with highest energy density and cleanest combustion of all hydrocarbons, can be easily and economically separated from the hydrate deposits, by simply altering temperature, pressure or composition. A number of research and development issues such as: structure, chemistry, thermodynamic and kinetic factors on formation and phase stabilities of hydrates, locations and quantification of hydrate deposits and stability zones, seafloor geophysical properties, nature of methane transport through sediments and environmental impacts need to be well understood before economic exploitation of this vital resource can be realized. Current efforts and future plans will be discussed.
About the Speaker
BHAKTA B. RATH is Associate Director of Research at the Naval Research Laboratory, Washington DC. He is also Head, Materials Science and Component Technology Directorate, placeing him in charge of all basic and applied research in structure of matter, condensed matter physics, chemistry, electronics, materials science, plasma physics, computational physics, fluid dynamics, and biomolecular science and technology conducted by the laboratory’s staff, contractors, visiting researchers and students. The Directorate manages over 250 research projects. Following his doctoral studies at the Illinois Institute of Technology, he joined the faculty of Washington State University in 1961 and held a tenured position until 1965. Between 1965 and 1976, he was a member of the research staff of the Edgar C. Bain Laboratory for Fundamental Research of the US Steel Corporation at Pittsburgh, and the McDonnell Douglas Research Laboratories at St Louis. He joined the Naval Research Laboratory in 1976 as Head of the Physical Metallurgy Branch, and in 1982 served as Superintendent of the Materials Science and Technology Division. During these periods he served as Adjunct Professor at Carnegie Mellon University, University of Maryland, and Colorado School of Mines. He also served as the principal engineer in solving a number of technical problems including failure of the SKYLAB active coolant system, structural integrity of air-superiority fighter aircraft and several proprietary technologies of the US Navy and the Department of Defense. He has published over 170 technical papers and reports, edited/co-edited over 20 books on diverse topics in Materials Science and Engineering, serves on the editorial board of a number of international technical journals and on the Executive Boards of the American Society of Materials, The Materials, Metals and Minerals Society, and the Federation of Materials Societies. He has given in excess of 300 keynote and distinguished lectures worldwide. He recently received the prestigious award, the “Distinguished Lecturer in Materials and Society” and the “ASM Distinguished Life Membership Award”. He serves as a member of several steering, planning, review, and advisory boards of Government agencies, universities and technical societies. He is recognized as a Fellow of the American Society for Materials (1982), the Washington Academy of Sciences (1984), The Materials Society (TMS) of AIME [an award limited to 100 members worldwide] (1992), and the Institute of Materials, United Kingdom (2002). He was presented the Charles S. Barrett Medal (1991), the George Kimball Burgess Memorial Award (1992), S. Chandrasekhar Award and Medal (1998), Distinguished Award, THERMEC-2000, election to the Academy of Metallurgical and Materials Engineering of the Michigan Technological University (1998), the Leadership Award of TMS (1996), Distinguished Oriya Award (1996), CNR’s Group Achievement Award [Sea Wolf project] (1996), National Materials Advancement Award (Federation of Materials Society) (2001), and Dedicated Meritorious Service to TTCP as Executive Chair, Defense Research at USA, UK, Canada, Australia and New Zealand (2001) for his several outstanding contributions to materials research. The Materials, Metals and Minerals Society honored him with an International Conference on “Science and Technology of Interfaces”, in 2002. The American Society for Materials has elected Dr. Rath to receive its most prestigious honor, The ASM International Gold Medal (2004). He was elected to serve as the 2004-2005 president of ASM International and to the Board of Trustees of the ASM Educational Foundation Board to promote science and mathematics education in high schools in the United States through organizing teachers and students camps. The Naval Research Laboratory presented Dr. Rath with its highest recognition, “The NRL Lifetime Achievement Award” (2004) for his exemplary performance and dedication to NRL, the Department of the Navy, and the Department of Defense. Dr. Rath was elected to receive in 1999 and 2004 the “Meritorious Presidential Rank Award”, presented by the President of the United States for sustained outstanding achievements of a Senior Executive, and was elected to receive the 2005 “Distinguished Presidential Rank Award”, the highest honor presented to a Senior Executive of the United States Government.
President William Saalbach called the 2,200th meeting to order at 8:18 pm January 20, 2006. The minutes of the 2,198th meeting were read and approved.
Mr. Saalbach then introduced the speaker of the evening, Mr. Bhakta Rath of the Naval Research Laboratory. Mr. Rath spoke on “An Abundance of Frozen Clean Energy from the Sea.”
Mr. Rath said he was pleased with the opportunity to discuss this extremely important issue. He began by discussing needs and the alternatives.
The world currently uses energy at the rate of about 13 terawatts. The largest part of it comes from oil, next coal, and then natural gas. Nuclear fission is a distant fourth, hydro a very distant fifth, and sources such as solar and wind are nominal.
He showed a curve of oil production in the lower 48 states. It peaked in 1970. It has declined substantially and is now under one/half its peak. This is called the Hubbert peak, after geophysicist M. King Hubbert. Though controversial, the prediction he made has proved fairly accurate. The world production peak is harder to pin down. The United States Geological Survey predicts 2010 is when it will peak and that by 2050 it will be a small fraction of what it will be in 2010. He quoted a president of ExxonMobil who said that by 2015 the world needs to find eight gallons of new oil production for each one used today.
Of natural gas, 72% of reserves are in the Middle East. In 1980, 4% of our natural gas was imported, in 1998, 14%, and in 2003, 20% was imported.
Some hope hydrogen will replace other fuels. Mr. Rath said hydrogen use faces enormous technological challenges. They include how to produce it, how to distribute it, how to store it, how to convert it to electricity, how to contain it for end use, and how to detect it. It is difficult to detect, notoriously leak-prone, and very dangerous. It has a ratio of energy to volume that is only 1/4 that of gasoline, so it cannot be used in planes, although he did show a whimsical concept of a pregnant-looking airliner with a big bulge of extra fuselage for hydrogen. Moreover, all means of producing hydrogen use fuel.
Wind energy requires large windmills located where there is good wind. The wind, unfortunately, happens to be in the part of the country where there are the fewest people. Millions of windmills would be required and the transfer cable could cost $79,000/km.
Tidal power is another possibility, and it would have a side benefit, reduction of coastal flooding. There are not very many sites that are suitable, however, and the transport of the energy would again be a major problem.
A gallon of liquid fuel can be produced from 24 pounds of coal. This, actually, is what Germany did during World War II, when they lost access to the North African oil fields.
The U.S. Navy uses 40 million barrels of oil a year. To produce that from coal would require mining 20 million tons. This would involve problems of transportation and disposal of solid waste and carbon dioxide.
So the alternatives all have problems – not enough, land use, cost, safety, pollution, national security, and so on.
Then, turning to his main point, he showed an enticing picture of something that looked like burning ice. This was a picture of a methane hydrate crystal, giving off methane, which burned readily as a gas. Incidentally, it yields less CO2 than any other fossil fuel.
More than half of the organic carbon in the earth's crust is in the form of gas hydrates, on and offshore, he estimated. These nice little rocks are a type of clathrate.
He presented distributions of pressure and temperature that showed the depths and temperatures where these clathrates exist, which he called the hydrate stability zone.
He showed a map of where they have been located so far. The United States appears to be lucky again. It seems there is an abundance of them around Alaska, off California, in the Gulf of Mexico, and even a fair amount of the stuff off the east coast. There appears to be a great deal of it elsewhere in the world, also.
The most important sources of data have been seismic studies. There have also been geochemical studies, electrographic, heat flow, micro- and macro-biology, and drilling studies. There are three possible ways to harvest it. One would be to pump the gas out of the substrates. Another would be to inject steam into the substrates to release the gas. Another would be to inject methanol into the substrates to release the gas. There are places where it is bubbling off naturally. Bubbles on the surface of the ocean can be seen, and there are craters in the ocean floor resulting from gasification.
Research challenges remain. They include construction of a collection system to capture the gas once it is produced down there.
Mr. Rath offered to answer questions. He was asked what would be the cost to a million BTU. He wasn't sure. There are some factors yet to be determined, such as working on the continental margins and the problem of deep and horizontal drilling.
Several questions related to why no action has been taken, no research funding from Congress or development or exploration by big energy companies. Mr. Rath, a scientist, said Congress is beyond his understanding. He and his staff have informed Congressional staff of these facts. He spoke of the problems related to collaborative research between agencies. He said that high fuel prices are not necessarily a problem for big energy companies.
People brought up some energy alternatives he had not mentioned, such as tar sands and shale oil. He acknowledged these as having potential, but they put a heavy burden on the atmosphere. They also require great amounts of water, particularly for shale oil, which is located where there is little water.
After the talk, Mr. Saalbach announced the next meeting. He made the usual housekeeping announcements. He invited guests to consider joining the Society. Finally, he adjourned the 2,200th meeting at 9:50 pm to the social hour.
The weather: Rather clear, perhaps 10% coverage by wispy clouds.
The temperature: 8°C
Ronald O. Hietala,