Technology
Gaseous fuel research program expanding Citing need for new, lasting sources of gaseous fuels, Gas Research Institute is allocating up to $3 million for long-range R&D projects The Gas Research Institute is expanding its basic research program in the area of indefinitely sustainable energy sources. The goal is eventually to develop new, clean, lasting sources of gaseous fuels from inorganic materials such as water, carbonate rocks, and atmospheric carbon dioxide. By 1984, GRI will allocate up to $3 million to qualified investigators submitting acceptable proposals. Robert V. Serauskas and Kevin Krist of GRI's basic research department note that a suitable technology base is being developed to supply gaseous fuel needs in the near term. Unconventional natural gas suppliers and new conventional gas strikes appear adequate. In the midterm and somewhat beyond, the production of fuel gases from coal, biomass, shales, and the like is expected to be sufficient for national needs. The problem becomes acute, though, when the fossil sources begin to dwindle and biomass growth can't keep pace. At that time, some radical new technology will be needed. It's in this context that GRI has begun its long-range gaseous fuels development program. To aid in assessing long-term needs, GRI sponsored a 10-week workshop last year to brainstorm the subject of long-range energy research. A panel was assembled at Texas A&M University, College Station, to consider four general areas of research that seem particularly valuable to explore: photochemistry and photoelectric chemistry, photobiology, thermochemistry, and advanced fuel production concepts. For the most part, the photochemistry group concentrated on solar radiation for splitting of water, with the evolved hydrogen being of greatest interest as a potential fuel gas. Other processes of interest in26
C&EN April 26, 1982
clude reduction of carbon dioxide to methane or other hydrocarbons. Photochemical water-splitting has been achieved with efficiencies of only less than 2% with some expensive materials. However, the photochemistry group believes that much higher efficiencies can be obtained with cheaper materials. Likewise, photoelectrolysis of water probably is possible at a semiconductor electrode surface, thereby eliminating many of the difficulties of conventional electrolysis. Most of the promise of photobiology for generating gaseous fuels is for hydrogen generation from water. Some of the biological processes of interest at present are "enhanced" and others mimic natural processes. The impetus is provided by the success of photosynthetic plants. Photosynthesis is very efficient under low light conditions but much less so when the light incident on the plant is very intense. One of the suggestions for research is deducing the mechanisms for low- and high-intensity photosynthesis and determining why they differ. Thermochemical processes are the most familiar to most chemists and engineers. They rely on heat to decompose fuel source materials. The two heat sources of interest in the long term are nuclear reactors and solar furnaces. Again, attention seems to be focusing on splitting of water. Unassisted, direct, thermal watersplitting doesn't occur appreciably below 1000 °F, and there are problems associated with the high temperatures. Few materials can be used economically at 1000 °F and higher. In addition, many of the suggested cycles involve materials that are extremely corrosive, particularly at high temperatures. Another problem is the temperature itself. Even nuclear reactors probably will have difficulty providing great amounts of heat at 1000 °F. Solar furnaces may be even more of a problem. However, the difficulties don't alter the likelihood that nuclear and solar sources will be relied on someday. The advanced concepts for fuel production are of the more exotic variety and, consequently, a bit farther out in terms of present day
practicality. Nevertheless, GRI isn't excluding anything from consideration in its funding program. One of the concepts that has been suggested is the radiolysis of water by nuclear radiation—particle and electromagnetic. Fusion seems, on the surface, to be more promising in the long term than does fission as a heat and a particle source. Another advanced-concept possibility may be a hybrid photo/thermochemical system operating at high temperatures. Whatever the eventual fuel gases may be, their general characteristics already have been defined. High energy content, stability, low explosion hazard, nontoxicity, ease of transport and storage, and minimal environmental impact are the desirable characteristics. At present, the two leading candidates are hydrogen and methane. The obvious choice as a hydrogen source is water, and for methane, carbon dioxide. Other possible fuel gases haven't been excluded, but there appear to be no serious rivals for hydrogen and methane. The depletion of natural gas has begun and in some cases is proceeding at an alarming rate. Considering the monumental problems associated with the engineering of a new energy system, GRI has opted to begin the search for it now with the expansion of its basic research program. GRI's fundamental research budget has grown from $2.3 million in 1980 to a projected $5.2 million in 1982. Although the $3 million allocated for the search for new fuel gas sources through 1984 amounts to more than half the total fundamental research budget, GRI anticipates that it will increase even more. One reason is the withdrawal of the Department of Energy from a number of projects. GRI expects to take up as much of the funding slack as possible. GRI anticipates further t h a t promising projects in force in 1984 will be continued thereafter at about the same level of funding. Prospective investigators may obtain specific information on the program by contacting Kevin Krist, basic research division, Gas Research Institute, 8600 West Bryn Mawr Ave., Chicago, 111. 60631. The decision on proposals to be funded is scheduled to be made by July. D
