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Show steam) injection, the regulating authority also demands that you provide a selective catalytic reduction flue gas treatment plant with its much poorer cost-effectiveness, then the cogeneration plant may simply be too costly. Consider the seminar on "Cogeneration: Advantages and Third Party Financing" put on by a packager of such deals. Third party financiers are critically interested in the financial attractiveness of cogeneration projects. The particular approach touted employed the Cheng Cycle which injects excess steam (when the demand for steam is low) into the gas turbine to produce more electricity, inherently providing NOx reduction, as well. Asked, "What is the effect on the attractiveness of the project when, in addition to steam or water injection, a selective catalytic reduction flue gas treatment plant is required by the regulating authority?", the promoter's reply was quite candid. "Too expensive. It kills the deal." Some attention by the combustion R&D community to improving the cost-effectiveness of NOx reduction in cogeneration might be a boon. Help Needed We have seen that the predicted shift to alternative fuels has not come true. We have seen that, on the contrary, economic and environmental pressures today force a return to the past, to greater use of the traditional gaseous fuels with which we are so familiar. Nevertheless, we have seen that there are a number of ways in which the combustion community can help the petroleum industry. Among them are -- o improved low NOx burners, particularly ones that would permit inexpensive retrofits while still retaining the flexibility for combination oiVgas firing; o "ultra" low NOx gas burners that would provide SCR-reductions at a burner price; o improved cost-effectiveness of stack waste heat recovery systems, recognizing that low excess air has definite limitations; o improved cost-effectiveness of NOx reduction in cogeneration, recognizing the exorbitant cost of selective catalytic reduction flue gas treatment plants; and especially, o improved understanding of combustion aerodynamics that will put burner design on a firmer footing. And we have seen that a good deal of help in those areas has already been provided by the combustion R&D community. Finally, like Woodrow Wilson, I use not only all the brains I have but all I can borrow. Some say that in my case that is a really good idea. In any event, in polling my colleagues, there emerged two other common themes. The first, low Btu gas. Actually, low Btu combustion is yet another example of how the combustion R&D community already has helped us. Low Btu Gas In the past, we didn't use low Btu gas in our refineries because we didn't have much. The lone exception was the CO boiler which doesn't have much CO to burn anymore because of processing improvements. So we don't know how to use low Btu gas and we think it won't "fit" through existing units without derating or rebuilding them. Nevertheless, with the advent of attractive processes that produce lots of low Btu byproduct gas, we might have to find homes for large quantities. The worry about "fit" is justified. Typical low Btu gas creates products of combustion that are 30 to 40 percent greater in volume than those from natural gas. But many of today's refinery heaters were oversized on the flue gas side in anticipation of future uprates and many don't run today at rated capacity, anyway. So the modest volume increase on the flue gas side isn't that big a deal. It just means you have to be a little careful in picking your heaters. And good burners for handling the typically low pressure, low Btu gas have already been developed by the combustion R&D community. Thus, the capability for utilizing low Btu gas seems to be pretty much in hand. However, a supporting body of emissions data on low Btu combustion does not seem to be so readily available and perhaps we could use a little help there. The second additional need brought to mind by my colleagues was waste incineration. Waste Incineration We can't open an industry joumal these days without learning that this commercially available combustion technology looms large in our future as a replacement for banned land treatment. Recently, the companies represented on the American Flame Research Committee were polled to express their preferences regarding the formulation of the research program of the International Flame Research Foundation. Cited |