In recent years, Krakow has been exploring several options to reduce air pollution crated by its industrial and residential beating and power facilities. Both technological and fuel source options have been considered.A change in fuel source appeared initially to offer the greatest promise for small industrial and residential boiler houses and furnaces. Krakow officials intended to convert the majority of the coal-fired systems to natural gas, including those in downtown Krakow, its "mini" heating stations, and the 200,000 residential heating systems. This would eliminate a major source of particulate and acid gas emissions. Officials also planned to reopen the coal gas distribution network, which bad been shut down in 1968, and use it for natural gas distribution (the existing natural gas distribution system is very limited). Technical advisers now investigating options for international aid agencies, however, are concerned that the condition of the coal gas distribution system is too poor to be used or repaired reliably and that natural gas would not be an economical fuel source at current, European-market-level prices. Krakow is therefore likely to suspend its plans to implement fuel conversions in residences and downtown. For the foreseeable future, Krakow must continue to rely on coal is its primary fuel for all facilities and focus improvements oil major district and industrial installations.
The general strategy for pollution control being pursued, therefore, is to find ways to burn less of a cleaner coal using more efficient equipment. Methods include changes in the coal supplied to the plant, modifications to plant equipment, improvements in the distribution system, and installation of devices to monitor and control energy consumption at the user sites.
Author Manczyk met with personnel of the local unit of heating and energy for the city of Krakow and vicinity in 1989 and discussed pollution control options. One of the best ways considered was to decrease the atmospheric emissions by reducing coal consumption by installing energy-saving devices and temperature controls into the central district beating system distribution network; a 10% reduction was estimated. This would save 90,000 tons of coal per year, reducing not only pollution but also saving $4 million in purchase costs (summer 1989 prices). The money saved could be invested annually for pollution controls. The coal not used locally would be available for export and thus bring in foreign exchange for the nation. They also talked about the concept of "co-firing," burning coal and gas simultaneously in large systems as a technique of combustion control and emissions reduction.
Manczyk discussed installing controls on the distribution system, which have proved highly dependable and cost-effective in the Rochester, New York, systems. They also discussed ways of saving power consumed by eight pumps used in distributing hot water from the Leg station. One option for reducing electrical and thermal costs is variable-volume pumping. Another is an energy management system that includes temperature- and demand- monitoring sensor points scattered throughout the high- temperature hot water distribution loop. This could reduce the current six-hour response time to minutes. Such a system has been installed in the city of Zielona, Czechoslovakia. At Manczyk's recommendation, the manufacturer's consultants have contacted Krakow officials to discuss implementation of such a system there.
They also discussed economic analysis of pollution control devices and reviewed examples of the methodology. The Polish analysts customarily calculate only simple payback periods and do not consider internal rates of return, present worth, or the discounted rate of money. Regulated prices, instability of foreign exchange rates, and inflation that recently varies from 500% to 700% per year combine to make such long-term calculations unreliable for comparing alternative investments. Further more, the artificially low price of fuel sources, compared to other commodities, results in long payback periods that discourage investments in energy-saving devices. Manczyk recommended that fuel prices be raised nationally to reflect the real cost of production or purchase. The authors have noted that the national government has reached the same conclusion; in early 1990 it announced a 250% increase in electricity rates, a 100% increase in gas prices, and a 50% increase in district heating charges. Price adjustments have continued. This will greatly improve the ability of Polish energy officials to justify investments in badly needed energy consumption and pollution control improvements.
Manczyk, Krakow personnel, and other advisers recommend that instrumentation be installed in each building and apartment unit to meter consumption and control temperature, including Btu meters, thermostats, and control valves. This would enable the district to change the basis of user charges from flat, area-based rates to rates based on actual consumption and would give users the incentive and ability to control their use.
Aid agency advisers are investigating several strategies for the major facilities. The emphasis is on particulate removal for thermal plants of 40 MW capacity and less and on particulate and acid gas removal at the larger plants. All of the boiler houses should be retrofitted with improved dampers, instrumentation, etc., to monitor and control combustion. The major plants, such as Leg and Skawina, might install controls and equipment to capture SO2 such as spray dryer scrubbers and limestone- injected multiple burners (LIMB). Fluidized-bed boilers have been considered for the Leg and Skawina plants but are likely to be rejected as too expensive. The smaller boiler houses might specify crushed coal longing in size from 1/4 inch to 1 1/4 inches with a low proportion of fine particles. This would mince (be dust, ash, smoke, and acid gas emissions from boiler house operations.
Some action has already commenced. The June 1990 issue of Chemical Engineering magazine carried a report, "Wanted: An SO2 Removal System for a Power Plant in Poland," announcing U.S. Department of Energy (DOE) plans to request proposals to "… retrofit an advanced pollution control system on a 50-MW coal-fired boiler at the Skawina power plant near Krakow. The technology should be able to reduce SO2 emissions by at least 70% and should have been successfully demonstrated at a comparable scale." The DOE would finance about $8 million of the cost. Such a system would not only reduce SO2 emissions but would also capture a major portion of the more reactive acid gases as well.
The line-loss problem was addressed initially by recommendations to install additional insulation on pipes and ducts in both the distribution network and in buildings. The results of recent leak location efforts will surely suggest additional strategies.