Concentrations Of Anthropogenic Emissions Research Articles

Comprehensive approach to static firing tests of micro gas turbine engines powered by liquid fuels

The paper presents test results on the combustion of liquid fuels in micro gas turbine engines (MGTE). A setup was designed and built to determine the following MGTE characteristics: thrust, inlet static pressure, compressor static pressure, compressor total pressure, combustor total pressure, turbine total pressure, turbine speed, and the air temperature at the inlet, inside the compressor, at the turbine outlet, and at the nozzle exit. Thermodynamic cycle analysis of MGTEs was performed in the operation mode providing the required thrust. Noise and vibration levels of the MGTE operation were measured using a noise and vibration analyzer. Concentrations of anthropogenic emissions (CO, CO2, NO, NO2, N2O, SO2, CH4, C3H8) were recorded using a set of sensors. The tests revealed consistent patterns in the variation of throttle characteristics, gas composition, noise, and vibration in different engine operation modes. The test results were processed to produce plots of the key MGTE characteristics. Recommendations were developed for testing new types of fuels in MGTEs.

Switching Coal-Fired Thermal Power Plant to Composite Fuel for Recovering Industrial and Municipal Waste: Combustion Characteristics, Emissions, and Economic Effect

Combustion characteristics were studied experimentally for single droplets of fuel slurries based on wet coal processing waste with municipal solid waste components (cardboard, plastic, rubber, and wood) and used turbine oil. We established the ignition delay time for three various groups of fuel compositions in motionless air at 600–1000 °C. The minimum values are 3 s, and the maximum ones are 25 s. The maximum temperatures in the droplet vicinity reach 1300 °C during fuel combustion for compositions with 10% of used oil. The combustion temperatures of fuel compositions without oil are 200–300 °C lower. The concentrations of anthropogenic emissions in flue gases do not exceed those from dry coal combustion. Adding used oils to composite fuels reduces the concentrations of dioxins and furans in flue gases when municipal solid waste in the fuel burns out due to high combustion temperatures. Based on the experimental research findings, we have elaborated a strategy of combined industrial and municipal waste recovery by burning it as part of composite fuels, as illustrated by three neighboring regions of the Russian Federation with different industrial structures and levels of social development. This strategy suggests switching three typical coal-fired thermal power plants (one in each of the regions) to composite liquid fuel. It will reduce the hazard of waste to the environment and decrease the consumption of high-quality coals for power generation. Implementing the developed strategy for 25 years will save 145 Mt of coal and recover 190–260 Mt of waste. The positive economic effect, considering the modernization of fuel handling systems at thermal power plants and the construction of a fuel preparation plant, will make up 5.7 to 6.9 billion dollars, or 65–78%, respectively, of the main costs of three thermal power plants operating on coal within the identical period.

The prospects of burning coal and oil processing waste in slurry, gel, and solid state

This paper presents the experimental investigation results of ignition and combustion characteristics of fuels based on typical coal flotation waste which is formed and accumulated around the world in large volumes (about 200–300 million tons per year). We focus on the comparison of these characteristics for waste-derived fuels in different states: slurry, gel, and solid. We analyze the ignition delay times, minimum (threshold) ignition temperatures, combustion heat, concentrations of anthropogenic emissions, and the relative efficiency of fuels. We have determined that minimum ignition temperatures and shorter ignition delay times are achieved in the solid state (50–80% lower than in the slurry and gel state). The lowest concentrations of the most hazardous emissions are present in the liquid (slurry) state (NOx and SOx are 18–75% lower than from the combustion of coal in the solid state). The conditions were identified for the efficient use of coal and oil processing waste as part of composite fuels. The relative fuel effective utilization factor of waste-derived fuel mixtures in different states ranged from 0.11 to 45.5. It is maximal for fuels in the slurry state. The obtained data has been compared with the results of other studies.

Experimental researches of the effect of vegetable oil addition on the emissions during combustion of coal liquid fuels

This paper presents the findings of research into combustion of vegetable oils in the composition of coal liquid fuel. The aim of the research was to study the influence of additives of typical vegetable oils (rapeseed, olive, coconut oil, etc.) on concentrations of anthropogenic emissions during combustion of coal water slurries based on coal processing waste. In order to study the effect of different parameters on the emissions efficiency, the tests were done in different operating conditions: muffle furnace temperature, share of oil (up to 15%) in the mixtures, and oil type. The differences between the concentrations of SOx and NOx in the combustion of typical filter cakes (waste coal), as well as those of suspensions with the addition of vegetable impurities have been investigated. It is shown that the concentrations of SOx can be reduced by 5-63% and those of NOx – by 5-62% in comparison with coal liquid fuels based on oil refinery waste. Using the generalizing criterion, the paper illustrates the advantages of adding vegetable oils to enhance the prospects of slurry fuels (even based on coal processing waste) in comparison with coal that is the most dangerous in terms of environmental pollution.