Environmental Costs Resulting from the Use of Hard Coal in Heating Plants of Thermal Power Under 50 MW

The purpose of this article is to estimate the environmental costs for Polish heating plants with thermal power lower than 50 MW, using hard coal. The draft new EU legislation (the Medium Combustion Plant (MCP) Directive) have the need to meet the national emission limits. To address them, the existing heating plants with thermal power lower than 50 MW using hard coal (stoker-fired boilers) must reckon with the need to upgrade or restore them in the new technologies. The heat generation market in Poland is local, due to high fragmentation of heating companies. The most strongly represented group of producers of heat are heat generation plants with capacity lower than 50 MW. These heating plants are equipped mainly stoker-fired boilers. In Poland, the production of heat and hot water in heating plants is mainly based on hard coal. Its average share in the structure of heat generation in the period 2008-2014 is as high as 74-77%. The article estimated costs of emissions of: SO2, NOx, CO, CO2, particulate matter and costs of solid waste disposal, which are produced in the combustion process of hard coal. The calculations focused on heating plants with stoker-fired boilers. These costs were calculated according to changes in hard coal quality parameters (calorific value - Q, Ash content - A, Sulphur content S). These costs were calculated for one tone of hard coal burned for a particular quality. The companies involved in the Polish heating sector are usually using hard coal of quality parameters (Q/A/S) containing in the range of: 1-22 MJ/kg calorific value, 19-21%A and 0.6-0.9%S. Total fees for emissions of SO2, NO2, CO, CO2 and solid waste disposal of 1 t hard coal this class would be 18-23 PLN/t. The combustion of coal for these parameters will require the need for the use of dust collecting equipment with an efficiency of 62-69%. Today, modern stoker-fired boilers meet these demands because they offer efficiency of extraction of approx. 70%. Considering the SO2 emission only in the case of hard coal of Q parameters amounting to 21-22 MJ / kg and 0.6%S - not required for desulfurization technology. In the case of burning low-grade coal is required desulfurization efficiency of the order of 6-30%. These estimates relate to the standards that will apply from the beginning of 2016. The conducted calculations show that the cost of the economic use of the environment depending on the quality parameters of coal burning may increase the cost of coal burned by 9-11%.