Determination of Lower Heating Value of Municipal Solid Waste by Mathematical Analysis of a Plant Production Data from a Real Waste-to-Energy Plant

Abstract

Lower heating value represents a key parameter influencing performance and economy of any combustion process. This article presents a methodology for determination of LHV of municipal solid waste (LHVW) by processing set of operational data from a real waste-to-energy plant. In the introductory part the LHVW is evaluated according to the procedures recommended by the Reference document on the Best Available Techniques for Waste Incineration (BREF/BAT). We discuss suitability of using the general regression-based equation for a specific plant with different technological solution of the particular subsystems. The acquired LHVW also served as an initial estimate for subsequent calculation of combustion chamber efficiency. There is strong relationship between the LHVW and boiler efficiency. The efficiency was calculated by three different methods: the direct, the indirect and the "modified" indirect method. The first two methods are commonly used in practice. Third method has been developed by the authors as a control mechanism and complementary approach to the first two. Because different input parameters are needed for each method, it is the purpose of this contribution to show difference in obtained results. Each method is variously sensitive to a change in input parameters and this was utilized to make values of input parameters more precise (especially the low heating value) and to estimate possible inaccuracy in their determination. For this purpose a computational tool has been developed and is introduced in the paper.