Coal-peat compositions for co-combustion in local boilers

Abstract

In article results of experiments on creation of coal and peat fuel compositions for burning in solid-fuel boilers are described. The main objective of research consisted in development of combination of coal dust and natural peat without binding additives. The role of peat consists that it increases efficiency of process of granulation, being natural binding. The method of granulation allows to utilize waste of the coal industry. Joint burning of two types of fuel – coal dust and peat reduces emission of sulfur dioxides. The cost of peat raw materials is lower, than artificial binding, applied to briquetting of coal dust. The composition of mix of coal dust and peat varied in the ratio 2:1, 1:1 and 1:2 in volume ratio at humidity of mix before extrusion of 65 %. In the course of preparatory operations of coal raw materials its crushing and sifting through sieve of 24 mesh (0,707 mm) was carried out. Procedure of hashing of samples of coal and peat was carried out before receiving homogeneous mixture. After hashing mix was located in piston press for receiving granules. Coal dust and wet peat pass semifixed extrusion on piston press with formation of cylindrical granules with a diameter of 16 mm. After extrusion of granule are dried to operational humidity of 25 %. Coal and peat fuel granules showed sufficient mechanical strength for transportation and power feed in solid-fuel boilers. Burning of coal and peat fuel granules in vitro at temperature of 800 °C does not lead to ashes agglomeration. The conducted preliminary researches showed prospects of utilization of coal waste by granulation method in mix with natural peat.