Results of Testing Olivine Sand As a Filler for a Furnisher with a Fluidized Bed When Burning Sunflower Husks

Russia is one of the world leaders in the production of sunflower oil, and the utilization of sunflower husks seems to be a very pressing problem. The husk has low humidity (4.4‒12.2%) and a fairly high calorific value (16–19 MJ/kg), but its ash contains a significant amount of potassium, calcium, and magnesium compounds, which cause slagging of the boiler furnace and rapid growth of ash deposits on its convective heating surfaces. Agglomeration and slagging are especially acute when burning crop waste in a fluidized bed of quartz sand, causing defluidization of the layer. This leads to frequent boiler shutdowns to clean the furnaces. Alternative materials to quartz sand are known, but the literature contains little data on their commercial application. The operation of a combustion device with a fluidized bed of quartz sand and olivine as part of a 2-MW heat-generating installation when burning sunflower husks is analyzed. The chemical composition of agglomerates is studied and the mechanism of their formation is described. The experiment on burning husks in a layer of olivine lasted continuously for 600 h. When carrying out periodic measurements of the fractional composition of the olivine layer, the concentrations of carbon oxide, dioxide, and oxygen in the flue gases and the formation of agglomerates was not detected.