INVESTIGATION OF PHYSICAL-MECHANICAL AND ENERGY PROPERTIES OF GRANULATED CEREAL PLANT WASTE AND ASH OBTAINED BY INCINERATION OF PRODUCED BIOFUEL

The world's population grows, so people need food. As the food demand increases, so does the demand for cereals. Lithuania is one of such countries where cereals are grown in abundance. After removing the grain, the received grain crop waste - straw may be used for a variety of purposes by farmers. Straw can be used as litter, left in the fields to rot as fertilizer, and straw can be used as a renewable energy source. For some time now, there has been talk of using straw as a solid biofuel, but not much research has been done to investigate the physical-mechanical and energy properties of such sort of straw biofuel - pellets. The aim of the study was to investigate the physical-mechanical, thermal, energy and other properties of barley and wheat cereal straw pellets and ash obtained from their burning. Pine sawdust pellets were also studied for comparison. Investigations of pellet quality showed that pressed granules are of high quality and density. The highest density pellets were obtained by pressing wheat straw - 985.2 +/- 81.5 kg center dot m(-3) DM (dry matter), and the lowest - by pressing pine sawdust (896.3 +/- 26.1 kg center dot m(-3) DM). Studies have shown that 5.65% of ash are released from barley straw pellets burning, 5.60% - from wheat straw pellets burning, and, after pine sawdust pellets burning, the ash content reached 0.54%. Research results of thermal properties showed that the calorific value of barley straw pellets was slightly higher than that of wheat straw pellets - for barley straw it reached 18.45 MJ center dot kg(-1), and for wheat straw - 18.54 MJ center dot kg(-1). However, the calorific value of cereal straw pellets is lower than that of wood sawdust pellets - the calorific value of pine sawdust pellets was reached even 20.51 MJ center dot kg(-1). Studies of harmful emissions (CO2, NOx, CO, CxHy) during pellet burning were also investigated, and the results obtained showed that emissions do not exceed the permissible limits. Summarizing the results of the research, it can be stated that in order to improve the thermal and energy properties of straw biofuel pellets, it is expedient to mix straw with wood sawdust.

Automated summary

With the growth of the world's population, the demand for food is increasing, leading to a higher demand for cereals. Lithuania is a country where cereals are grown abundantly. Straw, a byproduct of grain harvest, has various uses such as litter, fertilizer, and renewable energy source. Research indicates that the calorific value of cereal straw pellets is lower than that of wood sawdust pellets, but mixing straw with sawdust can improve their thermal and energy properties.