Publications

Waste from poultry farms represents the greatest danger to people and the environment among all types of bio waste. Approximate estimates show that in Russia up to 15 million tons of manure and a mixture of litter with sawdust or straw are formed annually. The original litter is a toxic substance; the main bacteria in the litter are E. coli and Salmonella. The process of torrefaction of a mixture of manure and sawdust was studied. The torrefaction proceeds in a reactor consisting of three sections with horizontal trays on which the processed material is moved with help of a two-bladed stirrer from the loading point to the discharge point from one plate to the other. The reactor has a jacket heated with a high-temperature oil. The analysis of content of pathogenic microflora after torrefaction shows that only low-temperature pyrolysis at 250 °C and treatment time of 60 min. allows full disinfection of this type of waste. To increase the outlet of gaseous products of low-temperature pyrolysis and to reduce the tar content in gaseous products, we proposed to pass the gaseous products obtained through a bed of carbonaceous particles heated to 800-1000 ° C. As a result of laboratory studies, the following characteristics of synthesis gas were obtained: Н₂ content - 49.0%, CO content - 46%, net calorific value - 11.34 MJ/Nm³, synthesis gas outlet - 0.9 Nm³ per 1 kg of raw material. The results of preliminary calculations of the complex for manure with litter processing into biofuel pellets with a nominal capacity of 2 t/h for the final product (pellets)

For improvement of the combustion efficiency in a fluidized bed and decrease of carbon monoxide
and nitrogen oxides emissions, biofuel is suggested to pre-heat treating (torrefaction). The
experiments on burning of initial (“raw”) and thermally processed pellets from sunflower husks were
carried out in a pilot sample of a furnace with a bubbly fluidized quartz sand bed. The “raw” pellets
had a lower calorific value of 16 MJ/kg and contained 75.6% volatile substances. After heat treatment
in a specially designed reactor at a temperature of 250 °C (treatment time of 60 minutes), the tor -
pellets had a lower combustion value of 20.7 MJ/kg and contained 54.8% of volatile substances. As a
result of heat treatment, the carbon content in the pellets increased by 1.21 times, the nitrogen
content increased by 1.36 times, the sulfur content boosted by 1.27 times, the calcium content
improved in 1.66 times, the content of potassium raised in 1.74 times. It was experimentally proved
that in a fluidized bed the intensive intralbed circulation of “Gulf Stream” type should be organized to
reduce the probability of ash agglomerates formation. For the circulation of “Gulf Stream” type, a
special air distribution grille was used, which provided a higher air velocity at the entrance to the bed
near the vertical walls of the furnace and a lower air velocity in the center of the furnace. During the
experiments with “VarioPlus” gas analyzer, the content of oxygen, carbon monoxide, and nitrogen
oxides in the flue gases was measured. It was found that:
1. When tor-pellets are burned due to the higher heat of combustion, the oxygen content in the flue
gases at the outlet from the fluidized bed is reduced by about 1.5 to 1.7 times, and the carbon
monoxide content is reduced about 2 times.
2. When tor-pellets are burned due to the lower oxygen content of the flue gases, the nitrogen oxides
content is reduced by about 1.7 times compared to “raw” pellets combustion.