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Abstract-Dry poultry waste can be used as a valuable fertilizer for seedbed preparation and spring fertilizing of winter crops. One of the major limitations for the direct application of organic waste in the soil is the presence of conditionally pathogenic and pathogenic microorganisms, preserving viability and virulence for a long time. The low-temperature pyrolysis of pelleted litter mass at 250° C and treatment time of 60 min. allows for complete decontamination of this type of waste. Reducing the pyrolysis temperature to 155 ° C even when the treatment time was 60 min. did not fully decontaminate the litter mass. There was also a series of experiments on the use of pelleted litter mass subjected to low-temperature pyrolysis for 1 hour at 250 ° C as a fertilizer. It was found that by introducing these pellets into the soil in an amount of 2 tons/ha, the barley yield increased by 16.2%; the timing of fruit formation of the tomato variety "Krasavets" reduced from 70 to 62 days from the start of germination, and the starting date of ripening decreased from 95 to 82 days; the yield of "Santana" potato variety increased by 36.5% up to 62 tons/ha.

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Poultry farms with floor-standing poultry generate large amounts of poultry litter waste. The direct application of this waste as an organic fertilizer does not ensure sustainable and cost-efficient utilization of all waste fractions, and can also be linked to environmental hazards. Therefore, the development of new technologies is required for processing poultry litter into a safe product with higher added value. In this work, the characteristics of activated carbon derived from hydrochar, along with the liquid products obtained from hydrothermal carbonization (HTC) and the wet torrefaction (WT) of poultry litter, were investigated. Poultry litter (PL) was applied in a mixture with sawdust (SD) in the following ratios: 1:0 (PL/SD 1:0), 1:1 (PL/SD 1:1), 1:2 (PL/SD 1:2), and 2:1 (PL/SD 2:1). WT processing took place in an innovative fluidized bed system in a superheated steam medium with low overpressure (less than 0.07 MPa) at 300 °C and 350 °C for 30–45 min. Conventional HTC processing was performed in a water medium at 220 °C for 1–4 h. The hydrochar produced in the experiments was activated with steam for 1 h at 450–750 °C. The porosity characteristics of activated hydrochar were measured, including pore size, pore volume, and specific surface area, in view of potential industrial applications as an adsorbent. Additionally, the contents of 5-hydroxymethylfurfural (HMF), as high-value product, were determined in the liquid products obtained from HTC processing, as well as in the condensate obtained after WT processing. Specific surface areas of the activated hydrochars may still be too low for application as adsorbent material. Hence, its use as a biofertilizer and soil improver should be preferred. Interestingly, the liquid fraction obtained from the innovative WT process displayed a significantly higher 5-HMF content compared to the conventional HTC process.