Production of biochar from tomato harvest residues and determination of its effects on carbon dioxide emission in field condition

In this study, it was aimed to convert from tomato harvest wastes (DHA) to biochar by slow pyrolysis method. The sub aim of the study was to (1) determine the pH, carbon (C), nitrogen (N), volatile solid, fixed carbon and ash properties of biochar produced at different pyrolysis temperatures and holding times, (2) production energy at different pyrolysis temperatures and holding times and (3) determine the effect of biochars on the CO2 emission from the soil. The pH value of biochars ranged from 5.82 to 10.08. The biochar yielded at 300°C (regardless of holding time) was acidic, while the biochar produced at 400-700°C was determined as alkaline. As the pyrolysis temperature and the holding time increased, the C content increased. N contents decreased with the increase of the holding time at the same temperature. When the pyrolysis temperature increased from 300 ° C to 700 °C, the content of volatile matter decreased, ash content increased and fixed carbon content increased. Biochar yield decreased with increasing temperature and holding time. With the increase in temperature and holding time, the electricity consumption of biochar production increased. With the increase in temperature and holding time, the electricity consumption per production of biochar produced increased very rapidly. The lowest cumulative CO2 emission measurement was realized for biochar produced at 500°C and 240 minutes of holding time. The highest cumulative CO2 emission measurement was achieved for biochars produced at 300°C for 40 minutes. Biochar produced at low temperatures caused lower soil CO2 emissions when mixed with soil, while biochars produced at lower temperatures caused higher soil CO2 emissions when mixed with soil.