(173al) Synthesis of biochar using economical pyrolysis processes as a remedial soil amendment

Post-harvest residues are greatly undervalued across Latin American countries, often either burned or left to decompose in piles, which contribute to the generation of greenhouse gases. Therefore, it is essential for the health of soils, the livelihood of farmers, and the protection of the environment to seek low-cost and efficient solutions for better utilizing these substantial agricultural by-products. This paper evaluates two cost-effective technologies for producing biochar: Kon-Tiki and TLUD (Top-Lit UpDraft), both of which have demonstrated efficiency.

Following the collection and processing of a corn crop, the equipment was put on a farm in the Colombian municipality of Flandes. To achieve this, corn cobs were taken and placed in each device, causing a layer to build at the bottom before being ignited. It has been added capable of biomasses after being left to produce flame and calcines. As more layers of feedstock are added, the temperature gradually drops below the primary pyrolysis zone and, depending on how long the batch is left in the furnace, eventually reaches a final quenching temperature of 150°C to 450°C. There are two techniques for quenching. Depending on the furnace and how tightly the quench layer is sealed, the temperature of the biochar in the first process can stay over 400 °C for more than a day. By slowly pouring water from the top for the TLUD or injecting it upward for the Kon-Tiki, the second method lessens the amount of vapor created. The biochar produced was subjected to proximate characterization. Ultimate and heating value analyses, as well as the characteristics of the pore structure, were also evaluated. On the other hand, biochar has been field tested and applied to a bean crop at a rate of 1%. The harvested plants were tested for phytotoxicity, and parameters such as organic matter, pH, electrical conductivity, and cation exchange capacity were evaluated.

The biochar produced by TLUD has been found to exhibit somewhat better qualities in the parameters studied. This is supported by the field investigations, which show that the soils treated with this biochar had greater percentages of organic matter and more favorable pH values. Because Kon-Tiki's carbon and fixed carbon levels were somewhat lower than TLUD's, there was less organic matter present in the sample and more electrical conductivity. Notwithstanding these variations, both forms of biochar offer the best circumstances for field application as enhancers of the physicochemical characteristics of soil, hence promoting plant health. The application of biochar to the soil produced results that are consistent with those reported by other authors, who discovered that biochar enhances the physicochemical characteristics of the soil, reduces the bioavailability of potential inorganic contaminants, and facilitates plant uptake of essential nutrients (Acosta-Luque et al., 2022; López & Saldarriaga, 2023; Serrano et al., 2024).

Two inexpensive technologies that were tested on post-harvest biomass leftovers in low-income nations have both shown promise in the production of biochar. It has been shown that the physicochemical qualities of soil can be improved by this biochar; Kon-Tiki raises pH and EC, while TLUD improves CEC and OM. Additionally, the application of both devices' biochar greatly increased the foliar nutritional content of plants, demonstrating their feasibility for incorporating circular economy systems in agriculture by using leftover biomass to make biochar. An economic study shows that the first year's cost of implementing Kon-Tiki is more than €900 greater than that of TLUD. With bio-inputs made from leftover biomass, TLUD becomes a feasible choice for farmers looking to use circular economy techniques while improving soil qualities. Subsequent investigations ought to examine the effects of biochar on crops, specifically its capacity to augment pesticide retention, curtail application, and raise biodegradability.

References

Acosta-Luque, M., López, J., Henao, N., Zapata, D., Giraldo, J., & Saldarriaga, J. (2022). Remediation of Pb-contaminated soil using Biochar-Based Slow- Release P Fertilizer and biomonitoring employing bioindicators. Scientific Reports. https://doi.org/10.21203/RS.3.RS-2289314/V1

López, J. E., & Saldarriaga, J. F. (2023). Surface Co-application of Dolomitic Lime with Either Biochar or Compost Changes the Fractionation of Cd in the Soil and Its Uptake by Cacao Seedlings. Journal of Soil Science and Plant Nutrition, 1, 1–11. https://doi.org/10.1007/S42729-023-01469-Z/FIGURES/5

Serrano, M. F., López, J. E., Henao, N., & Saldarriaga, J. F. (2024). Phosphorus-Loaded Biochar-Assisted Phytoremediation to Immobilize Cadmium, Chromium, and Lead in Soils. ACS Omega. https://doi.org/10.1021/ACSOMEGA.3C07433