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This research aimed to demonstrate the thermal pathway (torrefaction technology) to convert organic waste to be biochar/biocoal. Organic waste (cabbage) from Nonthaburi fresh market, Thailand was used as raw material. Torrefaction technology was processed in horizontal cylindrical batch reactor with Nitrogen gas purging during doing experiment. Temperature profile was preliminary checked to find out lag time. Amount of loaded weight and particle size of material were preliminary tested. Experimental conditions such as time and temperature were tested at 30 and 60 minutes, and range temperature of 220 to 300°C. Important property of product; calorific value of product in form of high heating value (HHV) and mass yield percentage were measured. The optimal conditions were evaluated with two parameters; increase of HHV compared to reference condition and % mass yield. Increase temperature was significant effect to increase HHV value of biochar. The optimal time and temperature for getting the highest heating value were 60 minutes and 280°C. [ABSTRACT FROM AUTHOR]

The highly acid sulfate Rangsit soil series of Rangsit, Pathum-Thani district, Thailand poses a major problem for agriculture in the area. Water hyacinth is a naturally occurring weed that can grow aggressively, causing eutrophication and leading to many severe environmental impacts. Here, through the pyrolysis process, we convert water hyacinth to biochar and use it for acid soil amendment. We found the ratio between biochar, soil, and sand suitable for the cultivation of water convolvulus to be 50 g of biochar, 400 g of soil, and 100 g of sand (1:8:2). This soil mixture improved the pH of the soil from 4.73 to 7.57. The plant height of the water convolvulus grown in the soil mixture was the greatest at 20.45 cm and the plant weight with and without roots was greatest at 2.23 g and 2.52 g, respectively. Moreover, we demonstrated the dominance and high abundance of Bacillus among the community in soil with biochar amendment. Here we provide the first assessment of the appropriate amount of water hyacinth-derived biochar for mitigation of soil acidity and promotion of optimal water convolvulus growth. Moreover, biochar can optimally modify soil bacterial communities that benefit plant development. [ABSTRACT FROM AUTHOR]

The mitigation of greenhouse gas (GHG) emissions and water usage optimization in rice cultivation is challenging for many agricultural countries, including Thailand, who have set goals of reaching net zero emissions and coping with droughts caused by climate change. Alternate wetting and drying (AWD) and biochar application are possible practices for achieving cleaner rice production through reduction of GHG emissions and water consumption. However, these methods' potential varies by site, especially in areas with limited control of water levels. This study assessed the effects of AWD at different drying levels (10, 15, and 20 cm below the soil surface) and rice straw biochar on GHG emissions, yield production, water use, soil characteristics, and economic aspects. This study was conducted over two rice cultivation seasons: a major season in 2022 and a second season in 2023 at a field in Kalasin Province, northeastern Thailand. Using AWD and biochar reduced annual GHG emissions by 48.2% and 8.01%, respectively. Deeper drying levels of AWD showed greater mitigation potential than shallow levels. The combination of AWD and biochar had additional potential for GHG mitigation, however, this impact did not show statistical change as compared to their separate potentials. The adoption of AWD and biochar could also maintain the amount of rice yield compared to traditional practice. All levels of AWD saved irrigation water consumption by an average of 16.8% per season; the highest potential was observed in AWD at 10 cm below the soil surface. Biochar improved soil health after two seasons by enhancing soil pH and organic carbon sequestration. The combination of AWD and biochar did not additionally augment the capacity in water saving of AWD or soil improvement of biochar. The AWD water regime also did not increase net profits, while biochar decreased net profits due to the required investment in biochar production. Using AWD is a feasible way to mitigate GHG emissions and save water without affecting rice productivity and net profits in northeastern Thailand. [Display omitted] • Alternate wetting and drying (AWD) mitigated greenhouse gas emissions by 48.2%. • AWD reduced irrigation water use by an average of 16.8%. • AWD at 15 cm of drying level without biochar is suggested as a mitigation tool. • Rice straw biochar showed the significant impact on soil organic carbon stock. [ABSTRACT FROM AUTHOR]

Durian peel is a type of biomass derived from agricultural residues, which are found in abundant in Thailand. This study aims to investigate the thermal and chemical properties of three indigenous durian peels, namely Monthong (MDP), Puangmanee (PDP), and Bacho (BDP), as well as the characteristics of biochar and pyrolysis liquid derived from slow pyrolysis of the durian peel. MDP had the greatest volatile matter and fixed carbon content, with 73.97 and 18.43 wt%, respectively. MDP was applied for further research in order to produce biochar and pyrolysis liquid at pyrolysis temperatures of 400 and 600 °C. The maximum biochar yield was 36.01% at 400 °C, while the maximum pyrolysis liquid yield was 37.25% at 600 °C. The largest high heating value of biochar (24.48 MJ kg−1) was obtained at 600 °C more than the high heating value of feedstock (14.32 MJ kg−1). Biochar obtained at 400 °C can be categorized as fertilizer class 4, while biochar obtained at 600 °C can be classified as carbon storage class 2 using the IBI biochar classification tool. The quality of the pyrolysis liquid was determined to be of 3.14 pH and 1.052 g mL−1 specific gravity at a pyrolysis temperature of 600 °C, which meets Thailand standards. As a result, both 400 °C and 600 °C pyrolysis liquids produced significant chemicals that are employed in a variety of industries. Consequently, this research is strongly recommended to be expanded to produce high-quality durian peel biochar and pyrolysis liquid. [Display omitted] • Comprehensive physical, chemical, thermal properties of durian peels were explored. • Durian peel biochar can be categorized by the IBI as carbon storage class 2. • The biochar can be classified by the IBI as a high fertilizer class 4. • Pyrolysis liquid derived from the durian peel meet Thailand standards. • 81 main compounds with essential chemicals were detected in the pyrolysis liquids. [ABSTRACT FROM AUTHOR]

The in-field burning of sugarcane leaf residues presents a major environmental and health burden in Thailand. In this study, sugarcane leaves were converted into a biochar-based slow release phosphorus (P) fertilizer via pyrolysis at 600 °C, and the influence of pre- and post-pyrolysis treatment on the P loading and release was investigated. The sugarcane leaves were pre-treated with an alkaline (diammonium phosphate, DAP) or an acidic P source (phosphoric acid, PA), with or without addition of MgO. Additionally, the biochar was post-treated with DAP to increase the P loading. Extraction of P in DI water and 2% formic acid were used as indicators for potential slow release. The microporous biochars had a specific surface area of 69–333 m2 g−1 and pre-treatment resulted in a P content of 34–82 g kg−1. When MgO was included in the pre-treatment, XRD analysis confirmed formation of crystalline Mg 2 P 2 O 7 , irrespective of the P source. This Mg 2 P 2 O 7 was responsible for slow P release in DI water over 240 h via a dissolution-controlled process. Post-treatment with DAP increased the P loading to 156 g kg−1 in the form of water-soluble monoammonium phosphate (MAP), which did not contribute to slow release. The tunable P release via combinations of pre- and post-pyrolysis treatment makes these engineered biochars attractive as P sources for crops and presents an attractive solution to mitigate in-field sugarcane residue burning. [Display omitted] • P-loaded biochar was prepared by co-pyrolysis of sugarcane leaves with P + MgO. • Addition of MgO in pre-pyrolysis treatment results in slow release of P. • The slow P release is controlled by dissolution of Mg 2 P 2 O 7. • Post-treatment with DAP increases water-soluble P but not slow-release P. [ABSTRACT FROM AUTHOR]

Organic amendments may improve the quality of acidic tropical agricultural soils with low organic carbon contents under conventional management (mineral fertilization and irrigation) in Southeast Asia. We investigated the effect of biochar, compost and their combination on maize growth and yield, soil physical, biological and chemical properties at harvesting time at four sites in three countries: Thailand, Vietnam and Laos. Treatments consisted of 10 t·ha−1 cow manure compost and 7 t·ha−1 of Bamboo biochar and their combination. Maize biomass production and cop yields were recorded for two seasons. Elemental content, pH and nutrient availability of soils were analyzed after the first growing season. We also characterized macrofauna abundance and water infiltration. Few changes were noted for maize biomass production and maize cop yield. Soil chemical parameters showed contrasting, site-specific results. Compost and biochar amendments increased soil organic carbon, pH, total K and N, P and K availability especially for sandy soils in Thailand. The combination of both amendments could reduce nutrient availability as compared to compost only treatments. Physical and biological parameters showed no treatment response. We conclude that the addition of compost, biochar and their mixture to tropical soils have site-specific short-term effects on chemical soil parameters. Their short-term effect on plants is thus mainly related to nutrient input. The site-dependent results despite similar crops, fertilization and irrigation practices suggest that inherent soil parameters and optimization of organic amendment application to specific pedoclimatic conditions need future attention. [ABSTRACT FROM AUTHOR]