Effects of Biochar from Torrefaction and Carbonization of Woody Biomass on Plant Growth

• Main Authors: Li-Wei Yu, 余立瑋
• Other Authors: 吳耿東
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/29391179614321850543

碩士 === 國立中興大學 === 森林學系所 === 102 === The objective of this study is to investigate the soil amendments by using biochar from torrefaction and carbonization of woody materials, and evaluating the plant growth promotion by using biochar. Cryptomeria japonica and Acacia confusa chips were used as feedstock for preparing the biochar by torrefaction or carbonization. The operating conditions for torrefaction or carbonization temperatures were 250, 300, 350, 400, 500 and 600oC, and the residence time is 60 minutes. The characteristics of biochar from torrefaction or carbonization processes, such as mass yield, ultimate and proximate analyses, specific surface area, total pore volume, pore size distribution and average pore diameter were examined. All plant growth experiments were carried out in pots containing 500 gram soil which was mixed with biochar and sandy soil. The biochar adding rates were 0, 5, 10, and 20 wt.%, and also the activated carbon and woody feedatock were employed as another additive. Three plants including Brassica rapa chinensis, Brassica chinensis Linn., and Brassica campestris were grown in the biochar-added soil to examine NH4-N, NO3-N, available phosphorous, Na, K, Ca, Mg, cation excange capacity (CEC), and water retention ability. The weight of plants after growing for 28 days in the soil was also investigated. The results show that specific surface area, total pore volume of biochar increased with increasing the torrefaction or carbonization temperatures, but the average pore diameter shows the contrary results. The average pore diameter of biochar carbonized at 600oC is similar to that of the activated carbon, but the specific surface area and the total pore volume were widely different. In addition, the higher carbon content, specific surface area and total pore volume of biochar form Cryptomeria japonica were found compared with those of biochar from Acacia confusa. The growth weight of Brassica rapa chinensis, Brassica chinensis Linn., and Brassica campestris after applying biochar increased with increasing the preparation temperature of biochar. The growth rate of plant by applying biochar form Cryptomeria japonica was better than applying that from Acacia confusa. The plant growth rate increased significantly by applying biochar prepared above 400oC, but the results shows the contrary results by applying biochar prepared above 600oC. In addition, adding biochar into the soil could increase the amount of NH4-N, NO3-N, available phosphorous, Na, K, Ca, Mg, CEC, and water retention ability to provide the nutritious for plant growth. The objective of this study is to investigate the soil amendments by using biochar from torrefaction and carbonization of woody materials, and evaluating the plant growth promotion by using biochar. Cryptomeria japonica and Acacia confusa chips were used as feedstock for preparing the biochar by torrefaction or carbonization. The operating conditions for torrefaction or carbonization temperatures were 250, 300, 350, 400, 500 and 600oC, and the residence time is 60 minutes. The characteristics of biochar from torrefaction or carbonization processes, such as mass yield, ultimate and proximate analyses, specific surface area, total pore volume, pore size distribution and average pore diameter were examined. All plant growth experiments were carried out in pots containing 500 gram soil which was mixed with biochar and sandy soil. The biochar adding rates were 0, 5, 10, and 20 wt.%, and also the activated carbon and woody feedatock were employed as another additive. Three plants including Brassica rapa chinensis, Brassica chinensis Linn., and Brassica campestris were grown in the biochar-added soil to examine NH4-N, NO3-N, available phosphorous, Na, K, Ca, Mg, cation excange capacity (CEC), and water retention ability. The weight of plants after growing for 28 days in the soil was also investigated. The results show that specific surface area, total pore volume of biochar increased with increasing the torrefaction or carbonization temperatures, but the average pore diameter shows the contrary results. The average pore diameter of biochar carbonized at 600oC is similar to that of the activated carbon, but the specific surface area and the total pore volume were widely different. In addition, the higher carbon content, specific surface area and total pore volume of biochar form Cryptomeria japonica were found compared with those of biochar from Acacia confusa. The growth weight of Brassica rapa chinensis, Brassica chinensis Linn., and Brassica campestris after applying biochar increased with increasing the preparation temperature of biochar. The growth rate of plant by applying biochar form Cryptomeria japonica was better than applying that from Acacia confusa. The plant growth rate increased significantly by applying biochar prepared above 400oC, but the results shows the contrary results by applying biochar prepared above 600oC. In addition, adding biochar into the soil could increase the amount of NH4-N, NO3-N, available phosphorous, Na, K, Ca, Mg, CEC, and water retention ability to provide the nutritious for plant growth.