- Thesis topic: A Study on the Transformation of Agricultural Waste into Reusable Resources by Pyrolysis Technology

- Doi: 

- Abstract: 

        Taiwan has a well-developed agricultural sector, with considerable volumes of agricultural imports and exports recorded annually. However, the production and processing of agricultural products also generate substantial quantities of agricultural waste, such as rice husks, banana peels, and sugarcane bagasse. To promote the efficient reuse of these resources and create added value, the implementation of appropriate valorization technologies is essential. This study focuses on three major crops: rice and sugarcane—both ranked among the world’s top ten crops—and bananas, the most produced fruit globally. These crops are also of significant agricultural importance in Taiwan.
In this research, pyrolysis technology was adopted as a method for agricultural waste valorization, aiming to investigate the transformation characteristics of pyrolysis products under various operational conditions. Banana peels, rice husks, and sugarcane bagasse were selected as feedstocks and subjected to pyrolysis in a horizontal tube furnace reactor. The experiments were conducted under three temperatures (300 °C, 500 °C, and 700 °C) and three nitrogen (N2) flow rates (50, 250, and 500 mL/min). The gaseous products: hydrogen (H2), methane (CH4), carbon dioxide (CO₂) and carbon monoxide (CO) were analyzed using gas chromatography (GC-TCD/BID) to determine their composition and yield, thereby evaluating pyrolysis efficiency and identifying optimal operating conditions.
A comparative analysis of the three feedstocks revealed that the highest hydrogen yield was achieved under the condition of 700 °C and 50 mL/min nitrogen flow rate. Specifically, sugarcane bagasse produced 26.262 mmol/g of hydrogen, the highest among all samples, followed by rice husks at 24.935 mmol/g and banana peels at 15.853 mmol/g. These results indicate that all three feedstocks exhibit favorable gas production efficiency under high-temperature and low-flow conditions.
Further results demonstrated that elevated temperatures significantly enhanced hydrogen production, while variations in nitrogen flow rate notably affected product distribution and pyrolysis efficiency. The composition of gaseous products differed markedly across operational settings, with nitrogen flow rate playing a critical role in facilitating gas release and suppressing secondary cracking reactions. Lower flow rates contributed to increased total gas yield, suggesting that operating parameters should be optimized according to the intended application of the products.
In conclusion, this study confirms that pyrolysis is an effective technique for converting agricultural waste into reusable energy resources. Moreover, the distribution of pyrolysis products can be modulated based on feedstock characteristics and process parameters, thereby supporting the advancement of agricultural waste valorization and contributing to circular resource utilization and environmental sustainability.

Keywords: Pyrolysis, Hydrogen, Nitrogen, Banana Peel, Rice Husk, Sugarcane Bagasse, GC-TCD/BID