Establishment of a novel technology permitting self-sufficient, renewable energy from rice straw in paddy fields

摘要

With global population growth, substantial increases in food demand have aggravated the problem of methane emissions, which most researchers have been focusing on reducing in paddy fields. Since methane is a clean energy source and the main component of natural gas, we established a novel and efficient on-site biomethane production and collection system using rice straw in the paddy field without any other methane fermentation tan, implying that this system will contribute to reduction of the greenhouse effect. We have termed this the "GET system": the efficient production of biomethane gas (G) as renewable energy (E) from a tanbo (T), which means "paddy field" in Japanese. The results showed that, during mesophilic (20-40 degrees C) digestion, the GET system could generate up to 100 L/day m(-2) of biomethane at a methane concentration of more than 60% from rice straw, which was at the optimum application amount of 14 kg m(-2) in the study. Moreover, the resulting 25.7% of carbon in rice straw was simultaneously stored in the soil as fermentation residue, improving soil fertility during the next rice-growing season and creating a carbon sink. The GET system is therefore a game-changing technology, offering a potential solution to the demand for food and energy without the emission of methane, thus reducing atmospheric carbon dioxide (CO2). Promotion and use of the GET system as effective clean technology will play a key role in global sustainable development in the near future. (C) 2020 Elsevier Ltd. All rights reserved.