Sustainable value added material use of occurring by-products from sugar and rice production in Vietnam

Abstract

Due to the worldwide growing population, the demand on food increases, which results in the need for a higher productivity in agriculture. Generally, this leads to larger amounts of agricultural residues and by-products, which may cause severe environmental risks due to emissions from simple burning or storing, especially in emerging and developing countries. In Vietnam agricultural by-products arise in total of 118 Mt per year, whereas 80% are coming from rice and sugar cane processing. By the selection of favorable plant varieties, seed, and/or seedlings, it is possible to improve the rice and sugar yield. Besides, the by-products offer a great potential for a value-added material use. We developed a flexible portable, integrated process scheme aside from high-tech biotechnology applications. Erosion control blankets, soil improvers/composts for an improved crop yield and soil management, and adsorbents with the focus on environmental issues for cleaning of fluid streams were produced from different fractions of the residue fractions via thermo-mechanical processes. As a consequence, fossil raw material input streams, e.g. polymer based textiles, inorganic fertilizing agents, and peat/coal can be avoided.In laboratory and field tests we demonstrate the producibility and the applicability and summarize the positive impact of the aforementioned products made from rice straw and bagasse: The improved varieties as well as the addition of selected soil improvers/composts made from the by-products improve the test plants' yield and quality. The application of erosion control blankets prevents soil loss and dehydration by covering soil surface for a period of transition. The produced shaped activated carbons show mechanical and adsorption specific properties, which are comparable to commercial products.