Study of the feasibility of a rice husk recycling scheme in Japan to produce silica fertilizer for rice plants

Abstract

Rice husks are resources that should be recycled in a sustainable way, thus creating a win-win relationship between stakeholders, consumers, and society. Silica is a very valuable material and used for many industrial purposes. A Rice husk contains 20% of silica by weight, and can therefore be considered a biological silica ore. To recycle rice husks in a sustainable way, the ash produced from burning rice husks must also be used as a resource. In this study, based on the concept that rice husk ash should be recycled as silica fertilizer, we compared the economic feasibility of two recycling systems: Heat recovery from hot water and generation of electricity from hot water. Questionnaires were also conducted regarding farmers' expectations of silica fertilizer made from rice husk ash. We found that the system involving heat recovery from hot water was sustainable; however, generating electricity from hot water was cost-prohibitive. It must be noted that the validity of this result might be limited to Japan, where electricity generation is highly regulated. On the other hand, areas that already struggle to dispose of their rice husks should consider using rice husks to produce energy.

Development of high purity amorphous silica from emulsifier silicon by pyrolysis process at temperature of 700 oC

“…It indicates that the silica is totally in the form of amorphous phase since a hump that has a width between 15 to 30 ° from a 2θ Bragg angle clearly can be seen on the figure 2. This is consistent with previous studies that amorphous silica has a hump between 15 to 35 o of 2θ [19][20][21]. This result is also in accordance with the standard pattern of silica in the Standards Joint Committee on Powder Diffraction (JCPDS) [10].…”

Characterization of rice husk ash prepared by open air burning and furnace calcination

“…Once obtained, RHA and silica from RHA has been used and studied for various applications that includes adsorbents for adsorption of dyes, pigments (Lawagon and Amon, 2019;Shukla, 2020) and heavy metal ions (Maingi et al, 2019) from aqueous solutions; catalytic support and catalyst (Ikhlaq et al, 2019); for manufacturing solar cells for photovoltaic power generation and semiconductors (Zamani et al, 2019); in the cement industries as a pozzolone component (Sonat and Unluer, 2019) and fertilizer industries (Sekifuji et al, 2019); in synthesis of advanced materials such as silicon tetrachloride, magnesium silicide, sodium silicate and zeolite (as reported by Genieva et al, 2008); as fillers in rubber (Xue et al, 2019) and plastic (Almirón et al, 2019) composites, due to their low densities, very low cost, nonabrasiveness, high filling levels, recyclability, biodegradability and renewable nature among many others. The aim of the present study is to compare the properties of RHA prepared under controlled conditions that is FRHA with RHA obtained through uncontrolled burning ORHA.…”

Utilization of rice husks as a fuel for gasification – A review

“…For instance, it's recently been used as a feedstock for gasifiers and boilers to generate heat and electricity through co-generation technology [6]. Besides that, by-products of rice husk's gasification like rice husk ash are often used as a source of nanostructured silicon for Li-ion battery anodes [7], silica fertilizer for rice plants [8], and solar cells [9].…”