Process development of silica extraction from RHA: a cradle to gate environmental impact approach
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India is one of the major rice-producing countries. Rice husk is a major agricultural by-product from rice production, which is used as a fuel in boilers. Its use as fuel produces huge amounts of silica-rich rice husk ash (RHA). This paper aims at providing an overall assessment of environmental impacts associated with the extraction of silica from RHA—a process developed by our study group. The functional unit used in this study is production of 100 kg of silica. The analysis included the extraction and transportation of other raw materials; RHA was assumed to be processed at the site. The study was conducted in accordance with the international ISO 14040 procedural framework. LCA is performed using GaBi Education software, and five midpoint indicators are chosen to assess the environmental impacts of silica extraction. The overall climate change (CC) of the extraction process is 7.26 kg CO2 equivalent per kg of silica produced. A high contribution of calcination to CC is attributed to the use of electricity. The comprehensive environmental impacts of silica-rich RHA resulting from processing of RHA and improvement options to achieve sustainable production are presented. The negative impacts that can be avoided during silica extraction are also discussed. It is observed that calcination is a major contributor to the overall environmental indicators. The work also stresses on the use of renewable energy for electricity generation, which would help in decreasing the overall greenhouse gas emissions during extraction while ensuring waste utilization.
KeywordsLife cycle assessment Rice husk ash Silica Environmental impacts
The authors are thankful to the SERB-Department of Science and Technology, India, for research funding (SB/S3/CE/077/2013). BDK acknowledges the support as SERB Distinguished Fellow.
- Carbolite Gero Limited (2017) Static or Bogie Chamber Furnace - SBCF Static or Bogie Chamber Furnace - SBCF. In: Carbolite Gero Ltd. www.carbolite-gero.com. Accessed 15 May 2017
- Foreign Agricultural Service / Office of Global Analysis International Production Assessment Division (IPAD) (2017) World Agriculture Production U.S. Department of Agriculture. 1–29Google Scholar
- Grbeš A (2016) A life cycle assessment of silica sand: comparing the beneficiation processes. Sustainability. https://doi.org/10.3390/su8010011
- ISO, ISO14040 (2006) 14040: Environmental management–life cycle assessment–principles and framework. British Standards Institution, LondonGoogle Scholar
- Putsch® GmbH & Co. KG (2010) Filtration and Separation Technology. In: Putsch® GmbH Co. KG. https://en.putsch.com/filtration-systems/products/filtration-systems/filter-presses/. Accessed 3 Mar 2017
- Samatya S, Kabay N, Yu M et al (2006) Removal of nitrate from aqueous solution by nitrate selective ion exchange resins. React Funct Polym 66:1206–1214. https://doi.org/10.1016/j.reactfunctpolym.2006.03.009 CrossRefGoogle Scholar
- Simcoa Operations Pty Ltd (2017) Production Process Silica redution process. In: Simcoa Oper. Pty Ltd. http://www.simcoa.com.au/. Accessed 24 May 2017
- Sukhras Machines Pvt. Ltd (2017) Bottom Discharge Centrifuge. In: Sukhras Mach. Pvt. Ltd. https://www.sukhras.com/. Accessed 24 May 2017
- Thind HS, Yadvinder-Singh, Bijay-Singh et al (2012) Land application of rice husk ash, bagasse ash and coal fly ash: effects on crop productivity and nutrient uptake in rice-wheat system on an alkaline loamy sand. F Crop Res 135:137–144. https://doi.org/10.1016/j.fcr.2012.07.012 CrossRefGoogle Scholar
- Wu XL, Tong S, Liu XN, et al (2014) X-ray diffraction study of alternating nanocrystalline silicon/amorphous silicon multilayers X-ray diffraction study of alternating nanocrystalline silicon/amorphous silicon multilayers. 838:102–105. https://doi.org/10.1063/1.118219