Renewable energy and high-tech silicates from rice hulls

High-Tech Silicate made of rice hulls

The Pörner Group developed a robust technology for the production of high quality silicon products from the ash of rice hulls. The Pörner rice hull technology enables the efficient and eco-friendly production of high-tech silicates. The new, patented process is ready for worldwide use and opens up diverse and sustainable applications.




    Silicate is a valuable base material usable for countless applications, since sodium and caliuilicates are a key product on each continent.

    Value chain profit from Pörner technology

    The Pörner rice hull technology can be used at any time along the value chain from the rice plant to the high-tech silicate. It offers significant advantages and high flexibility. Depending on requirements, the biomass power plant or the silicate plant alone or both can be realized or expanded jointly by Pörner as an overall concept.

    the pörner technology value creation process

    This technology offers several finacial benefits, ...

    • for rice farmers - an organic fertilizer from rice hulls (previously worthless waste product) for their fields
    • for rice mills - the profitability of the plant increases with a biomass power plant, thus covering the energy requirement locally
    • for silicate manufacturer - economically produced high-quality, high-purity water glass from renewable raw materials
      Ecological and economic benefits for economics

      The Pörner rice hull technology, ...

      • stabilize energy supply to emerging economies such as India will be stabilized and provide access to clean energy and high-tech products for many families
      • solves a serious ecological problem - currently the rice hulls rot in wild landfills or are burned in open fires polluting the environment (damage to air, soil and groundwater)
      • offers a better environmental balance - CO2 emissions alone are reduced by up to 70 % (compared to conventional production)

      Economic comparison

      The advantages of the Pörner technology for the production of silicates from rice hulls in contrast to conventional production from quartz sand:

      Silicate of Rice hulls ash
      Silicate of Quartz sand


      Rice hulls are a renewable resource,
      inexpensive available as a waste product

      High pureity quartz sand only limited available


      Moderate reaction conditions (T < 150 °C),
      enery demand can be met by
      combustion of the hulls themselves

      Very energy-consuming to produce (T > 1300 °C)


      Hardly any impurities in the final product,
      higher purity

      Ionic impurities, thus high cleaning costs


      Directly from rice hull ash to water glass
      in just one process step

      Two sub-processes needed



      Reaction to form CO2


      The process

      Pörner technology

      Rice is the main food source for half of the world's population. Each grain of rice is wrapped in a pellicle, the rice hull, a perfect protection against external influences. Its high resistance is explained by its material, mainly silicates and cutins. The weight of the rice hulls is equal 20 % of the total rice grain. Accordingly, in rice processing, large quantities of rice hulls are a waste product. Due to their chemical composition, they rot slowly, but they contain enormous energy potentials, which until now have largely remained unused.

      The Pörner technology converts rice hulls in modern biomass power plants into climate-friendly, renewable "green energy". During the combustion of the hulls, rice hull ash is produced in a CO2-neutral cycle in addition to electrical and thermal energy. This rice hull ash contains more than 90 % silicon dioxide (SiO2), which is modified into cost-effective and high-quality water glass in the Pörner silicate plant.

      In the subsequent filtration step, a filter cake is obtained, which consists of almost pure carbon, another recycleable by-product. The filtrate already has a high product purity and can be used as a water glass in industrial quality after subsequent decolorization. In this way, water glass can be produced for the high purity silicate market with relatively little effort.

      Pilot plant at Freiberg

      Pörner has a modern pilot plant in Freiberg/Germany. This pilot plant is specifically designed to represent and optimize the key parameters of the process.

      Depending on customer requirements, specifications for high-quality silicate products in liquid form are created. Using state-of-the-art laboratory and prototype equipment, analytical examinations can also be carried out on site at short notice.


      Product for a world market

      The use of silicates is varied - the spectrum ranges from bleach in the paper industry to additives in detergents, paints, construction materials, cosmetics, tires and construction chemicals. This allows silicon to be processed into eco-friendly fertilizer that not only improves crop growth, but also increases yields and crop quality by up to 25%.

      The world market for silicates is growing rapidly. It is forecasted to reach about $ six billion by 2020, with detergents accounting for around a quarter of the market. At present, precipitated water glass for car tire production is the fastest-growing market (“green tires”).

      Innovation Award 2018 for Pörner rice hull technology

      For the fourth time, Vogel Fachverlag honored the most innovative technologies, processes and apparatus in eleven categories at ACHEMA. Pörner received the coveted award in the category "Biotech for Chemistry" for the process "High-Tech-Silicate made of rice hulls". 

      With a sophisticated process, rice hulls, a waste material in every rice mill, can be converted into the purest silicate. Silicates are an indispensable element for the chemical industry. Silicates are currently obtained mainly with high energy expenditure from quartz sand. Rice hulls silicates have five advantages: eco-friendly production, the purest quality without heavy metal contamination, a wide range of possible uses, low production costs and low energy consumption.