(339f) Design and Scale-up of a Multiple Production Process of Food, Cosmetics and Biofuel from Unused Oil Derived from Rice Bran

Many technologies have been developed to utilize the large amounts of unused bioresources generated by existing industries, but only a few have been put into practical use. This is due to the difficulty of achieving both environmental compatibility and economic efficiency. We believe this is because the way the current manufacturing process is designed is not suitable for utilizing unused bioresources. So far, the focus has been on innovative products and designing processes to manufacture them efficiently. In this case, a process is designed to first select suitable raw materials for production, extract the desired components, efficiently convert them and remove impurities to make the product. However, the separation and purification process to remove unwanted components is a barrier to commercialization due to its high environmental impact and cost.

We have changed our thinking, focusing on components contained in unused bioresources and proposing a new method of designing processes that do not generate unwanted substances. The aim of this method is to evaluate the market value of each component, recover the higher ones in high purity and convert the lower ones into higher value-added products, thereby producing as much product as possible and improving the overall economics of the process.

In this research, we have applied this concept to unused oil generated in large quantities at rice bran oil refinery, and have successfully developed a practical device for a multiple production process to recover several functional ingredients at high purity, and to convert the remainder into biofuels. In traditional industries, these products are manufactured in separate processes from different raw materials. In contrast, our process allowed the production of all products from one unused bioresource without generating any unwanted components.

Our process utilizes three ion exchange resins as new catalysts and adsorbents in an oil solution system, allowing complete conversion of fatty acids and triglycerides to fatty acid esters without constraints of reverse reactions at 50°C and atmospheric pressure¹⁾. At the same time, by-products of water and glycerol are physically adsorbed onto the resin and removed from the solution, and phenolic compounds such as vitamin E are selectively retained in the resin by ion exchange²⁾.

Furthermore, the solution that flowed out of the resin packed reactor spontaneously formed a white precipitate when cooled to room temperature, which was collected by filtration and found to be paraffin with a purity of over 95% and a card structure, used as base materials for lipstick. This is the world's first biomass-derived paraffin, which has acquired its own CAS number as well as an international patent³⁾. Further distillation of the remaining alcohol precipitated phytosterols, which could be recovered with a purity of over 90%, and the remaining liquid was directly used as biofuel for power generation.

This process has already been commercialized by a Tohoku University start-up⁴⁾, and the products are sold both domestically and internationally. This technology can also be applied to deodorized distillates of various other vegetable oils, and can contribute significantly to the creation of a resource cycle for unused oils.

1)N.Siddique et al., Fuel, 289, 119884 (2021)

2)K.Hiromori et al., J.Clean. Prod.,189,223(2018)

3)K.Hiromori et al., WO2023/021593(2023)

4)https://phytochem-products.co.jp/en/