スキップしてメイン コンテンツに移動

Photochemical industry production

 This is an excerpt from the following book*1) as a memo of what I found interesting. Oxidation and reduction can proceed simultaneously in the same reaction field (on a photocatalyst), a characteristic unique to photocatalytic reactions that cannot be realized in other reaction systems.

 When L-lysine, a kind of essential amino acid, is used as a raw material for photocatalytic reactions in aqueous solution in an oxygen-free atmosphere, pipecolic acid is generated. The photocatalytic synthesis of pipecolinic acid is the only synthetic pathway known to date that does not require any special reagents and does not produce any byproducts because the reaction involves redox reactions with excited electrons and holes. 


 The only photochemical reaction currently used for industrial production is probably the PNC method of ε-caprolactam synthesis by photo-nitrosation, developed by Toray Industries, Inc. ε-caprolactam is the raw material for 6-nylon, which is probably synthesized in hundreds of thousands of tons per year worldwide. Organic synthesis reactions using photocatalysis also have many basic advantages over other reactions, but in order to actually industrialize them, it is necessary to start from scratch, i.e., to create equipment that has never been used before.


*1) Mechanism Illustration: Photocatalyst at its Best by Mai Takashima and Fumiaki Otani, 2019, 1st printing, p68, 170

コメント

コメントを投稿

このブログの人気の投稿

The production process of sake

 I heard that another company was making acrylamide, a chemical product , using bacteria to synthesize it (no byproducts), so out of curiosity, I went to see the production process of sake, which is made using bacteria. C 6 H 12 O 6 　　→　　                2C 2 H 5 OH　　+　　2CO 2 ↑ (glucose)　　bacteria                (ethanol) 1. Rice malt is grown on steamed rice to encourage  aspergillus  growth. 2.  Rice malt,  Yeast, steamed rice, and water are added to the tank in several times and maintained at low temperature (unrefined). ※ The quality of the water is most important. 3) Squeeze out the  unrefined , let the liquid stand, and filter out the supernatant liquid.
コメントを投稿
続きを読む

CO2 Reduction

  I will transcribe this from a chemical engineering journal*1) for my own understanding. 　Let's consider the reaction of a plant that reduces CO2 to oxygen. First, a water molecule is "photo-oxidized" to produce one mole of oxygen molecules, and at the same time, two moles of "hydride" (H-) are produced, and these two moles of "hydride" reduce CO2. In short, the equation for the photo-oxidation of water is ② from ①. H- = H+ + 2e-   ① 2H2O+4hν → O2+4e- + 4H+ → O2+2H- + 2H+   ② The "conversion of photons (hν) to electron energy (e-)" in equation ① above is achieved by the catalytic function of chlorophyll in plants. Artificially, it is done by photocatalysts. The author of this article has succeeded in "CO2 reduction to methanol" *2). The principle is the reduction of CO2 by 3 moles of "hydride" ③. 3H- + CO2 + 3H+ → CH3-OH (methanol) + H2O   ③ *1)Production Engineering Journal, Chemical Equipment, April 2021, p63 *2)Y. Mats...
コメントを投稿
続きを読む