Vanillin is one of the earliest synthesized, largest output and most widely used spice products. It is widely used to formulate various daily chemical and food flavors. It is also the only spice product in my country licensed for use in infant milk powder. This project has developed a green synthesis process and related engineering technologies for vanillin glyoxylic acid method, which belongs to the technical field of daily chemical manufacturing.
Chinese enterprises have always used the traditional nitroso method to produce vanillin. Compared with the glyoxylic acid method used by major international competitors, there are problems such as poor product quality and serious three wastes. However, the glyoxylic acid synthesis process is complex and it is difficult to implement engineering technology. Industrialization has not been achieved in China.
Through research and development and industrialization, integrated technologies have been formed that cover the entire production process from the condensation reaction of guaiacol and glyoxylic acid, oxidation of condensation intermediates, separation and recovery of oxidants, product separation and purification, and wastewater treatment. Among them, the main technological innovations include the following four points:

1. Original copper oxide chemical oxidation technology of 3-methoxy-4-hydroxymandelic acid, and on this basis developed copper oxide online regeneration technology. This technology solves the problems of low copper oxide concentration, strong basicity of the system, high temperature, many side reactions, and low yield in the traditional copper salt catalytic oxidation method; it also solves the problem that the copper oxide chemical oxidation method uses a large amount of copper oxide and the generated cuprous oxide needs to be oxidized, regenerated and recycled off line after recovery. This technology can maintain a high concentration of copper oxide in the entire oxidation reaction process, shorten the reaction period, prevent side reactions such as decarboxylation and increase the yield of vanillin, and at the same time reduce the CODCr concentration in vanillin production wastewater. An invention patent has been applied for.
2. The first three series solid-liquid separation methods of sedimentation centrifugation-butterfly centrifuge-membrane filtration to complete the engineering problem of solid-liquid separation of copper oxide, cuprous oxide and reaction solution, making it possible to implement the chemical oxidation method. This technology can achieve solid-liquid separation with a solid content of 5%(dry weight), a wide particle size distribution, and a minimum particle size of only 0.1μm. The recovery rate of copper oxide and copper oxide reaches more than 99.9%, and the residual copper is less than 50ppm. Has obtained one invention patent.
3. A non-polar resin has been developed to selectively adsorb and recover aromatic compounds in wastewater, and transformed it into a comprehensive wastewater treatment technology for ortho-vanillin and vanillin application through independently developed synthesis technology. The application of this technology can utilize the polarity difference between aromatic and aliphatic compounds in wastewater for efficient separation, and generate economic benefits through the utilization of aromatic compounds. This comprehensive wastewater treatment technology has been authorized for one invention patent, and this patent won the National Patent Excellence Award sponsored by the State Intellectual Property Office in 2013.
4. Using stripping technology to efficiently recover guaiacol in toluene extract, achieving 15% energy saving in the vanillin production process. Excess guaiacol in the condensation reaction needs to be recovered by toluene extraction. Usually, the extract is first recovered by rectification, and the remaining guaiacol can be separated by rectification before being used again. This process consumes high energy. Using alkali back extraction method, the purpose of separating guaiacol from solvent and impurities can be simultaneously achieved. The obtained guaiacol alkali solution can be directly used for condensation reaction after concentration adjustment. An invention patent has been applied for this technology.
   This project has applied for 6 invention patents, of which 2 have been authorized (Annex 1), and three national standards and industry standards have been drafted (Annex 2). It has been used in Jiaxing City Zhonghua Chemical Company for six years (Annex 5). The purity of the product reaches 99.9%(Annex 4). The quality is good, and the global market share of the product has increased to 60%(Annex 6). A total of 53,300 tons of vanillin have been produced, sales of 4.395 billion yuan, profits of 787 million yuan, and taxes of 409 million yuan have been completed (Annex 5). The overall level of the identified technology has reached the international leading level (Annex 3). At the same time, due to promoting clean production and technological progress in the fragrance and essence industry, the early technology of the project has won the 2010 Science and Technology Progress Award of China Light Industry Federation and the 2013 Invention Patent Excellence Award issued by the State Intellectual Property Office (Annex 6).