Method for preparing high-quality sodium alginate

Abstract

The invention relates to a method for preparing high-quality sodium alginate, which comprises the steps of brown algae soaking, brown algae chopping, washing, draining, color fixation, digestion, dilution, floating, filtering, flocculation, squeezing dehydration, neutralization, drying and milling. The method is characterized in that: in the floating step is to add a biosurfactant chitosan auxiliary floating agent into diluent; the filtering step is tumbling precoating vacuum-pumping filtration; the flocculation step is low-acidification flocculation. In the preparation method, by adopting the tumbling precoating vacuum-pumping filtration and the low-acidification flocculation, water insoluble substances of the prepared sodium alginate is reduced from 0.6 percent to less than 0.3 percent, calcium content is lowered from 0.4 to less than 0.1 percent, the quality indexes of products can reach U.S. FMC standards; and the sodium alginate is obvious in energy-saving effect by combining the biosurfactant auxiliary floating agent, namely water consumption is reduced from 1,200 tons to 800 tons in the sodium alginate per ton, energy consumption and emission are reduced by 40 percent; and thus, the additional value of the sodium alginate in our country is improved greatly.

Description

Technical field [0001] The invention relates to a preparation method of high-quality sodium alginate. Background technique [0002] Sodium alginate is a kind of highly active polysaccharide extracted from marine brown algae, also known as algin, which is composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G). ) Linear macromolecules formed by 1,4 bonds are widely used due to the special thickening, stabilizing, emulsifying, pseudoplastic, thixotropic, water-holding, film-forming and cohesive properties of sodium alginate In the technical fields of food, health products, medicine, cosmetics, chemical industry, printing and dyeing, metallurgy and aerospace. Sodium alginate is called "healthy and longevity food" by Japan, and it is called wonderful food by Americans. The main raw materials for sodium alginate production are kelp, kelp, sargassum, palm-shaped kelp, wakame and Eisen algae. The world output of sodium alginate is 58,000 tons, and China’s output is about 35,000...

AI Technical Summary

Problems solved by technology

[0003] The main process that affects the quality index of sodium alginate is filtration and decalcification. All production enterprises in my country adopt crawler filtration and calcification and decalcification process. Since crawler filtration is through the filter cloth through the weight of the filtrate itself, the mesh number of the filter cloth determines the filtrate. If the mesh number is too large, the filtrate cannot pass through, and if the mesh number is too small, there are too many impurities and water-insoluble substances in the filtrate. This is also the bottleneck affecting the quality of sodium alginate products in my country. my country's national standards for sodium alginate stipulate that water-insoluble substances Less than 0.6%, the European and American standard is less than 0.3%. The calcification and decalcification process is also a traditional production process in my country. The purpose of calcification is to increase the yield of sodium alginate, but due to incomplete decalcification, the calcium ion content in sodium alginate exceeds the standard , has seriously affected the water solubility and quality of sodium alginate. my country's national standard stipulates that the calcium content is less than 0.4%, and the European and American standards are that the calcium content is less than 0.1%.

Therefore, compared with the sodium alginate produced in Europe and the United States, there is still a big gap in the quality index of sodium alginate produced in my country. This gap not only makes the international price of sodium alginate in my country seriously low, but also seriously affects It is difficult to compete with similar foreign products because of its application field, and the production process of sodium alginate in my country has not changed for 40 years, and the production of 1 ton of sodium alginate consumes 1,200 tons of water, which not only consumes a lot of water and energy, but also produces a lot of waste. Wastewater and waste, causing huge pollution to the environment