Process for extracting salicin from populus euphratica fallen leaves

Abstract

The invention discloses a process for extracting salicin from populus euphratica fallen leaves. The process is characterized by comprising the following steps: adding calcium oxide into populus euphratica fallen leaf shreds, and adding water for decomposing; extracting the solution twice at the temperature of 30 DEG C, collecting filtrate, and combining the filtrate; adjusting the pH value to 10.0-12.5, allowing the solution to stand, and collecting the filtrate; concentrating the filtrate, adding a clarifying agent or an adsorbent for decolorizing while stirring at the temperature of 70 DEG C, and colleting the filtrate; adjusting the pH value to 3.0-5.0 at a normal temperature, allowing the solution to stand, and collecting the filtrate; adding ammonium water or ammonia gas into the filtrate for adjusting the pH value to 7.0-9.0, concentrating the filtrate till the specific weight is 1.2, and crystalizing the filtrate at the normal temperature in a static manner for 72 hours; and separating a crystal, drying the separated crystal at 80 DEG C, and smashing the dried crystal. The process has the beneficial effects that water with low environmental pollution is taken as an extraction solvent, so that the production cost and the workshop requirement are lowered; ash is removed by adopting sulfuric acid or sulfate, and the crystal is obtained through the crystallizing step, so that the purity of a final product is increased, and can be over 65 percent in general; and natural fallen leaves of populus euphratica in autumn are taken as raw materials, so that damage to vegetation is prevented.

Description

technical field [0001] The invention relates to an extraction process, in particular to a process for extracting salicin from fallen leaves of Populus euphratica, and belongs to the field of chemical technology. Background technique [0002] In the prior art, the process of extracting salicin is mainly as follows: after the red willow branch is crushed and cut into sections, 5% quicklime is added as the raw material, and then extracted twice with 75% methanol under heat reflux, each time for 1.5 hours, and then the extracted Concentrate the liquid and adjust the pH with quicklime, then filter, concentrate the filtrate until the specific gravity is between 1.14 and 1.16, and finally spray dry it. [0003] Since methanol is used as the solvent, not only the production cost is high, but also an explosion-proof workshop is required. The most important thing is that methanol will remain in the extracted salicin, which will affect human health and cause great environmental polluti...

AI Technical Summary

Problems solved by technology

[0003] Since methanol is used as the solvent, not only the production cost is high, but also an explosion-proof workshop is required. The most important thing is that there will be residual methanol in the extracted salicin, which will have an impact on human health, and the discharge will cause great environmental pollution.

[0004] In addition, since red willow (or white willow) branches and bark are used as raw materials, the damage to vegetation is great, which is not conducive to ecology, environmental protection and sustainable development.