| Deacidification is an important step in refining process of vegetable oil, which is related with the quality of edible oil. However, there are a lot of problems such as high consumption of water and energy, high loss of neutral oil and nutritive material in the traditional oil refining process. Moreover, constrained by the high costs, most of new deacidification techniques could not be applied widly. To solve the problems mentioned above and offer necessary and practical basis for the application of adsorption deacidification, this paper had one research in the preparation for new deacidification adsorbent, the application of the new adsorbent and the influence of the new adsorption deacidification on quality of oils. The main conclusions were obtained as follows:1. Selection of the raw material for deacidification adsorbent.The various materials were prepared to different deacidification adsorbents by the same process, and the deacidification effects, safety and separation of the different adsorbents were investigated. According to the test results, the seed hull SH1 was finally determined to be the best material for the preparation deacidification adsorbent.2. Preparation of the deacidification adsorbent.The optimum conditions for preparation of the deacidification adsorbent was: particle size of seed hull 60 mesh, activator concentration 20%, the ratio of seed hull to activator 1:15 (g:ml), whisk speed 150RPM. The deacidification adsorbent prepared under the optimum conditions showed excellent dispersing and separating properties in the oils. The surface of deacidification adsorbent was the major adsorption area, and the chemical adsorption played a great role in the choice adsorption of free fatty acids (FFA), the fatty acid salts and other impurities in oils were adsorbed mainly via physical adsorption.3. Application of the new adsorbent in adsorption deacidification.(1) In the process of adsorption deacidification, the absorption time and the amount of deacidification adsorbent had a significant influence on the removal of FFA. The optimun conditions of adsorption deacidification was:the whisk speed 200RPM, the adsorption time 2h, the amount of deacidification adsorbent 5% and the adsorption temperature 30℃; Under the optimum conditions, the acid value of rapeseed oil could be deacidified from 2.44 mgKOH/g to 0.35 mgKOH/g.(2) The result of adsorption test showed that shows that Langmuirisotherm best-fit the equilibrium data for adsorption of FFA on the deacidification adsorbent. The Langmuir equation was Ce/Qe=0.0015Ce+0.0017, R2=0.9998 at the temperature 30℃, the maximum adsorption capacity was 666.7 mg/g, and the absorption constant was 0.88, so we could know that the deacidification adsorbent ia a very good adsorbent of FFA. If the deacidification adsorbent would be applied in the other oils with different content of FFA, the amount of deacidification adsorbent could be obtained by the calculating formula:(3) The residual oil of waste deacidification adsorbent was 5.3±0.1%, and the loss of neutral oil during the process of adsorption deacidification was only 0.1%. The calorific value of waste deacidification adsorbent was 6762±265cal/g, similar to the standard coal. So the waste deacidification adsorbent could be used as a fuel free of pollution and waste.(4) Bothe of the two different technological combinations could remove the phospholipid and FFA of crude oils effectively. The integrated technique of adsorption deacidification and degumming was easier in operation and could save more refining time, but the different waste adsorbents were inseparable, and this would be detrimental to the reutilization of the different adsorbents. |
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