The Study On The Conjugated Reaction Of Safflower Oil Using Water As Solvent And Supercritical Co₂ Extraction Of Reaction Products

Conjugated linoleic acids (CLA), a group of conjugated dienoicderivatives of linoleic acid (LA), have several important physiologicalfunctions, such as anti-carcinogenic and anti-atherogenic properties, reducingbody fat, etc. It needs synthetic CLA because of its low content in the nature.CLA is often synthesized from vegetable oil by conjugated reaction withorganic solvent conventionally. But the problem of remainder of solvent oftenoccurs in the technology. In the thesis, CLA was synthesized from saffloweroil by alkali isomerization with water as solvent. The relationships betweenthe conversion yield of reaction and the operational parameters, such asreaction temperature, time, mass ratio of water to oil and mass ratio of oil toalkali has been investigated. The experimental results showed that the optimalconditions of the reaction was found that the temperature was 214℃, the timewas 4.9 hours, the mass ratios of water to oil was 4.3 and the mass ratio of oilto alkali was 1.3. Under the optimal reaction conditions, the conversion yieldof 97.74% of conjugated reaction could be obtained. The kinetics of thisreaction was also studied on the basis of previous research in the thesis. Theexperimemtal results showed that the reaction order of the conjugated reactionof safflower oil was 1, activation energy of the reaction was 52.204kJ/mol.It is significant to produce CLA with green technology because CLA willbe used ashealthy and functional food. The refinement and concentration ofCLA with supercritical CO₂ extraction technology substituting conventionalpurification technologies has been investigated. The experimental resultsshowed that it was not available to extract the physiological active isomerswith supercritical CO₂ extraction technology, but it was effective to removethe colored and odorous impurities, and the final fatty acid was low peroxidevalue(POV), light and no odour. This indicated it was available to refine CLAwith supercritical CO₂ extraction technology. Compared with conventionaltechnologies, this technology has several advantages, such as low separationtemperature, no remainder of solvent, etc. The phase equilibrium of the system is very important to the design forseparation process and optimization of operational conditions. The study onthe phase equilibrium of the system containing CO₂ and fatty acids hasdirective effect on developing the technology of refining CLA withsupercritical CO₂ extraction. So it has been investigated in the paper. The PRequation of state and the PR mixing rules were used in the simulation of thissystem. And the results showed the calculated results agreed with theexperimental data given in the literature fairly well.In a word, the green synthesis and separation technologies of functionalunsaturated fatty acid—CLA have been studied in this paper, and it providedfundamental conditions for its industrialization. At the same time, the phaseequilibrium of system containing supercritical CO₂ and fatty acids has beenalso investigated on the basis of experiment in this paper, and it could providethe necessary data for the industrial design of extracting CLA using themethod of supercritical CO₂ extraction.