吸附剂表征及改性对棕榈油中3-氯丙醇酯 和缩水甘油酯脱除效果的影响Effect of adsorbent characterization and modification on the removal of 3-monochloropropanol-1,2-diol esters and glycidyl esters from palm oil

Abstract

为探究吸附法脱除精炼油脂中3-氯丙醇酯(3-MCPDE)和缩水甘油酯（GEs）的效果，以精炼棕榈油为原料，采用3种类型吸附剂（活性炭、活性白土、凹凸棒土）对其中的3-MCPDE和GEs进行吸附脱除，测定不同吸附剂的3-MCPDE和GEs脱除率，对吸附剂进行表征，分析其固有特性与脱除率的相关性，并研究了酸碱改性方法对吸附剂吸附脱除3-MCPDE和GEs效果的影响。结果表明：3种吸附剂及其酸碱改性后均未对3-MCPDE起到有效吸附脱除效果，而不同吸附剂对GEs表现出了不同的吸附脱除效果；9种活性炭（添加量1%）对GEs的脱除率为6.50%～98.57%，其中有2种活性炭可以有效地将GEs控制在1.00 mg/kg以内；9种活性白土（添加量0.1%）对GEs的脱除率为11.56%～83.72%；3种凹凸棒土（添加量0.5%）对GEs的脱除率为40.86%～6964%，脱除效果均不理想；相关性分析表明，GEs脱除率与活性炭的pH呈极显著负相关（p＜0.01），与活性炭比表面积、介孔面积和介孔容积均呈显著正相关（p＜0.05），与活性白土的pH、平均孔径呈极显著负相关（p＜0.01），与活性白土的活性度呈显著正相关（p＜0.05）；酸改性有利于活性炭和活性白土对GEs吸附脱除，而碱改性不利于其对GEs吸附脱除。实际生产中可选择低pH、孔隙发达的活性炭或低pH、活性度高、孔隙发达的活性白土，另外可进行适当的酸改性，以达到较好脱除油脂中GEs的目的。In order to explore the effect of adsorption on the removal of 3-monochloropropanol-1,2-diol esters (3-MCPDE) and glycidyl esters (GEs) from refined oil, refined palm oil was used as raw material，three types of adsorbents (activated carbon, activated clay, attapulgite)were used for the adsorption and removal of 3-MCPDE and GEs from it, and the removal rates of 3-MCPDE and GEs with different adsorbents were determined. The adsorbent was characterized, the correlation between its inherent characteristic and removal rate was analyzed, and the effect of acid and alkali modification methods on the effectiveness of adsorbent adsorption for the removal of 3-MCPDE and GEs was investigated. The results showed that the three adsorbents and acid and alkali modified adsorbents did not have an effective removal effect on 3-MCPDE. Different adsorbents showed different removal effects on GEs. The removal rate of 9 kinds of activated carbon (1% addition) on GEs was 6.50%-98.57%, of which 2 kinds of activated carbon could effectively control GEs within 1.00 mg/kg. The removal rate of 9 kinds of activated clay (0.1% addition) on GEs was 11.56%-83.72%. The removal rate of 3 kinds of attapulgite (0.5% addition) on GEs was 40.86%-69.64%，and the removal effects were unsatisfactory. Correlation analysis showed that the GEs removal rate showed a highly significant negative correlation with the pH of the activated carbon (p<0.01), a significant positive correlation with the specific surface area, mesopore area, and mesopore volume of the activated carbon(p<0.05), a highly significant negative correlation with the pH of the activated clay and the average pore size (p<0.01), and a significant positive correlation with the activity degree of the activated clay (p<0.05). Acid modification of activated carbon and activated clay could improve the removal rate of GEs, while alkali modification was not conducive to the removal rate of GEs. In actual production, low pH, pore developed activated carbon or low pH, high activity, pore developed activated clay, in addition to appropriate acid modification can be carried out to achieve better removal of GEs from oil.

Keywords

• 3-氯丙醇酯；缩水甘油酯；吸附剂；表征；酸碱改性
• 3-monochloropropanol-1
• 2-diol esters; glycidyl esters; adsorbent; characterization; acid and alkali modification