Undaria pinnatifida残渣水热法资源化利用及产物中羟基羧酸分离技术研究

发布时间：2018-06-06 07:56

本文选题：生物质 + 裙带菜孢子叶(Undaria　；参考：《哈尔滨工业大学》2017年博士论文

【摘要】：采用水热液化技术综合利用生物质残渣已经成为目前研究的热点课题。本研究以undaria pinnatifida残渣为原料,使用胺类水热剂对其进行综合利用,得到了有价值的植物油基化合物和有机酸,并从水热液化液中分离出附加值较高的乳酸和乙醇酸。以undaria pinnatifida残渣为原料,胺类为水热剂,在反应釜中进行水热液化,研究了不同实验条件对水热液化产物分布和组成的影响。利用GC-MS和FT-IR对水热液化过程中的植物油基化合物进行分析,结果表明植物油基化合物的主要成分为棕榈酸,同时包含醇类、烷烃类、酮类、酰胺类和苯类衍生物。利用HPLC对水热液化过程中的液相产物进行分析,结果表明液相产物以酸类物质为主。进一步选出甲胺作为制备乙醇酸的水热剂,乙胺作为制备乳酸的水热剂,丙胺作为制备植物油基化合物的水热剂。通过对水热剂回收的研究,发现使用回收的胺得到的水热液化产物分布和各成分组成并未发生明显变化。通过响应面法对甲胺制备乙醇酸、乙胺制备乳酸和丙胺制备植物油基化合物的工艺进行优化。优化后乙醇酸的最高产率达到36.46g/L,乳酸的最高产率达到23.77g/L,植物油基化合物的最高产率达到34.73g/L。根据植物油基化合物的组成分析了各产物的形成路线,脂肪酸主要由undaria pinnatifida残渣中脂质水解得到;烷烃类物质主要是溶液中酸、醇等在碱性条件下发生消去反应得到;酮类物质主要是叶绿素支链断裂形成。通过理论计算分析葡萄糖的空间结构对胺类水热剂亲核进攻的影响,结果表明甲胺通过进攻葡萄糖碳链上的C3位置获得乙醇酸,乙胺通过进攻碳链上C4位置获得乳酸。选出体积分数100%的TBP、体积分数100%的A101和体积分数40%TOA+60%C 8作为萃取乳酸或乙醇酸的萃取剂。对萃取的单因素实验进行研究,得到最佳的萃取条件为:萃取温度25℃、搅拌速度300r/min、搅拌时间15min、静置时间5min。在萃取过程中,TBP与乳酸或乙醇酸的络合方式主要是1:1;40TO A与乳酸或乙醇酸的络合方式主要是2:1;A101与乳酸的主要络合方式为2:1,与乙醇酸的主要络合方式为3:1。萃取过程中A101和40TO A的吉布斯自由能、熵变和平衡常数都比TBP高,从热力学上解释了A101和40TOA萃取乳酸或乙醇酸分配比高的原因。经过活性炭进行预处理后,水热液化液中的杂质被有效去除,同时大部分的乳酸和乙醇酸得以保留。选择TBP作为萃取水热液化液中乳酸和乙醇酸的萃取剂。经过5级错流萃取后,溶液中的乳酸和乙醇酸的含量均低于0.50g/L,萃取率均高于98%;8级逆流萃取后,溶液中的乳酸和乙醇酸的含量均低于0.50g/L,萃取率均高于98.50%。在反萃工艺研究中发现高温有利于反萃,选择反萃温度为55℃、反萃相比为2:1,在该条件下单级乳酸的反萃率达到34.90%,乙醇酸的反萃率达到56.51%。通过5级逆流反萃,最终乙醇酸的反萃率为99.00%,乳酸的反萃率为75.60%,通过反萃可以将部分乳酸留在有机相中,达到分离乳酸和乙醇酸的目的。在分馏萃取过程中,通过串级理论计算得出流比的比值,选择流比为VF:VS:VW=1.50:1:3,萃取级数n=12,洗涤级数m=5对水热液化液进行萃取。在萃取温度25℃、水洗温度55℃、搅拌速度300r/min的条件下进行串级分离,根据物料平衡计算得出乙醇酸的总反萃率达到99.77%,乳酸的反萃率为67.49%。最终乳酸的纯度达到98.76%,乙醇酸纯度为68.94%。有机相再生研究表明,通过NaOH再生后的TBP经过两次水洗后即可循环使用。本文通过水热液化对生物质残渣进行综合利用,分析了不同胺类水热剂对产物的影响,结合溶剂萃取法对制备的有机酸进行了分离研究,为实际工业应用打下了一定的基础。
[Abstract]:The comprehensive utilization of biomass residue with hydrothermal liquefaction technology has become a hot topic at present. This study uses Undaria pinnatifida residue as raw material and uses amine type hydrothermal agent to synthetically utilize it. The valuable plant oil based compounds and organic acids are obtained, and the higher value added lactic acid is separated from the hydrothermal liquified liquid. Glycolic acid. The effects of different experimental conditions on the distribution and composition of hydrothermal liquefaction products were studied in the reaction kettle with Undaria pinnatifida residue as raw material and amine as hydrothermal agent. The effects of different experimental conditions on the distribution and composition of the products were studied by GC-MS and FT-IR. The results showed that the main oil based compounds were formed. It is divided into palmitic acid, including alcohols, alkanes, ketones, amides, and benzene derivatives. Using HPLC to analyze the liquid products in the process of hydrothermal liquefaction, the results show that the liquid products are mainly acid materials. Methylamine is selected as a hydrothermal agent to prepare glycolic acid. Ethylamine is used as a hydrothermal agent to prepare lactic acid and the preparation of amine as a preparation. A hydrothermal agent of plant oil based compounds. Through the study of the recovery of hydrothermal agents, it was found that the distribution of the products of hydrothermal liquefaction and the composition of the components did not change obviously. The process of preparing the ethanolic acid by the methylamine and the preparation of the oil based compound by lactic acid and amines by the response surface method was optimized. The highest yield of alkyd reached 36.46g/L, the highest yield of lactic acid reached 23.77g/L, the highest yield of plant oil based compounds reached 34.73g/L., according to the composition of plant oil based compounds, the formation route of each product was analyzed. Fatty acids were mainly hydrolyzed from lipid water in Undaria pinnatifida residue, and alkanes were mainly acid and alcohol in solution. The reaction of the ketone material is mainly the formation of the chlorophyll chain fracture. The effect of the spatial structure of glucose on the nucleophilic attack of the amine hydrothermal agent is analyzed theoretically. The results show that methylamine obtains ethylic acid by attacking the C3 position on the glucose carbon chain, and ethylamine is obtained by attacking the C4 position on the carbon chain. Lactic acid. 100% TBP of volume fraction, A101 of volume fraction and 40%TOA+60%C 8 of volume fraction are used as extractant for extraction of lactic acid or glycolic acid. The single factor experiment of extraction is studied. The optimum extraction conditions are as follows: extraction temperature 25, stirring speed 300r/min, mixing time 15min, 5min. in the extraction process, TBP The complexation mode with lactic acid or glycolic acid is mainly 1:1; the complexation mode of 40TO A with lactic acid or glycolic acid is mainly 2:1; the main complexation way of A101 and lactic acid is 2:1. The main complexation way with glycolic acid is the Gibbs free energy of A101 and 40TO A in 3:1. extraction process, and the entropy change constant is higher than that of TBP, and the A101 is thermodynamically explained. And 40TOA extraction of lactic acid or glycolic acid distribution is high. After pretreatment with activated carbon, the impurities in the hydrothermal liquified liquid are effectively removed and most of the lactic acid and glycolic acid are preserved. TBP is selected as extractant for lactic acid and glycolic acid in the extracted hydrothermal liquified liquid. After 5 stages of flow extraction, the lactic acid in the solution and the lactic acid are extracted. The content of glycolic acid is lower than 0.50g/L and the extraction rate is higher than 98%. After 8 stage countercurrent extraction, the content of lactic acid and glycolic acid in the solution is lower than that of 0.50g/L. The extraction rate is higher than that of 98.50%. in the study of the reverse extraction process. The extraction temperature is favorable to the stripping, the extraction temperature is 55, and the reverse extraction is 2:1. The extraction rate of single stage lactic acid is reached. To 34.90%, the stripping rate of glycolic acid reaches 56.51%. through 5 stage countercurrent stripping, finally the stripping rate of glycolic acid is 99%, and the reverse extraction rate of lactic acid is 75.60%. Through the stripping, some lactic acid can be left in the organic phase to separate lactic acid and glycolic acid. In the process of fractionation extraction, the ratio of flow ratio is calculated by cascade theory. The selection flow ratio is VF:VS:VW=1.50:1:3, the extraction series n=12 and the washing series m=5 to extract the hydrothermal liquid. The series separation is carried out at the temperature of 25, 55 and the stirring speed 300r/min, according to the material balance calculation, the total stripping rate of glycolic acid reaches 99.77%, the extraction rate of lactic acid is 67.49%. and the purity of the lactic acid. Up to 98.76%, the study on the regeneration of 68.94%. organic phase with the purity of glycolic acid shows that the TBP regenerated by NaOH can be recycled after two times of water washing. In this paper, the biomass residue was comprehensively utilized by hydrothermal liquefaction, and the effects of different amine hydrothermal agents on the products were analyzed, and the organic acids prepared by solvent extraction were separated. The research laid a foundation for practical industrial application.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ225.4;TQ028

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