1，3-丙二醇发酵液脱盐用离子交换树脂的筛选

研究了用离子交换树脂处理1,3-丙二醇发酵液,选用6种阳离子交换树脂和3种阴离子交换树脂,以交换容量、电导率和再生时间为指标,考察了树脂的脱盐效果。结果表明：阳离子交换树脂中的D001-cc对1,3-丙二醇发酵液的处理效果最好,150mL树脂的平均交换容量达到240mL,电导率能降到2250gS／cm,再生时间7h;3种阴离子交换树脂中,D301R的去盐效果最好。     

1,3-丙二醇发酵液离子交换耦联电渗析脱盐的中试研究

对1,3-丙二醇发酵液离子交换耦联电渗析脱盐工艺进行了初步研究,在发酵液小试脱盐研究的基础上,主要研究了电渗析脱盐实验、离子交换树脂的选型和离子交换耦联电渗析工艺。结果表明,单独采用电渗析脱盐1,3-丙二醇损失率为11.41%;通过比较多种阴阳离子交换树脂的pH、电导率以及处理能力,确定耦联中试实验采用树脂LSI296和LSI010;采用离子交换耦联电渗析两步脱盐,效率提高到96.2%,损失率降低到5.88%。     

离子交换法去除1,3-丙二醇发酵液中盐的研究

通过动态脱盐实验,研究了不同离子交换树脂对1,3-丙二醇发酵液的脱盐性能。实验结果表明,采用D001和732阳离子树脂脱盐时发酵液的最佳流速分别为40,60 m L/min,D001阳离子树脂对发酵液的处理效果较好;D315阴离子树脂和D363阴离子树脂的最佳流速均为40 m L/min。树脂再生实验发现D363阴离子树脂消耗较少的氢氧化钠溶液。     

离子交换法去除1,3-丙二醇发酵液中盐的研究

通过动态脱盐实验,研究了不同离子交换树脂对1,3-丙二醇发酵液的脱盐性能。实验结果表明,采用D001和732阳离子树脂脱盐时发酵液的最佳流速分别为40,60 m L/min,D001阳离子树脂对发酵液的处理效果较好;D315阴离子树脂和D363阴离子树脂的最佳流速均为40 m L/min。树脂再生实验发现D363阴离子树脂消耗较少的氢氧化钠溶液。     

发酵液中1,3-丙二醇分离提取的研究进展

1,3-丙二醇是合成聚乳酸的主要原料,以甘油为底物的生物法制备1,3-丙二醇是以绿色化学为特征的技术。但1,3-丙二醇极性很强、微生物发酵液成分较复杂,产品收率偏低,质量难符合制备高性能聚对苯二甲酸丙二醇酯的要求,故1,3-丙二醇的分离提纯成为了生物法合成技术的关键。对于1,3-丙二醇发酵液,提纯过程包括发酵液预处理、脱盐和浓缩提纯。本文讨论了用于1,3-丙二醇提纯的主要技术,包括采用离心、过滤、絮凝脱大分子物质,用离子交换、电渗析、双水相萃取或有机溶剂沉淀等方法脱盐类,及通过精馏、萃取、吸附对发酵液浓缩提纯,或是以上某几个分离工艺的组合。提出整个分离工艺仍存在很多问题,对各工艺路线不断进行优化,开发新的经济高效的分离提取工艺路线,是目前实现规模化生物法生产1,3-丙二醇的技术重点。     

1,3-丙二醇发酵液电渗析浓水分离工艺研究

采用分步结晶工艺能将1,3-丙二醇发酵液电渗析脱盐浓水中的有机盐和无机盐分别结晶析出,并将结晶母液进行二次电渗析脱盐,以回收其中的1,3-丙二醇,将电渗析脱盐工序1,3-丙二醇的收率由95%提高到98%。     

1,3-丙二醇发酵液电渗析脱盐工艺的优化

研究了1,3-丙二醇发酵液电渗析脱盐过程中某些工艺参数,例如不同交联度离子交换膜的选择、不同碱离子发酵液以及原料液预处理方式等工艺对脱盐过程的影响。同时在前期实验的基础上,研究了淡浓室流速比、淡室流速和浓室初始浓度三因素对电渗析脱盐操作过程的影响,并利用正交试验对脱盐过程的工艺优化作了进一步的探讨。     

离子交换树脂吸附分离1,3-丙二醇发酵液的研究

用大孔离子交换树脂吸附发酵液中的有机酸盐和1,3-丙二醇(1,3-PDO)。考察温度、树脂用量、pH等对吸附效果的影响,结果表明,D311树脂对乙酸钠和丁二酸钠具有良好的吸附效果,优化后吸附条件:温度45℃,pH=6,每100 mL溶液树脂用量为5 g。为了降低D311树脂对1,3-PDO的吸附,采用溴乙烷进行烷基改性,得到了高脱盐低1,3-PDO吸附的改性树脂。热力学研究表明,改性前后的D311树脂对1,3-PDO的吸附符合Langmuir方程,并且均是自发吸热的熵驱动的吸附过程。动力学研究表明,改性前后的D311树脂对1,3-PDO的吸附符合准一级动力学模型,烷基化改性使得活化能由4.4 kJ/mol提高到6.6 kJ/mol,有利于降低树脂对1,3-PDO的吸附。     

离子交换树脂吸附分离1,3-丙二醇发酵液的研究

用大孔离子交换树脂吸附发酵液中的有机酸盐和1,3-丙二醇(1,3-PDO)。考察温度、树脂用量、pH等对吸附效果的影响,结果表明,D311树脂对乙酸钠和丁二酸钠具有良好的吸附效果,优化后吸附条件:温度45℃,pH=6,每100 mL溶液树脂用量为5 g。为了降低D311树脂对1,3-PDO的吸附,采用溴乙烷进行烷基改性,得到了高脱盐低1,3-PDO吸附的改性树脂。热力学研究表明,改性前后的D311树脂对1,3-PDO的吸附符合Langmuir方程,并且均是自发吸热的熵驱动的吸附过程。动力学研究表明,改性前后的D311树脂对1,3-PDO的吸附符合准一级动力学模型,烷基化改性使得活化能由4.4 kJ/mol提高到6.6 kJ/mol,有利于降低树脂对1,3-PDO的吸附。     

纳滤膜用于1,3-丙二醇发酵液脱盐工艺研究

1,3-丙二醇(PDO)发酵液中PDO浓度7％～10％,水含量82％～85％,此外还含有2％～3％ 的盐,主要为二价盐丁二酸纳和硫酸钠,此外还有少量乙酸钠,常规脱盐工艺是电渗析脱盐,离子交换膜存在膜易污染等难题,尝试采用纳滤膜对PDO发酵液进行脱盐工艺研究,筛选了不同规格的几种纳滤膜分别对PDO发酵液进行脱盐,研究结果...     

基于离子交换层析技术提取发酵液中的丙酸

用7种不同性能的阴离子交换树脂吸附发酵液中丙酸,考察了发酵液酸化方式及pH值对吸附量的影响,分析了不同浓度H2SO4的解吸情况,比较了多柱串联组合层析提高丙酸收率的可行性. 结果表明,大孔弱碱性丙烯酸系阴离子交换树脂ZGD630对发酵液中的丙酸吸附量最高,采用H型阳离子交换树脂D001酸化工艺,当pH值由6.5降至3时,ZGD630树脂对发酵液中丙酸的静态吸附量从54.34 mg/g提高至110 mg/g,动态吸附量达152.5 mg/g. 用4 mol/L H2SO4进行解吸,丙酸浓度最高达81.8 g/L,为初始发酵液的2.12倍. 采用3柱串联组合层析时丙酸收率达62.15%,较单柱层析显著提高.     

阴离子交换树脂D318分离提取发酵液中的2-酮基-D-葡萄糖酸

采用弱碱性阴离子交换树脂D318直接吸附发酵液中的2-酮基-D-葡萄糖酸,之后用浓硫酸-甲醇混合液解吸,解吸液直接用于异Vc钠生产的后续酯化环节,简化了工艺流程,提高了效率。探讨了离交液浓度、离交液流速和树脂床高径比对单位树脂吸交量的影响,并结合离子交换原理对有关结果进行了讨论。     

Preparative Enrichment and Separation of Glycyrrhetinic Acid Monoglucuronide from Fermentation Broths with Macroporous Resins

Preparative enrichment and separation of Glycyrrhetinic acid monoglucuronide (GAMG) from the pretreated fermentation broth of glycyrrhizin was studied by using six macroporous resins with different physical and chemical properties. D101 resin showed the maximum effectiveness among the tested resins. The solute affinity towards D101 resin at different temperatures was described in terms of Langmuir and Freundlich isotherms, and the equilibrium experimental data were well-fitted to the two isotherms. The dynamic adsorption and desorption tests were carried out in order to optimize the operational parameters for the efficient separation of GAMG. After one run treatment with D101 resin, the contents of GAMG in the product were increased to 8.2-fold with recovery yields of 93.3%. The process achieved easy and effective enrichment and separation of GAMG with D101 resin, and it could be applied for the large-scale preparation of GAMG from the fermentation broth of glycyrrhizin.     

络合萃取法提取发酵液中丁二酸盐的研究

为提高微生物发酵法生产丁二酸的产品提取收率,研究利用三辛胺/正辛醇体系对发酵液进行络合萃取。比较硫酸和阳离子交换树脂两种前处理发酵液方式对络合萃取丁二酸的影响,以及用氨水反萃制备丁二酸铵。结果表明：通过阳离子交换树脂前处理发酵液,三辛胺/正辛醇体系对丁二酸的萃取率高于硫酸前处理,可达到91.3%;氨水是一种优良反萃剂,萃取剂重复使用5次,平均萃取率为90.4%,平均反萃率为94.9%,且萃取率和反萃率未见明显下降。     

络合萃取法提取发酵液中丁二酸铵

为提高微生物发酵法生产丁二酸的产品提取收率,用三辛胺/正辛醇体系对发酵液进行络合萃取。比较硫酸和阳离子交换树脂两种前处理发酵液方式对络合萃取丁二酸的影响以及用氨水反萃制备丁二酸铵。结果表明,通过阳离子交换树脂前处理发酵液,三辛胺/正辛醇体系对丁二酸的萃取率高于硫酸前处理,达到91.3%;氨水是一种优良反萃剂;萃取剂重复使用5次,平均萃取率为90.4%,平均反萃率为94.9%,且萃取率和反萃率未见明显下降。     

MATHEMATICAL MODEL OF L-LACTIC ACID FERMENTATION IN A RDC COUPLED WITH PRODUCT SEPARATION BY ION EXCHANGE

A Rotating Disk Contactor (RDC) was designed to perform the L-lactic acid fermentation with a filamentous fungus, Rhizopus oryzae, which was immobilized on the surface of rotating disks. The bioreactor was operated in repeated batch or continuous modes. The growth rate of the fungi was about 1 mm/day perpendicular to the disks' surface. A weak-base anionic resin, D354, was selected which was high in selectivity for lactic acid separation. Even at low concentration, the ion exchange capability was about 0.5 g Lac/g dry resin. A coupled process of L-lactic acid fermentation and ion-exchange separation was evaluated experimentally. The results indicated that the pH value of the fermentation broth could be maintained at pH 3.5 without any addition of alkali. The conversion ratio of glucose to L-lactic acid was about 0.7 g/g and the fermentation rate was able to reach as high as 62.5g glucose per hour per square meter of the disk surface area. A mathematical model was proposed to describe the simultaneous process of L-lactic acid fermentation and separation by ion exchange, in which the thickness increase of mycelia as well as the substrate and product inhibitions were included. The model simulation was in good agreement with the experimental data.     

大孔树脂分离发酵苹果酸的静态吸附工艺研究

通过5种大孔树脂对苹果酸吸附量的比较,其中阴离子树脂D301G吸附率最大。据此探讨了的D301树脂在不同时间、发酵液浓度、转速、pH、温度等影响因素下对静态吸附容量的影响。最终确定最佳操作条件为:转速150r/min、温度37℃、pH为5、吸附时间2 h、发酵液浓度10%。     

大孔树脂对喹乐霉素的静态吸附

考察了9种不同极性的大孔树脂对喹乐霉素的静态吸附解吸效果,探讨了吸附过程中树脂静态吸附动力学和25℃时的等温吸附过程,并用Langmuir与Freundlich方程分别对吸附过程进行了拟合。结果表明,XAD-16和D101树脂对喹乐霉素的吸附解吸效果较好,比较两种树脂等温吸附的Langmuir和Freundlich参数,D101树脂对喹乐霉素的吸附解吸作用最好,吸附量最大,达到0.976 mg/g干树脂,吸附过程更易发生。因此,D101树脂更适用于从标桩菌WXNXJ-B发酵液中吸附并解吸喹乐霉素。     

凝胶型强酸型阳离子交换树脂分离阿卡波糖:平衡、动力学与热力学研究(英文)

Acarbose, a potentα-glucosidase inhibitor, is widely used as an oral anti-diabetic drug for the treatment of the type 2, non-insulin-dependent diabetes. In this work, a gel type strong acid cation exchange resin 001×4 was applied to isolate acarbose from fermentation broth. It was demonstrated that cation exchanger 001×4 displayed a large adsorption capacity and quick exchange rate for acarbose. The static adsorption equilibrium data were well fitted to the Langmuir equation. Column adsorption experiments demonstrated that high dynamic adsorption capacity was reached at bed height of 104.4 mm, feed flow rate of 1.0 ml·min-1 and acarbose concentration of 4.0 mg·ml-1. Under the optimized conditions, the column chromatography packed with cation exchanger 001×4 recovered 74.3%（by mass） of acarbose from Actinoplanes utahensis ZJB-08196 fermentation broth with purity of 80.1%（by mass）, demonstrating great potential in the practical applications in acarbose separation.