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。     

对1,3-丙二醇发酵液用金属纳滤膜过滤的研究

考察了l,3-丙二醇发酵液金属膜过滤在不同条件下的通量、收率及蛋白含量的变化。在此基础上,初步探讨了膜的过滤机理,确定了金属膜过滤的工艺参数。结果表明,100 nm膜适用于过滤1,3-丙二醇发酵液,按料液体积20%从开始过滤2h后就持续加入去离子水,在4.2/3.6 MPa压力下,60℃,pH值为7的条件下,5h内完成过滤,并且收率达到87%以上,运行时间短而且对后续工艺压力最小。     

疏水硅沸石吸附1,3-丙二醇的研究

FX-Ⅱ型沸石对1,3-丙二醇单组分溶液中1,3-丙二醇的静态饱和吸附量达到121.1 mg/g;在1,3-丙二醇和甘油的混合溶液中,研究了甘油质量浓度、吸附时间、吸附温度和盐离子质量浓度对1,3-丙二醇吸附的影响,实验结果表明高的甘油质量浓度对1,3-丙二醇吸附影响较大,吸附时间为14 h时1,3-丙二醇吸附达到平衡,低温及低盐离子质量浓度有利于1,3-丙二醇吸附;对实际发酵液的静态吸附结果表明,增大发酵液pH值可以减少有机酸对1,3-丙二醇的竞争吸附;pH值为7时,1,3-丙二醇吸附量达到102.5 mg/g;筛选了与吸附剂相关的脱附剂,用体积分数50%的乙醇解吸,解吸率达到86%。在此基础上初步研究了沸石对发酵液中1,3-丙二醇的动态吸附,1,3-丙二醇解吸率为82%。与传统的蒸馏法相比,沸石吸附法工艺简单,具有较大的研究和应用前景。     

在线反冲在1,3-丙二醇发酵液膜过滤中的应用

膜过滤是生物法1,3-丙二醇(PDO)分离提取工艺中的关键工序,膜污染是影响膜过滤通量和清洗水用量的核心因素,在膜过滤过程中增加在线反冲,可以有效降低膜污染对过滤通量的影响,减缓膜过滤通量下降的速度,将膜过滤设备清洗周期由1d/次延长至5d/次。     

发酵液中1,3-丙二醇的分离工艺的研究进展

1,3-丙二醇是一种重要的化工原料,通过发酵转化甘油生产1,3-丙二醇是以绿色化学为特征的,但由于发酵液成分复杂,且1,3-丙二醇具有很强的极性,导致分离困难,使1,3-丙二醇的下游分离成为发酵法产业化的关键。本文将从发酵液的预处理、粗分离和精制这3个方面对1,3-丙二醇的分离工艺进行综述。     

专利文献

国内专利文献一种从发酵液中分离纯化1,3-丙二醇的方法本发明涉及一种从发酵液中分离纯化1,3-丙二醇的方法,该方法包括以下步骤:含1,3-丙二醇     

发酵液中低浓度l,3-丙二醇浓缩提纯工艺研究进展

介绍了各种浓缩提纯发酵液中低浓度 l,3-丙二醇的工艺,较详细地比较了蒸发精馏工艺、溶剂萃取法、阳离子树脂吸附法、分子筛吸附法以及反应萃取法的工艺流程与分离效果。提出在国内现有情况下,反应萃取工艺是提纯1,3-丙二醇比较适合的方法。     

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...     

发酵法生产1,3-丙二醇工艺优化及评价

1,3-丙二醇主要用途是和对苯二甲酸(PTA)一起合成新型聚酯对苯二甲酸丙二醇酯(PTT),但是1,3-丙二醇的高成本制约了PTT的发展,低成本1,3-丙二醇合成工艺的研究开发工作成为国内外的热点课题之一。本文是在以甘油为底物发酵生产1,3-丙二醇的工艺路线上进行优化,使用实验室2.5 L发酵罐进行试验,研究甘油发酵过程中搅拌速度、氮气通气率、发酵时间对最终发酵液中1,3-丙二醇含量的影响,在发酵温度37℃、pH值7.0、通气率0.2 vvm、发酵时间40 h、搅拌转速400 r/min的条件下,发酵液中1,3-丙二醇的含量高达80 g/L以上,产品纯度达到99.5%以上。     

1,3 丙二醇发酵液电渗析法脱盐

对1,3 丙二醇发酵液电渗析法脱盐的工艺进行了初步研究,主要就发酵液电导率与温度的关系、膜对电压、发酵液过滤与絮凝预处理、发酵液初始pH对脱盐效果的影响及膜的重复使用性进行了研究. 结果表明,发酵液电导率与温度呈线性关系,电导率温度校正系数为0.0217;膜对电压1.3~1.5 V为较适操作电压;脱盐过程耗时越长,1,3 丙二醇的损失越大;发酵液通过壳聚糖絮凝预处理后可以明显改善脱盐效果;发酵液pH对脱盐有明显影响,pH越低脱盐速率越快,膜连续重复使用15批次后性能下降明显,需要用NaOH和NaCl溶液进行清洗.     

The possibility of the desalination of actual 1,3-propanediol fermentation broth by electrodialysis

Electrodialysis (ED) was employed to remove the organic and inorganic salts from actual 1,3-propanediol (PDO) fermentation broth. These salts cause many problems during the purification of PDO if not removed. Suitable operation parameters such as applied potential and the flow rate of streams were selected to ensure a stable and durative desalination process for PDO fermentation broth. Under these conditions, the membrane fouling can be alleviated effectively by changing pole and cleaning membranes so that further industrial production is possible. The experiment results show that about 90% of organic acid salts in PDO broth are removed by the ED process. In addition, a simulated diffusion PDO experiment proved that the diffusion of PDO results in its loss from fermentation broth and the loss ratio is less than 6% under the chosen operating conditions.     

Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation and dilution crystallization

The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol. In this paper, the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investigated. The broth was first filtered by ultrafiltration, and 99% of cells, 89.4% of proteins and 69% of nucleic acids were removed. The obtained broth was further condensed by vacuum distillation, and then alcohol was added. The macromolecular impurities, such as nucleic acids, polysaccharides and proteins, were precipitated, and inorganic and organic salts were crystallized. The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to be 2:1. As a result, proteins, nucleic acids and electric conductivity decreased by 97.4%, 89.7% and 95.8%, respectively, compared with the fermentative broth. The influences of pH and water content in condensed broth on alcohol precipitation and dilution crystallization were also investigated. The experimental results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth. Translated from The Chinese Journal of Process Engineering, 2006, 6(3): 454–457 [译自: 过程工程学报]     

发酵液中1,3-丙二醇的分离方法研究进展

介绍了1,3-丙二醇的两大生产方法:化学法和生物法。重点介绍了生物发酵法,对发酵液中1,3-丙二醇的分离方法(包括蒸发精馏法、阳离子树脂吸附法、分子筛法、超滤和醇沉、萃取分离等)进行了分析,并对其前景进行了展望。     

离子交换在1,3-丙二醇发酵液脱盐中的应用

针对1,3-丙二醇发酵液分离提取过程中的脱盐难点问题,采用离子交换方法对1,3-丙二醇发酵液的脱盐进行了研究。选用D001强酸性阳离子交换树脂及D354弱碱性阴离子交换树脂,进行了静态、动态及连续交换工艺的实验,并对阳、阴离子交换树脂交换顺序进行了考察。结果表明,离子交换方法用于发酵液的脱盐工艺具有良好的效果,阳、阴两种离子交换树脂的交换、再生性能稳定,交换后的料液完全能够满足后续工艺的要求,为生物法1,3-丙二醇发酵液分离提取提供了一个新的工艺手段。     

Effective and simple recovery of 1,3-propanediol from a fermented medium by liquid–liquid extraction system with ethanol and K_3PO_4

1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L~(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.     

反应萃取法分离1,3-丙二醇中缩醛反应的研究

研究了反应萃取法分离提取发酵液中1,3-丙二醇的重要反应-缩醛反应.考察了反应温度,反应时间.乙醛的添加量,以及催化剂对1,3-丙二醇转化率的影响.结果表明,通过乙醛与1,3丙二醇可以发生可逆缩醛反应生成2-甲基-1,3-二恶烷,得到最佳的反应条件为反应时间1h,反应温度为55℃,乙醛与1,3-丙二醇的物质的量比为6:...     

酸处理改善1,3-丙二醇发酵液过滤效果的研究

克雷伯氏肺炎杆菌TUAC01产1,3-丙二醇生发酵液不能通过絮凝或过滤的方法得到澄清。研究采取酸处理的方法进行澄清,结果表明,酸处理后发酵液可经过滤进行澄清,同时发酵液还能自然沉降澄清。酸处理最适操作条件为:温度80—100℃、pH值为3.0、时间30—60 min。发酵液酸处理后滤纸过滤清液OD650降为0.01,降低了99.9%,黏度下降明显,其粘滞系数降为0.001 5 Pa.s;蛋白质质量浓度降低至0.05 mg/mL,降低了98%—99%。该酸处理方法经车间大规模实践,效果理想,可作为带荚膜菌种发酵所得发酵液的澄清处理方法。     

物性估算在ASPEN PLUS软件中的应用

利用Aspen Plus软件提供的物性估算功能，计算发酵液中低浓度1,3-丙二醇分离的中间产物2-甲基-1，3-二噁烷（2MD）的物性，从而模拟分离过程，确定工艺条件，得到理想的产物结果。