膜技术在万古霉素生产工艺中的应用

通过建立连续过滤数学模型VD=VO1n CBO/CE,定采用连续洗滤的操作方法,膜过滤最佳洗涤水量为起始发酵液体积的2.0-2.5倍;通过研究发酵液中固含量对过滤速率的影响,得出发酵液浓缩至原体积的70%-80%,固含量为30%-35%时开始加水洗滤,可以获得最佳操作时间.采用不锈钢膜过滤万古霉素发酵液较板框过滤收率提高15%.     

不同透过率下膜洗滤过程的参数关系

针对不同透过率P情况下的洗滤过程,建立了一个用于描述过程收率和目的物浓度变化的数学模型.围绕间歇洗滤过程(IFD)和连续洗滤过程(CFD),分别计算了保留液中的目的物浓度C和透过液中的目的物收率ξ,并引入了稀释比b、前浓缩比a、后浓缩比c和体积增长率K等参数.在连续和间歇操作的全混釜假设基础上,分析了不同透过率(0≤P≤1)时c-a, c-K, ξ-a 和K-a等参数间的变化关系.该模型能够为洗滤过程的优化及目的物浓度与收率的估算与控制提供理论依据.     

头孢菌素C过滤过程中总过滤时间的优化与控制

针对头孢菌素C(CPC)发酵液在工业生产中难过滤的问题,在收率衡算模型基础上,结合浓差极化机理引入时间参数,针对连续洗滤过程(CFD)建立考虑时间的膜分离过程估算式,并以最短膜处理时间t_min为目标进行了优化求解。结果表明,在优化的膜处理过程中,CPC收率从85%增长到95%所用时间占总处理时间的30%～40%;而前浓缩比a值在0.5～0.8范围内时,总膜过滤时间差别不大。在一个相对较宽的可操作范围内,适当调整前浓缩比或/和调整目标收率,可以对生产过程的时效性及CPC收率、滤液/保留液体积等生产指标进行优化与控制。     

膜过滤优化大观霉素提炼工艺

利用膜技术优化大观霉素提炼生产工艺,对金属膜过滤和板框分离进行了对比实验,对滤液的收率和质量进行了考察。结果表明,采用膜过滤,原液质量得到提高,可以省去原液复滤,过滤收率提高8%。     

头孢菌素C发酵液陶瓷膜过滤过程中的影响因素研究

为考察陶瓷膜在头孢菌素C发酵液膜过滤过程中的应用性能进行了实验研究,对影响较为显著的因素进行了分析讨论.给出了渗透通量在膜过滤过程中变化的完整曲线,分别分析说明了平均压差、顶洗、膜面流速等操作条件与渗透通量的关系.分析了不同温度下的CPC收率理论值与实测值的关系,并在此基础上考察了温度对渗透通量的影响.根据浓差极化理论,给出了渗透通量与浓缩比的关系式,并对其进行了实验验证.结果表明,较高的温度(15℃)有利于头孢菌素C发酵液膜过滤过程的进行,渗透通量与浓缩比a的对数呈线性关系,通量主要受到保留液主体固形物浓度CB的影响.此外,实验还发现,通过"清水置换-碱洗-清水置换-酸洗-清水置换"联合清洗方法,可使膜通量恢复到新膜通量的90%以上.     

膜振动过滤通量的实验研究

针对膜过滤过程中,因污染造成膜渗透通量下降等问题,提出了全新的将膜过滤与机械振动结合的膜振动过滤方式;用粘土悬浮液做正交实验,对比了在相同操作条件下,膜振动过滤及无振动膜过滤的膜过滤通量随时间的变化情况,表明膜振动过滤通量比无振动膜过滤通量大,并验证膜振动过滤方式的可行性;通过对影响因素的分析明确了振动频率适中、振动振幅较大时,膜过滤通量越大的原因。     

磷酸过滤系统技改点滴

1　大修后过滤系统生产状况我厂磷酸料浆的过滤采用翻盘式过滤机 ,其型号 PF 55,有效过滤面积为 46m2 ,采用 3次并流洗涤。一次洗涤水采用过滤机冲盘后的稠浆及硫酸系统净化排污水 ;二、三次洗涤用水原采用浓缩系统石墨换热器的部分冷凝水 ,2 0 0 0年大修时改为用浓缩中间冷凝器的部分冷却回水。过滤机过滤面的滤洗区间分配见图 1。磷酸系统在大修后 ,生产指标、产量、消耗的控制水平均有提高 ,过滤机盘面上磷石膏的吸干效果良好。随着过滤机过滤量的不断增加 ,滤液区的吸干效果虽略有下降 ,但料浆的滤液吸干状况仍然能保持良好状况 ;而洗…     

自动逆洗式压滤机在阿城糖厂通过鉴定

轻工业部甜菜糖业科学研究所设计,哈尔滨内燃机厂试制的TN_1—150/1200型自动逆洗压滤机最近在阿城糖厂通过鉴定。多年来,我国制糖工业废水污染江河,过滤下来的滤泥因湿法排放,对江河等造成的环境污染十分严重。为了改变制糖设备的落后状况,轻工业部甜菜糖业科学研究所和哈尔滨内燃机厂联合研制了自动逆洗式压滤机。经过阿城糖厂生产运行考核和专家鉴定:该机在国内甜菜制糖行业首次采用了滤泥逆洗,气吹脱水和液压拉板结构。同老产品比,由于采用逆洗结     

膜洗滤过程模型的在线优化策略及其应用

基于恒收率的时间优化模型,利用膜洗滤过程中在线反馈的数据,创新性地提出"走一步看一步"的优化策略,拓展得到了洗滤过程的即时优化模型。结果表明,采用该模型能够解决膜洗滤过程顶洗起点的在线判断问题,避免了为获取相应参数值进行的离线测试实验,能够为工业生产膜洗滤过程的在线优化与控制提供关键理论支撑。     

无机膜提取栀子黄色素的工艺研究

初步研究了无机膜提取栀子黄色素的工艺过程，采用无机陶瓷微滤膜对浸提液进行精密过滤，再用反渗透膜浓缩过滤液，确定了无机陶瓷膜微滤的操作条件。研究表明，膜法提取天然色素是一极有前途的新技术     

Diafiltration and water recovery of Reactive Brilliant Blue KN-R solution by two-stage membrane separation process

The conventional process of Reactive Brilliant Blue KN-R production is low purity, labor intensive, inconsistent in the production quality and also causes pollution. The improved process based on membrane technology still generates large volume of effluent though with low pollutants. In this paper, a two-stage membrane separation process is introduced to resolve these shortcomings, in which the first stage is used for diafiltration and concentration of dye solution, and the second is to recover the dye and salt water from the produced permeate. Comparing results from one ultrafiltration (UF) membrane (GH) and four nanofiltration (NF) membranes (AFC40, DL, CA865 and MPT-31), UF membrane ES404 showed the same dye rejection, higher permeate flux and lower sodium sulfate rejection. In the diafiltration and concentration stage, pre-concentration and constant volume diafiltration had the best salt permeability as compared to constant volume diafiltration and post-concentration in addition to variable volume diafiltration. In the dye and salt water recovery, membrane ES404 had the same dye rejection, but higher permeate flux and lower sodium sulfate rejection as compared to membrane GH. The proposed two-stage membrane separation process offers the advantages of high-purity, less labor intensive, consistent in production quality and less pollution.     

Laboratory Studies on Membrane Deoiling of Lecithin

Deoiling of lecithin using a nonporous membrane was examined in a favorable solvent (hexane) medium with soy and rice bran lecithins. During the membrane process, the acetone insoluble (AI) content of soy lecithin increased from 63.2 to 81.0% in a single step batch operation. The membrane exhibited an excellent selectivity since phospholipid (PL) reverse micelles formed in the system were rejected almost completely due to low solubility probably aided synergistically by size exclusion. Diafiltration achieved greater oil removal from lecithin as reflected in terms of higher AI and PL contents in the deoiled lecithin. In discontinuous diafiltration, the PL content increased from 33.3 to 85.5% in rice bran lecithin (150% dilution to feed) and 56.6 to 85.7% in soy lecithin (200% dilution), respectively. The simulated continuous diafiltration run showed slightly greater PL content in soy lecithin (91.3%) compared to discontinuous diafiltration (89.7%) besides offering higher productivity. The membrane showed a color reduction of ~60% in soy lecithin but there was no improvement in rice bran lecithin due to the retention of degradation products. The proposed integrated membrane process with nonporous (deoiling) and nanofiltration (solvent recovery) membranes could be an attractive preposition besides being an acetone free process.     

Process Duration and Water Consumption in a Variable Volume Diafiltration for Partial Demineralization and Concentration of Acid Whey

Process duration and fresh water consumption were determined (experimentally and statistically) for variable volume diafiltration (VVD) of cottage cheese through a flat sheet membrane (0.046 m²). The VVD process was performed at two volume decreasing ratios (α = 0.75 and α = 0.5). The VVD-0.75 process lasts much longer than the VVD-0.5 process if the same concentration degree is required. The VVD-0.5 process lasts longer than the VVD-0.75 process if it is aimed to achieve the same purification degree. At low purification degrees, both processes require similar quantities of fresh water, but better demineralization is possible after higher dilution, which is typical of the VVD-0.75 process. The mathematical model applied in estimating the duration of the process proved very accurate, which cannot be said about the fresh water consumption model.     

New liquid membrane technology for simultaneous extraction and stripping of copper(II) from wastewater

In this paper, a new liquid membrane technique, hollow fiber renewal liquid membrane (HFRLM), is presented, which is based on the surface renewal theory, and integrates the advantages of fiber membrane extraction, liquid film permeation and other liquid membrane processes. The results from the system of CuSO₄+D2EHPA in kerosene+HCl show that the HFRLM process is very stable. The liquid membrane is renewed constantly during the process, the direct contact of organic droplets and aqueous phase provides large mass transfer area. These effects can significantly reduce the mass transfer resistance in the lumen side. Then the mixture of feed phase and organic phase flowing through the lumen side gives a higher mass transfer rate than that of stripping phase and organic phase, because the aqueous layer diffusion of feed phase is the rate-controlling step. The overall mass transfer coefficient increases with increasing flow rates and D2EHPA concentration in the organic phase, and with decreasing initial copper concentration in the feed phase. The overall mass transfer coefficient also increases with increasing pH in the feed phase, and reaches a maximum value at pH of 4.44, then decreases. Also, there is a favorable w/o volume ratio of 20:1 to 30:1 for this process. Compared with hollow fiber supported liquid membrane and hollow fiber membrane extraction processes, HFRLM process has a high mass transfer rate. Mathematical model for the HFRLM process based on the surface renewal theory is developed. The calculated results are in good agreement with experimental results under the conditions studied.     

Eco-friendly separation and purification of soybean oligosaccharides via nanofiltration technology

Two NF membranes were applied to separate and purify the soybean oligosaccharide (SBOS) from SBOS broth. NF-3A membrane was more appropriate than NF-2A membrane because of its superior separation performance. Constant volume diafiltration mode was used to enhance the purity of SBOS. A difference in the rejection and the yield between the SBOS and other sugars ensured the purity enhancement. Under optimal operation conditions, the yield and the purity of the SBOS could reach up to 83.2% and 77.9%, respectively. Deteriorated membrane performance resulting from the membrane fouling could be recovered via specific chemical cleaning process. NF technology with high-efficiency and eco-friendly properties demonstrates the great potential for SBOS purification in practical application.     

膜技术分离纯化低聚半乳糖

用截留相对分子质量(以下简称分子量)1000的GE超滤膜对低聚半乳糖溶液进行分离纯化。结果表明,溶液的透过通量及ΔR(低聚糖与葡萄糖和乳糖之间的截留率差)随着温度的升高而增加;各种糖组分的表观截留率和分离选择性随透过通量的增加而增加,ΔR随透过通量的增加而降低,三者最终都趋于平缓,并且其变化趋势不受原料浓度的影响。当透过通量为20～40L/(m2.h)时,可达到膜的最佳分离效果。在最佳条件下对低聚糖原料进行连续渗滤,当累积透过体积为原料体积的3倍时,低聚糖的质量分数由36.4%提高到57.8%(1.59倍),收率为70.2%。     

生物甲烷膜分离提纯系统的设计与优化

以厌氧发酵生物气为原料生产压缩天然气是大规模利用生物质资源的重要途径。首先,在过程模拟软件UniSim Design中基于有限元方法建立了中空纤维膜的离散数值计算模型,适合于模拟渗透切割比非常高的生物甲烷膜分离过程。以单级聚酰亚胺膜分离系统为例研究了关键操作条件--膜的进料压力对处理能力、甲烷收率及压缩天然气生产单耗的影响。目前的评估体系下,提高进料压力有利于提高处理能力和甲烷回收率,而压缩天然气生产单耗在2.70 MPa时最低,为0.46 kW·h·m^-3压缩天然气。通过分析渗透气的甲烷浓度变化趋势,开发了一级二段气体膜分离系统,兼具流程简单、设备投资低、甲烷收率高、产值高的优点。以处理1000 m³·h^-1生物气为例,甲烷收率达95.0%,压缩天然气产量500 m³·h^-1。对应地,装置总投资为3.8×10⁶ CNY,年运行费用及设备折旧为1.5×10⁶ CNY,年经济效益（毛利）超过2.50×10⁶ CNY。     

A Compatible Membrane Process for Separation and Concentration of Pediocin PA-1 from Fermentation Broth

This work describes an effective combined ultrafiltration (UF)-nanofiltration (NF) membrane process for the separation and concentration of pediocin PA-1 from fermentation broth. Three polysulfone (PS) membranes with MWCOs of 5, 10, and 30 kDa were tested for ultrafiltration effectiveness. The 10 kDa membrane was selected because it displayed high permeability, good pediocin PA-1 recovery and reduced fouling. When the volume concentration factor (VCF) of UF reached 2.5, continuous diafiltration (DF) was carried out. The optimal diafiltration factor (DFF) was 1. The permeate obtained from UF was then concentrated by NF. When the VCF of NF reached 4.5, pediocin PA-1 recovery loss was only 10.5%. This two-stage membrane process improved the loading solutions by 4.5-fold, allowing up to 71.6% recovery of pediocin PA-1. After the membrane process, the NF retentate could be concentrated and subjected to preparative chromatography to obtain purified pediocin PA-1, or it could be dried to obtain a rich pediocin PA-1 preservative.     

Development of a Simulation Model Predicting Performance of Reverse Osmosis Batch Systems

Abstract

A model describing concentration profiles and performance relationships for the operation of a reverse osmosis system with a spiral-wound membrane module has been developed. The model is an enhancement of a previously proposed treatment and encompasses a discussion of mass transfer relationships and overall and component mass balances on a system operating in a closed-loop concentrating or recycling pattern. The presentation of mass transfer within a spiral wound membrane module is treated with an overall module approach with solution-diffusion mass transfer parameters empirically determined. A comparison with various methods to represent membrane feed side concentration and their effect on membrane performance is presented. A perspective is made on representing concentration polarization in this type of membrane configuration. The simulation model is verified with experimental data on simple aqueous salt systems. The simulations are excellent in predicting feed concentration profiles. Permeate flux deviates moderately and the permeate concentration only deviates significantly at high recoveries. A more exact depiction of the feed-side concentration improves the correlation to experimental data, but a more simplistic treatment may suffice under certain process conditions. The concentration polarization coefficient utilized was found to depend more heavily on the increase in flux due to a decrease in feed-side concentration rather than in the direct increase in feed concentration.