气升式反应器的优化

从强化传质与节能方面概述了近年来国内外在气升式反应器结构参数优化、操作参数的优化及溶液性质等方面的研究工作 ,提出了今后的研究方向     

盐藻在气升式光生物反应器中的光自养培养

在气升式光生物反应器中进行了盐藻培养特性的研究，确定了盐藻在2.5 L气升式光生物反应器中培养的适宜条件为：温度30℃，光强1.6 mW/cm2，盐浓度16%，通气量20 ml/min. 扩大到20 L反应器培养盐藻生长良好. 采用气升式光反应器培养盐藻生长快，周期短，4~7 d后即可进入稳定期；最终细胞密度大，最大为1.6?106 cells/ml；藻液中胡萝卜素含量高，最高含量32 mg/L.实验表明气升式光生物反应器适合于盐藻的培养.     

气升式反应器及其在生物技术中的应用

气升式反应器由于其优越的流体力学性能和广阔的应用前景,在传统化学工程和生物化工领域都是当前研究热点之一。本文简要介绍了气升式反应器的基本原理和特性,证介已有的主要研究结果、尚待解决的问题和趋势,以及气升式反应器在生物技术领域最重要的应用之一,即作为微藻养殖或某些植物细胞培养的光化生物反应器。     

赤芝在气升式反应器中的深层培养实验

用1.5 L外循环气升式反应器(OALR)对赤芝菌进行深层培养实验.结果表明其最适通风量为:0～24 h,0.4 vvm;24～72 h,0.6 vvm 72～96 h,0.8 wm 96～120 h,1.0 vvm;120～144 h,1.0 vvm.培养时间较摇瓶培养大约少12 h,菌丝干重可达17.4 g·L-1.     

多室气升式环流反应器的气含率研究

在四流道的多室气升式环流反应器中 ,常温常压下 ,以空气作为气相 ,以水、0 .5 %、1%、5 %NaCl及 0 .5 %、1%、5 %Na2 SO4 作为电解质 ,考察上升区气含率与操作气速及电解质密度的变化规律。并用回归分析的方法 ,建立了上升区气含率与电解质密度的半经验关联式 ,用该式得到的上升区气含率的计算值和实验值的平均相对偏差为 2 .5 8%。     

气升式内环流反应器中的液相轴向返混

在５５Ｌ工作体积的气升式内环流反应器中，用羧甲基纤维素溶液模拟生物发酵液的粘性非牛顿流体行为，研究了表观气速及流体物性等参数对气升式内环流反应器中液相在上升段及下降段区域中轴向返混系数的影响，并与其他作用的实验结果进行了比较和分析。     

气升式反应器中的西洋参细胞培养

在不同的气升式反应器中对西洋参细胞进行了大规模培养。西洋参细胞得率为11g～14gdwt/e,细胞中总皂甙含量为4.45％。讨论了西洋参细胞在新型的气升式反应器内培养过程中的流变学特性、传质特性以及流场剪切应力变化规律。文章还讨论了培养基成分对大规模培养结果的影响。     

气升式环流反应器研究与应用进展

综述了气升式反应器性能的主要影响因素研究及其最新的应用，提出今后研究工作的主攻方向，并介绍了最近超声气升式反应器及光气升式反应器的研究结果。     

缩放型导流筒气升式内环流生物反应器流体力学与传质特性

从气相含率、液体循环速度和体积氧传质系数方面研究缩放型导流筒气升式内环流生物反应器内的流体力学与传质特性。实验结果表明,与传统圆柱形导流筒相比较,缩放型导流筒气相含率和体积氧传质系数分别提高８％和１０％以上。气相含率和体积氧传质系数随固含率的增加而提高,液体循环速度随固含率的增加而减小;同一内管反应器随介质粘度的增加,体积氧传质系数减小。此外还在Ｈｉｇｂｉｅ穿透理论和Ｋｏｌｏｍｏｇｏｒｏｆｆ各向同     

Kinetic and technical studies on large-scale culture of Rhodiola sachalinensis compact callus aggregates with air-lift reactors

Compact callus aggregates (CCA) of Rhodiola sachalinensis, spherical, smooth-surfaced clumps of 2–8 mm in diameter displaying some level of tissue differentiation, were successfully cultured in 10 dm³ and 100 dm³ air-lift reactors. High salidroside yields of 60·0 mg dm⁻³ were obtained, which were 10-fold the dispersed cell cultures. The salidroside accumulation was found to be growth-associated due to the differentiated structure of CCA. No ‘foaming’ was observed since the broth remained almost clear throughout the culture cycle. The size of CCA conformed to normal distribution with average diameters varying from 3·1 mm to 3·6 mm during the culture. The depositing velocity of CCA in culture broth was small enough to be readily retained in suspension, therefore avoiding the clogging of the reactors. The significant increase in solid hold-up of the culture system was suggested to contribute to the variation of k_La during the culture. © 1998 SCI     

Volumetric mass transfer coefficients in an internal loop airlift reactor with low‐density particles

The influence of organic additives (propanol, benzoic acid, isoamyl alcohol and carboxymethylcellulose) on the volumetric mass transfer coefficient, k_La, in an internal loop airlift reactor with low‐density particles (nylon‐6 and polystyrene) was investigated. The k_La values increased with increase in superficial gas velocity, U_sg, and decreased with increase in solid loading. A draft tube to reactor diameter ratio, D_R/D, of 0.4 gave maximum k_La values. The addition of benzoic acid and propanol increased the k_La values owing to their coalescence inhibiting characteristics. The addition of isoamyl alcohol decreased k_La, owing to the formation of rigid bubbles and recirculation of small bubbles having a low oxygen content. The k_La values decreased with increase in the concentration of the non‐Newtonian fluid carboxymethylcellulose (CMC). The proposed correlations predicted the experimental data well. Copyright © 2006 Society of Chemical Industry     

Effects of light quality on the accumulation of oil in a mixed culture of Chlorella sp. and Saccharomyces cerevisiae

BACKGROUND: Chlorella strains rather than terrestrial oil crops having higher oil content and shorter generation time have been considered as promising candidates for alternative biodiesel. Since the influence of light quality on oil formation of microalgae in either monoculture or mixed culture has been shown to be either inconsistent or ambiguous, a light‐emitting diode (LED) photo‐bioreactor with different light sources and intensities was used in this study to investigate a cost‐effective lipid production process. RESULTS: The oil accumulation in a mixed culture of Chlorella sp. and Saccharomyces cerevisiae was higher than that in the monoculture under the different light sources used. Results of the influence of light quality on the mixed culture indicated that the optimal light wavelength and intensity for biomass formation was red LED light at 1000 lux, whereas the optimum for oil formation was blue LED light at 1000 lux. A novel two‐stage LED photo‐bioreactor was thus proposed and the highest P_max and productivity in this study were obtained as 261 mg L^?1 and 8.16 mg L^?1 h^?1, respectively. CONCLUSION: A novel two‐stage LED photo‐bioreactor using a mixed culture to optimize microalgal oil production was proposed and successfully demonstrated in this study. Copyright © 2011 Society of Chemical Industry     

大豆蛋白胶竹地板制作工艺的优化

以胶液固含量、热固化时间和热固化温度作为Box-Behnken设计的变量,用响应面法优化大豆蛋白胶竹地板制作工艺条件。结果表明,大豆蛋白胶竹地板制作的优化工艺条件为：胶液固含量13．1％,热固化时间为7．8h,热固化温度为131℃。在此条件卞,大豆蛋白胶竹地板的2h吸水厚度膨胀率为3．0％,静曲强度为107．3MPa。     

Critical gas velocity in a three‐phase internal loop airlift reactor with low‐density particles

In the present investigation the effects of the addition of organic additives (propanol, benzoic acid, iso‐amyl alcohol and carboxymethyl cellulose) on the critical gas velocity, (U_sg)_c, in an internal airlift loop reactor with low‐density particles (Nylon‐6 and polystyrene) were reported. Whereas the (U_sg)_c was reduced by adding the above additives, it increased with solids loading and density of the particles. The draft tube‐to‐reactor diameter ratio (D_E/D) in the range of 0.5–0.6 gave minimum (U_sg)_c values. The proposed dimensionless correlation predicted the experimental data well. Copyright © 2004 Society of Chemical Industry     

响应面优化连翘槲皮素的离子沉淀法分离工艺

利用响应面法(RSM)优化离子沉淀法分离连翘槲皮素的工艺条件。在单因素实验基础上,选取醋酸锌和碳酸钠用量以及沉淀温度为影响因子,以槲皮素提取率为响应值,应用Box-behnken中心组合试验设计建立数学模型,并进行响应面分析。结果表明,碳酸钠和醋酸锌用量分别为0.65 g和1.41 g,50℃下沉淀40 min,连翘槲皮素的提取率为9.76%。     

Measurement of mass transfer coefficient in an airlift reactor with internal loop using coalescent and non‐coalescent liquid media

In this work the sulfite oxidation (SOM), dynamic pressure‐step (DPM) and gassing‐out (GOM) methods were compared for volumetric mass transfer coefficient measurement in an airlift reactor with internal loop. As a liquid phase both, non‐coalescent and coalescent media were used. Among the methods discussed here, the mass transfer coefficient (k_La) values obtained by the DPM appear as the most reliable as they were found to be independent of oxygen concentration in the inlet gas, which confirmed the physical correctness of this method. The difference between data measured using air and oxygen was not higher than 10%, which was comparable to the scatter of experimental data. It has been found that the sulfite oxidation method yielded k_La values only a little higher than those obtained by the DPM and the difference did not exceed 10%. Up to an inlet gas velocity (U_GC) of ?0.03 m s^?1 the GOM using oxygen as a gas medium gave k_La values in fact identical with those obtained by the DPM. At higher flows of the inlet gas, the GOM yielded k_La values as much as 15% lower. The enhancement in oxygen mass transfer rate determined in non‐coalescent media was estimated to be up to +15%, when compared with a coalescent batch. The experimental dependence of k_La vs the overall gas hold‐up was described by an empirical correlation. 1 Copyright © 2004 Society of Chemical Industry     

Lipase-catalyzed acidolysis of menhaden oil with CLA: Optimization by factorial design

Menhaden oil was interesterified with CLA in a packed-bed reactor containing an immobilized lipase from Mucor miehei (L9) as the biocatalyst. Process optimization was studied using a sequence of 2²×3 factorial designs involving the mole ratio of reactants, the reaction temperature, and the space-time of the reactor as experimental parameters. Three different responses—percentage of incorporation of CLA, level of n−3 residues remaining, and conversion of CLA—were considered as objective functions. The parameters studied showed opposite effects for incorporation of CLA and the retention level of n−3 residues. A desirability function was constructed to describe a desirable balance of the conflicting response variables. Optimal conditions correspond to a molar ratio of CLA to fish oil of 0.8 to 1, a temperature of 60°C, and a space-time of 5 h.     

Modification of menhaden oil by enzymatic acidolysis to produce structured lipids: Optimization by response surface design in a packed bed reactor

Structured lipids from menhaden oil were produced by enzymatic acidolysis in a packed bed reactor. Response surface methodology was applied to optimize the reaction. Lipozyme IM from Rhizomucor miehei lipase was the biocatalyst, and caprylic acid was the acyl donor. Parameters such as residence time, substrate molar ratio, and reaction temperature were included for the optimization. High incorporation of acyl donor and retention of high levels of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in the original menhaden oil were obtained. Good quadratic models were obtained for the incorporation of caprylic acid and for the content of EPA plus DHA retained, by multiple regression with backward elimination. The coefficients of determination (R ²) for the two models were 0.91 and 0.87, respectively. The regression probabilities (P) were below 0.003 for both models. Also, the predicted values from the two models had linear relationships with the observed responses. All parameters studied had positive effects on the incorporation of caprylic acid, but only residence time and substrate molar ratio had negative effects on the content of EPA plus DHA retained. The optimal conditions generated from models were temperature =65°C, substrate molar ratio=4–5, and residence time=180–220 min. Incorporated caprylic acid did not replace DHA, but the content of EPA decreased somewhat with an increase in caprylic acid incorporation.