乙醇发酵反应器的研究进展

主要介绍了气升式反应器、固定化细胞反应器及膜生物反应器在乙醇发酵生产酒精的应用,讨论了各反应器的优缺点,探讨了其工业化应用的可能性,最后分析了各反应器设计的发展方向。     

气升式反应器在发酵工业中的应用研究进展

气升式反应器是一种用于气液两相或气液固三相过程的接触式反应装置,简要综述了气升式反应器在发酵工业中的应用研究进展,按照集成强化的思路开发的气升式膜生物反应器被重点介绍。     

环流反应器中固定化酵母乙醇连续发酵研究

制备了一种重化固定化酵母颗粒，可有效防止发酵过程中固定化颗粒上浮，用于气升式内环流反应器，可与器内流体形成良好循环。同时在气升式内环流反应器内对固定化酵母乙醇连续发酵过程进行了研究，得到发酵最优控制条件。通过与其它发酵器对比发现，内环流反应器用于固定化酵母乙醇发酵过程，可大大提高乙醇产率。     

环流反应器中固定化酵母之醇连续发酵研究

制备了一种重化固定化酵母颗粒，可有效防止发酵过程中固定化颗粒上浮，用于气升式内环流反应器，可与器内流体形成良好循环，同时在气升式内流反应器内对固定化酵母乙醇连续发酵过程进行了研究，得到发酵最优控制条件，通过与其它发酵器对比发现，内环以应器用于固定化酵母之醇发酵过程，可大大提高乙醇产品。     

气升式内环流反应器在红霉素发酵中应用初探

针对需要流加补料的发酵过程 ,设计出分段导流筒气升式内环流反应器。对在该反应器内进行的红霉素发酵过程进行了实验研究 ,从不同角度考察了该反应器用于红霉素发酵生产过程的可能性。     

搅拌气升式生物反应器的研究进展

搅拌气升式反应器作为一种新型高效的生物反应器,因为其独特的优势而越来越受到重视,具有良好的研究和应用前景.概述了搅拌气升式反应器的国内外研究进展,着重评述了搅拌气升式反应器相比于传统机械搅拌式反应器和气升式反应器的所体现出的优点,详细介绍和分析了该新型反应器的基本结构、流体力学性质及相关的重要表征参数,并对其在生物发酵和化工行业中的应用和发展进行了回顾和展望.     

提高发酵过程乙醇分离效率的新型反应器

设计了一种新型的带侧臂循环的气升式反应器,该反应器可以有效地把真空闪蒸发酵和汽提发酵2项技术结合起来。实验结果表明,与单独的汽提和闪蒸过程相比,利用此反应器进行同步汽提闪蒸操作,大大提高了乙醇的移出效率,从而进一步提高了发酵强度。     

分段式内循环气升反应器的实验研究

８００Ｌ分段式内循环气升反应器冷模实验结果表明：该型式的反应器具有良好的混合与传质性能。应用于Ｌ－苹果酸发酵，菌体收率、发酵周期等指标均优于同等规模的机械搅拌罐。     

苏云金杆菌在环隙气升式内环流反应器中深层发酵特性研究

在建立的 4.7L 环隙气升式内环流反应器中研究了 Bt菌的深层发酵特性 ,通过对生长曲线、溶氧(DO)曲线、p H曲线、总糖曲线、还原糖曲线和氨基氮曲线的分析发现 ,在整个发酵过程中碳源和氮源的供给是充足的 ,但溶氧供应不足 ,是 Bt发酵的限制性因素。文章还考察了同一亚种不同菌株及不同亚种对该系统的适应性 ,并与机械搅拌罐发酵进行了对比。实验表明 ,环隙气升式内环流反应器体系优于机械搅拌罐 ,适合 Bt菌发酵     

气升式振荡环流反应器的数值模拟和结构优化

气升式振荡环流反应器（ARLR）作为一种新型的气升式环流反应器,能够有效地提高反应器的气含率和传质系数,并已得到生物发酵实验的验证。本文通过CFD的手段研究了反应器内的流动和传质状况,并利用CFD模拟和响应面分析相结合的方法,优化了反应器的结构参数,如高径比（H/D）、升液区降液区面积之比、导流筒高度等。经过实验测量,优化后的气升式振荡环流反应器与传统的气升式环流反应器相比,气含率提高了32%以上,传质系数提高了11%以上。结果表明,气升式振荡环流反应器作为生化反应器有着非常广阔的应用空间。     

Hydrodynamics and mass transfer study of aliphatic alcohols in airlift reactors

Gas holdup and gas–liquid mass transfer coefficient were considered in an external airlift reactor. Air was sparged through some aliphatic alcohols (methanol, ethanol, n-propanol, and n-butanol) with different concentrations (0–1%, v/v). It was observed that gas holdup and mass transfer coefficient increased with increasing the number of carbons in alcohols. Furthermore, an increment in alcohols concentration increased gas holdup and mass transfer coefficient. The same behavior was observed in external and internal loop airlift reactors although gas holdup and mass transfer coefficient values were less than those of internal airlift reactor. According to the experiments, two correlations for gas holdup and mass transfer were developed.     

气升式发酵罐生产核酸酶P_1发酵过程的动力学

利用15L外循环气升式反应器,初步研究了桔青霉分批式液体深层发酵生产核酸酶P1的发酵动力学过程。Logistic模型可以较好地反映菌体的生长动力学规律,Luedeking-Piret则比较好地描述了发酵过程中的核酸酶P1的活力与菌体生长的关系,并利用此模型可以判断桔青霉发酵生产核酸酶P1的过程中,核酸酶P1的产出与菌体的生长是属于部分耦联的,其发酵过程属于部分耦联型发酵。     

生物肥料生产的工业性试验

介绍５０Ｌ气升式发酵罐用于生物肥料发酵生产的工业性试验。采用菌体光密度、活菌数等指标对细菌的生长情况进行了测定,并用溶氧电极法对该设备的传质性能进行测定。证明用５０Ｌ气升式发酵罐发酵生产生物肥工业化是可行的。     

78.5升气升式环流反应器内构件优化

研究了78.5L气升式环流反应器内部结构对流动性能的影响规律, 并给出最佳区间来为工业装置提供理论指导。利用Fluent软件建立数学模型与实验装置作对比, 模拟了不同气液分离区高度与外筒高度比、导流筒长度与外筒长度比和筒内外直径比对流动行为的影响规律。结果表明:数学模型和实验结果误差较小, 可以用来预测气升式环流反应器流动行为。气液分离区高度与外筒高度比值过大会导致环流阻力增大, 从而不利于流动, 比值为0.34~0.36时流动性能最佳;导流筒长度与外筒长度的比值增大可增加气含率和环流液速, 但是比值过大会引起气泡的聚合, 从而影响流动性能, 当比值为0.60~0.62时流动性能最佳;在一定范围内增加内外筒直径比会改善流动效果, 但环隙面积过小会增加环形阻力, 内外筒直径比为0.73~0.77时流动效果比较理想。     

Alcoholic Fermentation with Self‐Flocculating Yeast in a Tower Upflow Reactor

Ethanol production using self‐flocculating yeast in a batch tower upflow reactor system operating with a recirculation loop was examined. Ethanol productivity, yield, and residual sucrose concentration were evaluated experimentally according to a central composite design with initial cell and sucrose concentrations and recirculation flow rate as independent variables. Yeast cell concentration strongly influenced the reactor performance. Alcoholic fermentation was conducted using this strain and reactor configuration which allowed for high productivity and high sucrose conversion. The ethanol yield was comparable with industrial yields. A kinetic study of the fermentation process under optimized conditions was performed using the experimental data and considering inhibition by sucrose and ethanol.     

Mass transfer studies in pneumatic reactors

Local mass transfer studies have been carried out in an external loop airlift reactor and indicated the existence of significant non-uniformities in aeration capacity in the various sections of the reactor. The traditional assumption of a single well mixed unit with a single k_L a value for external loop airlift reactors was found to be poor and cannot represent adequately the reactor as a whole. The liquid head in the gas/liquid separator was found to have a significant negative negative effect on the local mass transfer coefficient k_L a. Visualization of flow patterns showed the existence of strong vortices in the riser and downcomer which contributed to a reduction in local aeration capacity. Mass transfer experiments in an aerated tank showed that the aeration capacity can be reduced by half in viscous media but improved significantly in the presence of salts.     

Influences of top clearance and liquid throughput on the performances of an external loop airlift slurry reactor integrated mixing and separation

A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry reactor due to its prominent advantages such as achieving continuous separation of clear liquid from slurry and cyclic utilization of solid particles without any extra energy, energy-saving, and intrinsic safety design. The principal operating parameters, including gas separator volume, handling capacity, and superficial gas velocity, are systematically investigated here to promote the capabilities of mixing, mass transfer, and yield in the pilot external loop airlift slurry reactor. The influences of top clearance and throughput of the clear liquid on flow regime and gas holdup in the riser, liquid circulating velocity, and volumetric mass transfer coefficient with a typical high solid holdup and free of particles are examined experimentally. It was found that increasing the gas separator volume could promote the liquid circulating velocity by about 14.0% at most. Increasing the handling capacity of the clear liquid from 0.9 m~3·h~(-1) to 3.0 m~3·h~(-1) not only could increase the output without any adverse consequences, but also could enhance the liquid circulating velocity as much as 97.3%. Typical operating conditions investigated here can provide some necessary data and guidelines for this new external loop airlift slurry reactor to upgrade its performances.     

环流反应器的流动、混合与传递特性

由于环流反应器内存在定向循环,与鼓泡塔反应器相比,其混合性能大幅提升,已广泛应用于许多工业过程,如发酵、反应器结晶等工业过程,近年来成为国内外学者研究的热点。针对环流反应器内操作条件下的流动形态、流体力学（包括相含率分布、循环液速、混合时间以及离集指数等）及传质/传热特性,总结了其最新研究进展,分析了相含率尤其是固含率变化对反应器中关键参数如循环液速和化学反应速率的影响,展望了从机理上研究相互耦合的多相流动、传质/传热和化学反应规律,为进一步推动其工业应用提供参考。