黄原胶发酵工艺条件研究

黄原胶是一种具有广泛用途的微生物多糖产品。研究了培养基组成,培养温度、pH值、接种量及种龄对黄原胶发酵的影响,实验确定了黄原胶的优化培养基组成及培养条件。     

钻井液黄原胶胶液的流变特性研究

以钻井液黄原胶水溶胶液为研究对象，研究了浓度、pH值、温度、剪切速率等因素对低浓度黄原胶水溶胶液流变性的影响，以及黄原胶水溶胶液体系的流变模型。研究表明，在一定剪切速率下，黄原胶水溶胶液浓度越大，黏度越高，非牛顿性越强；温度升高会使体系黏度降低，当温度恢复到初始温度时，黏度恢复到初始黏度的70%～80%；pH值在6～7时，黏度最大；剪切速率为1～100 s^-1时，黏度急剧下降，剪切速率为100～500 s^-1时，黏度下降缓慢；体系流变模型符合Herschel Bulkley方程；体系剪切稀释性明显，触变性较小。在石油天然气钻井工程中，低浓度（0.1%～0.7%）的XC水溶胶液就能满足钻井、完井液增黏、降滤失、改善流型等方面的需要。     

黄原胶抗温稳定性的研究

石油工业中使用的黄原胶(XG)在高温下易发生降解,粘度和切力下降,本文概述了抗温添加剂对黄原胶胶液耐温性能的影响。     

黄原胶溶液及其冻胶的流变特性研究

为拓宽黄原胶(XG)的应用范围,采用一种有机锆交联剂ZW35对黄原胶溶液进行交联,形成黄原胶冻胶。对黄原胶溶液及其冻胶的交联比、剪切变稀性、粘弹性、触变性以及耐温耐剪切性能进行了研究。结果表明,0.2%XG溶液的表观黏度为17.5mPa·s,随着交联剂用量的增加,黄原胶冻胶的表观黏度先增加后降低,在交联剂用量为0.4%时,表观黏度达到较大值200.4mPa·s。黄原胶冻胶的弹性模量G′、黏性模量G″和触变环面积均比黄原胶溶液有显著的提高,表明黄原胶冻胶的网络结构强度得到增强。0.2%XG溶液在30℃的表观黏度为17.5mPa·s,而黄原胶冻胶(0.2%XG+0.4%ZW35)在80℃、170s~(-1)下剪切90min后的保留黏度仍有82.6mPa·s,耐温耐剪切性得到提高。黄原胶溶液及其形成的黄原胶冻胶均呈现出剪切变稀特性,其流动曲线均可采用非线性共转Jeffreys本构方程进行表征,各体系的模拟值与实验值吻合良好。     

黄原胶降解菌的降黏作用研究

从土壤和水中分离筛选出具有较强降解能力的黄原胶降解菌,研究了黄原胶降解菌降黏作用的规律和降黏过程中pH值的变化和菌数的变化,确定了黄原胶溶液降黏的适宜条件接种量为5%,初始pH值为7,矿化度为5×103 mg/L,温度为30～40℃,摇床转速为120 r/min.研究表明,溶液的降黏效果与溶液的初始黏度有关.通过对黄原胶降解菌的降黏作用研究,掌握了黄原胶溶液黏度下降的规律,这对于如何使含黄原胶的钻井液、压裂液等工作液在现场施工时避免失效有重要意义.     

黄原胶抗温稳定性的研究

石油工业中使用的黄原胶在高温下易发生降解，粘度和切力下降，本文概述了抗温添加剂对黄原胶胶液耐温性能的影响。     

黄原胶调剖技术的研究与应用

黄原胶调剖剂具有增粘性、抗盐敏性、抗剪切性等优良特性,适合在高矿化度地层中进行大剂量深部调剖。本文介绍了黄原胶的研制、室内岩心模似试验、技术特点、矿场试验及效果.结果证明,黄原胶的应用可以改善整个井组注采动态,提高注入水的利用率和油藏的注水采收率。     

三相强制环流反应器局部传质行为的研究

在00 mm×1 700 mm的实验装置内,采用新型的氧气气提-空气解吸法,考察了环流反应器局部流动区域和整体的体积传质系数.研究结果表明,环流反应器整体的体积传质系数随内环表观气速和外循环液速的增加而增加,随固含量的增加略有降低;在各流动区域内,外循环液流影响区的体积传质系数最大,外环环隙区的体积传质系数最小,环流反应器整体的体积传质系数与气液分离区体积传质系数接近.适当扩大内、外环截面积比有利于提高环流反应器的传质性能.     

提高黄原胶浓度测试精度的方法研究

运用苯酚-浓硫酸法测试现场产出液中黄原胶浓度时，存在很多干扰因素，致使测试结果偏差大，其中主要的影响因素是样品处理、加样速度、反应时间。通过对这些因素的分析研究，确定了合理的测试控制条件，结果表明：现场样品用三氯甲烷处理效果要好于苯处理；加浓硫酸速度为10s，反应时间为15～25s时，反应和显色充分，测试精度高、测试结果重现性好。     

填料定子对分层填料错流超重力装置强化气膜控制传质过程的研究

以化学吸收体系CO_2-NaOH测定分层填料错流旋转填料床中不同超重力因子β、空床气速u、喷淋密度q等条件下的有效传质比表面积a_e,采用气膜控制体系—NaOH溶液吸收气体中的SO_2测定气相体积传质系数k_ya_e,从而得到气相传质系数k_y。研究了β、u、q对k_ya_e、k_y、a_e的影响规律,对比了有无填料定子时分层填料错流旋转填料床的传质性能,从而验证了填料定子对分层填料错流超重力装置气相传质的强化作用。研究结果表明,k_ya_e和a_e均随着β、u、q增大而增大;k_y随着u增大而增大,但是随着β、q增大,先增大后减小;有填料定子时,k_y增加显著,是无填料定子时的1.3~2倍,表明填料定子能够进一步有效地强化气膜控制传质过程,提高气相传质系数。     

A Mass Transfer Study of Methane and Ethane During Hydrate Formation

In the present work, mass transfer coefficients of main natural-gas components, methane and ethane, are determined during the hydrate formation. A complete explanation is given to show that the liquid mass transfer resistance at the gas-liquid interface predominates in the process. A fast and precise model has been also proposed to predict the rate of gas consumption. The advantage of the developed model is that there is no need to use fugacity and flash calculations in water-hydrate phase.     

Hydrodynamics and Mass Transfer in a Modified Three-phase Airlift Loop Reactor

A modified internal-loop airlift reactor (MIALR) with a continuous slurry phase was studied to investigate the local hydrodynamic characteristics, including gas holdup, bubble size, bubble rise velocity and local mass transfer properties. Based on the analysis of geometrical construction and fluid properties of gas and slurry, MIALR was divided into six flow regions. In these flow regions, the local hydrodynamic characteristics were investigated over a wide range of operating variables. Furthermore, a new method was developed to measure the dissolved oxygen concentration. The volumetric mass-transfer coefficient in six flow regions was also calculated for comparison.     

Mass Transfer Characteristics of H_2 and CO in Mimicked F-T Slurry Bubble Column Reactor

The equilibrium solubilities,volumetric gas-liquid mass transfer coefficients kLa of H_2 and CO were measured as functions of temperature(298―513 K),pressure(1―3 MPa),superficial gas velocity(0.5―3 cm/s) and solid volume fraction(5%―25%) in liquid paraffin/iron-based catalyst slurry bubble column reactor.The volumetric mass transfer coefficients kLa were obtained by measuring the dissolution rate of H_2 and CO.The influences of the operation conditions,such as pressure,temperature,superficial gas velocity and catalyst concentration on kLa,were investigated.Two empirical correlations were proposed to predict kLa values of H_2 and CO in liquid paraffin/solid particles slurry bubble column reactor.The results showed that the equilibrium solubilities of H-2 and CO increased with an increasing temperature and pressure,and the solubility of CO was greater than that for H_2.It was found that the equilibrium solubility can be expressed by Henry's law.The volumetric mass transfer coefficients of H_2 and CO were of the same order of magnitude,and increased with the increase of pressure,temperature and superficial gas velocity.The presence of solid particles decreased kLa values of both H_2 and CO.     

极限扩散电流技术测定管内强化传质系数

采用极限扩散电流技术(LDCT)测定管内液体传质系数(k),通过使用静态混合器、筛板和不锈钢θ环填料与筛板耦合体等强化元件,考察了不同强化手段对管内k的影响,研究了气液多相体系的传质过程。实验结果表明,LDCT能较好地测定单相和多相体系的k。在液体流量为1.00m3/h的条件下,空直管中的k为2.38×10-2m/s;使用筛板、静态混合器和填料与筛板耦合体时,k分别为3.64×10-2,3.96×10-2,5.90×10-2m/s。由实验测定的k结合传递类比定律可得到液体传热系数。     

气体搅拌萃取塔传质系数的研究

为研究萃取塔内气体搅拌对传质系数的影响,在萃取塔中用水萃取煤油中的苯甲酸的实验考察了液相流速、气体流速和内构件对传质系数的影响。实验结果表明,传质系数随水、油、气的表观流速的增加而增加,分散相表观流速对传质系数的影响大于连续相的表观流速;萃取塔内构件的不同组合方式对传质系数有一定的影响,其中以SL-SP-SL型组合方式的传质效果最好。     

乙烯在液体苯中的溶解度和体积传质系数的测定

在温度314～473K、压力0.130～3.641MPa、搅拌转速150r/min的条件下,在机械搅拌高压釜中,测定了乙烯在液体苯中的溶解度(c*)和体积传质系数(kLa)。实验结果表明,c*随压力的升高而增大,随温度的升高而减小;kLa随温度和压力的升高而增大;温度高于343K时,c*与压力的关系基本呈线性。建立了c*和kLa与温度和压力的经验关联式,采用麦夸特方法回归得到经验关联式的参数;c*的计算值与实验值的相对误差基本小于10%,kLa的计算值与实验值的相对误差基本小于3%。     

甲醇、水蒸气在液体石蜡中的溶解度和体积传质系数的研究

在机械搅拌高压釜中,测定了433.15~533.15K、0.110~0.960MPa之间甲醇和水蒸气在液体石蜡中的溶解度和体积传质系数。实验结果表明,甲醇和水蒸气的溶解度均随压力的升高而增加,随温度的升高而减小,溶解度与压力的关系曲线为通过原点的直线,符合亨利定律。回归了甲醇和水蒸气的亨利系数与温度的关联式,甲醇和水蒸气的溶解度的计算值与实验值的相对误差小于6.00%。甲醇和水蒸气的体积传质系数随温度和压力的升高而增加。     

耐蚀瓷质波纹填料流体力学与传质性能的研究

耐蚀瓷质波纹填料具有很强的抗高温硫化氢和环烷酸腐蚀的性能,在腐蚀严重的高温传质环境中应用,可以替代不锈钢填料,延长检修周期。实验研究了耐蚀瓷质波纹填料的流体力学和传质性能,回归了经验关联式,可供工程设计参考。在试验范围内实测的25℃时的传质单元高度等于90 -410mm,最大气速操作范围可达F=3.5m/s,与一般常用填料相比,瓷质波纹填料具有较好的流体力学和传质性能,良好的再分配性能,较低的液相传质单元高度。同时指出了瓷质板波纹填料结构尺寸的优化方向。     

Mass Transfer of CO2 Into Water and Surfactant Solutions

The mass transfer of CO₂ into water and aqueous solutions of sodium dodecyl sulphate (SDS) is experimentally studied using a pressure, volume, temperature (PVT) cell at different initial pressures and a constant temperature (T = 25°C). It is observed that the transfer rate is initially much larger than expected from a diffusion process alone. The model equations describing the experiments are based on Fick's Law and Henry's Law. The experiments are interpreted in terms of two effective diffusion coefficients—one for the early-stages of the experiments and the other one for the later stages. The results show that at the early stages, the effective diffusion coefficients are one order of magnitude larger than the molecular diffusivity of CO₂ in water. Nevertheless, in the later stages the extracted diffusion coefficients are close to literature values. It is asserted that at the early stages, density-driven natural convection enhances the mass transfer. A similar mass transfer enhancement was observed for the mass transfer between a gaseous CO₂ rich phase with an oil (n-decane) phase. It is also found that at the experimental conditions studied addition of pure SDS does not have a significant effect on the mass transfer rate of CO₂ in water.