The esterification of abietic acid with methanol was selected as a probe reaction.The thermodynamics of reaction was analyzed by group-contribution method.The reaction enthalpy, entropy, Gibbs free energy and equilibrium constant were calculated in the temperature range of 473—653 K and the pressure range of 0.1—20 MPa.The effects of temperature and pressure on the reaction were also discussed.The calculation indicates that the reaction enthalpy is -46.31—-10.10 kJ·mol^-1 and free energy is -53.26—-25.49 kJ·mol^-1, showing an exothermic and spontaneous reaction.The equilibrium constant is 136.32—748.89 at standard pressure and (1.1×10⁴)—(3.2×10⁴) in the range of 5—20 MPa.The experimental results show the conversion of abietic acid of 85.94%—94.89% and 73.80%—81.20% without catalyst in super/subcritical methanol, which is in agreement with thermodynamic calculation by the group-contribution method.

As the ratio of height-to-width of planar nozzle is less than 1, the planar opposed jets are regarded as two-dimensional impinging streams.A numerical study of gas-solids two-phase planar opposed jets was conducted by using two-fluid model (TFM).It was concluded that periodical oscillation was the main flow regime for large nozzle separation with ratio of particle-to-gas mass flow m≤8.2, particle diameter 60 μm≤d_p≤175 μm and ratio of nozzle separation (L) to nozzle height (H) 12—20.This oscillation was resulted from pressure release on the impinging surface and the inertia of incessant axial jets, which was based on the instantaneous and mean distributions of static pressure and velocity at the jet axis.The effects of different simulation conditions on oscillation period were discussed.The period would be increased by enlarging nozzle separation or increasing particle diameters, while the period would be decreased by increasing jet Reynolds number or ratio of particle-to-gas mass flow.

A new style asymmetrical outward convex corrugated tube (ACT) was studied with numerical simulation based on the three-dimensional Reynolds stress transport (RST) model.The ACT is compared with the traditional symmetrical corrugated tube (SCT) to investigate their difference in flow and heat transfer characteristics.The calculation results from existing direct numerical simulation (DNS) are compared to those from RST model under the same condition to check the reliability of RST model for the corrugation tube.The calculation results for velocity and pressure coefficient at different profiles from RST and DNS are in good agreement.The fluid flow and heat transfer mechanism are investigated in the outward convex corrugated tube.Compared to SCT, ACT presents up to 32.3% higher overall heat transfer.

The hydraulic characteristics of gas-liquid two-phase flow in distillation process are important factor for separation efficiency.With water and air as working medium, a CFD model based on Navier-Stokes equations, RGN k-ε turbulent model and two-phase model of volume of fluid is employed to analyze the hydraulic characteristics of liquid film flow on the structured packing surface at normal temperature and pressure.The model and simulation method are validated by experimental results in literature.The spatial and temporal evolution of liquid film, velocity fields and influences of liquid mass flow rate are simulated and analyzed.Liquid will accumulate below the peaks of corrugation, forming a drop.At valleys, the liquid drop spreads and the film thickness increases, and as it reaches the upper slope of the next corrugation, the drop appears again.The instantaneous liquid film thickness oscillates with time.Along the packing surface the volume-averaged film thickness decreases first, and then keeps stable.Liquid accumulation and dropping have an important effect on the form of dry batches.The velocity profile within the bulk of film varies significantly at different positions of corrugation, and along the packing surface, the average velocity of liquid film increases first, then decreases or keeps stable.The liquid film will accelerate at the convex of corrugation and decelerate at the concave.With the increment of liquid mass flow rate, the average film thickness and velocity increase.

This paper presents a temperature difference driven self-feedback heat convective system with an additional thermal power conversion subsystem based on a traditional heat conduction system.This self-feedback system converts a portion of thermal energy into mechanical energy to make fluid flow in the system.Numerical simulation of the flow and heat transfer performance of the system shows that the heat transfer coefficient of the self-feedback system is 10 times as much as that of heat conduction system and 8.4 times that of natural convection system.Thus the self-feedback system can enhance heat transfer without external mechanical energy input.

Three kinds of solid desiccant dehumidifier are compared, which are desiccant wheel dehumidifier, heat pump driven inner-cooling desiccant dehumidifier, and heat pump driven multi-stage desiccant dehumidifier.Mathematical models of desiccant wheel and multi-stage desiccant dehumidifiers are set up and validated by experimental results.The dehumidification performance of the three dehumidifiers shows that the inner cooling desiccant method gives the best heat and mass transfer process, while the desiccant wheel dehumidifier is the worst.Regeneration temperature of desiccant wheel is usually above 80℃, while that of inner cooling desiccant bed and multi-stage desiccant bed are both below 50℃.To obtain the same humidity ratio of the supplied air, air states of desiccant wheel is near isenthalpic line with high supplied air temperature, while the COP of inner cooling desiccant bed and multi-stage desiccant bed is above 4 with low supplied air temperature.

The turbulent flow and heat transfer characteristics of rectangular channel with groove bottom surface are investigated by use of large eddy simulation.To validate the accuracy and reliability of the simulation method, the simulation results for plate channel are compared with the direct numerical simulation results of reference. The heat transfer surface Nusselt number is compared to that calculated by Dittus-Boelter equation.The differences are less than 5%.From the simulation results for rectangular channel with groove bottom surface, it is found that the groove structure of the channel bottom surface changes the flow structure near the groove surface.Groove heights and lengths influence the flow resistance and heat transfer effect.Compared with the plate rectangular channel with specific geometric parameters, the time-averaged Nusselt number of groove surface is increased nearly by 50.5%, and the time-averaged friction drag coefficient decreases by 35.17%, and the comprehensive coefficient is increased by 73.89%.The flow structure in the channel shows that there is a region near the groove surface, in which the flow is perpendicular to the wall.The fluid flows forward and backward in the vertical flow region.Since the friction drag coefficient does not increase significantly and the Nusselt number is obviously enhanced, the comprehensive flow characteristic is the best.

The liquid film thickness inside the scrubbing-cooling pipe in the process of coal gasification with multi-burners was investigated by parallel conductivity probe.The results showed that the liquid film was not uniform, especially in the entrance region of 200—400 mm, with the difference up to 3 mm.The unsteady fluctuation of liquid film was related to the film thickness.For a thicker liquid film, the fluctuation range was larger, but the change of fluctuation lagged.It was also found that the film thickness increased with increasing liquid flow rate.On the basis of the experimental data, an empirical equation was proposed for the mean film thickness in the fully developed zone.The slot width of quench ring had a significant influence on the thickness of liquid film.In this study, the best slot width was 3 mm, and larger slot width would make the film thickness more non-uniform.In addition, the film thickness became thinner under the effect of gas phase.In some way, the film thickness was more uniform because the drag force increased with increasing superficial gas velocity.

Dense-phase pneumatic conveying of pulverized coal was investigated in an commercial-scale horizontal pipe (50 mm I.D.) by using compressed air as carrier gas.Minimum pressure drop velocity was obtained from the Zenz-type phase diagram, which was influenced by solids mass flux significantly.Based on electrical capacitance tomography (ECT) system, the flow in the experimental range was classified into four regimes:stratified flow, dune flow, moving bed flow and slug flow.Using probability density function (PDF) and power spectral density (PSD) function to analyze the pressure signals of typical cases, pressure fluctuations were well correlated with flow patterns.The relative stability characteristics of different operating conditions showed that the critical velocity between stable and unstable conveying was smaller than minimum pressure drop velocity due to the transitions of flow patterns.

Geometrical parameters have great influences on the formation of gas bubbles or liquid droplets in the microchannel.The effects of gas inlet angle and cross-section aspect ratio on gas-liquid flow in the microchannel were investigated numerically by employing the volume of fluid (VOF) method.Generally, Taylor flow pattern could be observed in microchannels with various gas inlet angles and cross-section aspect ratios.A uniform distribution of bubble length could also be obtained under most circumstances.It was found that a 60° gas inlet angle helped to generate shortest bubble when cross-section aspect ratio was in the range of 0.5 to 2, while bubble length reached a minimal value when gas inlet angle was 45° and cross-section aspect ratio was 4 or 8.The dimensionless bubble length increased with increasing cross-section aspect ratio, and poor uniformity of bubble length distribution was observed when cross-section aspect ratio became larger.More specifically, a non-uniform bubble length distribution was observed when cross-section aspect ratio reached the value of 8.

MIP (maximizing iso-paraffins process) process utilizes the technique of linking two reaction zones in series, and hence effectively improves gasoline quality.Cold simulation of MIP reactors can reveal the flow structures in the second reaction zone and also the effects of geometrical structures, but cannot provide the changes in hydrodynamics resulting from catalytic cracking reactions.To capture these changes, this work aimed at carrying out three-dimensional simulation of the MIP reactor by considering the reactions.The simulation was based on the two-fluid model and 12-lump kinetic model.The inter-phase momentum transfer and heat transfer models took into account the effects of multi-scale flow structures, and were compared with the traditional models based on homogeneous state.The simulation found that the multi-scale models could reasonably predict the flow structures and solids volume fraction in the second reaction zone as well as the temperature profiles, compared to the traditional model.For predicting product yields, both models showed similar results.They had good predictions in slurry and diesel, but fail to predict LPG and dry gas.The above finding implied that the effects of multi-scale structures should not only be considered in the momentum transfer and heat transfer models, but also be taken into account in the lumped kinetic model.

Organic Rankine cycle (ORC) has excellent low temperature performance, which is very suitable for combined heat and power (CHP) system.An experimental study is carried out to test the performance of an ORC-CHP system, with the temperature of heat source at 100℃ and that of turbine waste heat in the range of 21.6—48.7℃.The overall energy efficiency of ORC-CHP 96%—97%, power efficiency 4.4%—5.1%, and hot water heat gain efficiency 91%—92% are obtained.Overall exergy efficiency is 50.0%—75.3%, with power output exergy efficiency 5.1%—4.4% and hot water gain exergy efficiency 25.7%—56.2%.ORC-CHP system can utilize waste heat efficiently, so that both energy and exergy usage are greatly improved.

The study on evaporation processes of brine solution at reducing pressure mainly concentrates on falling film evaporation in the sea-water desalination and flat surface evaporation in industrial processes.In this study, the phase change of droplets was investigated.Various factors influencing the temperature of multicomponent droplet were examined experimentally, with brine solutions of 15% and 6% as working medium, initial environmental pressure of 94.5—97 kPa and final pressure of 50—3000 Pa, initial droplet temperature of 7—30℃, and initial diameter of 1—3 mm.The experimental data show that with the change of central temperature of salt water droplets at reducing pressure, the process can be divided to that with salting and without salting.As the water evaporates, reaching droplet density of 22.4% and temperatures low enough, the salt precipitated, otherwise the salting would not appear.At different concentrations, final pressures, initial temperatures and sizes, the relationship between the temperature change in the phase change of droplet and the environmental pressure was obtained.

Flow maldistribution is the major factor that influences the heat exchange efficiency of plate fin heat exchangers (PFHEs).By the traditional gas-liquid distribution method with mixing prior to distribution, the gas-liquid separation will occur due to the direction change in the distributing fins, which may lead to flow maldistribution.To solve this problem, a new gas-liquid distributor based on the concept with distribution prior to mixing is proposed.The gas and liquid flow into their respective channels and mix uniformly in the distributor, and then the gas/liquid mixture flows into the heat exchanger to exchange heat with materials with high temperatures.The calculation results show that the non-uniformity of flow distribution rises increases with flow rate, and the flow rate of liquid phase has greater influence on the flow distribution than that of gas phase.In addition, the standard deviation of the distributor is one magnitude lower than that of the header.The distributor can obviously improve the gas-liquid flow uniformity in PFHEs and increase their heat exchange efficiency.

In this paper, a new envelope of buildings, the breathing-type glazing curtain wall with energy storage function, is put forward based on the concept of low-energy consumption buildings, and the analysis on the bottleneck related to prevent heat loss in enclosed structures of building and the weakness concerned with thermal performance of building envelopes.The structure is studied and designed. Considering the energy conservation of traditional glazing curtain wall with thermal channel, a new thermal calculation model for breathing-type glazing curtain with energy storage function is established.Combined with the calculation results of engineering examples, the characteristic parameters of the new envelop is analyzed in detail.The results show that heat transfer coefficients of the new envelop in winter and summer are within 1 W·m^-2·K^-1 and superior to those of traditional glazing curtain wall with thermal channel.The time of heat lag in summer and winter is triple and twice that of traditional curtain wall.In the region with heavy solar radiation intensity and small wind speed, the heat insulation and time of heat lag in summer are worse, but it is helpful to heat preservation and time of heat lag in winter.The new envelop has the characteristics of simple structure and easy operation, which may be helpful to the development of glazing curtain wall in the future.

Pulsating heat pipe (PHP) is a high efficiency heat transfer device and has unique advantages in cooling electronic apparatus with high heat flux in tiny space.With simple structure, it operates with complex internal rule.The variation of the thermal resistance changing with heating power and filling ratio and the characteristics in nature is analyzed.The dryout characteristic of the PHP is discussed.From experiments on the PHP with four working fluids including water, methanol, ethanol and acetone under different operation conditions, four conclusions can be derived. (1) There is a limitation of thermal resistance for the PHP phase-change convection heat transfer mechanism.And the limitation has little to do with the filling ratio. (2) For different working fluids and filling ratios without dryout phenomenon, the thermal resistances are almost the same under high heating power. (3) The dryout phenomenon only emerges in some of the individual pipes in the evaporation section periodically.When the heat load is further intensified, dryout will occur in more pipes in the evaporation section and last for a longer time, but the temperature will not increase rapidly so that the PHP will not be burned out. (4) Before valid oscillation starts, the experimental data show that the decrease of thermal resistance may slow down or change to increase first and then decrease, with an inflection point, which is different from the almost linear decrease described in literature.This work provides a reference for establishing theoretical model and understanding the heat-transfer of pulsating heat pipe.

A two-stage segregation auto-cascade refrigeration system was studied.The vapor-liquid equilibrium characteristics of a ternary mixed-refrigerant, composition change rules and operating characteristics of the ternary system were investigated.Refprop 8.0, general software for mixed-refrigerant property analysis with abroad applications, was used.The composition proportion of mixed-refrigerant was discussed according to the cooling capacity balance characteristics of evaporative condense and a reasonable proportion was obtained.The separation, mixing and operating characteristics of auto-cascade refrigeration system mixed-refrigerant were analyzed on the basis of spatial changes of five plane pressure-enthalpy diagrams.According to the experimental research, high-low pressure bypass and phase separator outlet vapor bypass of circulatory system could effectively improve the high discharge pressure and discharge temperature in the starting process.The throttle cooling process of each stage was analyzed, and the suction and discharge temperatures and evaporative temperature of compressor were studied.

With air-water as working fluid, the gas-liquid two-phase flow pattern and evolvement characteristics in a microchannel with periodic expansion-constriction cross sections were investigated experimentally by means of IDT high-speed camera mounted together with a Nikon microscope.The observed flow patterns were intermittent flow and separated flow.For intermittent flow, gas scattered in liquid phase or liquid scattered in gas phase, and the two forms appeared in turn.For separated flow, gas flowed mainly along the wall side of gas inlet, and liquid flowed mainly along the liquid side of water inlet.There was an obvious interface between two phases and the interface fluctuated along the flow direction.According to gas phase and liquid phase superficial velocities, flow pattern maps were drawn and correlations for describing flow pattern transition in the newly proposed microchannels were obtained.It was found that for a given liquid phase superficial velocity, the flow pattern transition gas phase superficial velocity for the microchannel with triangular reentrant cavities was slightly smaller than that for the microchannel with fan-shaped reentrant cavities.

Considering expansion and compression ratios, the entrainment ratio was analyzed for ejectors with cylindrical and conical mixing chambers using water, ammonia, R290, R22 and R134a as working fluid separately.The equivalent compression ratio, equivalent parameter line and equivalent parameter region of entrainment ratio were defined.At a constant expansion ratio, the cylindrical mixing chamber can reach a higher entrainment ratio than the conical chamber when the compression ratio is smaller than the equivalent compression ratio of entrainment ratio, and different case will occur when the compression ratio is less than the equivalent one of entrainment ratio.The equivalent parameter line of entrainment ratio shows that the equivalent compression ratio decreases with the increase of expansion ratio.In the equivalent parameter region of entrainment ratio, the two types of ejectors have almost the same efficiency.A cylindrical mixing chamber ejector is prior when compression ratio and expansion ratio locate in the left of the equivalent parameter region of entrainment ratio, while a conical mixing chamber ejector is preferable when they are in the right.The location of equivalent parameter region is determined by the adiabatic exponent.

Considering size distribution of dispersed droplets, the motion of dispersed droplets in W/O emulsion was simulated in a demulsification process under high electrostatic voltage.The results from simulation and experiment showed that under the effect of electrostatic electrical field, the droplet group moved from one electrode to the other electrode, so that the local droplet concentration increased gradually along the motion direction and the concentration reached a maximum value in the vicinity of the other electrode.The droplet concentration in the vicinity of electrode approximately linearly increased with the time of electrostatic action.The rate of increase of droplet concentration in the vicinity of electrode under a higher applied voltage was larger than that under a lower applied voltage in same time interval.To improve demulsification efficiency by increasing voltage was therefore superior to that by extending time.In addition, since the large droplet had a relatively larger velocity, the demulsification efficiency for the emulsion with large dispersed droplets would be higher.

A Taylor-vortex flow reactor was constructed by using a new type of gas distributor consisting of static mixers, nozzles and gas distributor box.Flow and reaction performance of the constructed Taylor-vortex flow reactor was studied experimentally.The results showed that different from conventional stirred tank reactors, fluid flow in Taylor-vortex flow reactor was more close to ideal piston flow.Taylor vortices created local piston flow areas in the reactor and depressed back mixing.Reaction performance of Taylor-vortex flow reactor was also enhanced, and under the same experimental conditions conversion rate of sucrose hydrolysis carried out in the Taylor-vortex flow reactor was 26.7% higher than that in the conventional stirred tank reactor.Within a specific operation range, local piston flow area would expand and reaction conversion rate would increase with increasing agitation speed or air flow rate.A flow model of the Taylor-vortex flow reactor was presented, and reaction kinetic correlations were deduced.

A mathematical model predicting particles flux ratio between internal circulation and external circulation processed in a coupled reactor with gas-solids loop fluidized bed was established.In a wide range of operating conditions, particles circulation flux ratio was predicted, and the particles circulation ratio n_p=20 was determined as a criterion to analyze the particles mixing behavior in internal and external loops.The results showed that the calculated values basically agreed with experimental data, and the average relative error approached 15.35%.Particles circulation ratio increased with increasing superficial gas velocity in the draft tube, however decreased with increasing particles external circulation flux and opening rate of a lotus-shaped distributor, with the change in two stages, first fast and then slow.The transition points were U_g,d=0.50 m·s^-1, G_s,r=110 kg·m^-2·s^-1, and α=10% respectively.Under the operating conditions of riser superficial gas velocity U_g,r=10—21.17 m·s^-1, draft tube superficial gas velocity U_g,d=0.57—1.50 m·s^-1, particles external circulation flux G_s,r ≥110 kg·m^-2·s^-1, and distributor open rate α≥10%, the particles complete mixing status in the riser and the gas-solids loop bed reactor could be avoided.

The accurate measurement of solid-solid reaction kinetics, such as reduction of iron oxide by carbon, is of great significance in scientific research and practical applications.In this paper solid-solid reaction characteristics between iron oxide and graphite was studied using thermogravimeter (TG) measurement for both samples prepared respectively by directly mixing and grinding graphite and Fe₂O₃ as well as by impregnating Fe₂O₃ on the graphite.Their reaction kinetic parameters were calculated using the Flynn-Wall-Ozawa and Coats-Redfern equations.The variation trends of activation energy are related with the aggregation morphology of Fe₂O₃ on the surface of carbon.The reduction kinetics for impregnated sample is of the characteristics of strong endothermic reaction.Combining the results of XRD characterization and online gas determination, in the initial stage of Fe₂O₃ reduction the products are Fe₃O₄ and CO₂, reaction follows second order reaction mechanism and activation energy is about 530 kJ·mol^-1.

N,N,N',N'-tetraglycidyl -1,3 - diamino-propyl-1,1,3,3-tetramethyl disiloxane (TG-siloxane) was synthesized by using phase transfer catalyst and was characterized with FTIR and ¹³C NMR. The kinetics of curing reaction for a system of bisphenol F epoxy resin (BPFER) /TG-siloxane with m-xylylenediamine (mXDA) as curing agent was monitored with differential scanning calorimetry (DSC).The apparent activation energy was obtained by the Starink equation.The kinetic parameters, such as frequency factor and the values of reaction order were obtained based on the Šesták-Berggren model.The kinetic equation suggested that the curing reaction was influenced greatly by heating rate.It was shown that the predicted reaction progress was very close to the experiment.The TG curves indicated that cured BPFER/TG-siloxane/mXDA system had better heat-resistance than that of BPFER/mXDA.

The catalytic performance of some SO₃H-functionalized ionic liquids ([HSO₃-bmim]CF₃SO₃,[HSO₃-bmim]P-TSA,[HSO₃-bmim]HSO₄ and [HSO₃-bmim]H₂PO₄) in the etherification of glycerol with methanol was evaluated,and the results showed that the catalytic performance of the ionic liquids correlated well with their acid strength.[HSO₃-bmim]CF₃SO₃ had the highest acid strength and showed the best catalytic performance.Under the suitable reaction conditions of mass ratio of [HSO₃-bmim]CF₃SO₃ to glycerol 0.5:1, molar ratio of methanol to glycerol 8:1, reaction temperature 190℃ and reaction time 8 h, conversion of glycerol was 84.5%, selectivity to methyl glycerol ethers and total selectivity to both dimethyl glycerol ethers and trimethyl glycerol ethers were 41.4% and 34.1%, respectively.In addition, the reaction mechanism for etherification of glycerol with methanol in the presence of[HSO₃-bmim]CF₃SO₃ was proposed.

The temperature programmed steam gasification and isothermal steam gasification (TPSG and ISG) of Shengli lignite were studied on a fixed-bed micro-reactor equipment.The TPSG results suggested that some inherent minerals effectively improved steam gasification of Shengli lignite.The initial reaction temperature and gas-reaction temperature for steam gasification decreased by about 96℃ and 150℃, respectively, when the mineral elements were retained in the lignite.The minerals in the lignite which were assumed to be catalysts aiding the lignite-steam gasification could be separated with hydrochloric acid.The effect of different acid treatments of the lignite on steam gasification was also studied.The H₂/CO molar ratio in the syngas produced from the steam gasification of raw lignite (SL-raw) and the lignite back- added with HCl eluate (SL-HCl-Re) were as high as 17.3 and 4.3, respectively, but it was only 1.22 for the lignite treated with HCl or HF.It was speculated that the enhanced steam gasification of Shengli lignite could be attributed to the promotion effect of inherent minerals on water-gas shift reaction (WGSR).Finally, the possible in-situ catalytic mechanism of inherent minerals in Shengli lignite for steam gasification reaction was suggested.

Cu-Cr₂O₃ catalysts were prepared by the coprecipitation method.The effect of Cu content on catalytic performance for hydrogenation of methyl difluoroacetate to 2,2-difluoroethanol was investigated.The catalysts were characterized with XRD, H₂-TPR, BET and Raman techniques.The results showed that the reduced Cu-Cr₂O₃ catalysts contained mainly Cu and Cr₂O₃, while catalysts with a high Cu content (e.g.30 Cu-Cr₂O₃ and 50 Cu-Cr₂O₃) contained CuCr₂O₄ and CuCrO₂ oxides.It was also found that with increasing Cu content, conversion of methyl difluoroacetate first increased and then slightly decreased and selectivity to 2,2-difluoroethanol was about 70%.The 30Cu-Cr₂O₃ catalyst exhibited the highest conversion of 97%.In addition, conversion of methyl difluoroacetate increased gradually in bi-component Cu-Cr₂O₃ catalysts with increasing Cu content, which was probably due to the presence of CuCr₂O₄ and CuCrO₂ oxides.

The calculated Sauter average drop size of the dispersed phase is 330 μm in the liquid-liquid static settlement experiment for the polycarbonate mixture.The liquid-liquid separation process is simulated and analyzed using mixture multiphase flow model.Different types of coalescence plates are compared, including parallel plates, corrugated plates and inclined plates.The results show that inclined plates are more suitable to the polycarbonate liquid-liquid separation.For the water-oil volume ratio of 0.6, the optimal parameters for the inclined plates are:inclined angle 20°, board length 0.8 m, and plate spacing 40 mm.The maximal flow rate in the separator is 5.3×10^-3 m·s^-1.According to the calculation results, a polycarbonate liquid-liquid separator is designed and applied in the pilot scale test, which presents a good separation effect.The concentration of water/oil phases is close to the solubility.The maximal material flow rate in the actual liquid-liquid separator is 3.9×10^-3 m·s^-1.The common disc centrifuges can be replaced by the designed static separators, reducing the cost of equipment and operation greatly.

Adsorption equilibrium isotherms of CO₂,CH₄ and N₂ on zeolite 13X-APG were measured by Rubotherm magnetic suspension balance in the pressure range of 0—500 kPa at temperatures of 293,303,333 and 363 K.The multi-site Langmuir model and Sips model were used to fit the experimental data,and the model parameters were obtained by the non-linear regression.Furthermore,the adsorption capacities of CO₂,CH₄ and N₂,as well as the separation factors of CO₂/CH₄,CO₂/N₂ and CH₄/N₂ gas mixtures on zeolite 13X-APG were compared with those on other materials reported in literature,including zeolites,activated carbon,mesoporous silica and metal-organic frameworks.The evaluation is given on the feasibility and efficiency of adsorption using 13X-APG as adsorbent to capture CH₄ from both landfill gases and CO₂ enhanced coal bed gases (CO₂/CH₄),to capture CO₂ from flue gases of coal-fired power plants,cement plants and coking plants (CO₂/N₂),and to concentrate CH₄ from coal mine gases (CH₄/N₂).

Industrial processes are often operating under different modes, while there are nonlinear correlations between data monitored.Aiming at these problems, a fault detection method based on relative isometric mapping (RISOMAP) was proposed.Relative geodesic distance was used to establish distance matrix in the high dimensional space, and multi dimensional scaling (MDS) was used to calculate output in the low dimensional embedded space.Information of sub-manifold and error could be obtained, and then monitoring statistics were built for fault detection.Meanwhile, kernel ridge regression was used to obtain the lower dimensional output of test data.Besides,kernel matrix was updated through integrated similarity.The simulations of visualization case and TE process illustrated that in contrast to fault detection methods based on kernel principal component analysis (KPCA) and ISOMAP, the proposed method could detect process fault more effectively and quickly.It also provided an idea to implement fault detection without prior knowledge in the multimode process.

Because of various uncertainties in a real chemical process, it is necessary to add enough margins on design variables to let the operating point be within the boundaries of process constraints during process design.According to first-order sensitivity analysis of process steady-state optimal design, local margins added on design variables result in that there are boundary distances on process constraints, and the maximum potential economic benefits which can be obtained from operation optimization of manipulated variables are determined by the boundary distances of active constraints.Therefore, the potential economic benefits derived from operation optimization can be used to evaluate the whole margin of the device.The potential economic benefits through operation optimization were used to evaluate the whole margin of FCCU, and a dynamic optimization approach for whole margin division was presented.The whole margin was divided into control margin for ensuring controllability and process margin for realizing economic benefits of the device.Through the analysis of the relationship between local margins of design variables and the whole margin of the device, the bottlenecks of process design could be found.

The forced-circulation evaporator is a multi-input and multi-output process with complex dynamics, such as strong nonlinearity, strong coupling.Therefore, the existing conventional control strategy can not satisfy production demand.The dynamic characteristics of forced-circulation were studied.According to the structure characteristics of the evaporator model, decoupling control was achieved by using the global input and output feedback linearization control technology and zero-dynamic stability of system was proved subsequently.Simulation results showed that the global input and output feedback linearization control technology could not only reduce the effect of nonlinearity on the system, but also eliminate the coupling between density loop and level loop.At the same time, the method could improve production quality and evaporation efficiency simultaneously.

An iterative method for designing hydrogen networks with purification units is presented.First, the purified source flow rate is assumed to be large enough, regarding the purified source as a new source.And then, the initial hydrogen network with purification units is constituted.By using the source matching method, the hydrogen network is designed, the purified source amount F_reg that can be used and the purified source amount F_reg^total from purifying all internal sources that have not been reused are obtained.When F_reg^total<F_reg,F_reg^total is regarded as the initial value of the purified source in the next iteration, and the final design is obtained by only a few iterations.When F_reg^total≥F_reg,F_reg is used as the value of the purified source of the final design, and the internal source with the lowest impurity concentration that has not been reused for purification is selected.In the latter case, the final design is obtained without further iterations.By examining some examples reported in literatures, it is found that the method are simple and effective, moreover, not only the hydrogen consumption target value but also the specific design of hydrogen network can be obtained by using this method.

Mesoporous TiO₂ whiskers (MTiO₂_ws) were chemically modified with 3-aminopropyltriethyloxy silane (APTES).As a result, the point of zero charge (pzc) for the modified material (MTiO₂_ws-APTES) rose from 5.3 to 6.8.Also the specific surface area of MTiO₂_ws-APTES slightly increased, but the pore structure had little change compared to that of MTiO₂_ws.Then, MTiO₂_ws-APTES was used as the support for γ-glutamyltranspeptidase (GGT) immobilization.MTiO₂_ws-APTES showed better loading capacity than MTiO₂_ws.While the enzyme concentration was less than 150 U·g^-1, the recovery of activity was above 99% and the highest specific activity for immobilized GGT (MTiO₂_ws-APTES-GGT) was 184.0 U·g^-1.Although both optimal temperature and thermal stability of MTiO₂_ ws-APTES-GGT slightly decreased compared with the native enzyme, pH stability was greatly improved.The affinity constant (K_m) of MTiO₂_ws-APTES-GGT toward γ-glutamyl-p-nitroaniline (GpNA) was also determined to be 0.889 mmol·L^-1, which was higher than that of the native enzyme, but less than that of MTiO₂_ws-GGT.After storage at 4℃ for 60 days and reused for 21 batches, MTiO₂_ws-APTES-GGT maintained 80.07% of its initial activity.

Glycerol dehydrogenase (GDH) is one of the key enzymes for production of dihydroxyacetone (DHA) and 1,3-propanediol (PDO) by the enzymatic method.Based on scale-up of laboratory experiment, the Superpro Designer^® emluator was used to design and simulate the whole process of industrial technology for GDH production, by coupling with costing and economic evaluation of flowsheeting.Simulation results indicated that the process design was reasonable with main process data in agreement with experimental results.The economic analysis showed that raw materials and supplies shared the larger proportion of operating cost reaching 16% and 60% respectively.The expected return on investment (ROI) was to reach 50.48% of approximately 75.36 million CNY project total investments of a 17.9 t·a^-1 plant, as the after-tax profits about 21.08 million CNY·a^-1.

For methanol steam reforming process in a micro-channel reactor, a steady-state multi-component three-dimension transport-reaction model was established.The catalytic process over Zn_Cr/CeO₂/ZrO₂ taken place in rectangular parallel micro-channels and in comby fractal micro-channel network was simulated numerically, and the effect of operating condition on reaction performance was investigated. The results indicated that the use of these micro-channels can make methanol conversion and hydrogen yield increase.Meanwhile, compared with rectangular parallel micro-channels, comby micro-channel network is of several advantages:much smaller requirement for pump power, adsorbing more heat under the same heating area and producing more uniform distribution of temperature.So, methanol conversion can be enhanced and CO reduced, which improve quality of hydrogen production.

In order to deal with lots of waste water containing tar, oil and phenols generated by fixed-bed gasification process of coal to synthetic natural gas (SNG), two integrated systems are proposed, which combine two gasification processes in fixed-bed and coal-water slurry (CWS) entrained-bed.One is that the waste water generated by fixed-bed gasification process of coal is directly used for CWS preparation and another only using waste water containing phenols without tar or oil.In coal to SNG project,they are investigated and evaluated from the view of energy, and the system of highest cold gas efficiency is analyzed from economic point of view.The results show that compared with single entrained-bed gasification process, the fixed-bed/entrained-bed integrated strategies can improve cold gas efficiency. When the ratio of handling capacity of fixed-bed/entrained-bed is 2, coal consumptions are 563 kg·km^-3 (CO+H₂+3.12×CH₄) for the first integrated gasification system and 599 kg·km^-3 (CO+H₂+3.12×CH₄) for the second one, oxygen consumptions 212 m³ O₂·km^-3 (CO+H₂+3.12×CH₄) and 206 m³O₂·km^-3 (CO+H₂+3.12×CH₄), cold gas efficiencies 84.44% and 86.74%, and total thermal efficiencies are 72.53% and 74.87% respectively.Compared with fixed-bed gasification process, the production cost of coal to SNG doesn't increase remarkably for the first integrated system, the strategy is economically available.

Carbon source plays an important role in nitrogen and phosphorus removal for municipal sewage treatment, and the deficiency of carbon source can lead to decreasing nitrogen removal and unqualified TN of effluent.To solve the problem of poor nitrogen removal capacity caused by insufficient carbon source,the experiment adopted the hydrolysis-denitrification technology, in which a combination of hydrolytic acidification and denitrification replaced anoxic-denitrification, and effectively solved the problems.As the use of the hydrolysis-denitrification technology to treat municipal sewage, NH₄⁺-N, TN and COD of effluent all met the standard A, with removal rates of 98.0%, 69.4% and 82.7% respectively.TN removal rate was 17.5% higher than the sewage treatment plant by AAO process in the same period.With BOD₅/TN 3 to 5, sludge denitrification rate in the hydrolysis tank was 1.2 to 1.7 times than that in the anoxic tank, less carbon source was needed to remove the same N.When BOD₅/TN was 3:1, 3.5:1,4:1 and 5:1, for the removal of unit N utilization of COD by denitrification bacteria in the hydrolysis tank could be saved by 59.5%, 52.2%, 19.9% and 23.1% respectively, which effectively solve the problem of the lack of carbon source in the denitrification process.

The impact of nitrite (44.64, 70.3, 94.33, 112.36 mg NO₂^--N·L^-1) on denitrifying phosphorus removal metabolism was investigated by using 92%±3% polyphosphate accumulation organisms domesticated in acetate/propionic acid for 340 d.The results showed that denitrifying phosphorus removal metabolism also occurred when nitrite was used as electron acceptor at first, and the metabolism was inhibited when the concentration of nitrite increased.Nitrite reduction rate, phosphorus uptake rate and PHA degradation rate all reduced with initial nitrite increasing, and the complete inhibition concentration was higher than 112.36 mg NO₂^--N·L^-1.Nitrite reduction rate and phosphorus uptake rate were 2.61 mg NO₂^--N·(g MLSS) ^-1·h^-1 and 3.0 mg PO₄^3--P·(g MLSS) ^-1·h^-1 at initial 112.36 mg NO₂^--N·L^-1.N₂O was produced in the denitrifying phosphorus removal process.Initial nitrite stimulated nitrite reduction to exceed N₂O reduction rate, resulting in greater quantities of N₂O production.The proportion of N₂O-N/TN were 63.5%, 49.0%, 30.2%, 24.0% respectively corresponding to initial concentration of 44.64, 70.3, 94.33, 112.36mg NO₂^--N·L^-1.The accumulation of N₂O could be transformed to N₂ in order to improve denitrification when the system had enough substrate and extended anoxic mixing time.

Solid oxide fuel cell (SOFC) is of advantages of high efficiency, low pollution,flexibility of usable fuel types and high power, etc.Its performance and work condition is strongly affected by electro-chemical reactions coupling with various kinds of transport processes occurring in the porous anode.In this work, a 3D model is developed to describe the coupling processes based on a in-house code program.A mechanism with 42-step elementary reactions was used to evaluate the catalytic surface reaction taking place in porous anode of SOFC.The results indicate that reforming reaction providing H₂ and CO for electrochemical reaction consumes heat produced by electrochemical reaction and occur mainly in near inlet side of anode.The 70% to 80% of surface coverage in anode is covered by Ni_s, 20% to 25% by CO_s, 6% by H_s and 1.5% by O_s, and it is also found that the low utilization of Ni_s catalytic surface means in sufficient usage of fuel.The coverage of surface species depends on operating temperature, Ni_s coverage increases with increasing temperature while H_s, CO_s and O_s decrease.Reaction rate constant can affect specific coverage and operation temperature in some degree, higher rate constant of elementary reaction can make increase fuel consumption and operation temperature.So,it is possible to go up the utilization rate of fuel by improving some steps in elementary reactions.Gas transport is improved by increasing permeability that can not enhance catalytic surface reaction.

The immobilization of Pseudomonas aeruginosa GF31 and its enhancement of biodegradation of cypermethrin were investigated.Zeolite was chosen as a suitable support for the immobilization by taking into account the properties of cypermethrin and mass transfer in the bioremediation.Scanning electron microscope (SEM) images demonstrated that strain GF31 grew well in the pore of the zeolite.After immobilization,cypermethrin removal efficiency was improved significantly from 37% to 61.4% at initial cypermethrin concentration of 100 mg ·L^-1 in 6 d.The specific degradation rate of free cells and immobilized cells were 487 and 917 mg·[L·d· (g dry biomass) ]^-1 respectively, at 300 mg·L^-1 cypermethrin.It was also found that the immobilized cells exhibited higher tolerance to pH and cypermethrin concentration, keeping its activities even at pH 10 or higher cypermethrin concentration up to 800 mg·L^-1.The results of actual soil remediation by the immobilized cells showed that cypermethrin degradation could be well described by a first-order reaction rate equation.As compared to natural degradation, cypermethrin half life (t_1/2) was shortened from 34.3 d to 8.02 d, which illustrated a good result of bioaugmented remediation by the immobilized Pseudomonas aeruginosa GF31.

Aqueous ammonia is one of reagents absorbing CO₂ and is of vast development potential.In this paper the reaction between decarbonization rich liquid and carbide slug is used for assisting CO₂ storage and recycle of aqueous ammonia at normal temperature and pressure.Using aqueous NH₄HCO₃ as rich liquid, pH and conductivity change during carbonation process were measured,and XRD, SEM and TGA employed for analysis of carbonation reaction products.Meanwhile, compared with aqueous ammonia having same concentration, carbonation reaction solution was also used to absorb CO₂.The results show that the carbonation reaction can be accomplished in short time, and the higher temperature and liquid-solid ratio are, the faster the reaction rate is.Besides, ultrasonics can make carbide slug particles smaller, and carbonation reaction solution can be recycled as its property is similar to aqueous ammonia of the same concentration.

The second generation hyperbranched polyester (HBP-0) was synthesized by the pseudo-one step method with 2,2-bis (hydroxyl-methyl) propionic acid as AB₂ monomer, trimethylolpropane as core monomer and p-toluene sulfonic acid as catalyst.HBP-0 was modified with ε-caprolactone and lauric acid to prepare modified hyperbranched polyesters (HBP-1, HBP-2, and HBP-3).The structure and molecular weight of HBPs were characterized by FT-IR,¹H NMR and GPC.HBP-0 was synthesized with 0.43 degree of branching and its molecular weight approached the theoretical value and distribution factor was 1.72.The film properties of modified HBPs cured by toluene diisocyanate adduct were studied, and the results showed that the modified HBPs displayed excellent film properties in the gross, impact resistance, adhesion and flexibility.HBP-3 modified by both ε-caprolactone and lauric acid exhibited the best properties, including lowest viscosity up to 7500 mPa·s, surface drying time of 40 min and pencil hardness of F.While the corresponding data of HBP-1 and HBP-2 modified only by ε-caprolactone or lauric acid were 7×10⁵ mPa·s, 20 min and HB; 17500 mPa·s, 90 min and 2B, respectively.

Based on the solubilities of three kinds of epoxy resins and three kinds of modified resins and three kinds of curing agents in 77 kinds of solutions at 25～80℃ obtained by experiment, the Hansen solubility parameters of polymers were calculated.The solubility parameters can be used to calculate the overlap rate of epoxy resin- modified epoxy resin system, epoxy resin-curing agent system and epoxy resin-modified resin-curing agent system, which in turn can be used to calculate the Flory-Huggins interactive parameters χ₁₂.The results of the overlap rate were used to choose suitable co-solvents and solvent formulas.They could also be used to match different resins and prepare anticorrosive and antifouling self-stratifying coatings.The miscibility of the solvent-free curing system was predicted by the value of χ₁₂ or the phase equilibrium calculated by χ₁₂.The resins and curing agent system which form an anticorrosive and antifouling self-stratifying coating could be chosen from their experimental data of Hansen solubility parameters.If the modified resin had enough time to diffuse to the surface and stratify with the aid of an appropriate mixed solvent, optimum effect and performance of the coating could be obtained.

Waterborne polyurethane (WPU) was prepared by using toluene diisocynate (TDI) and polyethylene glycol (PEG) as raw materials, and 2,2-dimethylolbutyric acid as chain extender. Hydroxyethyl methacrylate (HEMA) was used to terminate WPU.The self-emulsifying method was adopted to prepare HEMA-grafted WPU (HEMA-WPU) emulsion.Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) and thermogravimetric analysis (TG) were used to characterize the molecular structure and thermal endurance of HEMA-WPU.Compared with WPU, the thermal endurance of HEMA-WPU was raised obviously.The inter-laminar shear strength (ILSS) of carbon fiber/epoxy resin composite samples after sizing by the prepared emulsion was raised by 7.5%, reaching 64.5 MPa, compared with the un-sized samples.

Polyaniline-lignosulfonate (PANI-LS) nanocomposite was prepared via an unstirred polymerization by using lignosulfonate (LS) as dispersant.The morphology, structure and properties of the PANI-LS nanocomposite were characterized by using scanning electron microscopy, transmission electron microscopy, FTIR, UV-vis spectra and wide angle X-ray diffraction.Moreover, the silver ions adsorbability of the PANI-LS nanocomposite was examined.The maximal sorption capacity of silver ions onto PANI-LS nanocomposite was up to 500 mg·g^-1 at initial silver ion concentration of 0.03 mol·L^-1.The product of PANI-LS nanocomposite after sorption was investigated by transmission electron microscopy and wide angle X-ray diffraction.The results showed that silver nanoparticles with diameters of 2—7 nm were homogeneously dispersed on the surface of the PANI-LS nanocomposite after sorption.This indicated that the PANI-LS nanocomposite possessed reactive adsorbability for silver ions.

PS-b-P4VP block copolymers were solution-blended with polyacrylic acid (PAA) and polyethylene oxide (PEO), respectively, followed with spin-coating on glass substrates.The resulting thin films were imaged by atomic force microscope (AFM) to investigate the tuning effects of the two homo-polymers on the micro-phase separation morphologies of PS-b-P4VP thin films.The results showed that thermodynamic repulsion between P4VP and PS segments was enhanced due to strong interaction between PAA and P4VP by hydrogen bonds.In the thin film with 10% (mass) of PAA, micro-phase separation morphology with cylindrical PS micro-domains dispersed regularly into P4VP/PAA matrix was observed.The cylindrical PS micro-domains oriented perpendicularly to the film surface.In the PS-b-P4VP/PEO thin films, micro-phase separation morphologies with PS as matrix and cylindrical micro-domains of PEO/P4VP oriented perpendicularly to the film surface were formed.The top of PEO/P4VP cylindrical micro-domains was not covered by PS segments, leading to the holes on the surface of the film.Also, cone-shaped projections could be found at the bottom of holes due to crystallization of PEO segments inside PEO/P4VP micro-domains.With the increase of PEO content, the size of holes increased and the cone-shaped projections at the bottom of holes became more apparent.

The key issue of preparing high pore volume material is strengthening the microscopic supersaturation of precipitation reaction and reducing the particle size.Ultrafine SiO₂ was prepared with the fast precipitation method in a membrane dispersion micro-reactor by using sodium silicate and sulfuric acid as raw material.The effects of two-phase flow rates, final pH, salt concentration, aging time, and drying temperature on the specific surface and pore volume were investigated.The results showed that silica powder primary particle size prepared with the membrane dispersion micro-reactor was 10.2 nm, while primary particle size prepared with the stirring method was 20.8 nm, specific surface could be up to 380 m²·g^-1 and pore volume was 2.6 ml·g^-1 when final pH value was 9.55.Flatting performance test of SiO₂ showed that the SiO₂ prepared with the membrane dispersion micro-reactor had excellent flatting performance, and extinction index of SiO₂ was up to -10.2.

The phase morphology of polypropylene/poly (ethylene-co-octene) /polyamide 6 (PP/POE/PA6) ternary blend was predicted by using spreading coefficient and minimum free interfacial energy models. The results showed that a core (PA6) -shell (POE) structure was formed. The PP/POE/PA6 (50/25/25,mass ratio) ternary blends were prepared through two mixing sequences and their phase morphologies were investigated. It was demonstrated that when three components were blended together, POE and PA6 droplets were distributed independently in the PP matrix. When POE was blended with PA6 first, and PP was then added, both PA6 droplet and fibril were formed. For POE, some migrated into PP phase and some other encapsulated small PA6 droplets or adhered to the surface of the large PA6 fibrils. Thus, POE phase was located between PA6 and PP phases and played the role of connecting the two phases.

SiO₂/polyurethane (SiO₂/PUL) latexes modified by nano-SiO₂ (treated with γ-amino propyltriethoxy silane (KH550)) and end capped by hydroxyethyl methacrylate (HEMA) were first prepared through the prepolymer process.Then a series of nano-SiO₂/polyurethane-fluorinated polyacrylate (SiO₂/PUFA) hybrid latexes were synthesized via the seed emulsion polymerization process using hexafluorobutyl methacrylate (HFMA) as modifier, SiO₂/PUL as macromolecule emulsifier and seed emulsion.The properties of nano-SiO₂/PUFA emulsions and their films were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), contact angle (CA),differential scanning calorimetry (DSC), thermogravimetry (TG) and tensile test machine.FT-IR characterization demonstrated that the polyurethane (PU) was successfully modified by modified nano-SiO₂ and HFMA.TEM result indicated that the nano-SiO₂ treated with KH550 was well dispersed in ethanol.Particle morphology of hybrid latex showed inverse core-shell structure, in which the core region was formed by acrylate (PA), while the shell region was formed by PU.TG result showed that the thermal stability of the latexes film was obviously improved by nano-SiO₂ particles.Water resistance and mechanical properties of nano-SiO₂/PUFA films were greatly improved due to the multiple cross-linking formed by modified nona-SiO₂ and fluorinated acrylate through the chemical bonds with polyurethane chains.

Thermoplastic waxy corn starch (WTPS) and maise starch (MTPS) were prepared by melt blending.Furthermore, WTPS/poly (butylenes succinate) (PBS) blends and MTPS/PBS blends were prepared for investigating the effects of starch type on the morphology and viscoelastic behavior of the blends.The results showed that plasticization of waxy corn starch was more easily performed than that of maise starch and WTPS had a lower melt viscosity than that of MTPS.The WTPS/PBS blends had a better homogeneous fracture surface than that of MTPS/PBS blends.When blending ratio of TPS/PBS was 60/40, dynamic rheological behavior of the blends was mainly attributed to TPS phase and MTPS/PBS blends had higher storage modulus and complex viscosity than those of WTPS/PBS blends.When blending ratio of TPS/PBS was 40/60, PBS phase played an important role in dynamic rheological behavior of the blends and the MTPS/PBS blends in low shear rates (ω<1 r·s^-1) showed more apparent solid-like dynamic rheological behavior.