In the coming low carbon era under the climate change constraint，the turning point of the world primary energy structure would appear in 2020—2025.In the future 40—50 years，oil would quit gradually from transportation fuel market.This would result in slowing the pace of oil’s price rising，extending its life time， and would be mainly used in petrochemical，and keeping its competitiveness with coal chemical industry and biomass chemical industry.In the future，the market of organic chemical raw material would be the battlefield among petroleum，coal，and biomass.The scenario will depend upon scientific and technological progress.It is necessary to study the technology progress and economics of CCS on the three raw materials routes.China has to make its countrywide optimization strategy of natural gas and NGPL resources and global arrangement strategy of its organic chemical industry.

Loop flow technology has been widely studied and used in the fields of bioengineering，wastewater treatment，organic chemical，direct coal liquefaction，etc.，but existing research mostly focuses on gas-liquid，liquid-solid and gas-liquid-solid system.In the recent years，not only the research of loop flow technology has developed to gas-solid system，but also the application has entered to the field of petroleum processing.This paper mainly summarizes the processes in research and industry application of gas-solid loop flow technology in rough cyclone separation，stripper，heat exchanger，olefin reduction reactor，combustor for petroleum coke and so on of FCCU.Furthermore，the studies and applications of gas-liquid loop flow technology in heavy oil suspending bed hydrogenation and gas-liquid-solid loop flow technology in separating hydrogen from refinery gas by hydration are reviewed.

The progress of developing the multistage fluidized bed technology in Tsinghua University was reviewed in the present work.First part presents the experiment on cold model fluidized bed to determine the operating regime, the relationship of height of dense phase of solids in different stages with gas velocity and the structure of downcomer.Second part described the application of reactor structure above in hydrogenation of nitrobenzene to aniline, ammoxidation of m-xylene, synthesis of methanol, vinyl chloride monomer from acetylene, and synthesis of carbon nanotube. The structure of multistage bed is adaptable to special processes, calling for the temperature shift, different gas atmosphere, high conversion of gas reactants or long catalyst life time.Finally, the industrial scale application was addressed, which broaden the application of multistage fluidized bed in heterogeneous catalytic processes.

Advanced CFD simulation has been regarded as one of important tools for dealing with the complicated non-linear fluid dynamics in the fluidized beds. Different momentum balances of particles and fluid phases in Eulerian-Eulerian models have been proposed due to different opinions on fluid-particle and particle-particle interactions. Particle viscous force, solid pressure force and inter-phase drag force are discussed in this paper. Then, authors provided a simple hydrodynamic model based on the two-fluid theory, which considered the effect of discrete particles on both the fluid- and solid-phase momentum equations under a quasi-equilibrium state. One of its main features is that the characteristic length in the model is of the order of the particle diameter. Numerical simulations were conducted in the platform of a commercial software package, CFX 4.4, by adding user-defined Fortran subroutines. After the independence of grid size, time step and the maximum solid volume fraction were explored, case studies including homogeneous fluidization of liquid-solid system, homogenous/aggregative fluidization of Geldart A particle and bubbling/collapsing/jetting fluidization of Geldart B/D particle for gas-solid system were conducted in 2D/3D fluidized beds. The majority of results were compared with classic theories, experimental data and simulations in the literature and good agreements were obtained, which indicates that this model can be used to predict the fluid dynamics of the dense particle-fluid two-phase flow in the fluidized beds.

The concentration profiles of jet gas are investigated in the feed injection zone of a cold-model FCC riser by using a hydrogen trace technique.Experimental results demonstrate that six types of jet gas concentration profiles can be used to describe the mixing process of the jet gas with pre-lift gas and catalyst particles in the feed injection zone.The six types are a distinct M-shaped profile for no mixing region，an indistinct M-shaped profile，a distinct three-peak profile，an indistinct three-peak profile and an one-peak profile for mixing region，and a annular-core profile for full mixing region.The heights for regions of initial and full mixing reduce when decreasing the jet gas velocity or increasing the pre-lift gas velocity. Furthermore，the momentum ratio，M_j/M_r，is introduced to describe effects of gas-solid physical properties，operating conditions，and equipment configuration on the jet gas concentration distribution.The heights for regions of no mixing，mixing and full mixing between jet gas with pre-lift gas and catalyst particles are found to be 0—0.375 m，0.375—0.525 m and 0.525—0.675 m when M_j/M_r≤0.29，0—0.525 m，0.525—1.225 m and 1.225—1.375 m when M_j/M_r>0.54，and 0—0.375 m，0.375—0.875 m and 0.875—1.075 m when M_j/M_r between 0.29 and 0.54，respectively.

Gas/liquid-solid two-phase flow is ubiquitous in chemical engineering.This paper theoretically and experimentally analyzes the mass conservation of solid phase in a CFB riser.It is revealed that the time-average particle velocity and arithmetical-average particle velocity are misused in the traditional viewpoint of two-phase flow.The introduction of solid volume fraction in a two-phase flow actually denotes an assumption that the discrete particles are treated as a continuum.Then the misuse of time-average particle velocity and arithmetical-averaging appears inevitable.The physical meaning of time-average particle velocity in a gas/liquid-solid two-phase flow is discussed on a microcosmic scale.An equation for computing the time-average particle velocity in a discrete two-phase flow is given.Furthermore，a proper approach is proposed to analyze the mass conservation of discrete particles.

The hydrodynamics in a gas-solid airlift loop reactor were simulated by using two-fluid model and granular kinetics theory in this paper.The gas-solid inter-phase drag force function included in the two-fluid model was modified accounting for the interparticles clustering.The simulated time averaged values of solid fraction and particle velocity agree well with the experimental data, verifying the feasibility of the numerical simulation method.The simulated results demonstrate that the profiles of transient solid fraction present the similar heterogeneous feature of aggregative fluidization usually occurred in normal fluidized beds.The axial profiles of bed pressure fluctuation qualitatively reflect the information about the bubble movement in a certain extent.The time series of particle velocity and their probability density functions display that both the particle upward and downward movement appears at each local bed position.The microcosmic internally circulating flow pattern of particles exists simultaneously when the mainstream of particles move upward in the bed.The particle transient velocity profiles offer a microcosmic interpretation for the macroscopical lateral nonuniform distribution of time averaged particle velocity.

A large scale cold model experimental setup for a coupled reactor mainly composed of lower riser and upper gas-solid loop fluidized bed was established，aiming at the industrial application background of olefin reduction technology with auxiliary reactor for FCC naphtha upgrading.The hydrodynamic behavior in the upper loop fluidized bed was experimentally investigated.The results show that，under the coupling operation of loop fluidized bed and riser，two kinds of circulating driving forces exist in the loop fluidized bed viz.the static pressure difference and the particle jet driving force.The total averaged solid holdup difference between the draft tube and the annulus region increases with increasing superficial gas velocity in the draft tube，but decreases with increasing external particle circulating flux.Particle circulating velocity increases with increasing superficial gas velocity in the draft tube and external particle circulating flux.Furthermore，a flow mathematical model describing the coupling operation of riser and loop fluidized bed was established on the basis of momentum balance principle of loop fluidized bed，and the model average relative errors were within 15.95%.

The experiments on the characteristics of the fluid discharging through the streamlined contractive orifice and the vertical sharp-edged orifice with same diameter were carried out.The mechanical energy loss of the fluid flowing in front of vertical sharp-edged orifice was imitated by that of the fluid through the streamlined contractive orifice, which was compared with the mechanical energy consumed in the whole orifice discharge process through vertical sharp-edged orifice.Thus, the proportion of the upstream mechanical energy loss to total mechanical energy loss can be obtained quantitatively with respect to typical “large orifice” and “small one” at different operating conditions.The proportion reflects the difference of the mechanical energy consumed inside orifice between large orifice and small orifice, as well as the effects of the plate thickness.Moreover, the flow mechanism of orifice discharge proposed in the study before this work was verified.Afterwards, according to the physical model of the contributing flow region in front of orifice and the data of the flow field simulated with computational fluid dynamics (CFD) software Fluent 6.2 before this work, the basic mode of equation on the resistance coefficient of the contributing flow region in front of orifice was obtained.Therefore, the model of mechanical energy consumed upstream at fully developmental turbulent regime was founded by simulated the experimental data.

Extensive research on air loop reactors (ALR) has been conducted, but mostly limited to gas-liquid and gas-liquid-solid systems.Work associated with gas-solid systems has been rare and mainly focused on draft tube-lifted fluidized bed and spouted bed.The present paper addressed a gas-solid air-loop reactor treating fine Geldart A particles and operating in a new annulus-lifted mode, with bubbling or turbulent bed upward flow in the annulus in parallel with bubbling bed downward flow in the draft tube.The influence of operating conditions and axial position of draft tube gas distributor on the distribution of bed density, particle circulation velocity and circulation mass flowrate is discussed.By mounting draft tube gas distributor in the bottom region, bed density radial distribution and particle circulation mass flowrate is significantly improved.Bed density in 0.367 <r/R<0.49 is still high, signifying a limited influence range and potential optimization of gas distributor.Particle circulation velocity and circulation mass flowrate for the axial position of 32 mm is greater than that for other axial positions.

The gas-solid two-phase flow in the guide vane cyclone tube with different dust discharge structure is studied by numerical simulation method.The studies show that the downward flow and upward flow pass through the same discharge section of the cylinder type discharge structure，so the upward flow may entrain fine particles from the hopper and result in poor performance of the cyclone.With the cone shape discharge structure，the gas flow rotation in the cyclone is improved and the downward flow can be controlled，which is helpful to obtain better performance.However，vortex flow is found in the discharge cone，which will cause flow erosion to the wall of cyclone tube.The opening slots in the wall of discharge cone can change the state of gas-solid two-phase flow，which give different paths for discharge flow and upward flow，stabilize the flow in the hopper，avoid the entrainment of particles from the hopper，so that the performance of cyclone tube is improved.

The gas phase flow fields in cyclone separators in the same size are simulated with different flow parameters.The diameter of the cyclone was 300 mm.The inlet velocities range from 0.5 to 30 m·s^-1, the gas temperatures range from 293 to 1273 K, and the pressures in the cyclone separator are from 0.1 to 6.5 MPa, which are the flow parameters usually used in the industry.Based on the simulation results, the effect of flow parameters on the similarity of dimensionless velocity is investigated.The similarity criterion of flow field in the model and prototype is also analyzed.The results show that the flow fields are similar for different flow parameters, but the dimensionless velocities are different.When the inlet velocity is higher than 20 m·s^-1, or the pressure is higher than 3.0 MPa, the Euler number approaches a constant. It is not affected by Reynolds number, so the flow field keeps approximate similarity.When the temperature is higher than 1000 K, the influence of Reynolds number on Euler number is very weak, so that the flow field also keeps self-similarity.Moreover, the mechanics of the self-similarity of flow field is discussed in view of the energy losses and the relationship between Euler and Reynolds number.

The gas phase flow fields in the geometrically similar cyclone separators are simulated by Fluent 6.1.The cyclone diameter in the simulation ranges from 100 mm to 2100 mm.Based on the simulation results，the effect of cyclone size parameters on the dimensionless velocity similarity is investigated.The results show that the flow fields are similar for different cyclone diameters，but the dimensionless tangential velocities are different.Hence，the flow field is not strictly similar.As the cyclone diameter increases，the flow field develops from weak similarity to strong similarity.When the cyclone diameter is more than 2000 mm，the dimensionless velocities are constant，indicating that the Eu number is not affected by Re number and the flow field is in self-similarity.The self-similarity of the flow field reflects the contribution of the inertia resistance loss and viscous friction loss to the total energy loss.As the cyclone diameter increases，the viscous friction loss decreases while the inertia resistance loss increases，but the Eu number decreases.When the cyclone diameter increases to some value，Eu number is independent of Re number，and the flow field is in self-similarity.

The distributing gas performance of the pipe distributor was analyzed based on the flow field numerical simulation of pipe distributor used in FCCU （Fluid Catalytic Cracking Unit).The result from simulation shows that the pressure increases along the branch pipe and the axial flow rate decreases，which leads to the nozzle flow rate increasing gradually.Furthermore，an obvious bias flow was found in the inlet of branch，which brings the nozzle flow rate less than the designed flow rate and causes an uneven gas distribution in the fluidized bed.Meanwhile，the momentum equation with variable-mass flow was applied to analyze the flow in the pipe distributor.The flow type in the branch pipe belongs to the “momentum exchange controlling model”.The pressure in the branch pipe always increases from the inlet to the end and the pressure distribution is not consequentially uniform.The uneven gas distribution of the pipe distributor results in fluidized gas non-uniformity in the bed and the erosion in branch pipe and nozzle.Finally，according to the pressure characteristics in fluidized bed system，relationship between the pressure drop of branch pipe and pressure drop of nozzles，as well as of the critical nozzle pressure drop and the designed nozzle pressure drop，was discussed.The gas distributor performance could be optimized by means of the structural improvement of branch pipe.

Spatio-temporal evolution of solid holdup in the liquid-fluidized bed was predicted by Brandani and Zhang model, which includes additional terms in both the liquid- and solid-phase momentum equations based on the two-fluid theory by considering particle-fluid interactions under a quasi-equilibrium state.Numerical simulations were conducted in the platform of commercial Computational Fluid Dynamics (CFD) code, CFX4.4, by adding user-defined Fortran subroutines.Based on the independences of mesh, time step and convergence criterion obtained, the effects of the physical properties of liquid-solid system and the operational conditions on the solid holdup profiles were investigated numerically in the 0.5 m (long)×0.1 m (wide) 2D fluidized bed.The computational results show that the solid holdup profile within the stable bed transfers to a new equilibrium state once the physical property of the system or the operational condition is changed.The bed surface decreases and the average solid holdups increase in all the vertical planes, due to the downward acceleration of particles, when particle density or size is increased.The similar phenomenon is observed with a decrease of liquid density or viscosity.When the liquid inlet velocity is abruptly increased, however, the motion of each particle accelerates upwardly and solid holdups decrease in the bed.Both liquid density and viscosity reduce with an increase of temperature, which leads to downward motion of particles and solid holdups increase.The above simulated data can be explained reasonably by the forces acting on particles.

The fluidization quality and gas back-mixing property in a two-dimensional and a large-scale three dimensional gas-solids fluidized beds of FCC particles were compared in the range containing both bubbling and turbulent flow regimes.The experimental results indicated bed shape’s sound effects on fluidized beds of Geldart A particles.The hydrodynamics and gas-solids mixing demonstrated both similar and different properties in the two-dimensional and three dimensional beds.The bed expansion with increasing superficial gas velocity showed similar trends in both beds.However, the fluidization quality and axial gas dispersion coefficient were much lower in the three-dimensional beds.Moreover, there were different trends of pressure fluctuation and axial gas dispersion coefficient with increasing superficial gas velocity and even different gulf streaming patterns in the two beds.In general, it can be concluded that the two-dimensional bed in this study represented a small-scale bed with strong wall effect, while the three-dimensional bed represented a large-scale bed with strong effect from static bed height.

Standard k-ε turbulence model is used to simulate the fluid field and mixing characteristics in a tank stirred by a Smith turbine in a platform of commercial CFD software package，CFX10.0.The relative rotation between baffles and the impeller is numerically simulated by a Multiple Reference Frame approach.The numerical results indicate that when the impeller off-bottom clearance decreases from 1/2 to 1/3 of the impeller diameter，flow pattern is always the “typical two loops”; however，when the impeller off-bottom clearance decreases from 1/3 to 1/6 of the impeller diameter，flow pattern changes from the “typical two loops” into a “single loop”.Power number predicted by this work is in good agreement with design value and predicted value by other researchers.The snapshots of concentration distribution of tracer indicate that mixing time depends heavily on the flow field in the stirred tank.Both feeding and monitoring points have significant influence on the mixing results.It is important to choose appreciate monitoring points when collecting the mixing time data in practical industrial or experimental work.The above CFD simulation results indicate that the model employed in this paper can predict the mixing characteristics in the stirred tank with a Smith turbine，which provides helpful information for optimization and improvement in the future design of the Smith turbine.

Subcooled boiling model suitable for high pressure and high subcooling condition was established based on two-fluid model.The influence of liquid subcooling and wall heat flux on heat characteristics was investigated.The results show that distribution of gas phase throughout the cross section is nonuniform，and bubbles are intensive near the wall.The volume fraction increases with decreasing entrance subcooling which prompts the boiling heat transfer.With increasing heat flux，the surface heat transfer coefficient generally increases along the axial direction，however，decreasing tendency can be observed in local area，which becomes unclear with decreasing entrance subcooling.

This paper studies the mass transfer performance of the jet external loop reactor using the water-HAc-kerosene system and the effect of the section structure of the reactor and the material velocity on the mass transfer performance.The loop reactor is divided into five sections according to the hydrodynamic characteristics, which are bottom, premixing, mixing, looping and separation sections.There is almost water phase in the bottom section and its mass transfer could be neglected.An empirical expression between the equilibrium concentration of HAc in water phase and the initial concentration of HAc in oil phase was obtained by the regression of experimental data.And then the mass transfer performance of the other four sections was researched.The results show that the mass transfer performance of all sections increased as the superficial velocity of both oil and water phases went up.The mass transfer performance of all sections could be greatly increased by feeding in the distributing pipe.And the higher the velocity in the distributing pipe, the better the mass transfer performance.The mass transfer coefficient of four sections with a sequence from large to small under the same condition was as follows, premixing section, mixing section, looping section, and separation section.

Fiber film extractor is novel high-efficiency equipment for two-fluid mass-transfer.In this paper，the kerosene-benzoic-acid-water was used as the experimental mass-transfer system.Under two different liquid distributor，varying the packed density of fibers from 1.89% to 5.08% and the flow ratio from 3 to 6，the performance of the fiber-film extractor was investigated on a cold model that made of 70 mm-ID，2630mm-height plexiglass pipe.The experimental results show that the optimal packed density of fibers is 3%—3.5% under different liquid distributors，feeding sequences as well as flow ratios.The optimal packed density corresponding to “feeding kerosene first” is somewhat less than that to “feeding aqueous benzoic acid first”. Based on the cold model experimental results as well as the maximum Reynolds number，a fiber-film extractor for caustic treating a 0.01 Mt·a^-1 stream of RFCC gasoline was investigated.The industrial side-stream experimental results indicate that the efficiency of the fiber-film extractor for demercaptan is distinctly higher than that of the traditional apparatuses.

In order to evaluate the performance and select the filtration and separation equipments used in natural gas distribution station，a particular pressure reducing device was designed by using throttling effect.An on-line dust measurement method in high-pressure natural gas pipeline was proposed.Numerical calculation and experiment result show that there is no liquid droplet generated during pressure reducing.The influence of the pressure-reducing device on particle concentration and size distribution can be ignored.The method of dust on-line measurement in high-pressure natural gas pipeline is accurate and reliable.

The high temperature gas flow field in a PV^TM cyclone separator was measured by using a specially-fabricated，hemispherical five-hole pitot probe.The temperature of test air ranged from 293 K to 973 K and the cyclone inlet velocity from 16 m·s^-1 to 36 m·s^-1.The experimental results showed that the three-dimensional velocity components are good in axisymmetry and similarity along the axis but the tangential velocity value attenuated down the axis.The non-dimensional tangential velocity increased slightly and the dividing surface between inner and outer vortex also moved outwards with the increase of inlet velocity.With the rise of gas temperature，the tangential velocity decreased and its attenuation along the axis became greater.The effect of the gas temperature and inlet velocity can be reflected by a Reynolds number based on the axial flow in the vortex finder and an empirical expression for the maximum non-dimensional tangential velocity vs.Re was given.

The axial solid concentration distributions were measured by using pressure inspection instrument in a 286 mm I.D.and 7 m height burned-oil-sand fluidized bed of wide size distribution.The change trend of axial solid concentration distributions were investigated under different superficial gas velocities，particle size and particle density.The results showed that the burned-oil-sand particles had a wide size distribution，and there was difference in densities and particle sizes for burned-oil-sand particles obtained in different regions and buried depth.The axial average solid concentrations were indicated the whole characteristics of dense in bottom and dilute in top，and kept consistent when bed height was above the transport disengaging height（TDH).With increasing superficial gas velocity，the solid concentrations in dense region decreased，but increased in dilute region.The burned-oil-sand particles whose particle size and particle density were smaller had good fluidization quality.According to the analysis of experimental results，a model of index was established in order to associate with experimental data.It was concluded that the empirical formula can reflect well the law of axial particle concentration distributions under different factors.

An indirect expansion technique was proposed to measure the gas holdup in a non-transparent bubble column with 0.1 m inner diameter and height of 5.2 m.Air and distilled water were employed as gas and liquid phases, respectively.The experimental results show that the average and maximum errors of gas holdup are less than 2% and 4.5%, respectively, between the indirect expansion and pressure drop methods at atmospheric or elevated pressure.Moreover, the gas holdup increases with operating pressure when the superficial gas velocity is a constant, while the effect of static liquid height on gas holdup can be ignored when the operating pressure and superficial gas velocity are fixed.

Re₂O₇/meso-Al₂O₃ catalysts with different Re₂O₇ loadings were prepared by wetness impregnation of Re₂O₇ on mesoporous alumina.The catalytic performance of the catalysts was also investigated, and compared with Re₂O₇/γ-Al₂O₃ catalyst.The results showed that with the increase of Re₂O₇ loading, the BET surface area and pore volume of the catalysts decreased while the acid amount increased.The metathesis catalyst was prepared by impregnation under the conditions of 60℃, 1 h^-1 and atmospheric pressure, and the initial conversion of butene was about 54%, by using Re₂O₇/meso-Al₂O₃ as the catalyst.The Re₂O₇/meso-Al₂O₃ with m(Re₂O₇)∶m(Al₂O₃)=0.2 exhibited the best catalytic performance of olefin metathesis among the Re₂O₇/meso-Al₂O₃ catalysts.The reaction selectivity of propylene was about 55%, and the life-time of catalyst was 120 h.

Reaction performance and product properties of catalytic pyrolysis of HGO (heavy gas oil) and LGO (light gas oil) derived from Canadian synthetic crude oil were investigated in a riser unit.The yield of total light olefins (ethylene, propylene, and butylene) showed a maximum with increasing reaction temperature and catalyst-to-oil mass ratio, decreased with increasing reaction time, and enhanced with increasing steam-to-oil mass ratio.The optimal reaction temperature, catalyst-to-oil mass ratio, reaction time and steam-to-oil mass ratio of catalytic pyrolysis of HGO were 620—640℃, 16, 2 s and 0.5, respectively.Under these optimal reaction conditions, the yields of ethylene, propylene and total light olefins reached 9.0%（mass）, 15.8%（mass） and 32.6%（mass）, respectively.There were large amounts of aromatics in pyrolysis gasoline, diesel and heavy oil fractions.Gasoline fraction contained above 80%（mass） of aromatics which were mainly toluene and C₈ aromatics.Diesel fraction contained above 60%（mass） of aromatics which were mainly single-ring and double-ring aromatics.Heavy oil fraction contained above 70%（mass） of aromatics which were mainly multi-ring aromatics.

Silica support materials with different and uniform pore size were fabricated by ordered-packing of monodisperse SiO₂ spheres through evaporation assembling method.The pore structure was characterized with low temperature N₂ adsorption-desorption method，mercury porosimeter and SEM.The results showed that the SiO₂ spheres were closely and orderly packed with face centered cubic packing structure in the silica materials with uniform pore sizes.This method is especially appropriate for the assembling of small size（D<300 nm)SiO₂ microspheres，and the assembly time is about 7 d.It is found that the uniformity of pore sizes of silica materials is affected by assembly condition and the optimal temperature of assembling opal is 50℃.

The tangential velocity and static pressure distribution at the outer wall of vortex finder through a single and a double inlet cyclone were simulated using RSM model.It is shown that the adverse and favorable pressure gradient zone along the outer wall of vortex finder of the double-tangential-inlet cyclone separator is much smaller than that in single-tangential-inlet cyclone separator.The tangential gas velocity around the vortex finder wall has no significant fluctuation and the easy deposit area for oil drip and catalyst is relatively small.There is no stagnant flow area, and the back flow zone near vortex finder wall is not prone to yield.Consequently the probability of coke accumulation on the outer wall of vortex finder of a double-tangential-inlet cyclone is less than that in a single-tangential-inlet cyclone.On the other hand, in double-tangential-inlet separator, the average shearing strength to the coke deposited on the outer wall of vortex finder is large and the average radial pressure grads force is small, which suggests less coking and thinner coke layer on the outer wall of vortex finder.

Based on theoretical analysis, a laboratory test was carried out using several coalescing internals with different structures to investigate the effect of coalescing internals acting on the separating performance of oil-water gravity separator.Residence time, oil concentration distribution, separating efficiency, oil concentration and median particle diameter difference in front and at the back of different coalescing structures were comprehensively contrasted.Results indicate that, reticulate corrugated plate has a good coalescing effect for small droplets, which can significantly improve oil-water separating efficiency and shorten residence time.The effect of opening corrugated plate is worse, while joggled-lap corrugated plate is the worst among the three structures.It was found that excellent performance of the coalescing structures should satisfy three conditions.Firstly, having good oleophilic and hydrophobic property; secondly, having sufficient channels for oil droplets to rise upward; thirdly, having larger contact area for mixture phase.This work provides good foundation for further development of effective and compact oil-water gravity separation equipment.

A number of vacuum residua (VR)in China and abroad were separated by using supercritical fluid extraction and fractionation technology (SFEF).It is showed that the properties of the obtained narrow cuts depend on the solvent solubility, by which the asphaltene and metals are enriched in the unextractable endcuts and thus the properties of extract cuts greatly improved.A new process of heavy oil deep stage separation is put forward based on the discovery.Research on deep stage separation of Dagang VR and Liaohe VR was carried out on 1 kg·h^-1 and 10 kg·h^-1 capacity unit with n-pentane as solvent.Effects of solvent to feed ratio S/O, temperature and pressure on the yield and the properties of the deasphated oil (DAO)were investigated and the optimized process parameters were determined as following: extraction temperature within 160—170 ℃, pressure 4.0—5.0 MPa and S/O (mass ratio)4.0—4.5.The appropriate supercritical solvent recovery conditions were determined in range of temperature of 200—220℃ and pressure 4.0—4.5 MPa.The novel aspect is that deoiled asphalt (DOA)are discharged as fine particles by coupling the supercritical extraction and spraying granulation.The fluidization properties of the DOA powders were measured also for transportation purpose.The results provide the basis for industrial scale-up of the heavy oil deep stage separation.

The hydrate separation tower is the most important unit operation equipment in the process of separating pyrolysis gas with the aid of hydrate technique for recovering ethylene.The water-in-oil emulsion could enhance the hydrate formation rate and improve the flow behavior of hydrate slurry.In this work，the simulation algorithm of absorption-hydration separation tower for the water-in-oil emulsion system was developed，which was involved with the vapor-liquid-liquid-hydrate four phase equilibria.The operation conditions，separation efficiency and energy consumption of the hydrate separation tower were studied under the different gas-liquid ratio conditions by combining the equilibrium and non-equilibrium stage approach.The calculation results indicated that the lower gas-liquid ratio could improve the separation efficiency，but may bring about the high energy consumption.The results also showed that hydrogen and methane could be separated effectively from C₂ plus-components at around 0℃ through hydrate technique.The calculation results are of significance for the design of hydrate separation equipment，the determination of operation conditions and the planning of separation process for the ethylene pyrolysis gas.

The gas flow of cyclones with various vortex finders was numerically simulated using the commercial computational fluid dynamics（CFD）software package，FLUENT 6.1.The result indicated that，two types of axial velocity structures appeared，upended V-shape and M-shape，by varying the diameter of vortex finder.With the increase of vortex finder diameter，the distribution pattern of axial velocity changed from upended V-shape to M-shape.The dip of axial velocity appeared inside the vortex finder initially and then grew up to the separation space continuously.When the vortex finder diameter was larger than a certain value，the back-flow could even extend to the whole inner separation space of cyclone.Likewise，the radial region of back-flow increased.While，the axial velocity nearby the centerline decreased with the increasing vortex finder diameters，and became negative even.In addition，the structure of vortex finder，flared end or shrink end，also has some effect on the axial velocity.It was considered that the distribution pattern of axial velocity was related to the axial gradient of pressure.When the energy loss in the vortex finder was small to a certain value，the pressure gradient turn to positive，and the back-flow of axial velocity appeared.

Based on concluding the pressure drop models of single and multicyclone separator under atmosphere pressure，and on-site measurement pressure drop values，a pressure drop model has been built up to predict and calculate the pressure drops for multicyclone separators operating at different pressures and temperatures in natural gas transportation.The reliability of pressure drop models has been calibrated by experiments，the results showed that the pressure drop models could calculate exactly the pressure drop values for corresponding cyclone separators，and the differences of pressure drop values between calculated by models and measured by experiments could be ignored.Therefore，the pressure drop model of multicyclone separator at high-pressure can be used to calculate the pressure drop values for multicyclone separators under different pressures and temperatures.

In order to evaluate the gas-liquid separation performance of cyclone separator for purification of natural gas at low liquid concentration，membrane filtration method and optical particle counter Welas 2000 were applied to measure the overall collections and droplet size distributions，respectively，with inlet velocities of 8—24 m·s^-1 and liquid concentrations of 0.1—2 g·m^-3 and under atmospheric pressure and room temperature.Comparisons of separation performance have been done between gas-liquid and gas-solid separation under the same inlet velocity and liquid/solid concentration.The results of experiments showed that the gas-liquid separation efficiencies increased with the increase of inlet velocity of 8—24 m·s^-1 and liquid concentration 0.1—2 g·m^-3.The separation efficiencies of gas-liquid separation were 2%—6% higher than those of gas-solid separation under the same conditions.The droplets with the diameter size bigger than 4 μm could be removed clearly，however，there were particles with the diameter bigger than 10 μm existed in cyclone separator outlet.

PIV technique（particle image velocimetry）is utilized to measure the instantaneous velocity fields in swirling pulverized coal nonpremixed combustion under different staged air injections. The influence of turbulent coherent structure on combustion characteristics and NO formation is studied.Near the inlet of the combustor，larger secondary air ratio leads to early spread of coherent structures and entrainment of small pulverized coal particles into these structures，therefore，the central gas temperature is higher;smaller secondary air ratio makes more big particles move to the vicinity of the wall under the effect of inertial centrifugal forces，resulting in higher gas temperature near wall.In this experiment，larger secondary air ratio contributes to the formation of longitudinal vortices in shear layers and transverse vortices in the field，combustion of small particles and volatilization of big particles，and initially enhances the NO formation，but subsequently stimulates the reaction of NO reduction by intermediate products，and finally slightly decreases the NO concentration.

The basic data of thermodynamics, kinetics and catalytic packing are used in this thesis to simulating the process of methyl acetate hydrolysis via catalytic distillation by the method of chemical engineering process simulation and analysis.By comparing the simulation results and experimental results, the correctness of the mathematical model is also validated.The feeding position of methyl acetate and water from overhead, the ratio of water to methyl acetate in feed and the ratio of top reflux to feed methyl acetate ranges are obtained by the tool of sensitivity analysis of software.Two new processes for hydrolysis of methyl acetate were proposed on the basic of the process simulation and industrial practice.

To investigate the performances of rough-cut cyclone in FCC disengager, two-fluid model provided by Fluent 6.2 was used for simulation of the dense phase flow.Agglomeration among particles was calculated by a set of improved gas-solid drag expressions.The results show that separation efficiency of rough-cut cyclone for catalyst reaches 98.48%.The solid concentration influences on the leakage of gases off dipleg are involved in three mechanisms: weakening on the gas swirling motion, dragging forces fundamentally caused by the particle gravitation and the wrapping effects onto the gas.The leakage ratio of the dipleg is 32.17% and it can be reduced to 20.97% by adding a hopper.It is proved that the concentration turning point for pressure drop is a function concerning particle density, viscosity and granular sizes.Pressure drops of rough-cut cyclone calculated by the wall film growth theory have good agreement with numerical simulation results.

A complex system of activated sludge and bio-membrane system was used for enrichment of denitrifying phosphorus bacteria (DPB).DPB strains were isolated and identified.In order to study their metabolic mechanism,activity test of denitrifying and accumulating phosphorus was carried out on both fermented and non-fermented bacteria.The result shows: (1)YU-1 and YU-2 were obtained by separation of DPB with combined activated sludge and biofilm method.The former is similar to Acinetobacter junii, a kind of non-fermented DPB and the latter similar to Escherichia coli, a kind of fermented DPB.(2)During the anaerobic stage for every 1 mg of PHA generated the phosphorus release is 0.2 mg larger for non-fermented bacteria YU-1 than the fermented bacteria YU-2.The energy required for the synthesis of PHA is mainly from the degradation of poly-phosphate, the majority of carbon from the acetic acid, reduced coenzyme NADH not from the glycolysis process of glycogen.The mechanism for generation of ATP,PHA and NADH are different from the traditional metabolic mechanism.(3)Under anoxic environment for every 1 mg of PHA decomposed the phosphorus accumulation is 0.3 mg higher for non-fermented bacteria YU-1 than the fermented bacteria YU-2,which means the accumulating efficiency is 12.8% higher.The reason can be that in this stage the most of ATP generated from the decomposition of PHB is used for the transport of phosphate and the synthesis of poly-phosphorus, reduced coenzyme NADH come from the breakdown of PHA for the reduction power required for anaerobic process.The mechanism of PHA decomposition is different from the metabolic mechanism of traditional phosphorus accumulating bacteria.

An experiment is performed to investigate the effects of several key factors on the efficiency of ammonia desulphurization.The experimental results show that it is possible to improve the desulphurization efficiency by some ways，such as increasing the liquid-gas ratio and slurry pH value，lowering the flue gas temperature or its flow speed.Based on the two-film theory，a mathematical model for ammonia desulphurization in spray towers is established.With the analysis on the correlation between the mass transfer rate equation of SO₂ and the spiral-type nozzle droplet diameter，this model is used to calculate the main factors affecting the desulphurization efficiency.The calculation results are consistent with experimental data.

The objective of this work is to study the mixed incineration of municipal solid waste（MSW）and Chinese low-grade coal in a 1.5 MW circulating fluidized bed boiler（CFB）presenting experimental results regarding some composition emissions involving CO，HCl，SO₂，NO_x，H₂O and dioxins.The flue gas online monitor is used to analyze the composition and concentration to evaluate the emissions characteristics.The experimental results show that CO content in flue gas increases with the increasing in proportion of W_waste/W_coal+waste.While with the increasing in proportion of W_waste/W_coal+waste，the increase of HCl content is nearly linear，and the concentration of SO₂ decreased.Test results have also confirmed that the properties of CFB incineration lead to considerable reduction of NO_x，but the significant increase of N₂O emission.Furthermore，the concentration of H₂O and dioxins increase with the increasing in proportion of W_waste/W_coal+waste，so removal of dioxins must be considered in the practical application of this technology.

The hydrous thermo-simulation experiments on Liushuhe oil shale were conducted in autoclave.Consecutive first order reaction model involving bitumen as an intermediate product was developed to determine the kinetic parameters.It was found that the apparent activation energy of kerogen pyrolysis was about 110 kJ·mol^-1, which was lower than the apparent activation energy of bitumen pyrolysis.According to the results, the mechanism of oil shale pyrolysis and the influence of aqueous medium were tentatively investigated.Compared to anhydrous pyrolysis, the maximum pyrolysis temperature under saturated condition was about 120℃ lower.

TG analysis was used to investigate the thermal decomposition of flax fibers which are a potential gasification feedstock.10 mg flax shive samples with the particles between 0.60 and 0.85 mm was linearly heated to 550℃ at heating rates of 10, 20, 30, 50 K·min^-1,respectively, under high-purity nitrogen. Coats-Redfern model fitting method and model-free methods include Kissinger method and three isoconversional methods (Friedman, Flynn-wall-Ozawa, Vyazovkin and Wight methods) were used to estimate the apparent activation energy of the fax fibers.With the three isoconversional methods,it can be concluded that the activation energy increases with increasing conversion.The four model free methods indicated activation energies in the range of 155—175 kJ·mol^-1.Activation energies by Coats-Redfern model fitting method was about 175 kJ·mol^-1,close to the values by model free method.These activation energy values provide the basic data for the thermo-chemical utilization of the flax fibers.

In order to investigate different influencing parameters acting on ultrasonic demulsification effect, a comprehensive analysis of ultrasonic intensity, dehydration temperature, acting time and emulsion water content was carried out with emulsified waste oil and machinery oil as experimental materials.Results indicate that, with ultrasonic intensity and demulsification temperature increasing, the displacement and demulsification effects of ultrasound enhance.With the increase of ultrasonic time, demulsification velocity enhances rapidly at first and then tends to slow.Water content of emulsion takes on complex influencing laws, which is depended on water droplet granularity distribution in waste oil emulsion and the characteristics of ultrasonic demulsification.Besides, oil viscosity and density affect ultrasonic demulsification greatly.The demulsification of oil with higher oil viscosity and density is less affected by ultrasound intensity, while it is sensitive to the dehydration temperature.

To explore an effective method for reducing tar yield in biomass gasification, effects of petroleum coke on tar cracking during the gasification process of lees were examined. The influences of petroleum coke feeding mode and particle size, water content in lees were tested in an electrically heated fixed bed tubular reactor at 700℃ under atmospheric pressure. Results show that the petroleum coke obviously affects the tar cracking in biomass gasification. Entering petroleum coke before lees into the reactor and using small petroleum coke particles are favorable for the tar cracking. The water content in lees also promotes the tar cracking and the yields of H₂ and CO, however has little impact on the productions of CH₄. The results are helpful to the research and development of the new co-gasification process of high water content biomass and petroleum coke.