Experiments and simulations on flow and heat transfer behavior of Therminol-55 liquid phase heat transfer fluid have been conducted in a ribbed tube with the outer diameter and inner diameter 25.0 and 20.0 mm, pitch and rib height of 4.5 and 1.0 mm. respectively. Experimental results show that the heat transfer and thermal performance of Therminol-55 liquid phase heat transfer fluid in the ribbed tube are considerably improved compared to those of the smooth tube. The Nusselt number increase with the increase of Reynolds number. The increase in heat transfer rate of the ribbed tube has a mean value of 2.24 times. Also, the pressure drop results reveal that the average friction factor of the ribbed tube is in a range of 2.4 and 2.8 times over the smooth tube. Numerical simulations of three-dimensional flow behavior of Therminol-55 liquid phase heat transfer fluid are carried out using three different turbulence models in the ribbed tube. The numerical results show that the heat transfer of ribbed tube is improved because vortices are generated behind ribs, which produce some disruptions to fluid flow and enhance heat transfer compared with smooth tube. The numerical results prove that the ribbed tube can improve heat transfer and fluid flow performances of Therminol liquid phase heat transfer fluid.

The aim of this study is to use a new configuration of porous media in a heat exchanger in continuous hydrothermal flow synthesis (CHFS) system to enhance the heat transfer and minimize the required length of the heat exchanger. For this purpose, numerous numerical simulations are performed to investigate performance of the system with porous media. First, the numerical simulation for the heat exchanger in CHFS system is validated by experimental data. Then, porous media is added to the system and six different thicknesses for the porous media are examined to obtain the optimum thickness, based on the minimum required length of the heat exchanger. Finally, by changing the flow rate and inlet temperature of the product as well as the cooling water flow rate, the minimum required length of the heat exchanger with porous media for various inlet conditions is assessed. The investigations indicate that using porous media with the proper thickness in the heat exchanger increases the cooling rate of the product by almost 40% and reduces the required length of the heat exchanger by approximately 35%. The results also illustrate that the most proper thickness of the porous media is approximately equal to 90% of the product tube's thickness. Results of this study lead to design a porous heat exchanger in CHFS system for various inlet conditions.

The flow of pseudoplastic power-law fluids with different flow indexes at a microchannel plate was studied using computational fluid dynamic simulation. The velocity distribution along the microchannel plate and especially in the microchannel slits, flow pattern along the outlet arc and the pressure drop through the whole of microchannel plate were investigated at different power-law flow indexes. The results showed that the velocity profile in the microchannel slits for low flow index fluids was similar to the plug flow and had uniform pattern. Also the power-law fluids with lower flow indexes had lower stagnation zones near the outlet of the microchannel plate. The pressure drop through the microchannel plate showed huge differences between the fluids. The most interesting result was that the pressure drops for power-law fluids were very smaller than that of Newtonian fluids. In addition, the heat transfer of the fluids through the microchannel with different channel numbers in a wide range of Reynolds number was investigated. For power-law fluid with flow index (n=0.4), the Nusselt number increases continuously as the number of channels increases. The results highlight the potential use of using pseudoplastic fluids in the microheat exchangers which can lower the pressure drop and increase the heat transfer efficiency.

The accurate prediction of the droplet size distribution (DSD) in liquid-liquid turbulent dispersions is of fundamental importance in many industrial applications and it requires suitable kernels in the population balance model. When a surfactant is included in liquid-liquid dispersions, the droplet breakup behavior will change as an effect of the reduction of the interfacial tension. Moreover, also the dynamic interfacial tension may be different with respect to the static, due to the fact that the surfactant may be easily desorbed from the droplet surface, generating additional disruptive stresses. In this work, the performance of five breakup kernels from the literature is assessed, to investigate their ability to predict the time evolution of the DSD and of the mean Sauter diameter, when different surfactants are employed. Simulations are performed with the Quadrature Method of Moments for the solution of the population balance model coupled with the two-fluid model implemented in the compressibleTwoPhaseEulerFoam solver of the open-source computational fluid dynamics (CFD) code OpenFOAM v. 2.2.x. The time evolution of the mean Sauter diameter predicted by these kernels is validated against experimental data for six test cases referring to a stirred tank with different types of surfactants (Tween 20 and PVA 88%) at different concentrations operating under different stirrer rates. Our results show that for the dispersion containing Tween 20 additional stress is generated, the multifractal breakup kernel properly predicts the DSD evolution, whereas two other kernels predict too fast breakup of droplets covered by adsorbed PVA. Kernels derived originally for bubbles completely fail.

This research work numerically analyzes 2D, steady state, mixed convective heat transfer for Newtonian fluids in lid driven square enclosure with centered triangular block (blockage-10% or 30%) maintained either at the constant wall temperature or constant heat flux thermal conditions. The fluid flow in the enclosure is initiated by top moving wall in + x-direction, while all other walls are stationary. The top and bottom walls are thermally insulated. In particular, the governing field equations are solved for range of governing parameters such as, Reynolds number (1-1000), Prandtl number (1-100), and Grashof number (0-10⁵). It is observed that the increase in inertial force enhances the heat transfer rate up to certain Reynolds number range (80-200), later deterioration of heat transfer rate is observed. Such behavior is found to be true for lower blockage (10%). Finally, functional dependence of average Nusselt number values with flow governing dimensionless parameters is developed and presented for its possible utilization in engineering and design purpose.

The hydrophobically modified ceramic membranes have great potential for energy-efficient membrane distillation. In this work, flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-perfluorooctyltrichlorosilane or 1H,1H,2H,2H-perfluorodecyltriethoxysilane and followed by ultraviolet irradiation. The surface water contact angle was improved from 46° of original ceramic membrane to 159°, which exhibited a stable and excellent superhydrophobic effect. The modified membranes showed a high flux of 27.28 kg·m^-2·h^-1 and simultaneously maintained an excellent retention rate of 99.99%, when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl (75℃) aqueous solution. These results suggested that superhydrophobic modification of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance. The superhydrophobically-modified ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.

In this study, polyvinyl alcohol (PVA)-ionic liquid (IL) membranes were prepared for the separation of isopropyl alcohol (IPA)-water azeotropic mixtures by pervaporation. PVA-IL composite membranes were prepared by simple solvent evaporation method using four ILs, viz., 1-n-butyl-3-methylimidazolium chloride (BMIMCl), 1-hexyl-3-methylimidazolium chloride (HMIMCl), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) and 1-octyl-3-methylimidazolium chloride (OMIMCl). Three ILs were used to study the effect of alkyl chain on the pervaporation performance. The study had focused on the effect feed water concentration from 10%-40% and effect of feed temperature from 50-80℃. Physiochemical properties of all the membranes were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement. The Arrhenius activation energies for permeation were estimated to be in the range 4-12 kJ·mol^-1 from the temperature dependent permeation values.

In the present work, the effect of pre-calcination on carbonation conversion and cyclic stability of modified CaObased sorbent was investigated by thermogravimetric analyzer (TGA). The modified CaO-based sorbents with CaAc₂ as precursor were respectively doped with different elements (Mg, Al, Ce, Zr and La). The specific surface area, pore volume and pore size distribution were tested by N₂ isothermal adsorption measurements. The phase compositions of sorbents were characterized by X-ray diffraction (XRD). The results showed that the cyclic stabilities of the sorbents were improved by pre-calcination. The pre-calcination was conducted at 900℃ for 5 h in air by the muffle furnace. With pre-calcination, the cyclic stabilities of sorbents could be as high as 96% after 22 cycles, such as CaO-Al, CaO-Ce and CaO-La. After contact with air, the carbonation conversions of spent sorbents with pre-calcination suddenly increased by about one-sixth due to the change of channel structure by hydration. Both the cyclic stability of sorbent and the durability of reactivation were related to the structural stability of sample, especially the stability of mesopores between 2 nm and 5.5 nm. The present work also provided an easy and low-cost method for reactivating the spent CaO-based sorbents.

A systematic study of the synthesis of C.I. Acid Blue 9 leuco compound in water is reported. The kinetic analysis of experimental data for the condensation reaction between 2-formylbenzenesulfonic acid sodium and N-ethyl-N-(3'-sulfonic acid benzyl) aniline obtained at four different temperatures ranging between 85 and 100℃ is discussed. It is shown that the reaction followed second-order rate kinetics. The overall rate constant (k) increased with the increase of temperature. On the basis of the value of k, activation energy (E_a) of the reaction was evaluated. Importantly, it is found that reactant concentration has great effect on the formation of C.I. Acid Blue 9 leuco compound, implying that it is not enough to improve the conversion of N-ethyl-N-(3'-sulfonic acid benzyl) aniline by only prolonging reaction time in the late period of the reaction.

The Fe-modified sepiolite-supported Mn-Cu mixed oxide (CuxMny/Fe-Sep) catalysts were prepared using the co-precipitation method. These materials were characterized by means of the XRD, N₂ adsorption-desorption, XPS, H₂-TPR, and O₂-TPD techniques, and their catalytic activities for CO and ethyl acetate oxidation were evaluated. The results show that catalytic activities of the CuxMny/Fe-Sep samples were higher than those of the Cu1/Fe-Sep and Mn2/Fe-Sep samples, and the Mn/Cu molar ratio had a distinct influence on catalytic activity of the sample. Among the CuxMny/Fe-Sep and Cu1Mn2/Sep samples, Cu1Mn2/Fe-Sep performed the best for CO and ethyl acetate oxidation, showing the highest reaction rate and the lowest T₅₀ and T₉₀ of 4.4×10^-6 mmol·g^-1·s^-1, 110, and 140℃ for CO oxidation, and 1.9×10^-6 mmol·g^-1·s^-1, 170, and 210℃ for ethyl acetate oxidation, respectively. Moreover, the Cu1Mn2/Fe-Sep sample possessed the best lowtemperature reducibility and the lowest temperature of oxygen desorption as well as the highest surface Mn⁴⁺/Mn³⁺ and Cu²⁺/CuO atomic ratios. It is concluded that factors, such as the strong interaction between the Cu or Mn and the Fe-Sep support, good low-temperature reducibility, and good mobility of chemisorbed oxygen species, might account for the excellent catalytic activity of Cu1Mn2/Fe-Sep.

The uncatalyzed reaction of p-tolyl isocyanate (p-TI) with water in N,N-dimethylformamide (DMF) was investigated by high performance liquid chromatography (HPLC). The reactions were carried out at different temperatures from 293 K to 323 K, using various molar ratios of water to p-TI. DMF, as a special amide, was proved to be an efficient catalyst for water-isocyanate reaction. Under the reaction conditions in this study, substituted urea was the only final product observed. An appreciable amount of intermediate p-toluidine was detected. Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time. New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism, instead of a simple second order reaction as usual. Kinetic constants were calculated using the software MATLAB. Furthermore, the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed. The activation energy of each step was also determined.

Carbon deposition is sensitive to the metal particle sizes of supported Ni catalysts in CH₄/CO₂ reforming. To explore the reason of this phenomenon, Ni4, Ni8, and Ni12 which reflect the different cluster thicknesses supported on the MgO(100) slabs, have been employed to simulate Ni/MgO catalysts, and the reaction pathways of CH₄/CO₂ reforming on Nix/MgO(100) models are investigated by density functional theory. The reforming mechanisms of CH₄/CO₂ on different Nix/MgO(100) indicate the energy barriers of CH₄ dissociated adsorption, CH dissociation, and C oxidation three factors are all declining with the decrease of the Ni cluster sizes. The Hirshfeld charges analyses of three steps as described above show only Ni atoms in bottom two layers can obtain electrons from the MgO supporters, and the main electron transfer occurs between adsorbed species and their directly contacted Ni atoms. Due to more electron-rich Ni atoms in contact with the MgO supporters, the Ni/MgO catalysts with small Ni particles have a strong metal particle size effect and lead to its better catalytic activity.

A new generic reaction in the form of PC_i → PC_m +[i,m] → PC_m + λ_i,m coke + surplusage has been proposed for describing the catalytic cracking behavior of petroleum narrow cuts or pseudo-components (PCs), where the rate constant formula is derived from the transition state theory and the coking amount is correlated to the properties of the intermediate substance[i,m]. In composing the cracking reaction network for feedstock and product oils, only the product PC_m of the proposed generic reaction is used, which together with a criterion for excluding exothermic reactions, distinctly reduces the number of reactions in the network. With the proposed cracking reaction scheme coupled with special pseudo-components, a predictive one-dimensional steady state model for fluid catalytic cracking risers is formulated in the sense that for a given riser and given catalyst, the model parameters are independent of stock oils, product schemes and other operational conditions. The great correlating and predicting capability of the resulted model is tested with production data in different scenarios of four commercial risers.

The solubility of meropenem trihydrate in water + acetone mixtures and water + tetrahydrofuran mixtures were determined from T=(278.15 to 303.15) K by static method under atmospheric pressure. Effects of solvent composition and temperature on solubility of meropenem trihydrate were discussed. To extend the applicability of the solubility data, experimental solubility data in two kinds of binary solvent mixtures were correlated by the Apelblat equation and NIBS/Redlich-Kister model. It was found that the two models could satisfactorily correlate the experimental data and the Apelblat equation could give better correlation results.

Solid-liquid phase equilibrium data for binary (L-arabinose-water) and (D-xylose-water) systems at temperatures from (269.85-298.05) K and ternary (L-arabinose-D-xylose-water) system at temperatures of 273.85 K, 278.85 K and 284.45 K were measured at atmospheric pressure. The ternary phase diagrams of the systems were constructed on the base of the measured solubility. Two pure solid phases were formed at given temperatures, including pure L-arabinose and pure D-xylose, which were confirmed and determined by the method of Schreinemakers' wet residue. At the same temperature, the crystallization region of L-arabinose was larger than D-xylose's. The acquired solubility data were then correlated using the NRTL model, Wilson model and Xu model. The calculated solubility with the three models agreed well with the experimental values.

The solubilities of trimethylolethane in butanol, methyl acetate, ethyl acetate as well as in mixed solvents of (methanol + ethyl acetate) and (ethanol + ethyl acetate) were measured with the gravimetric method in the temperature range from 283.15 K to 318.15 K under atmosphere pressure. The experiment results showed that the solubility of trimethylolethane increased with the temperature, or along with the concentration of methanol or ethanol in the solvents of (methanol + ethyl acetate) and (ethanol + ethyl acetate). In addition, the experiment values were correlated by the van't Hoff equation, Modified Apelblat Equation, λh Equation, CNIBS/R-K equation and Jouyban-Acree Model. The Modified Apelblat Equation provided the best fitting results of the solubility data of TME in the pure solvents while the CNIBS/R-K model showed the best estimation of the solubility in the binary solvent mixtures. Furthermore, the density functional theory (DFT) calculations showed that solubility in different solvents related to the strength of the interaction between the trimethylolethane and the solvent molecules. Finally, the standard molar enthalpy and molar entropy of trimethylolethane during the dissolving process was also calculated by Modified Apelblat equation in this work.

The thermodynamic properties of metamizol monohydrate in pure solvents (methanol, ethanol, n-propanol and isopropanol) and two binary mixed solvent systems including (methanol + ethanol) and (methanol + isopropanol) were measured from 283.15 K to 313.15 K by gravimetric method under atmospheric pressure thought as 0.1 MPa. The modified Apelblat equation, the CNIBS/R-K equation, the Hybrid model and the NRTL model were used to correlate the solubility of metamizol monohydrate, respectively. The results show that the solubility of metamizol monohydrate in all the tested solvents increases with the rising temperature which means that it has temperature dependence. What's more, the effects of solvent components of the binary solvent mixtures on solubility were discussed, it illustrates that the increasing of the molar fraction of methanol gives the system a greater dissolving power. Furthermore, according to the NRTL model, the enthalpy, the Gibbs energy and the entropy of the mixing process were also obtained and discussed.

Recovering waste heat from industrial processes is beneficial in order to reduce the primary energy demands and heat pumps can be used to this purpose. Absorption heat pumps are energy-saving and environment-friendly because use working fluids that do not cause ozone depletion and can reduce the global warming emissions. The hybrid heat pump processes combine the conventional vapor-compression and the absorption heat pump cycles. Studies about the simulations and modeling of hybrid heat pumps are few in literature. In this research a mathematical model for single effect absorption and hybrid heat pump is carried out with ChemCad^® 6.0.1. LiBr-H₂O is used as working fluid while electrolytic NRTL and electrolytes latent heat are used as thermodynamic model due to the better results. Binary parameters of activity coefficients are regressed from experimental vapor pressure data while default constants are used for the solubility expressions. A design of heat pumps is developed and a new modeling of generator is analyzed. The coefficient of performance of absorption heat pump and hybrid heat pump is equal to 0.7 and 0.83 respectively. For absorption heat pump a sensitivity analysis is carried out to evaluate the effect of temperature and pressure generator, the concentration of Li-Br solution on coefficient of performance, cooling capacity and working fluid temperature. For hybrid heat pump, the different coefficients of performance, the primary energy ratio, the generator heat, and the compressor power are analyzed for different values of compressor proportion. Results show that comparing the two systems the hybrid pump allows to save more primary energy, costs and carbon dioxide emissions with respect to absorption heat pump with the increasing of compressor proportion parameter. Future researches should focus on the construction of this heat pumps integrated in chemical processes as a biogas plant or trigeneration systems.

Oxytetracycline (OTC) and tetracycline (TC) are the most common TC antibiotics used in human and veterinary medicine. Residual amounts of these antibiotics in manure pose a potential threat to public and ecological health as a result of the potential for them to be released to the environment following land application of manure from animals treated with antibiotics. We investigated the degradation of OTC and TC during anaerobic composting. We tested the effects of temperature and antibiotic concentration on degradation rates in a control and in manure spiked with TCs. We examined changes in pH, biological degradation material (BDM), and moisture corresponding with antibiotic degradation of TCs in the swine manure. Results showed that the OTC and TC concentrations decreased by between 68.54% and 95.50% in all nine treatments following 14 days of anaerobic composting, and the highest removal efficiencies were observed at an incubation temperature of 55℃ and initial concentrations of 10.36 μg·g^-1, and 5.96 μg·g^-1 of OTC and TC, respectively, which were degraded by 95.50%, and 90.06%. During composting at 55℃ and at added concentrations of 5 μg·g^-1, OTC decreased rapidly, and the time required for 50% and 90% degradation was 4.1 and 9.8 days, respectively; for TC, these values were 4.4 and 14.0 days, respectively. Removal efficiencies for all TCs correlated well with moisture content of the manure. These results show that composting may be a practical and useful means to reduce concentrations of OTC and TC in swine manure prior to its land application.

Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor (TPPB). The liquid phase consisted of a mixture of water and PDMS 50 (PolyDiMethylSiloxane, i.e. silicone oil, viscosity of 46 mPa·s) in the volume ratio of 75%/25%. Two series of experiments were carried out:in the first, the reactor was sequentially supplied with toluene whereas in the second, toluene was continuously supplied. Activated sludge from the wastewater treatment plant of Beaurade (Rennes, France) was used at an initial concentration of 0.5 dry mass g·(mixture L)^-1. The elimination capacity (EC) was investigated as well as the change in biomass concentration over time. Toluene biodegradation was very efficient (removal efficiency, RE=100%) for toluene flows ranging from 0.2 to 1.2 ml·h^-1, corresponding to elimination capacities of up to 104 g·m-³·h^-1. For a toluene flow of 1.2 ml·h^-1, the biomass concentration measured at the end of the experiment was 4.7 dry mass g·(mixture L)^-1. The oxygen concentration in the liquid phase was clearly not a limiting factor in these operating conditions. Based on these results, an extrapolation leading to the design of a large-scale pilot TPPB can now be considered to study toluene degradation performances in industrial conditions.

Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Brønsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate ([BHSO₃MIM] [HSO₄]) was systematically investigated. The optimum molar ratio of methanol to waste oils, catalyst amount, reaction temperature and reaction time were 8/1, 10% (based on the mass of waste oils), 140℃ and 6 h, respectively, under which the obtained yield of biodiesel reached 94.9%. Also,[BHSO₃MIM] [HSO₄] as a catalyst still retained around 97% of its original catalytic activity after successive re-use of 5 batches (6 h per batch), showing the excellent operational stability. Moreover, the acidic IL[BHSO₃MIM] [HSO₄] was able to efficiently catalyze conversions of waste oils with different amounts of FFAs (free fatty acids) into biodiesel, and showed tremendous application potential. Therefore, an efficient and environmentally friendly catalyst is provided for the synthesis of biodiesel from waste oils with high acid value.

Aiming to identify the validity of fabricating microencapsulated phase change material (PCM) with polymethylmethacrylate (PMMA) by ultraviolet curing emulsion polymerization method using iron (Ⅲ) chloride as photoinitiator, SA/PMMA microcapsules were prepared and various techniques were employed to determine the ignition mechanism, structural characteristics and thermal properties of the composite. The results shown that the microcapsules containing SA with maximum percentage of 52.20 wt% formed by radical mechanism and only physical interactions existed in the components both in the prepared process and subsequent use. The phase change temperatures and latent heats of the microencapsulated SA were measured as 55.3℃ and 102.1 J·g^-1 for melting, and 48.8℃ and 102.8 J·g^-1 for freezing, respectively. Thermal gravimetric analysis revealed that SA/PMMA has good thermal durability in working temperature range. The results of accelerated thermal cycling test are all shown that the SA/PMMA have excellent thermal reliability and chemical stability although they were subjected 1000 melting/freezing cycles. In summary, the comparable thermal storage ability and good thermal reliability facilitated SA/PMMA to be considered as a viable candidate for thermal energy storage. The successful fabrication of SA/PMMA capsules indicates that ferric chloride is a prominent candidate for synthesizing PMMA containing PCM composite.

Friedel-Crafts alkylation of benzene with linear chain olefin (C₁₀-C₁₄), which is an important reaction of synthetic detergent, was studied via different catalysts of aluminum impregnated silica molecular sieves. AlCl3 was immobilized on silica molecular sieves with different channel structures, hexagonal packing channels network (SBA-15, MCM-41), and disordered channel network (SiO₂, SiO₂-Gel) by impregnation. XRD and N₂ adsorption-desorption isotherms confirmed that the specific mesoporous structures were maintained for order channel network catalyst after impregnation. Catalytic activities were investigated under different conditions. The influences of channel structure were discussed. The results showed that catalyst based on mesoporous like SBA-15 had the highest catalytic activities and 2-LAB selectivity compared with other catalysts in this work. The highest 2-LAB selectivity was nearly 50% when 1-dodecene conversion was nearly 100%. At low 1-dodecene conversion or higher benzene/1-dodecene molar ratio, 2-LAB selectivity was nearly 60%.

In Na₂O-CaO-SiO₂-H₂O system, systematic investigations of phase and morphology of calcium silicate in hydrothermal conditions were concisely conducted for high-value utilization of silicon resource in high-alumina fly ash (HAFA). The results show that crystal composition and phase may be affected by relatively low concentration of NaOH, and sodium ions are rearranged into the structure to form NaCaHSiO₄ and Na₂Ca₃H₈Si₂O₁₂ with different C/S ratio at high concentration of NaOH. In addition, phases in wollastonite group possess the morphology of nanofiber. Formation of nanofiber is attributed to the difference of surface energies between axial and radial direction, and higher temperatures lead to easier growth along radial direction. The preparation of C-S-H with different phases and morphologies can guide for the application of silicate solution with high alkalinity with different purposes.

Sodium carbonate and carboxymethyl cellulose powders are compressed into two-component tablets with three mass ratios, 97%:3%, 95%:5% and 93%:7%. The dissolution tests for two-component tablets and reference pure sodium carbonate tablets are carried out at various temperatures. The dissolution process of each tablet is measured by electrical conductivity tracking method and the concentration of dissolved sodium carbonate is quantified with calibrated conductivity-concentration converting equation of sodium carbonate. The quantified dissolution data is fitted with both surface reaction model and diffusion layer model and the results clearly show that surface reaction model is suggested as the appropriate dissolution model for all measured tablets. Therefore, it is determined that carboxymethyl cellulose is a stable element to remain the dissolution mechanism of tablet unchanged. The dissolution rate constant quantified with surface reaction model presents that carboxymethyl cellulose-sodium carbonate two-component tablets obtain significant higher dissolution rate constant than pure sodium carbonate tablet and higher proportion of carboxymethyl cellulose leads to apparent higher dissolution rate constant. The results prove for the usage of carboxymethyl cellulose in most practical applications at a relative low-level, the effect of carboxymethyl cellulose is effective and positive for two-component tablet to enhance the dissolution process and improve dissolution rate constant and this effect is speculated coming from its dynamic physical transforming process in water including dilation and conglutination.