共查询到20条相似文献,搜索用时 0 毫秒
1.
Heon Jung Jung Hoon Yang Ho-Tae Lee Dong Hyun Chun Hak-Joo Kim 《Fuel Processing Technology》2010,91(12):1839-1844
A bench scale slurry bubble column reactor (SBCR) with active-Fe based catalyst was developed for the Fischer-Tropsch synthesis (FTS) reaction. Considering the highly exothermic reaction heat generated in the bench scale SBCR, an effective cooling system was devised consisting of a U-type dip tube submerged in the reactor. Also, the physical and chemical properties of the catalyst were controlled so as to achieve high activity for the CO conversion and liquid oil (C5+) production. Firstly, the FTS performance of the FeCuK/SiO2 catalyst in the SBCR under reaction conditions of 265 °C, 2.5 MPa, and H2/CO = 1 was investigated. The CO conversion and liquid oil (C5+) productivity in the reaction were 88.6% and 0.226 g/gcat-h, respectively, corresponding to a liquid oil (C5+) production rate of 0.03 bbl/day. To investigate the FTS reaction behavior in the bench scale SBCR, the effects of the space velocity and superficial velocity of the synthesis gas and reaction temperature were also studied. The liquid oil production rate increased up to 0.057 bbl/day with increasing space velocity from 2.61 to 3.92 SL/h-gFe and it was confirmed that the SBCR bench system developed in this research precisely simulated the FTS reaction behavior reported in the small scale slurry reactor. 相似文献
2.
Chufu Li 《中国化学工程学报》2018,26(5):1102-1109
To optimize industrial Fischer–Tropsch(FT) synthesis with the slurry bubble column reactor(SBCR) and ironbased catalyst, a comprehensive process model for FT synthesis that includes a detailed SBCR model, gas liquid separation model, simplified CO_2 removal model and tail gas cycle model was developed. An effective iteration algorithm was proposed to solve this process model, and the model was validated by industrial demonstration experiments data(SBCR with 5.8 m diameter and 30 m height), with a maximum relative error b 10% for predicting the SBCR performances. Subsequently, the proposed model was adopted to optimize the industrial SBCR performances simultaneously considering process and reactor parameters variations. The results show that C_(5+) yield increases as catalyst loading increases within 10–70 ton and syngas H_2/CO value decreases within1.3–1.6, but it doesn't increase obviously when the catalyst loading exceeds 45 ton(about 15 wt% concentration).Higher catalyst loading will result in higher difficulty for wax/catalyst separation and higher catalyst cost. Therefore, the catalyst loading(45 ton) is recommended for the industrial demonstration SBCR operation at syngas H_2/CO = 1.3, and the C_(5+) yield is about 402 ton" per day, which has an about 16% increase than the industrial demonstration run result. 相似文献
3.
4.
Kwang-Jae Woo 《Fuel Processing Technology》2010,91(4):434-439
The CO conversion and selectivity to C1+ and C11+ wax products over Co/Al2O3 as well as Ru/Co/Al2O3 Fischer-Tropsch (F-T)catalysts were investigated by varying reaction temperature (210-250 °C), system pressure (1.0-3.0 MPa), GHSV (1000-6000 L/kg/h), superficial gas velocity (1.7-13.6 cm/s) and slurry concentration (9.09-26.67 wt.%) in a slurry bubble column reactor (0.05 m diameter × 1.5 m height) to determine the optimum operating conditions. Squalane or paraffin wax was used as initial liquid media. The overall CO conversion increased with increasing reaction temperature, system pressure and catalyst concentration. However, the local maximum CO conversion was exhibited at GHSV of 1500-2000 L/kg/h and superficial gas velocity of 3.4-5.0 cm/s. The CO conversion in the case of Ru/Co/Al2O3 was much higher and stable than that in the case of Co/Al2O3. The selectivity to C11+ wax products increased slightly with increasing GHSV; on the other hand, it decreased with increasing reaction temperature, system pressure, and solid concentration in a slurry bubble column reactor. It could be concluded that the optimum operating conditions based on the yield of hydrocarbons and wax products were; UG = 6.8-10 cm/s, Cs = 15 wt.%, T = 220-230 °C, P = 2.0 MPa in a slurry bubble column reactor for F-T synthesis. 相似文献
5.
Low Temperature Liquid State Synthesis of Lithium Zirconate and its Characteristics as a CO2 Sorbent
《分离科学与技术》2012,47(2):283-296
Abstract In this study, a new preparation method providing greatly improved CO2 sorption is introduced. Li2ZrO3 sorbent was prepared by low temperature co‐precipitation and compared in CO2 sorption performance with a sorbent prepared by the conventional high temperature solid‐state reaction method. The two sorbents were characterized using scanning electron microscopy, X‐ray diffraction and thermo‐gravimetric analysis. The Li2ZrO3 powder prepared by the relatively simple co‐precipitation method showed significantly better performance than the one prepared by solid‐state reaction with respect to both kinetics and CO2 sorption capacity. Extensive study of the powder prepared by co‐precipitation has been performed at various conditions. 相似文献
6.
Reaction performance of a CuCr/CH3ONa catalyst for the low-temperature methanol synthesis was examined in a bubble column slurry reactor with a flash column (BCSR/FC). The BCSR/FC was operated at 4.5 ± 0.2 MPa/110–120 °C for BCSR and 0.4 ± 0.1 MPa/80–90 °C for FC, although fluctuation of operation parameters was larger. Syngas conversion decreased from 71.0% to 19.8% during the operation test in 100 h, which was attributed to consumption of CH3ONa and a negative effect of the emulsifier OP-10 used. 相似文献
7.
《分离科学与技术》2012,47(5):772-780
In this study, the performance enhancement of CO2 capture and separation by the SiO2 nanoparticles and surfactants is evaluated. The main objectives are to test the dispersion stability of nanofluids (DI water with nanoparticles and surfactants), to quantify the effect of the nanoparticles and surfactants on the CO2 capture and separation performance, and to find the optimum conditions of the nanoparticles and surfactants. It is found that the CO2 capture and separation performances are enhanced up to 13.1% and 7.8% at the nanoparticle concentration of 0.01 vol%, respectively. It is concluded that nanoparticles enhance both CO2 capture and separation rates, while the surfactants enhance the CO2 capture rate but they interrupt the CO2 separation rate. 相似文献
8.
Qi Zhang Dong Peng Sai Zhang Qian Ye Yongqiang Wu Yanhui Ni 《American Institute of Chemical Engineers》2017,63(6):2153-2164
The absorption behaviors of Li4SiO4 sorbent under various CO2 partial pressures and temperatures were investigated through numerical and experimental methods. It was found that Li4SiO4 showed poor absorption capacity at high temperatures (>525°C) under CO2 partial pressure of 5066 Pa. This phenomenon was explained by the thermodynamic results from FactSage5.5 software. Meanwhile, a modified Jander‐Zhang model based on the double‐shell structure of the Li4SiO4 sorbent was developed to describe the absorption kinetic behaviors of CO2 on Li4SiO4. The results showed that the modified Jander‐Zhang model could fit the kinetic experimental data well. Furthermore, the influence of steam on CO2 absorption was also analyzed by the modified Jander‐Zhang model. The results showed that the activation energy in the absorption process with steam was smaller than that without steam, which indicated that the presence of steam could promote the CO2 diffusion in product layer, therefore, improving the sorption capacity. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2153–2164, 2017 相似文献
9.
In this work, a mathematical model was developed for the prediction of packed-bed reactor behavior for CaO+CO2 reaction based on the random pore model. A natural limestone and a modified sorbent using acetic acid washing were used for the experiments. The performances of these sorbents were initially determined using a thermogravimeter analyzer. Then, the reaction was accomplished in a packed-bed reactor for obtaining CO2 breakthrough curves and investigation of model predictions. This model was able to successfully predict the effect of process conditions and solid texture on the breakthrough curves of the packed-bed reactor. 相似文献
10.
Zhang Qi Han Daying Liu Yang Ye Qian Zhu Zibin 《American Institute of Chemical Engineers》2013,59(3):901-911
The CO2 sorption/desorption kinetic behaviors on Li4SiO4 were analyzed. The theoretical compositions of the sorption/desorption reactions were calculated using FactSage. The sorption/desorption process on Li4SiO4 was investigated by comparing the shrinking core, double exponential, and Avrami–Erofeev models. The Avrami–Erofeev model fits the kinetic thermogravimetric experimental data well and, together with the double‐shell mechanism, clearly explains the sorption/desorption mechanism. The sorption process is limited by the rate of the formation and growth of the crystals with double‐shell structure consisting of Li2CO3 and Li2SiO3. The whole desorption process is found to be controlled by the rate of the formation and growth of the Li4SiO4 crystals. Furthermore, the influence of steam on the CO2 sorption process was analyzed. It has been observed that the presence of steam enhance the mobility of Li+ and, therefore, the rate of diffusion control stage. © 2012 American Institute of Chemical Engineers AIChE J, 59: 901–911, 2013 相似文献
11.
A Middle East-based amine sweetening unit, with an overall capacity of about 2.2 BSCFD of gas, is among the world’s largest process plants and currently processes sour gas with 10 mol% of hydrogen sulfide (H2S) and carbon dioxide (CO2) put together. Current expectation is that acid gas contents in the feed may increase beyond the design limit of the plant. The present work is an effort to quantify the effects of the feed gas CO2 increase on the plant and to proffer solutions to handle these effects efficiently. We revised the kinetics of amine-based CO2 absorption correlation of an existing model using real-data-driven parameters re-estimation. Evolutionary technique that employs particle swarm optimization algorithm is used for this purpose. The new CO2 kinetic model is inserted in a first-principle process simulator, ProMax® V4.0, in order to analyze various solutions necessary to mitigate the operational challenges due to increased feed CO2. The process plant with present design and operating conditions is determined to handle up to 8.45 mol% CO2 contents in the sour gas feed. Further results revealed that methyldiethanolamine, diethanolamine, and dimethyl ether propylene glycol (DEPG) could not handle this high feed CO2 challenge, even at maximum (design) steam and solvent usage. However, diglycolamine exclusively renders the solution as it treats high CO2 feed gas efficiently with allowable utility consumption, while satisfying the constraints imposed by product gas specifications. 相似文献
12.
13.
《分离科学与技术》2012,47(15):2498-2506
ABSTRACTA series of experiments on CO2 hydrate formation were carried out in the presence of titanium dioxide (TiO2), silicon dioxide (SiO2), multi-walled carbon nanotubes (MWNTs) nanoparticles. The effects of these nanoparticles on induction time, final gas consumption, and gas storage capacity have been investigated at the temperature of 274.15 K and the initial pressure of 5.0 MPa.g. The induction time of CO2 hydrate formation was remarkably shortened to 12.5 min in the presence of 0.005 wt% MWNTs nanoparticles. The high thermal conductivity and heat capacity of MWNTs nanoparticles presented better heat transfer, and large surface area provided more suitable sites for heterogeneous nucleation of CO2 hydrate. 相似文献
14.
E.J Molga K.R Westerterp 《Chemical Engineering and Processing: Process Intensification》1997,36(6):489-495
Gas–liquid interfacial areas have been determined by means of chemically enhanced absorption of CO2 into DEA in a packed bed bubble column reactor with an inner diameter of 156 mm. The influence of the gas velocity and particle diameter on the interfacial areas, pressure drops and liquid holdups has been investigated. For both packings the limiting values of the gas velocities have been determined above which the interfacial areas and liquid holdups stabilize. In particular gas channelling has been found, which is less pronounced in the bed of larger particles. 相似文献
15.
In this study, the decomposition conditions of limestone particles (0.25-0.50 mm) for CO2 capture in a steam dilution atmosphere (20-100% steam in CO2) were investigated by using a continuously operating fluidized bed reactor. The results show that the decomposition conversion of limestone increased with the steam dilution percentage in the CO2 supply gas. At a bed temperature of 920 °C, the conversions were 72% without steam dilution and 98% with 60% steam dilution. The conversion was 99% with 100% steam dilution at 850 °C of the bed temperature. Steam dilution can decrease not only the decomposition temperature of limestone, but also the residence time required for nearly complete decomposition of CaCO3. The hydration and carbonation reactivities of the CaO produced were also tested and the results show that both the reactivities increased with the steam dilution percentage for decomposing limestone. 相似文献
16.
FTIR spectra are reported of CO2 and CO2/H2 on a silica-supported caesium-doped copper catalyst. Adsorption of CO2 on a “caesium”/silica surface resulted in the formation of CO2
− and complexed CO species. Exposure of CO2 to a caesium-doped reduced copper catalyst produced not only these species but also two forms of adsorbed carboxylate giving
bands at 1550, 1510, 1365 and 1345 cm−1. Reaction of carboxylate species with hydrogen at 388 K gave formate species on copper and caesium oxide in addition to methoxy
groups associated with caesium oxide. Methoxy species were not detected on undoped copper catalyst suggesting that caesium
may be a promoter for the methanol synthesis reaction. Methanol decomposition on a caesium-doped copper catalyst produced
a small number of formate species on copper and caesium oxide. Methoxy groups on caesium oxide decomposed to CO and H2, and subsequent reaction between CO and adsorbed oxygen resulted in carboxylate formation. Methoxy species located at interfacial
sites appeared to exhibit unusual adsorption properties. 相似文献
17.
The reforming of CH4 with CO2 over supported Rh catalysts has been studied over a range of temperatures (550–1000 K). A significant effect of the support on the catalytic activity was observed, where the order was Rh/Al2O3>Rh/TiO2>Rh/SiO2. The catalytic activity of Rh/SiO2 was promoted markedly by physical mixing of Rh/SiO2 with metal oxides such as Al2O3, TiO2, and MgO, indicating a synergetic effect. The role of the metal oxides used as the support and the physical mixture may be ascribed to the promotion in dissociation of CO2 on the surface of Rh, since the CH4 + CO2 reaction is first order in the pressure of CO2, suggesting that CO2 dissociation is the rate-determining step. The possible model of the synergetic effect was proposed. 相似文献
18.
19.
《分离科学与技术》2012,47(16):2320-2330
In this research, continuous SAPO-34 membranes were synthesized via secondary growth method onto both α-Al2O3 and mullite supports at three levels of synthesis temperature: 185, 195, and 220°C for 24 h. The synthesized membranes were characterized using XRD and SEM analysis and single gas permeation experiments. It was found out that support material and synthesis temperature both have significant effects on the membrane performance. At higher synthesis temperature, SAPO-34 crystals grown over the mullite support become more uniform and smaller in size but those grown on the α-Al2O3 support become larger. Effect of synthesis temperature on single gas permeation properties of the synthesized SAPO-34 membranes was also studied. For the mullite supported membranes, the CH4 and CO2 permeances decrease as synthesis temperature increases; but in the case of the alumina supported membranes, by increasing synthesis temperature, CH4 and CO2 permeances first decrease up to 195°C and then increase up to 220°C. Even in equal membrane thicknesses, the mullite supported membrane shows lower gas permenaces. Increasing synthesis temperature decreases CO2/CH4 ideal selectivity for the α-Al2O3 supported membranes, while increases for the mullite supported membranes. Under optimum synthesis conditions, at room temperature and 2 bar feed pressure, the CO2 permeance through the α-Al2O3 and the mullite supported SAPO-34 membranes are 8.2 × 10?7 and 8.5 × 10?8 (mol/m2 · s · Pa), respectively, and CO2/CH4 ideal selectivities are 51 and 61, respectively. 相似文献
20.
《分离科学与技术》2012,47(3):428-433
The separation of bulk quantities of H2S from CO2 was investigated through a series of pressure-swing adsorption experiments utilizing 4A, 5A, and 13X molecular sieves. High selectivity of H2S over CO2 was encountered for all sieves, particularly for the 13X and 5A. Practically pure CO2 was produced in the adsorption stage with fresh 5A and 13X sieves, at high product recovery rates. Efficient H2S purification was obtained with fresh 5A and regenerated 4A zeolites. The experimental results were in line with theoretical predictions of the literature. 相似文献