Rotating Packed Bed Research Articles

Optimizing economic feasibility of CO2 capture processes with rotating packed bed (RPB): Strategies for scale and modularization

Rotating Packed Bed (RPB) technology is increasingly recognized in the field of carbon capture for its potential to broaden application scopes and significantly reduce capital expenditures by minimizing packing volume. However, the commercialization of RPB-based CO2 capture presents several challenges at the process level, including enhancing energy efficiency, refining equipment design, and achieving scalability. Given the mechanical constraints, designing excessively large RPB units may be impractical. Thus, the economic scalability of RPB-based CO2 capture under practical constraints remains an unresolved issue. This study explores the cost-optimal CO2 capture scale through rigorous process simulation using 30-70 wt% monoethanolamine (MEA) solvents. It optimizes the process design and operating parameters to minimize the specific CO2 avoidance costs, within the bounds of practical RPB design limitations. The findings suggest that a capture scale of 100–200 Tons Per Day (TPD) is cost-optimal when using 50 wt% MEA for flue gases with CO2 concentrations above 14.5 mol%. However, cost-effective RPB design becomes challenging at CO2 concentrations as low as 4 mol%. The analysis suggests that the optimal scale might increase with future advancements in RPB design technologies. Current design constraints necessitate a modular approach as the most economically viable strategy for scaling up RPB-based CO2 capture. This modularization strategy supports the wider adoption of CO2 capture technologies at small- to medium-scales, facilitating industry-wide implementation and sustainable progress by reducing initial investment and allowing for phased scaling.

Hydrogenation process intensification of 2-nitro-4-acetylamino anisole by HiGee technology

The catalytic hydrogenation of 2-nitro-4-acetylamino anisole (NMA) is the main path to synthesize 2-amino-4-acetylamino anisole (AMA), belonging to a typical gas-liquid-solid system. However, the small mass transfer rate of traditional hydrogenation reactor can't match its intrinsic fast reaction rate, resulting in the low hydrogenation efficiency. In this work, a rotating packed bed (RPB) reactor with excellent mass transfer performance was applied for the hydrogenation process intensification of NMA. The characterization analysis of the commercial Raney-Ni catalyst shows that the liquid-solid mass transfer resistance during the reaction process can be ignored, and improving the gas-liquid mass transfer rate is the key to improve the macroscopic reaction rate. The effects of operating conditions (solvent, rotational speed, hydrogen pressure, temperature, and catalyst dosage) on NMA conversion and AMA selectivity were investigated. A macro-kinetic equation of NMA catalytic hydrogenation in the RPB reactor was proposed. Under optimized conditions, the NMA was completely converted in the RPB reactor within 30 min, while it took 4 h in the stirred tank reactor. The overall reaction efficiency of RPB reactor was increased by 87.5 % in comparison with STR. This study provides practical guidance for the industrial application of RPB reactor for gas-liquid-solid hydrogenation.

CO2 absorption with polyethyleneimine solution intensified by a rotating packed bed with liquid detention

This study explored the absorption of CO2 by the polyethyleneimine (PEI) solution in a rotating packed bed (RPB). In order to boost the CO2 absorption effect, the liquid detention phenomenon in the RPB was utilized to overcome the short residence time of liquid. The effects of different operating parameters on CO2 absorption efficiency (η) and gas-phase volumetric mass transfer coefficient (KGav) in the RPB were investigated. The experimental results indicated that the RPB can greatly intensify the absorption of CO2. η and KGav increased from 3.3 % and 0.041 kmol·m−3·h−1·kPa−1 to 76.0 % and 1.634 kmol·m−3·h−1·kPa−1, respectively, as the rotational speed of the RPB rose from zero to 700 rpm with 250 mL detained liquid. It was also found that the liquid detention phenomenon can significantly elevate η and KGav as a result of extended liquid residence time and increased liquid holdup in the RPB. When the detained liquid volume increased from zero to 250 mL, η and KGav increased by 55.6 % and 113.1 %, respetively. In addition, it was observed that CO2 load in the rich PEI solution increased from 9.650 to 11.189 molCO2/kg PEI while η remained around 85 % after five cycles of absorption–desorption, suggesting an excellent cyclic stability of PEI. This work contributes to the development of viable CO2 capture technologies by intensifying the CO2 absorption process in the RPB with an efficient absorbent.

Modeling selective absorption of H2S from a gas mixture containing CO2 within rotating packed bed based on surface renewal theory

Compared to conventional packed beds (PBs), the rotating packed beds (RPBs) demonstrate superior selectivity for H2S. RPBs can selectively absorbing more than 99 % of H2S in CO2-rich gas mixtures, while the co-absorption rate of CO2 in RPBs is only 1/9 of that in PB columns. Therefore, RPBs have been well applied in the gas purification for natural gas, blast furnace gas, and refinery gas. While, modeling the selective reaction process in RPBs under conditions of rapid liquid film renewal remains challenging. Here, a diffusion–reaction mass transfer model based on surface renewal theory is established. The model elucidates the mechanism behind the selective absorption of H2S, and also demonstrate how RPBs enhance liquid film absorption. Experimental data collected from an RPB operating under actual conditions were used to validate the model. The model demonstrates high precision in predicting the removal efficiency of H2S and CO2.

Steam Stripping for Recovery of Ammonia from Wastewater Using a High-Gravity Rotating Packed Bed

Steam stripping of ammonia from ammonia-rich wastewater (5000–20,000 mg/L) was conducted in a continuous-flow rotating packed bed (RPB) at a pH of 11. This study aimed to elucidate the influence of key operational parameters, including the steam-to-liquid ratio, rotational speed (ω), initial ammonia concentration, steam inlet temperature (TSi), and liquid inlet temperature (TLi), on critical performance metrics such as the ammonia removal efficiency (ARE), the volumetric liquid mass transfer coefficient (KLa), and the concentration of the recovered ammonia solution (CR). The findings revealed that a CR of 22.88 wt.% was achieved under the optimal conditions of a steam-to-liquid ratio of 0.175 kg/kg, an initial concentration of 20,000 mg/L, a TSi of 120 °C, and a TLi of 70 °C. Key experimental factors, including the initial ammonia concentration, TSi, and TLi, significantly impacted the achievement of higher ARE and CR values. The KLa values exhibited a decrease with the increase in the steam-to-liquid ratio, while they increased with ω. However, the KLa remained relatively consistent with ω values within the range of 600 to 1200 rpm. In comparison with prior studies, steam stripping of ammonia exhibits a higher ARE than air stripping with RPB and a higher CR than conventional stripping methods. Moreover, RPB requires a smaller size to achieve equivalent ARE compared to conventional stripping apparatuses. Thus, the steam stripping process with RPB equipment emerges as a suitable method for ammonia recovery from ammonia-rich wastewater.

Appraisal of the Flooding Behaviour of Rotating Packed Beds

Rotating packed beds (RPBs) enhances mass transfer processes because a centrifugal force which is several -times greater than gravity is used as the driving force. The complexity of fluid flow across RPBs has made predicting and accurately determining their hydrodynamic behaviours difficult. The flooding point as a hydrodynamic characteristic is essential for the accurate design and scale-up of RPBs. However, variations in flooding point definitions and methodologies across the literature highlight the need for standardized approaches in studying RPB flooding phenomena. This study compared four approaches based on pressure drop fluctuations and the volume of liquid ejected from the RPB to determine the onset of flooding in RPBs using experimental results from a pilot-scale counter-current RPB. For rotational speeds of 300 -1500 rpm, gas flow rate of 100-300 Nm3/h, and liquid flow rates of 0.39-0.75 m3/h, the pressure drop varied from 314 to 2,100 Pa. Quantitative comparisons of the results based on different flooding point definitions showed wide variations with the values of the pressure drop at the onset of flooding differing by as much as 325 %. A quantitative approach based on virtual observations and the ejection of 8 % of the total liquid flow rate from the rotor’s eye is proposed as the standard method for identifying the onset of flooding in RPBs.

Machine-learning aided calibration and analysis of porous media CFD models used for rotating packed beds

The proposed research is an attempt to advance the state-of-the-art of the numerical modelling of RPB by combining Computational Fluid Dynamics and Machine Learning approaches. The latter creates an accurate framework that should help quantify the potential of Rotating Packed Beds (RPB) technology to intensify conventional CO2 capture processes. To this end, a direct sensitivity analysis is detailed to supplement a machine-learning (ML) algorithm built for calibrating resistance coefficients needed for porous media modelling. The algorithm is used to improve CFD predictions of dry pressure drop in rotating packed beds (RPBs) for a wide range of operating conditions. The sensitivity derivatives with respect to the packing resistance coefficients are demonstrated for the first time in RPBs, which is not available in the current CFD open source and commercial codes. In this regard, sensitivity differential equations are derived from three-dimensional Navier-Stokes equations for porous media in a rotating reference frame. These sensitivity equations are discretized using a finite volume scheme and solved to obtain the sensitivity pressure drop differences at the packing edges. The results are validated against the predictions of the analytical sensitivity analysis and the finite difference approximation. After, the Newton – Gauss method that employs the sensitivity pressure drop derivatives, is used to minimize the error (cost function) between the pressure drop obtained from CFD simulations and the available experimental data. This is achieved by tuning the packing resistance coefficients to the RBPs' operating conditions (gas flowrate and rotating speed) and correlate them using an artificial neural network (ANN). The results of the proposed approach show a significant improvement in porous media-based CFD predictions of RPBs' pressure drop across a wide range of operating conditions and this over conventional porous media-based CFD models. This is necessary for CFD models to be reliably used as a tool that can efficiently improve existing RPBs' designs and/or participate in RPBs' design innovation.

An efficient technology for dye intermediate production: Process intensification of catalytic hydrogenation of aromatic nitrocompounds in a rotating packed bed reactor

AbstractThe rotating packed bed (RPB) is suitable for catalytic hydrogenation of aromatic nitrocompounds whose reaction rate is limited by the mass transfer rate. However, the matching mechanism between the mass transfer rate and intrinsic reaction rate in the RPB reactor is still unclear. In this work, the matching relationship in the RPB reactor is studied by combining the characteristics of mass transfer and reaction in detail. Effects of various operating conditions on the gas–liquid mass transfer coefficient up to 0.31/s, under working conditions were studied and the mass transfer correlation was proposed. The hydrogenation of p‐nitroanisole was used as a probe reaction to analyze the matching mechanism. Various aromatic nitrocompounds in the RPB and stirred tank reactors were investigated. The reaction efficiency of the former is 5–20 times that of the latter, which further explained the universality of the matching mechanism in the RPB reactor.

Efficient synthesis of MOF-808 nanoparticles for rapid hydrolysis of V-series nerve agent simulant

The degradation of nerve agents is essential due to their high toxicity and lethality. The Zr-based metal–organic framework MOF-808 has emerged as a promising catalyst for the destruction of nerve agents and their simulants. However, its efficient synthesis is still a great challenge. In this study, we reported a convenient method for rapidly preparing MOF-808 nanoparticles in a rotating packed bed (RPB) reactor using high-gravity technology. Compared to a conventional stirred tank reactor, the preparation time of MOF-808 in the RPB was greatly shortened from 12 h to 30 min, while the mean particle size was obviously decreased by about 74 %. The obtained MOF-808 nanoparticles exhibited excellent catalytic performance for the hydrolysis of the nerve agent simulant O, O-diethyl S-phenyl phosphorothioate (DEPPT). Particularly, the 339 nm MOF-808 can rapidly degrade DEPPT with a half-life (t1/2) of 4.36 min and an equilibrium degradation rate of 92.6 % at a dosage of 2.5 mg, respectively 1.5 and 1.25 times higher than those of 1.3 µm MOF-808 (t1/2 = 6.36 min, 74.3 %). Furthermore, the DEPPT degradation mechanism was elucidated through a combination of experimental studies and density functional theory calculations. This work provides valuable insights into the efficient synthesis of nano-MOFs with enhanced catalytic activity for the hydrolysis of nerve agents.

Optimization of BOFS high-gravity carbonation technology: Consideration of theoretical guidance for up-scaling applications

This study investigated the high-gravity (higee) carbonation reaction of a basic oxygen furnace slag (BOFS)-water-CO2 three-phase system via a rotating packed bed (RPB). The effect of different carbonation conditions on the higee carbonation process was explored. To achieve enhanced mass transfer, energy savings, and cost-effectiveness, this study aimed to optimize parameters such as BOFS component, acceleration, gas-liquid velocity ratio, and gas flow rate. Comparative analysis revealed that portlandite-rich BOFS exhibited a significantly higher Ca conversion ratio (2.1 times) and mass transfer coefficient values (KGαe) (5.5 times) than calcium silicate-rich BOFS. Systematic graphical presentation identified an acceleration of 430 m/s2, a gas-liquid velocity ratio of 25–30, and a gas velocity to RPB volume range of 4.7–6.6 min−1 as the optimal operating conditions for high KGαe (>0.2 s−1) and low energy consumption (144–151 kWh/t-CO2). Furthermore, prolonged RPB operation led to a 1.5-fold reduction in mass transfer performance, but reducing the liquid-to-solid ratio was a cost-effective measure to compensate for efficiency losses. The estimated cost for the higee carbonation process ranged from 106 to 111 CNY/t-CO2. These findings can provide valuable insights and practical recommendations for the industrial application of the higee carbonation technology in steel-making plants.

Evaluation of Effective Interfacial Area in a Rotating Packed Bed Equipped with Dual Gas Inlets

This study investigates the effective interfacial area in a novel rotating packed bed (RPB) equipped with dual gas inlets instead of the conventional single-gas-inlet RPB. The aim is to enhance the mass transfer efficiency of gas-liquid contacting processes in RPBs by increasing the number of gas inlets to improve the spread of gas supply into the packing. The RPB is a promising gas-liquid contactor configuration known for its intensified mass transfer characteristics. However, the impact of additional gas inlets on the effective interfacial area of the packing remains unexplored. An experimental method assessed the interfacial area under varying operational conditions which include a liquid flow rate of 0.30-0.60 m3/h, a gas flow rate of 100-300 Nm3/h, and a rotation speed of 600-1000 rpm. At operating conditions covering the maximum rotation speed of 1400 rpm, gas flow and liquid flow rates of 300 Nm3/h and 0.60 m3/h respectively, the results showed that on average, 55 to 97% of the 2400m2/m3 specific packing area can be effectively utilized for gas-liquid mass transfer during separation operations using the RPB. Compared to results reported for single-gas-inlet RPBs using similar packings, the RPB with double gas inlet proved to provide higher utilization of the packing. By simply doubling the number of gas inlets, the findings provide valuable insights into optimizing RPB designs and operations which could enhance mass transfer efficiency for various chemical and environmental applications.

Comprehensive Analysis of Pressure Drop Phenomena in Rotating Packed Bed Distillation: An In-Depth Investigation.

A rotating packed bed (RPB) is an innovative intensification technology that improves its separation capabilities in high-gravity conditions. This process increases efficiency with smaller equipment size and footprint than conventional packed columns. Although significant advancements have been made regarding RPBs, most studies only focused on single or dual rotor configurations in addressing dry pressure drop. Hence, multiple rotor systems in industrial settings can enhance economic efficiency by minimizing the necessity for numerous RPBs. This study investigated the pressure drops and holdup in a three-stage rotor-based RPB under actual process conditions using natural gas as the feed. A novel pressure drop correlation was introduced based on the nitrogen removal process from the natural gas in continuous RPB distillation operations. Consequently, the correlation between centrifugal acceleration, turbulent, and momentum effects demonstrated remarkable accuracy within ±15%. This outcome also highlighted the importance of meticulous design considerations in RPB-based applications due to the complex correlation between centrifugal forces, liquid holdup, and gas flow rates. The reflux feed ratio, liquid holdup, rotating speed, and F-factor effects were examined to comprehend the RPB distillation process. Overall, the correlations between the critical parameters offered crucial insights to prevent process upsets (such as flooding), contributing to advancing RPBs in practical industrial settings.

Investigations on transport behaviours of rotating packed bed for CO2 capture by chemical absorption using CFD simulation

A rotating packed bed (RPB) has been proposed to overcome the limitations of high operating and capital costs involved in conventional columns which are used for chemical absorption-based carbon dioxide (CO2) capture. The design of large-scale RPBs depends on their transport characteristics. Owing to the difficulties in predicting the transport characteristics of RPBs experimentally, Computational Fluid Dynamics (CFD) simulation has been implemented. In this study, a two-dimensional (2D) volume of fluid (VOF) simulation is conducted to predict transport characteristics of RPB including, hydrodynamics, and physical and reactive mass transfers. To predict hydrodynamics of RPBs accurately, the liquid holdup by CFD simulation is compared against experimental prediction, showing a strong agreement between simulation and experimentation. Various liquid phase flow patterns within RPB are observed and these are cross-referenced with findings in the existing literature. Additionally, the impacts of rotational motion and flow rate are further assessed in the study. For the mass transfer performance, the prediction of the volumetric mass transfer coefficient, kLae of the air-water system from CFD simulation is studied. Two different mass transfer theories such as surface renewal theory and penetration theory are studied to predict kLae. It is observed that the kLae from the penetration theory closely follows the trend of the experimental data. Finally, a 2D simulation of the reactive absorption of CO2 by diethylenetriamine (DETA) in RPB is developed and compared with the existing available data in the literature. The present model underpredicts CO2 capture efficiency in RPB, which needs further improvement in reaction kinetics. In general, the present CFD model has the capability of predicting the transport characteristics of RPB.

Devolatilization of high viscous fluids with high gravity technology

Volatile organic compounds (VOCs) are generally toxic and harmful substances that can cause health and environmental problems. The removal of VOCs from polymers has become a key problem. The effective devolatilization to remove VOCs from high viscous fluids such as polymer is necessary and is of great importance. In this study, the devolatilization effect of a rotating packed bed (RPB) was studied by using polydimethylsiloxane as the viscous fluid and acetone as the VOC. The devolatilization rate and liquid phase volume (KLa) have been evaluated. The results indicated that the optimum conditions were the high-gravity factor of 60, liquid flow rate of 10 L·h−1, and vacuum degree of 0.077 MPa. The dimensionless correlation of KLa was established, and the deviations between predicted and experimental values were less than ±28%. The high-gravity technology will result in lower mass transfer resistance in the devolatilization process, enhance the mass transfer process of acetone, and improve the removal effect of acetone. This work provides a promising path for the removal of volatiles from polymers in combination with high-gravity technology. It can provide the basis for the application of RPB in viscous fluids.

Micromixing efficiency of non-Newtonian fluid in rotating packed beds with novel tube-tube premixers

Rotating packed beds (RPBs), as the typical chemical intensification devices, have been widely applied in liquid-phase fast reactions and precipitation processes. In this study, three novel tube-tube premixers were designed, and three-dimensional CFD models of the flow and mixing processes for non-Newtonian fluids in tube-tube premixers were established. Meanwhile, the micromixing efficiency in RPBs with different tube-tube premixers was experimentally investigated. The results show that TG-2 premixer exhibits the best premixing performance. The segregation index decreases as the rotational speed or flow rate increases, indicating the increase in micromixing efficiency. With the increase of CMC mass fraction, the segregation index initially decreases and then increases. Moreover, the micromixing efficiency of TG-0-RPB is the highest in aqueous solution, the micromixing efficiency of TG-4-RPB is the highest in 0.2 wt.% CMC system, and the micromixing efficiency of TG-2-RPB is the highest when the CMC concentrations is equal to or greater than 0.4 wt.%. The micromixing times of non-Newtonian fluid in RPBs range from 2 to 10 ms.

CFD simulation and experimental study of CO2 absorption in a rotating packed bed

The rotating packed bed (RPB), a process intensification equipment, has been widely studied and applied to chemical engineering processes such as gas absorption, nanomaterial preparation, and polymer devolatilization. In this study, we presented a typical RPB model to study the intensification mechanism of high gravity on gas-liquid mass transfer. Based on this, three-dimensional computational fluid dynamics (CFD) simulations and experiments of CO2 physical absorption were conducted to investigate the gas-liquid mass transfer characteristics in the RPB. The predicted and experimental values of CO2 saturation rates of the liquid phase showed good agreement, and the errors were within ± 15 % under various operating conditions. Moreover, detailed flow field and mass transfer information that are difficult to measure experimentally, such as the distribution of CO2 mass fraction in the liquid, liquid holdup, turbulent kinetic energy dissipation rate, and gas-liquid interfacial area, were analyzed by CFD simulation results. These results provide a solid foundation for the further development and application of RPB.

Simultaneous absorption of H2S, MM and COS into a novel SRSG absorbent using a rotating packed bed

In industries, many gases are required to remove hydrogen sulfide (H2S) and organic sulfur. However, it is still a huge challenge to achieve the efficient and simultaneous removal using a single process. Herein, a novel simultaneous removal sulfide gas (SRSG) absorbent is developed to simultaneously absorb H2S, methyl mercaptan (MM) and carbonyl sulfide (COS). The absorption mechanism between the SRSG absorbent and H2S, MM, COS is explored by quantum chemistry calculations (QCC) and controlled experiments in a rotating packed bed (RPB). Results indicate that the interaction between SRSG and H2S, MM belongs to physical absorption while COS absorption in SRSG obeys two molecule reaction mechanism. Furthermore, the effect of different operating conditions, including rotating speed (N), liquid flow rate (L), gas–liquid ratio (G/L) and temperature (T), on the absorption efficiencies (η) and gas volumetric mass transfer coefficient (KGa) of H2S, MM and COS is systematically investigated. It can be found that both η and KGa are dependent on those operating conditions. The optimal η value for H2S, MM and COS is up to 99.99%, 100%, 100%, respectively. Moreover, nondimensional equations for Sherwood number (Sh) are established, and the calculated and experimental values of Sh(H2S), Sh(MM) and Sh(COS) are in agreement with a deviation within ±13%, ±13%, and ±20%, respectively. These results will provide a valuable potential technique for simultaneously removing acidic gas components from industrial gases.

Liquid dispersion behaviors in a rotating packed bed with different packing arrangements: A comparison study

Wire mesh packing is widely used in the rotating packed bed (RPB). Packing arrangements have been proven to influence the mass transfer of an RPB. However, the liquid dispersion behaviors including dispersion characteristics and mechanisms for packing with different arrangements require further study. In this work, the dispersion behaviors of wire mesh packing with coiled and concentric arrangements were compared. An in-situ Doppler optical probe method was firstly employed to obtain fundamental parameters of liquid dispersion characteristics, such as the Sauter mean diameter, size distribution, and velocity of liquid droplets. The obtained results showed that the coiled arrangement was conducive to generating droplets with large velocity and narrow size distribution owing to the capturing and spreading of liquid inside the packing, while the concentric arrangement was beneficial in decreasing droplet size due to the shearing and carrying actions of the packing. Based on the optimization of liquid dispersion, the max and average reductions of d32 were 34.8% and 19.0% for packing with concentric arrangement than a coiled one. Further comparison results of dispersion characteristics indicated that the optimized concentric arrangement with 3 layers could provide better liquid dispersion than that of a coiled one with around 20 layers.

Design and optimizing the liquid distributor of a rotating packed bed by the analysis of liquid flow behavior

Rotating packed beds (RPBs) have been widely applied in multiphase systems. When handling some extreme operating condition systems, finding a suitable pump to provide pressure to force the feeding liquid to be evenly distributed by the distributor of the RPB is very costly. In this work, we designed new liquid distributors by using the kinetic energy of the rotating shaft as driving force to obtain uniform distribution. The performance of the liquid distribution has been investigated in terms of liquid flow behavior, liquid velocity, and impacting angle (α). Compared with bar and cantboard distributors, the radlamelle liquid distributor had the best distribution performance. By further optimization of the radlamelle structure, the left-hand wheel had better dispersion performance with α varying from 24.3 to 79.1°. This new liquid distributor without pump pressure expands the applications of the RPB in ultra-low or high temperature and high pressure operating conditions.

The controllable and efficient synthesis of two-dimensional metal-organic framework nanosheets for heterogeneous catalysis.

Two-dimensional (2D) MOFs exhibit unique periodicity in surface structures and thus have attracted much interest in the fields of catalysis, energy, and sensors. However, the expanded production scale of 2D MOFs had remained a great challenge in most previous studies. Herein, a controllable and efficient crystallization method for synthesizing 2D MOF nanosheets using high-gravity reactive precipitation is proposed, significantly improving heterogeneous catalysis efficiency. The two-dimensional ZIF-L nanosheets prepared in a rotating packed bed (RPB) reactor show a smaller lateral and lamellar thickness and a higher BET surface area compared to ZIF-L nanosheets prepared in a conventional stirred tank reactor (STR), with a greatly shortened reaction time. Applying the ZIF-L-RPB nanosheets as a catalyst, the catalytic Knoevenagel condensation as a probe reaction displays a high conversion rate of benzaldehyde (99.3%) within 2 h at room temperature, greatly exceeding that displayed by ZIF-L-STR and other reported catalysts. Furthermore, ZIL-L-RPB nanosheets of only 0.2 wt% enhanced the catalytic activity for the glycolysis of poly(ethylene terephthalate) (PET) with a PET conversion and a monomer yield of 90% in a short period of 15 min at 195 °C and almost completely depolymerized PET with a monomer yield of 94% in 30 min, which was far above that achieved by ZIL-L-STR. These results indicate the promising prospects of a high-gravity reactive precipitation strategy with precise size control in an economical way to prepare high-activity 2D MOF nanosheets for a wide range of heterogeneous catalysis.