Separation-and-Recovery Technology for Organic Waste Liquid with a High Concentration of Inorganic Particles

The environmentally friendly and resourceful utilization of organic waste liquid is one of the frontiers of environmental engineering. With the increasing demand for chemicals, the problem of organic waste liq- uid with a high concentration of inorganic pollutants in the processing of petroleum, coal, and natural gas is becoming more serious. In this study, the high-speed self-rotation and flipping of particles in a three- dimensional cyclonic turbulent field was examined using a synchronous high-speed camera technique; the self-rotation speed was found to reach 2000-6000 rad.s 1. Based on these findings, a cyclonic gas- stripping method for the removal of organic matter from the pores of particles was invented. A techno- logical process was developed to recover organic matter from waste liquid by cyclonic gas stripping and classifying inorganic particles by means of airflow acceleration classification. A demonstration device was built in Sinopec＇s first ebullated-bed hydro-treatment unit for residual oil. Compared with the T-STAR fixed-bed gas-stripping technology designed in the United States, the maximum liquid-removal effi- ciency of the catalyst particles in this new process is 44.9% greater at the same temperature, and the time required to realize 95% liquid-removal efficiency is decreased from 1956.5 to 8.4 s. In addition, we achieved the classification and reuse of the catalyst particles contained in waste liquid according to their activity. A proposal to use this new technology was put forward regarding the control of organic waste liquid and the classification recovery of inorganic particles in an ebullated-bed hydro-treatment process for residual oil with a processing capacity of 2×106 t.a^1. It is estimated that the use of this new tech- nology will lead to the recovery of 3100 t.a 1 of diesel fuel and 647 t.a^1 of high-activity catalyst; in addi- tion, it will reduce the consumption of fresh catalyst by 518 t.a^1. The direct economic benefits of this process will be as high as 37.28 million CNY per year.

Analysis of Causes Leading to High Bromine Number of C_8^+ Aromatics and Short Clay Service Life and Countermeasures Proposed

After comparing the operating status of other catalytic reforming units and evaluation of the side-cut stream tests, the refinery investigated the influence of the feedstock property, clay types, and operating regime of the clay tower and catalytic reforming unit on the service life of the clay. Test results had revealed that the low potential aromatic content of the reformer feed and high operating severity were the critical causes leading to high bromine number of the C8^＋ aromatics feed for the PX unit and the shortened service life of clay. This article also puts forward the corresponding remedial measures.

Fuzzy self-tuning PID control of the operation temperatures in a two-staged membrane separation process

A two-staged membrane separation process for hydrogen recovery from refinery gases is introduced. The principle of the gas membrane separation process and the influence of the operation temperatures are analyzed. As the conventional PID controller is difficult to make the operation temperatures steady, a fuzzy self-tuning PID control algorithm is proposed. The application shows that the algorithm is effective, the operation temperatures of both stages can be controlled steadily, and the operation flexibility and adaptability of the hydrogen recovery unit are enhanced with safety. This study lays a foundation to optimize the control of the membrane separation process and thus ensure the membrane performance.

Radial Basis Function Neural Networks-Based Modeling of the Membrane Separation Process: Hydrogen Recovery from Refinery Gases

Membrane technology has found wide applications in the petrochemical industry, mainly in the purification and recovery of the hydrogen resources. Accurate prediction of the membrane separation performance plays an important role in carrying out advanced process control （APC）. For the first time, a soft-sensor model for the membrane separation process has been established based on the radial basis function （RBF） neural networks. The main performance parameters, i.e, permeate hydrogen concentration, permeate gas flux, and residue hydrogen concentration, are estimated quantitatively by measuring the operating temperature, feed-side pressure, permeate-side pressure, residue-side pressure, feed-gas flux, and feed-hydrogen concentration excluding flow structure, membrane parameters, and other compositions. The predicted results can gain the desired effects. The effectiveness of this novel approach lays a foundation for integrating control technology and optimizing the operation of the gas membrane separation process.

Multi-technique integration separation frameworks after steam reforming for coal-based hydrogen generation

Coal-based H2 generation has abruptly increased in recent years.The PSA-VPSA-SC process is the matured and standard framework for H2 purification and CO_(2) capture in many existing plants,including normal and vacuum pressure swing adsorption units in series(PSA-VPSA),and shallow condensation unit(SC).However,this standard process is frequently subjected to low H2 recovery ratio and high purification cost.In this work,H2-selective and C02-selective membrane units,i.e.,HM and CO_(2) M,are attempted to support the standard process and ameliorate constraints.In the beginning,HM unit is arranged after VPSA to enhance H2 recovery from the decarbonized stream,i.e.,the PSA-VPSA-SC/HM process.As a result,H2 recovery ratio can be enhanced significantly from 83%to 98%.In the following,VPSA is replaced with CO_(2) M unit to reduce investment and operation cost,i.e.,the PSA-CO_(2) M-SC/HM process.Accordingly,the specific purification cost is diminished from 33.46 to 32.02 USD·(103 m^(3) H_(2))-1,saved by 4.3%,meanwhile the construction cost is falling back and just a little higher than that for the standard process.In the end,another CO_(2) M unit is launched before PSA,i.e.,the CO_(2) M-PSA-CO_(2) M-SC/HM process,which could unbundle CO_(2) enrichment partially from H2 purification,and then save more investment and operation cost.In comparison with the standard process,this ultimate retrofitted process can be superior in all the three crucial indices,i.e.,recovery ratio,investment,and specific purification cost.On the whole,coal-based H2 generation can be ameliorated significantly through high efficient H2-selective and CO_(2)-selective membrane units.

2D Janus polymer nanosheets for enhancing oil recovery:From material ppreparation to property evaluation

Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have been scarcely reported in the field of enhancing oil recovery(EOR).Herein,a kind of organic-based flexible JAPNs was prepared by paraffin emulsion methods.The lateral sizes of JAPNs were ranging from hundreds of nanometers to several micrometers and the thickness was about 3 nm.The organic-based nanosheets were equipped with remarkably flexible structures,which could improve their injection performance.The dispersion and interfacial properties of JAPNs were studied systematically.By modification of crosslinking agent containing multiple amino groups,the JAPNs had excellent hydro-philicity and salt resistance compared with conventional inorganic or composite nanosheets.The settling time of nanosuspension with NaCl and CaCl_(2) at a low salinity of 1000 mg/L was over 240 h.The value could also remain 124 h under the salinity of 10,000 mg/L NaCl.With the dual functionalities of Janus amphiphilic nature and nanoparticles'Pickering effect,JAPNs could change rock wettability and form emulsions as"colloidal surfactants",In particular,a new technology called optical microrheology was pioneered to explore the destabilization state of nanosuspensions for the first time.Since precipitation lagged behind aggregation,especially for stable suspension systems,the onset of the unstable behavior was difficult to be detected by conventional methods,which should be the indicator of reduced effec-tiveness for nanofluid products.In addition,the oil displacement experiments demonstrated that the JAPNs could enhance oil recovery by 17.14%under an ultra-low concentration of 0.005%and were more suitable for low permeability cores.The findings can help for a better understanding of the material preparation of polymer nanosheets.We also hope that this study could shed more light on the nano-flooding technology for EOR.

Development and Application of Heat-integrated Aromatics Fractionation Process

The PRO/Ⅱ process simulation software was applied to carry out simulated calculation of the aromatics fractionation unit and the heat integrated rectification process was proposed for the aromatics fractionation section of the 1.0 Mt/a toluene disproportionation unit at the Zhenhai Refining and Chemical Company. The optimized operating parameters were obtained through the energy utilization analysis,process simulation,heat exchanger calculations and comparisons of utility consumption. The operation of commercialized unit has revealed that the design parameters of each rectification column were consistent with the operation results,and the utility consumption was about 47% lower than the traditional heat integrated process.

Study on Flue Gas Desulfurization Process with Selective SO2 Removal by N-formylmorpholine

Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a lab-scale absorption tower at atmospheric pressure using N-formylmorpholine (NFM) as the absorbent is developed to capture and concentrate the SO2 from flue gas, in which the CO2 content is several orders higher than that of SO2. The investigation of the effects of different operating conditions on the SO2 removal efficiency shows that the SO2 removal efficiency can be obviously enhanced by increasing NFM concentration, or decreasing the absorption temperature, the superficial gas velocity, the gas-liquid ratio, or the SO2 concentration in absorption solution. Under the optimum operating conditions (covering a temperature of 40 °C, a superficial gas velocity of <0.0165 m/s, a gas-liquid ratio of 200—250, a SO2 concentration in lean NFM solution of 0—10 mg/L, and a NFM concentration of 3 mol/L), the SO2 removal rate reaches over 99.5% while the absorption of CO2 is negligible. Similarly, the SO2 removal rate is as high as 99.5% obtained in consecutive absorption-desorption cycles. Desorption experiment results indicate that the absorption of sulfur dioxide is completely reversible and the release of SO2 from NFM is very easy and rapid at 104 °C. The absorption simulation result for desulfurization of flue gas vented from the industrial catalytic cracking regenerator shows that 98.0% of SO2 can be absorbed in the absorber and most of them are released in the desorber. The experimental and simulated results show that the desulfurization ability and regenerability of NFM solution is encouraging for the development of FGD process to capture the SO2 from flue gas.