Pengbo Fu

Inlet Particle-Sorting Cyclone for the Enhancement of PM2.5 Separation

Many cities are suffering from severe air pollution from fine particulate matter. Cyclone is an effective separator for particulate pollutant but has low efficiency for those with an aerodynamic diameter of 2.5 μm or less (PM2.5). In this research, four novel inlet particle-sorting cyclones were first developed to enhance the separation of PM2.5. The energy consumption, overall separation efficiency, particle grade efficiency,outlet particle concentration and size distribution were compared with common cyclone (CM-C). It was found that the vertical reverse rotation cyclone (VRR-C), which made the smaller particles enter cyclone from radially outer side and axially lower side at the rectangular inlet, had the best separation performance, especially for PM2.5 separation. The mean diameter of inlet particles was 15.7 μm and the particle concentration was 2000 mg/m3, the overall separation efficiency of the VRR-C reached 98.3%, which was 6.4% higher than that of CM-C. PM2.5 grade efficiency of the VRR-C exceeded 80%, which was 15∼20% higher than that of CM-C. The PM2.5 content at the VRR-C outlet was 30.8 mg/m3, while that of CM-C was still 118.4 mg/m3. The novel inlet particle-sorting cyclone is an effective separation enhancement for PM2.5 source control in the process of industrial production and environment protection.

Reliable on-site characterization of aromatic compounds adsorbed on porous particles with SERS in a dynamic adsorption-hydrocyclone separation process

A novel method for reliable on-site characterization of aromatic compounds adsorbed on porous particles with surface enhanced Raman spectroscopy (SERS) in a dynamic adsorption-hydrocyclone separation process (DAHS) was introduced. Aromatic compounds found in printing and dyeing wastewater were adsorbed on functionalized porous alumina particles (FPAPs). The SERS-active FPAPs were prepared by decorating and growing silver nanoparticles (Ag NPs, ∼70 nm diameter) on the surface of porous alumina particles (PAPs). Samples were then characterized with a portable Raman spectrometer. SERS offers quantitative analyses of the pollutants adsorbed on the surface of FPAPs directly and the quantity of benzidine adsorbed on porous particles was 20.5 mg kg−1. It shows that the SERS-DAHS technique could be readily applied to the quantitative characterization of aromatic compounds adsorbed on SERS-active FPAPs. Furthermore, both qualitative and quantitative detection of aromatic compounds in wastewater produced on-site were readily accomplished using the SERS-DAHS method and its analytical ability compares well with GC-MS and the detection results deviating between these two techniques was less than 10%. The results demonstrate that the SERS-DAHS method is straightforward, rapid, and preferable for the real-time detection and quantitative characterization of aromatic compounds/pollutants adsorbed on porous materials.

Application of Gas Cyclone–Liquid Jet Absorption Separator for Purification of Tail Gas Containing Ammonia

ABSTRACT In this experiment, with stainless steel gas cyclone–liquid jet absorption separator as carrier, NH3 as experimental gas, and water and H3PO4 solution as absorbents, corresponding NH3 absorption rate change is obtained through the adjustment of experimental parameters, such as NH3 inlet concentration, inlet velocity of mixed gas, injection flow rate of absorbent, temperature of absorbent, and H3PO4 absorbent concentration. The NH3 absorption rate decreases with the increase in NH3 inlet concentration and inlet gas velocity. The NH3 absorption rate will increase first and then tends to remain unchanged after reaching a certain degree with the increase in liquid injection flow rate and absorbent concentration. The NH3 absorption rate will increase first and then decrease with the increase in the absorbent temperature. The maximum NH3 removal efficiencies of water and H3PO4 were 96% and 99%, respectively. GRAPHICAL ABSTRACT

Enhancement of PM2.5 Cyclone Separation by Droplet Capture and Particle Sorting

Fine particulate matter (PM2.5) is one of the most serious environmental pollutants worldwide, and efficient separation technologies are crucial to the control of PM2.5 emission from industrial sources. We developed a novel method to enhance PM2.5 cyclone separation by droplet capture and particle sorting using a vertical reverse rotation cyclone (VRR-C, inlet particle-sorting cyclone). The separation performances of common cyclone (CM-C) without droplets, CM-C with droplets, and VRR-C with droplets were compared in terms of energy consumption, overall separation efficiency, particle grade efficiency, outlet particle concentration, and outlet particle size distribution. The results show that the highest overall separation efficiencies were 51.7%, 89.9%, and 94.5% for CM-C without droplets, CM-C with droplets, and VRR-C with droplets, respectively, when the mean diameter of the inlet particles was 3.2 μm and the inlet particle concentration was 500 mg/m3. The PM2.5 grade efficiency of VRR-C with droplets was as high as 89.8%, which was 6.2% and 49.9% higher than those of CM-C with droplets and CM-C without droplets, respectively. This novel method was first successfully applied to the deep purification of product gas in the methanol-to-olefin (MTO) industry, for which the separation efficiency of fine catalyst particles was considerably improved.