石化工业水循环经济的发展现状及发展对策分析

基于循环经济概念对石油化工行业的水资源管理进行引导,是解决水资源紧缺、加强水质污染管控以及推动经济发展之间冲突的关键手段。遵循减量化、水资源的再利用与循环再生(3R原则),即通过优化水资源的抽取方式及其量化管理,增强水使用效率,以及有效执行废水的回收使用。通过分析循环经济与水循环经济原理、对比分析了国内外水循环经济政策现状(减量化、再利用、再循环),提出了我国发展对策,以期为今后行业提供参考性建议。

Microbial community study in a petrochemical industry wastewater treatment system by PCR-DGGE

To improve the efficiency of petrochemical wastewater purification, the relationship between bacterial community structure and pollutants loading/degrading rates in A/O process for petrochemical wastewater treatment was investigated by denaturing gradient gel eleetrophoresis （DGGE） of the 16S rRNA gene fragments amplified by polymerase chain reaction （PCR）. Results show that while the influent COD and NH4^＋ -N concentrations are 425.92 -560 mg/L and 64 - 100 mg/L respectively, the corresponding average concentrations of the effluent are 160 mg/L and 55 mg/L, which are 1. 6 and 3.6 times more than the national standards respectively. It demonstrates that the performance of pollutants removal process is inefficient. The analysis of PCR-DGGE profile indicates that the bacterial community structure of the activated sludge in A/O system is species-rich but unstable, and the highest and the lowest similarity coefficients are 36% and 6. 25% respectively, which shows that remarkable community structure evolution exists in the system. The variation of bacterial community structure and pollutants loading influences the removal efficiency of pollutants obviously, and relatively stable com- munity structure leads to the stable operational performance of biological wastewater treatment system.

Synthesis of ZSM-5 with the silica source from industrial hexafluorosilicic acid as transalkylation catalyst

A new effective process to improve the utilization of industrial fluorosilicic acid of phosphate fertilizer by-product has been investigated to comprehensive application of the silicon and fluorine source. Two-step ammoniation was applied to recover high-quality silica. The recovered silica can be used to hydrothermal synthesize ZSM-5 zeolite without impurity phase contamination, which was confirmed by XRD, TG, SEM, BET and EDS characteristic techniques. It was found that with the increase of SiO_2/Al_2O_3 ratio and the extension of reaction time, the crystal type transform from the orthorhombic to the monoclinic phase. The impurity fluorine content of the recovered SiO_2 from H_2SiF_6 has great influence on the hydrothermal process for ZSM-5 crystal structure formation.Moreover, the increase of fluorine ions content in the hydrothermal process can control the crystal morphology and size of synthesized ZSM-5. Catalytic properties of synthesized HZSM-5 with different SiO_2/Al_2O_3 ratio in transalkylation of toluene and 1,2,4-trimethylbenzene show good and stable catalytic performance. The ZSM-5 synthesized with recovered silica source exhibits similar catalyst life as the performance of small particle size HZSM-5, because the ZSM-5 synthesized with the silica source from industrial hexafluorosilicic acid prefers a thin disk crystal along the b axis direction, which shortens the diffusion distance of generated products.

Solvent-free synthesis of zeolite catalysts

The most used method for preparation of zeolites is hydrothermal synthesis from silicate or aluminosilicate gels at temperatures in the range of 60-200 ℃. Excess water used in the industrial process results in several issues, including high autogeneous pressure, low efficiency, pollution, etc. To solve these problems, several strategies have been developed. This review describes the solvent-free synthesis of zeolites. The combination of solvent-free synthesis and organotemplate-free synthesis can open the pathway to a highly sustainable zeolite synthesis protocol in industry.

Floating production storage and offloading systems＇ cost and motion performance： A systems thinking application

Floating production storage and offloading （FPSO） units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opporamity to seek a balance between FPSO technical performance（s）, with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options＇ that address technical-motion（s）, with respective life-cycle cost analyses （LCCA）. Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub- component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary considera- tion to facilitate extraction, production and storage of deep- water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAM DeepC, while life-cycle cost analysis （LCAA） studies give net-present-value comparsons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 - 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25- year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design （FEED） phase of fit-for-purpose configured FPSOs, in waters off Malaysia and Australia.