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1、炼化企业综合管控BAT技术 BAT 1. 为阻止或减少VOC逸散，将应用以下的BAT技术 2、储存和转运过程中的BAT技术 BAT 2.为减少挥发性有机液体在储存过程中向大气逸散VOC，采用高密封性能的浮顶罐或配备油气回收设施的固顶罐进行储存。 BAT 3.为减少挥发性有机液体在储存过程中向大气逸散VOC，采用以下一种或技术组合。 BAT 4. 为减少VOC在装卸过程中的排放，采用以下一种或多种技术组合可实现95%的回收。 5.20.6 VOC控制技术描述 一、油气回收/Vapour recovery Volatile organic compounds emissions fromloading and unloading operations of most volatile products, especially crudeoil and lighter products, can be abated by various techniques e.g.: （1）吸收技术/Absorption: the vapour molecules dissolvein a suitable absorption liquid (e.g. glycols or mineral oil fractions such askerosene or reformate). The loaded scrubbing solution is desorbed by reheatingin a further step. The desorbed gases must either be condensed, furtherprocessed, and incinerated or re-absorbed in an appropriate stream (e.g. of theproduct being recovered) （2）吸附技术/Adsorption: the vapour molecules areretained by activate sites on the surface of adsorbent solid materials, e.g.activated carbon (AC) or zeolite. The adsorbent is periodically regenerated.The resulting desorbate is then absorbed in a circulating stream of the productbeing recovered in a downstream wash column. Residual gas from wash column issent to further treatment （3）膜分离技术/Membrane gas separation: the vapourmolecules are processed through selective membranes to separate the vapour/airmixture into a hydrocarbon-enriched phase (permeate), which is subsequentlycondensed or absorbed, and a hydrocarbon-depleted phase (retentate). （4）两级冷凝/冷凝（Two-stage refrigeration/condensation）:by cooling of the vapour/gas mixture the vapour molecules condense and areseparated as a liquid. As the humidity leads to the icing-up of the heatexchanger, a two stage condensation process providing for alternate operationis required. （5）组合技术/Hybrid systems: combinations ofavailable techniques 二、销毁技术（Vapour destruction） Destruction of VOCs can be achieved throughe.g. thermal oxidation (incineration) or catalytic oxidation whenrecovery is not easily feasible. Safety requirements (e.g. flame arrestors) are needed to prevent explosion. （1）热力氧化/Thermal oxidation occurs typically in single chamber,refractory-lined oxidisers equipped with gas burner and a stack. If gasoline ispresent, heat exchanger efficiency is limited and preheat temperatures aremaintained below 180 °C to reduce ignition risk. Operating temperatures rangefrom 760 °C to 870 °C and residence times are typically 1 second. When aspecific incinerator is not available for this purpose, an existing furnace maybe used to provide the required temperature and residence times. （2）催化氧化（Catalytic oxidation）requires a catalyst to accelerate the rate ofoxidation by adsorbing the oxygen and the VOCs on its surface The catalystenables the oxidation reaction to occur at lower temperature than required bythermal oxidation: typically ranging from 320 °C to 540 °C. A first preheatingstep (electrically or with gas) takes place to reach a temperature necessary toinitiate the VOCs catalytic oxidation. An oxidation step occurs when the air ispassed through a bed of solid catalysts 三、泄漏检测与修复技术/LDAR (leak detection and repair) An LDAR (leak detection and repair) programmeis a structured approach to reduce fugitive VOC emissions by detection andsubsequent repair or replacement of leaking components. Currently, sniffing(described by EN 15446) and optical gas imaging methods are available for theidentification of the leaks. （1）便携式检测/Sniffing method: The first step is the detection using hand-held VOCanalysers measuring the concentration adjacent to the equipment (e.g. by usingflame ionisation or photo-ionisation). The second step consists of bagging thecomponent to carry out a direct measurement at the source of emission. Thissecond step is sometimes replaced by mathematical correlation curves derivedfrom statistical results obtained from a large number of previous measurementsmade on similar components. （2）红外成像检测/Optical gas imaging methods: Optical imaging uses small lightweighthand-held cameras which enable the visualisation of gas leaks in real time, sothat they appear as 'smoke' on a video recorder together with the normal imageof the component concerned to easily and rapidly locate significant VOC leaks.Active systems produce an image with a back-scattered infrared laser lightreflected on the component and its surroundings. Passive systems are based onthe natural infrared radiation of the equipment and its surroundings 四、VOC逸散监测/diffuse emissions monitoring Full screening and quantification of siteemissions can be undertaken with an appropriate combination of complementarymethods, e.g. Solar occultation flux (SOF) or differential absorption lidar(DIAL) campaigns. These results can be used for trend evaluation in time, crosschecking and updating/validation of the ongoing LDAR programme. VOC diffuse emissions monitoring （1）红外掩日法/Solar occultation flux (SOF): The technique is based on the recording andspectrometric Fourier Transform analysis of a broadband infrared orultraviolet/visible sunlight spectrum along a given geographical itinerary,crossing the wind direction and cutting through VOC plumes. （2）差分吸收激光雷达/Differential absorption LIDAR (DIAL): DIAL is a laser-based technique usingdifferential adsorption LIDAR (light detection and ranging) which is theoptical analogue of sonic radio wave-based RADAR. The technique relies on theback-scattering of laser beam pulses by atmospheric aerosols, and the analysisof spectral properties of the returned light collected with a telescope. 五、高密封性设备/High-integrity equipment High-integrity equipment includes e.g.:
结语
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