Transformation Of Organic Matter In Oliy Sludge Under Microwave Radiation And Microwave Treatment Process

With the development of mining and processing petroleum,environmental pollution caused becomes more and more serious, resulting incontracting more and more attention all over the world. How to treat oilysludge with recovery and harmless low energy oily sludge, whichcontains poisonous and harmful substances, has become the focus of energyand the environment.The treatment of oily sludge by microwave technology was studied. Inconjunction of thermogravimetric analysis technique, the process feature andacceleration mechanism of microwave thermal treatment of oily sludge werestudied firstly. Then, the output features of products during microwave thermaltreatment were studied by gas chromatography. Finally, on the basis ofthe experimental data, the technological process of microwave treatment ofoily sludge was put up for recycling oils from oily sludge. The appearance of oily sludge changed significantly during microwavethermal treatment, and that there were two important processes: theevaporation process of hydrocarbons and water, the microwave pyrolysis andcalcining processes of heavy component. The former was physical process andthe later was chemical process. The pyrolysis process of heavy componenttook too long time, leading to the whole time of microwave treatment of oilysludge was very long. However, if the residues as microwave absorbent, whichgenerated from the microwave thermal treatment of oil sludge were mixedwith oily sludge, for example2%, can effectively mainly accelerat pyrolysisprocess of macromolecular organic material, resulting in decreasing the timeof pyrolysis process at58.10%. Furthermore, the appropriate amount ofresidues can increase the recovery of oil. This indicated that residues used asmicrowave absorbent can speed up the process of microwave treatment of oilysludge with the higher treatment efficiency. At the same time, this method cansave energy with resource utilization of oily sludge.The oil generated from200℃⁴00℃during the microwave thermaltreatment of oil sludge was composed of22.46%gasoline,48.55%diesel and21.46%heavy oil. It consisted of22.89%gasoline,34.85%diesel and33.39%heavy oil from400℃⁸00℃. This indicated that the transformation of organicmatters in oily sludge into oil mainly happened in microwave pyrolysis stage.The non-condensable gases from microwave pyrolysis stage and calciningstage were accounted for94.12%and were composed of C₂^C₅and less H₂, N₂, O₂. The residues which were generated from the microwave thermaltreatment of oil sludge can be discharged in accordance with Chinese GBstandard.Compared with traditional electrical heating treatment, oily sludge wastreated by microwave technology with higher efficiency of the transformationof organic matters, better quality of oils, more combustible gases and highercalorific value of product.Finally, the technology process of microwave thermal treatment of oilysludge from preprocessing material to recovering and analysis product was putup. This technology process divided into six parts: pretreatment and feedsystem, microwave treatment system, gas condensing and fluid separationsystem, purification and utilization of non-condensable gas system, detectionand control system, accessory system. Some key factors should be consideredfor process design, for examples, composition of oily sludge, feeding form andspeed, heating method and reaction temperature, cooling temperature offraction. This technological process would be beneficial to the engineeringapplication of microwave thermal treatment of oily sludge.