PYROLYSIS OF A REFINERY SEWAGE-SLUDGE - A MATERIAL RECYCLING PROCESS

Stronger laws for waste water disposal lead to more efficient waste water treatment. But as a consequence of this, the amount of sewage sludges which have to be disposed is rising. As an alternative to incineration or landfilling deposits, the treatment via pyrolysis can make use of the biomass contents of the sewage sludges. Sewage sludge from the waste water plant of an oil refinery was treated at temperatures from 560 to 685-degrees-C by the Hamburg Pyrolysis Process. Gas, oil water and a solid fraction have been produced. The gasfraction has a calorific value of up to 30 MJ/kg and could be used as a fuelgas for the production of process heat. The mainly aliphatic oilfraction could easily be fed into the crudeoil stream of the refinery. The water formed through pyrolysis could be cleaned in the waste water plant. Only the solid product-fractions (the inorganic input material covered with pyrolysis coke and sooth) needs to be disposed. Therefore a material recycling of sewage sludge can be obtained.