Petroleum sludge oil waste from exploitation, refining, distribution and storage of petroleum cause many environment problems if not handle properly. Sludge oil in the form mud with black color, sometimes mixed with soil, stone, etc. The mud come from sedimentation of petroleum powdery particles. Sludge sediment will be more in bottoms storage tank and distributor. Basically the mixture of oil, water, and solid in the sludge oil makes colloid system that difficult in ordinary physic separation. The sludge oil contain many chemical compounds that harmful to environment but can be used optimally if properly processed. The composition of sludge oil namely short hydrocarbon chain with carbon quantity 1 or 2 unit (C1, C2) until long chain hydrocarbon molecules (C15-C30+). The thermal route with pyrolysis is effective and efficient way to process the waste. With pyrolysis the processing can be done in shorter time, compared with biological route with microorganism that need longer time. Pyrolysis or thermal decomposition make the material into plain chemical compounds from complex compounds will be effective way for the sludge oil processing. Heavy metal contain from the sludge oil will be in solid product of the pyrolysis so the next handling will be easier.
Beside the petroleum refinery, sludge oil also be found in the bunker oil. The sludge oil quantity up to 5% from the mass of the bunker oil. Petroleum industry grow rapidly in Indonesia, started with the operation on Processing Unit (PU) I in Pangkalan Brandan with capacity 5,000 barrel/day, PU II in Dumai and Sungai Pakning with capacity 170,000 barrel/day, PU III Plaju and Sungai Gerong with capacity 135.000 barrel/day, PU IV Cilacap with capacity 348,000 barrel/day, UP V Balikpapan with capacity 270,000 barrel/day, UP VI Balongan with capacity 125,000 barrel/day. And UP VII Kasim Irian Jaya with capacity 10,000 barrel/day. Hundreds thousand tons of sludge oil is estimated from the petroleum industrial activities. Right now sludge oil processing usually with manual cleaning and then directly injected into petroleum well so will cause pollution in surrounding area but more of them only store in the waste ponds. If the sludge oil is processed with pyrolysis so will be produced many products mainly useful oil, have economic value, can be reused again in petroleum process, and overcomes many environment problems.
Sludge oil have characteristic like mud so it is very difficult to be separated of the liquid fraction namely oil and water and also the solid fraction with sedimentation. With pyrolysis so the sludge oil will be separated based on the boiling points. Some products in the form, solid, liquid and gas will be obtained. Liquid product in the form of oil with plain chemical structure and can be mixed with water but then can be separated easily with decantation, the gas product contain with light gases can be burned like methane, then the solid product namely soil, sand, stone and organic char. The continuous pyrolyser can process sludge oil with large capacity. JF continuous pyrolysis with indirect heating is the equipment that can process the sludge oil with capacity up to 200 tons/day sludge oil (input). With low heating rate and maximum temperature in the range 500 C so the pyrolysis process can be operated well.
The various usage of pyrolysis oil in example for mixture of bunker oil, liquid fuel powerplant, burner fuel, can be reuse for petroleum refinery so the oil can be recovered more. For the excess gas product can be used for energy source or fuel in many sectors. And the last, the solid product can be used for building material and so on.
