Spent Bleaching Earth (SBE) which is solid waste produced from the bleaching process in the CPO processing industry into cooking oil and oleochemicals is increasing along with the production of palm oil derivative products or downstream palm oil industries such as cooking oil and oleochemicals. The amount of bleaching earth used generally ranges from 0.5-2.0% of the total CPO refined, depending on the quality of the CPO to be processed in the refining process. SBE is included in category 2 hazardous toxic material (B3) waste from specific sources with waste code B413. SBE is categorized as hazardous toxic material (B3) waste because it contains high oil and has characteristics that are flammable and corrosive. SBE can be categorized as non-B3 waste if its oil content is below 3%.
The classification of SBE status as hazardous toxic material (B3) waste in Indonesia is different from the status of SBE in Malaysia, which is also the second largest palm oil producer in the world. SBE waste produced by the Malaysian refinery industry is not classified as B3 waste but is still categorized as solid waste from refinery factories whose processing is regulated in the Solid Waste Regulation (SWR) so that the waste can be reused into products with high economic value.
According to the Indonesian Vegetable Oil Industry Association (GIMNI, 2021), with a refinery capacity of palm oil/CPO between 600 tons to 2,500 tons per day, and assuming the use of bleaching earth (BE) of 1%-2%, the average will produce 6-50 tons of SBE per day. And according to the Directorate General of Waste Management, Toxic and Hazardous Materials (PSLB3) of the Ministry of Environment and Forestry, the SBE produced from the vegetable oil refining process in Indonesia in 2019 reached 779 thousand tons. Of that amount, 51.47% (401 thousand tons) of SBE was processed, while the remaining 48.39% (378 thousand tons) was stored or stockpiled. A very large amount and has the potential to pollute the environment.
SBE has an oil content of around 20-40%, so it has the potential to be utilized. In addition, SBE also contains color, gum, metals namely Silica, Aluminum oxide, Ferrioxide, Magnesia, other metals and water. Basically, SBE processing is done by separating oil from its solids. The separated oil can then be used as raw material for biodiesel and even aircraft fuel (bio-jet fuel) such as POME / PAO and UCO. With the amount of unprocessed SBE reaching around 378 thousand tons per year, the potential oil that can be extracted reaches around 115 thousand tons per year.
With pyrolysis, the process of separating solid and liquid fractions from SBE is easy to do, as well as oil recovery can be maximized, as well as SBE becomes non-hazardous toxic material (non-B3) waste because its oil content is below 3%. More specifically, with continuous pyrolysis, the volume of SBE waste reaching 50 tons per day in the CPO refinery unit can be easily done. The large potential economic value that can be obtained from the utilization of SBE is a shame if it is not optimized. The market opportunity for processed products from SBE waste is also expected to be bright in the future, along with the development of market preferences that demand the availability of eco-friendly and sustainable products.
