At ITC, we have our own, unique bio reactor at our disposal, which is used to clean tanks in an environmentally responsible manner. In cooperation with Paques (www.paques.nl) and partners Wageningen University and Research, and LeAF, we have developed this bio reactor. It has been operational on our location since 2009. The reactor is the first of its kind and utilizes an innovative anaerobic (oxygen free) system to generate as much valuable biogas as possible from fatty wastewater. In addition, the installation purifies the wastewater.
In this anaerobic (oxygen free) installation, the organic constituents in the water and in the solids are converted to valuable biogas. The system (Biopaq®-AFR, short for Anaerobic Flotation Reactor) is a new reactor concept where bacteria grow into flakes and are kept within the system by an integrated flotation unit, which floats on the fatty wastewater. So firstly, the fatty wastewater is pumped into the reactor and mixed with the bacteria that produce the biogas and purify the wastewater simultaneously. It is then pumped to the flotation unit where the with biogas saturated effluent (purified wastewater) is added which creates tiny bubbles that make the bacteria flakes float to the top. The effluent is pumped out from under this floating layer and the anaerobic flaky sludge remains in the floatation unit of the reactor. Next, the effluent or purified wastewater is discharged in the sewer.
The advantage of the system is that it is very compact; the quantity of bacteria material per cubic meter reactor content is much larger in comparison to a conventional fermenter. The system is suitable to treat wastewater streams with an organic matter content too high to treat in a grain reactor and too low to be cost effectively treated in a conventional fermentation plant (approximately between 20 and 100 kg/m3 CVZ). When utilizing an anaerobic grain system the water needs to be stripped from solid matter (fats and such) and has to be pre-acidified in a separate tank. In the new system, these steps are integrated into a single step and the decomposition of the matter yields biogas as well. The system is compact and it is closed off so no extra measures need to be taken to prevent odor emissions. The yield of biogas, of course, is the largest advantage of the bio reactor. The generated biogas is burned in a special steam boiler and used to heat the rinsing water that is needed for new cleanings. The purified water that is emitted by the reactor is discharged into the sewer.
The major advantage of the application of the bio reactor is the high yield of biogas. The fats and other solids that first were discarded, can now be converted to valuable biogas. After a test period, the operation has been optimized and in the future we strive to produce even more biogas. With this extra yield we could possibly fuel our own trucks to come full circle and to operate as CO²-neutral as possible.