Kolovos, A.1, Kjorlaug O.2 and Nilsen, P.J.2
The Cambi SolidStream process is a modification of the traditional Cambi Thermal Hydrolysis Process (THP) which is designed to enhance breakdown and stabilization of digested biomass, improve dewatering and boosting biogas production through recirculation of final dewatering centrate to the digester. The first full-scale installation is showing an outstanding performance with 75%Volatile Solids Reduction (VSR), 50% more biogas and a cake reduction of 62%. To develop the understanding of this system further the process became subject for a master thesis from TU Berlin. Within the scope of the master thesis a simulation model has been developed and assessed for the Cambi SolidStream process using Dynamita´s Sumo modelling software.
The model shows the same impact of the SolidStream installation as full scale results in terms of improved VSR with 25-26% points, and more work will be done to calibrate and optimize the model further. The centrate going back to the digester was shown to be easily degradable, giving an immediate increase in biogas production when introduced to the digester. Both full-scale data and the model showed stable operation of the digesters with very low Volatile Fatty Acid (VFA) to Total Alkalinity (TA) ratio.
Anaerobic Digestion, Cambi SolidStream, Modelling, Sumo
Depending on the country and the plant size, sludge management can have a share of 65-75% of the operating costs of a wastewater treatment plant (WWTP) (Vliegen 2016; Neyens et al. 2004) and 40% of total greenhouse gas emissions from wastewater treatment plants (Anjum et al. 2016). In this context, the scope of anaerobic digestion is expanding and new technologies are available, whose emerging drivers are energy and nutrient conservation and recovery as well as an intelligent sludge management concept (Batstone and Virdis 2014). The Cambi THP has been implemented in WWTPs around the globe in order to meet the growing demands on sludge management (Higgins et al. 2016) as well as nutrient and energy recovery (Rosenwinkel et al. 2015).