The focus of this work is to test variables of fast pyrolysis conditions in a free fall reactor in order to better understand their impact on pyrolysis products, specifically optimization of biooil yields. In the first study, a design of experiments was performed and products were analyzed to evaluate the effects of temperature, sweep gas flow rates, and particle heating time, on bio-oil yields...

A mathematical model of a mixed culture of bacteria in a fully three dimensional flow reactor which accounts for the colonization of the reactor wall surface by the microbes is studied both analytically and by simulation. It can be viewed as a model of the large intestine or of the fouling of a commercial bio-reactor or pipe flow. The primary focus is on coexistence of microbial populations in ...

In present paper, dynamic behavior and control of a fluidized bed reactor for polyethylene production has been considered. A double active sites model for Ziegler-Natta catalysts is used for simulation of polymerization reaction. Hydrodynamic behavior of the bed is modeled using a two phase model including bubble and emulsion phases in which bubble phase has plug flow pattern with different...

This study was undertaken to evaluate the potential future use of three biological processes in order to designate the most desired solution for on-site treatment of wastewater from residential complexes, that is, conventional activated sludge process (CASP), moving-bed biofilm reactor (MBBR), and packed-bed biofilm reactor (PBBR). Hydraulic retention time (HRT) of 6, 3, and 2 h can be achieved...

Using dark fermentation, hydrogen can be generated from renewable organics including waste materials. Key to successful application of anaerobic fermentation is to uncouple liquid and biomass retention times in reactor system. This paper reviews reactor configurations (fixed-bed, fluidized-bed, upflow anaerobic sludge blanket and continuous stirred tank reactors) and operating processes (batch,...

In this paper, combustion of char in the riser of circulating fluidized bed was modeled using ASPEN PLUS. Since physical and chemical phenomena are involved in the process, the model integrates the two-phase hydrodynamic sub-model with the reaction sub-model derived from the literature. In the proposed model, the fluidized bed is divided into several sections and the behavior of each section wa...

Moving bed biofilm reactors (MBBRs) are increasingly used for nitrogen removal with nitritation-anaerobic ammonium oxidation (anammox) processes in wastewater treatment. Carriers provide protected surfaces where ammonia oxidizing bacteria (AOB) and anammox bacteria form complex biofilms. However, the knowledge about the organization of microbial communities in MBBR biofilms is sparse. We used n...

Factors affecting filtration characteristics in submerged hollow fiber membrane were investigated in membrane-coupled moving bed biofilm reactor (M-CMBBR). The trend of membrane biofouling in M-CMBBR was quite different from that in a conventional membrane bioreactor (MBR). The M-CMBBR showed much lower biofouling rate than a conventional MBR. Whereas the membrane biofouling in conventional MBR...

Treatment of waste water containing ethylene glycol (EG) by implementing a sequence of two Moving Bed Biofilm Reactors (MBBR) were studied. Reactors were operated at different hydraulic retention times (HRT) of 48, 24, 18, and10 hours while EG concentration was in the range of 10 mg/l to 1,150 mg/l. Throughout the experiments the ratio of EG Chemical Oxygen Demand (COD) to total COD was changed...

A kinetic model for propane dehydrogenation in an industrial moving bed reactor is developed based on the reported reaction scheme. The kinetic parameters and activity constant are fine tuned with several sets of balanced plant data. Plant data at different operating conditions is applied to validate the model and the results show a good agreement between the model predictions and plant observa...