IDENTIFYING ANAEROBIC DIGESTION MODELS USING SIMULTANEOUS BATCH EXPERIMENTS

2010 ◽  
Vol 9 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Xavier Flotats ◽  
Jordi Palatsi ◽  
Belen Fernandez ◽  
M. Angels Colomer ◽  
Josep Illa
Keyword(s):  
Anaerobic Digestion ◽  
Batch Experiments

scholarly journals Improving the Anaerobic Digestion of Swine Manure through an Optimized Ammonia Treatment: Process Performance, Digestate and Techno-Economic Aspects

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 787
Author(s):  
Anna Lymperatou ◽  
Niels B. Rasmussen ◽  
Hariklia N. Gavala ◽  
Ioannis V. Skiadas
Keyword(s):  
Anaerobic Digestion ◽  
Large Scale ◽  
Treatment Process ◽  
Aqueous Ammonia ◽  
Swine Manure ◽  
Batch Experiments ◽  
Ammonia Treatment ◽  
Aqueous Ammonia Soaking ◽  
High Ammonia ◽  
Reduction Efficiency

Swine manure mono-digestion results in relatively low methane productivity due to the low degradation rate of its solid fraction (manure fibers), and due to the high ammonia and water content. The aqueous ammonia soaking (AAS) pretreatment of manure fibers has been proposed for overcoming these limitations. In this study, continuous anaerobic digestion (AD) of manure mixed with optimally AAS-treated manure fibers was compared to the AD of manure mixed with untreated manure fibers. Due to lab-scale pumping restrictions, the ratio of AAS-optimally treated manure fibers to manure was only 1/3 on a total solids (TS) basis. However, the biogas productivity and methane yield were improved by 17% and 38%, respectively, also confirming the predictions from a simplified 1st order hydrolysis model based on batch experiments. Furthermore, an improved reduction efficiency of major organic components was observed for the digester processing AAS-treated manure fibers compared to the non-treated one (e.g., 42% increased reduction for cellulose fraction). A preliminary techno-economic analysis of the proposed process showed that mixing raw manure with AAS manure fibers in large-scale digesters could result in a 72% increase of revenue compared to the AD of manure mixed with untreated fibers and 135% increase compared to that of solely manure.

Effects of thermochemical pretreatment on the anaerobic digestion of waste activated sludge

1997 ◽  
Vol 35 (8) ◽  
pp. 209-215 ◽  
Author(s):  
Shuzo Tanaka ◽  
Toshio Kobayashi ◽  
Ken-ichi Kamiyama ◽  
Ma. Lolita N. Signey Bildan
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Production Rate ◽  
Methane Production ◽  
Waste Activated Sludge ◽  
Batch Experiments ◽  
Industrial Wastewaters ◽  
Thermochemical Pretreatment ◽  
Chemical Heating ◽  
Methane Production Rate

Effects of pretreatment on the anaerobic digestion of waste activated sludge (WAS) were investigated in terms of VSS solubilization and methane production by batch experiments. The methods of pretreatment studied are NaOH addition (chemical), heating (thermal) and heating with NaOH addition (thermochemical) to the domestic WAS and to the combined WAS from domestic, commercial and industrial wastewaters. The thermochemical pretreatment gave the best result among three methods in the combined WAS, i.e., the VSS was solubilized by 40-50% and the methane production increased by more than 200% over the control when the WAS was heated at 130°C for 5 minutes with the dose 0.3 g NaOH/g VSS. In the domestic WAS, the VSS solubilization rate was 70-80% but the increase of the methane production was about 30% after thermochemically pretreated. The domestic WAS consists of 41% protein, 25% lipid and 14% carbohydrate on COD basis, and the solubilization rate of protein, which is the largest constituent of the WAS, was 63% in the thermochemical pretreatment. Although the effect of the thermochemical pretreatment on the methane production was higher to the combined WAS than to the domestic WAS, the methane production rate was 21.9 ml CH4/g VSSWAS·day in the domestic WAS and 12.8 ml CH4/g VSSWAS·day in the combined WAS.

Anaerobic digestion of sludge differing in inorganic solids content: performance comparison and the effect of inorganic suspended solids content on degradation

2016 ◽  
Vol 74 (9) ◽  
pp. 2152-2161 ◽  
Author(s):  
Nina Duan ◽  
Xiaohu Dai ◽  
Bin Dong ◽  
Lingling Dai
Keyword(s):  
Anaerobic Digestion ◽  
Suspended Solids ◽  
Degradation Process ◽  
Performance Comparison ◽  
Batch Experiments ◽  
Biogas Yield ◽  
Stirred Tank Reactors ◽  
Volatile Fatty Acid Concentration ◽  
Substrate Conversion ◽  
Solids Content

High inorganic suspended solids (ISS) content of sludge in many areas (especially with combined sewage systems) results in low VS/TS (volatile solids, VS; total solids, TS) levels and raises concerns about its effect on anaerobic digestion. The performances of sludge anaerobic digestion with different feeding VS/TS levels as well as the effect of ISS content on the anaerobic degradation process were investigated in completely stirred tank reactors by semi-continuous and batch experiments. In semi-continuous experiment with sludge at VS/TS of 61.4%, 45.0, 30.0% and 15.0%, biogas yield, VS reduction and methane content decreased logarithmically with the feeding VS/TS decreasing; slightly higher volatile fatty acid concentration was observed at VS/TS 15%. Results of the batch experiments suggested that acetogenesis and methanogenesis are obviously affected by high ISS addition, while hydrolysis is less affected. The retardment of substrate conversion rate is probably attributed to decreased mass transfer efficiency at high ISS content.

scholarly journals In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) process. Part I: Model Development and Calibration

2015 ◽  
Vol 4 (2) ◽  
pp. 165 ◽  
Author(s):  
Mahsa Madani Hosseini ◽  
Catherine N. Mulligan ◽  
Suzelle Barrington
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Model Development ◽  
Laboratory Data ◽  
Batch Process ◽  
Municipal Sludge ◽  
Batch Experiments ◽  
Fed Batch ◽  
Microbial Kinetics ◽  
Good Agreement

<p class="emsd">In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is a treatment system applicable to wastewaters stored for over 100 days, such as livestock wastes and municipal sludge. The ISPAD system differs from conventional reactors by being a sequentially fed batch process operating at a temperature fluctuating with ambient. The objective of this study was to develop a mathematical model to simulate the ISPAD process, verify the value of its microbial kinetics, and to simulate the pH evolution of its content along with its methane (CH<sub>4</sub>) production. Furthermore, the values of the ISPAD microbial kinetics were compared to that of previous years to track for further acclimation to psychrophilic conditions. Simulation of ISPAD was achieved using the Simulink/Matlab software. The model was calibrated using laboratory data obtained from batch experiments using 7-year-old ISPAD inoculum, and glucose as substrate, and where glucose, VFAs and pH changes were monitored along with biogas production. The ISPAD model showed good agreement with the experimental data representing the system behaviour between 4 and 35 ºC. Although microbial activity at 4 °C was much slower than that at 18 and 35 ºC, it showed acclimation to low temperatures. Furthermore, comparison of microbial kinetic values over 3 years of field ISPAD monitoring demonstrated continued population acclimation, especially for the methanogens.</p>

Effects on anaerobic digestion of sewage sludge pretreatment

1997 ◽  
Vol 35 (10) ◽  
pp. 207-211 ◽  
Author(s):  
H. B. Choi ◽  
K. Y. Hwang ◽  
E. B. Shin
Keyword(s):  
Anaerobic Digestion ◽  
Protein Concentration ◽  
Operating Conditions ◽  
Waste Activated Sludge ◽  
Batch Experiments ◽  
Mechanical Pretreatment ◽  
Sludge Pretreatment ◽  
Volatile Solids ◽  
Vs Removal ◽  
Removal Efficiencies

This research investigates the effect of sludge pretreatment on the anaerobic digestion of waste-activated sludge (WAS). In the key of this sludge pretreatment process, bacteria in the WAS were ruptured by mechanical jet and smashed under pressurized conditions. The protein concentrations in the sludge varied significantly after pretreatment. Protein concentration increased according to jet times and pressure. In batch experiments, volatile solids (VS) removal efficiencies were 13∼50% when the WAS pretreated once under 30 bar was fed into an anaerobic digester with 2∼26 day retention time. In the same operating conditions, when intact WAS was fed into the digester, VS removal efficiencies were 2∼35%. Therefore, it is recognized that higher digestion efficiencies of the WAS were obtained through a mechanical pretreatment of sludge.

scholarly journals On the Effect of Aqueous Ammonia Soaking Pre-Treatment on Continuous Anaerobic Digestion of Digested Swine Manure Fibers

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2469 ◽  
Author(s):  
Chrysoula Mirtsou-Xanthopoulou ◽  
Ioannis V. Skiadas ◽  
Hariklia N. Gavala
Keyword(s):  
Renewable Energy ◽  
Anaerobic Digestion ◽  
Solid Fraction ◽  
Aqueous Ammonia ◽  
Swine Manure ◽  
Methane Yield ◽  
Batch Experiments ◽  
The Past ◽  
Aqueous Ammonia Soaking ◽  
Pre Treatment

(1) Background: The continuously increasing demand for renewable energy sources renders anaerobic digestion as one of the most promising technologies for renewable energy production. Due to the animal production intensification, manure is being used as the primary feedstock for most biogas plants. Their economical profitable operation, however, relies on increasing the methane yield from the solid fraction of manure, which is not so easily degradable. The solid fraction after anaerobic digestion, the so-called digested fibers, consists mainly of hardly biodegradable material and comes at a lower mass per unit volume of manure compared to the solid fraction before anaerobic digestion. Therefore, investigation on how to increase the biodegradability of digested fibers is very relevant. So far, Aqueous Ammonia Soaking (AAS), has been successfully applied on digested fibers separated from the effluent of a manure-fed, full-scale anaerobic digester to enhance their methane productivity in batch experiments. (2) Methods: In the present study, continuous experiments at a mesophilic (38 °C) CSTR-type anaerobic digester fed with swine manure first and a mixture of manure with AAS-treated digested fibers in the sequel, were performed. Anaerobic Digestion Model 1 (ADM1) previously fitted on manure fed digester was used in order to assess the effect of the addition of AAS-pre-treated digested manure fibers on the kinetics of anaerobic digestion process. (3) Results and Conclusions: The methane yield of AAS-treated digested fibers under continuous operation was 49–68% higher than that calculated in batch experiments in the past. It was found that AAS treatment had a profound effect mainly on the disintegration/hydrolysis rate of particulate carbohydrates. Comparison of the data obtained in the present study with the data obtained with AAS-pre-treated raw manure fibers in the past revealed that hydrolysis kinetics after AAS pre-treatment were similar for both types of biomasses.

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