Novel Solutions in Modeling of Anaerobic Digestion Process - Two-Phase AD Models Development and Comparison

2018 ◽  
Vol 16 (8) ◽  
Author(s):  
Karol Postawa
Keyword(s):  
Anaerobic Digestion ◽  
Process Model ◽  
Large Scale ◽  
Reference Model ◽  
Biogas Production ◽  
Current Model ◽  
Pilot Scale ◽  
Two Phase ◽  
Novel Approach ◽  
Model Predictions

Abstract This work focuses on Two Phase Anaerobic Digestion – a novel approach to split reactions’ chain in two separated tanks, each with specialized microbe community to achieve the best possible efficiency for each part of conversion. More specifically, the article tackle the topic of evaluation the possibility to adapt a mathematical model, previously dedicated for Autogenerative High Pressure Digestion (AHPD), to make use of it in simulation of Temperature Phased Anaerobic Digestion (TPAD) process. A comprehensive study of available solutions for biogas production simulation in conventional and TPAD configuration is additionally performed. Basing on its results, a reference model from literature, for comparison purpose is selected. Revisions and modifications, necessary to adjust previously developed model, to TPAD process, are described. Also, additional improvements like redesigned pH calculating algorithm is presented. Finally, the comparison between model predictions, a reference model and pilot-scale data is carried out. The results show that our current model needs further optimization, however even at this stage it provides acceptable results in short-range simulations (not longer than 42 days). Further works should focus on process stability improvement, especially in the thermophilic stage of biogas production. There's an opportunity for innovation as the research shows that requirement of accurate, large-scale optimized TPAD process model, is still not fulfilled.

Biogas Production Using Anaerobic Digestion of Industrial Waste

2016 ◽  
Vol 832 ◽  
pp. 55-62
Author(s):  
Ján Gaduš ◽  
Tomáš Giertl ◽  
Viera Kažimírová
Keyword(s):  
Anaerobic Digestion ◽  
Industrial Waste ◽  
Large Scale ◽  
Biogas Production ◽  
Biogas Plant ◽  
Parallel Operation ◽  
Paper Production ◽  
Biochemical Conversion ◽  
Mixed Biomass ◽  
Economic Balance

In the paper experiments and theory of biogas production using industrial waste from paper production as a co-substrate are described. The main aim of the experiments was to evaluate the sensitivity and applicability of the biochemical conversion using the anaerobic digestion of the mixed biomass in the pilot fermentor (5 m3), where the mesophillic temperature was maintained. It was in parallel operation with a large scale fermentor (100 m3). The research was carried out at the biogas plant in Kolíňany, which is a demonstration facility of the Slovak University of Agriculture in Nitra. The experiments proved that the waste arising from the paper production can be used in case of its appropriate dosing as an input substrate for biogas production, and thus it can improve the economic balance of the biogas plant.

Enhancing Emergency Response Management using Emergency Description Information Technology (EDIT)

2016 ◽  
pp. 1264-1278
Author(s):  
Michael A. Erskine ◽  
Will Pepper
Keyword(s):  
Emergency Response ◽  
Process Model ◽  
Large Scale ◽  
Design Science ◽  
Future Research ◽  
Sporting Events ◽  
Emergency Responder ◽  
Response Information ◽  
Novel Approach ◽  
Future Research Directions

This paper presents a novel approach toward facilitating the effective collection and communication of information during an emergency. Initially, this research examines current emergency response information workflows and emergency responder dispatch criteria. A process for the optimization of these workflows and criteria, along with a suggested method to improve data collection accuracy and emergency response time using a mobile device application, are suggested. Specifically, a design-science approach incorporating the development of an expert system designed to facilitate efficient and effective sharing of emergency information is applied. The resulting benefits could improve emergency communications during large-scale international gatherings, such as sporting events or festivals, as well as the sharing of industry-specific safety incidents. A process model for conducting analyses of additional emergency response processes is also presented. Finally, future research directions are discussed.

scholarly journals Influence of Temperature on Biogas Production Efficiency and Microbial Community in a Two-Phase Anaerobic Digestion System

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 133 ◽  
Author(s):  
Shiwei Wang ◽  
Fang Ma ◽  
Weiwei Ma ◽  
Ping Wang ◽  
Guang Zhao ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Anaerobic Digestion ◽  
Production Efficiency ◽  
Biogas Production ◽  
Two Phase ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Acidogenic Phase ◽  
Methanogenic Phase

In this study, the influence of temperature on biogas production efficiency and the microbial community structure was investigated in a two-phase anaerobic digestion reactor for co-digestion of cow manure and corn straw. The results illustrated that the contents of solluted chemical oxygen demand (SCOD) and volatile fatty acid (VFA) in the acidogenic phase and biogas production in the methanogenic phase maintained relatively higher levels at temperatures ranging from 35–25 °C. The methane content of biogas production could be maintained higher than 50% at temperatures above 25 °C. The microbial community structure analysis indicated that the dominant functional bacteria were Acinetobacter, Acetitomaculum, and Bacillus in the acidogenic phase and Cenarchaeum in the methanogenic phase at 35–25 °C. However, the performances of the acidogenic phase and the methanogenic phase could be significantly decreased at a lower temperature of 20 °C, and microbial activity was inhibited obviously. Accordingly, a low temperature was adverse for the performance of the acidogenic and methanogenic phases, while moderate temperatures above 25 °C were more conducive to high biogas production efficiency.

Modeling of Boiling Liquid Expanding Vapor Explosion (BLEVE): Plane, Cylindrical and Spherical 1D Model

2008 ◽  
Author(s):  
G. A. Pinhasi ◽  
Y. Dahan ◽  
A. Dayan ◽  
A. Ullmann
Keyword(s):  
Shock Wave ◽  
Current Model ◽  
Dynamic State ◽  
Vapor Explosion ◽  
Two Phase ◽  
Boiling Liquid ◽  
Energy Models ◽  
Model Predictions ◽  
1D Model ◽  
Tnt Equivalence

A 1D plane, cylindrical and spherical numerical model was developed for estimating the thermodynamic and the dynamic state of the boiling liquid during a boiling liquid expanding vapor explosion (BLEVE) event. The model predicts, simultaneously, the flow properties of the expanding two-phase flashing mixture and its surrounding air. The possible presence of a shock wave formed by the fluid expansion through the air is accounted for in the model. Model predictions of the shock wave strengths, in terms of TNT equivalence for the various coordinate systems, were compared against those obtained by simple energy models. As expected, the simple energy models over predicts the shock wave strength. However, the simple model which accounts for the expansion irreversibility, produces results which are closer to current model predictions. For the 1D plane case the model simulates a BLEVE scenario in a tunnel, whereas for the spherical case the more realistic BLEVE scenario in free space is being studied.

Ultrasound pre-treatment for anaerobic digestion improvement

2009 ◽  
Vol 60 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
S. Pérez-Elvira ◽  
M. Fdz-Polanco ◽  
F. I. Plaza ◽  
G. Garralón ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Energy Balance ◽  
Specific Energy ◽  
Biogas Production ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Net Generation ◽  
Batch Reactors ◽  
Anaerobic Reactors ◽  
Pre Treatment

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT = 20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT = 15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR = 20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3–10 kW per kW of energy used.

Comparison of One-Phase and Two-Phase Anaerobic Digestion of Swine Manure

2013 ◽  
Vol 726-731 ◽  
pp. 2875-2880
Author(s):  
Wen Hao Liu ◽  
Shi Jie Tian ◽  
Shu Biao Wu ◽  
Xiao Qian Zhang ◽  
Chang Le Pang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Swine Manure ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Two Phase ◽  
Biogas Yield ◽  
Loading Rates ◽  
Significant Difference ◽  
The One

The possible exploitation of two-phase anaerobic digestion for swine manure was investigated in this study. One-phase and two-phase anaerobic digestion process were investigated in continuous stirred-tank reactor with hydraulic retention times 15 days (hydrolysis and acidification for 3 days and methanogenic12 days in two-phase). When the organic loading rates were equal to or less than 4 g VS/L day, the biogas yield and volumetric production of two processes were no significant difference. However, in the case of organic loading rates being equal to or higher than 5.0 g VS/L day, two-phase biogas yield and volumetric biogas production averaged 0.294 L CH4/g VS added and 2.218 L/L day, compared with one-phase averaged 0.255L CH4/g VS added and 2.168 L/L day, respectively. Significant advantages in saving cost of biogas project were indicated by the comparison of biogas production and COD degradation in the one-phase and two-phase processes.

Fast Startup of Semi-Pilot-Scale Anaerobic Digestion of Food Waste Acid Hydrolysate for Biogas Production

2017 ◽  
Vol 65 (51) ◽  
pp. 11237-11242 ◽  
Author(s):  
Chao Huang ◽  
Cheng Zhao ◽  
Hai-Jun Guo ◽  
Can Wang ◽  
Mu-Tan Luo ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Biogas Production ◽  
Pilot Scale ◽  
Acid Hydrolysate ◽  
Waste Acid

Experimental and Artificial Neural Network Modeling of a Upflow Anaerobic Contactor (UAC) for Biogas Production from Vinasse

2016 ◽  
Vol 14 (6) ◽  
pp. 1241-1254 ◽  
Author(s):  
Ousman R. Dibaba ◽  
Sandip K. Lahiri ◽  
Stephan T’Jonck ◽  
Abhishek Dutta
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Neural Network Modeling ◽  
Artificial Neural

Abstract A pilot scale Upflow Anaerobic Contactor (UAC), based on upflow sludge blanket principle, was designed to treat vinasse waste obtained from beet molasses fermentation. An assessment of the anaerobic digestion of vinasse was carried out for the production of biogas as a source of energy. Average Organic loading rate (OLR) was around 7.5 gCOD/m3/day in steady state, increasing upto 8.1 gCOD/m3/day. The anaerobic digestion was conducted at mesophilic (30–37 °C) temperature and a stable operating condition was achieved after 81 days with average production of 65 % methane which corresponded to a maximum biogas production of 85 l/day. The optimal performance of UAC was obtained at 87 % COD removal, which corresponded to a hydraulic retention time of 16.67 days. The biogas production increased gradually with OLR, corresponding to a maximum 6.54 gCOD/m3/day (7.4 % increase from initial target). A coupled Artificial Neural Network-Differential Evolution (ANN-DE) methodology was formulated to predict chemical oxygen demand (COD), total suspended solids (TSS) and volatile fatty acids (VFA) of the effluent along with the biogas production. The method incorporated a DE approach for the efficient tuning of ANN meta-parameters such as number of nodes in hidden layer, input and output activation function and learning rate. The model prediction indicated that it can learn the nonlinear complex relationship between the parameters and able to predict the output of the contactor with reasonable accuracy. The utilization of the coupled ANN-DE model provided significant improvement to the study and helps to study the parametric effect of influential parameters on the reactor output.

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