scholarly journals In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) process. Part II: Model Validation

2015 ◽  
Vol 4 (2) ◽  
pp. 193 ◽  
Author(s):  
Mahsa Madani Hosseini ◽  
Catherine N. Mulligan ◽  
Suzelle Barrington
Keyword(s):  
Anaerobic Digestion ◽  
Water Solubility ◽  
Biogas Production ◽  
Laboratory Data ◽  
Coefficient Of Determination ◽  
Batch Tests ◽  
Experimental Values ◽  
Microbial Groups ◽  
Batch Treatment ◽  
Changes Over Time

<p class="emsd">In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is a sequentially fed batch treatment system operating at a temperature fluctuating with that of ambient. Because of its specific operation modes and the acclimation of its microbial groups, its microbial kinetics were determined from laboratory data, and a specific mathematical model was developed to simulate its process and to optimize its management. The objective of this study is therefore to validate this ISPAD model using further laboratory data obtained from batch tests conducted in flasks. For this purpose, glucose at 630 mg/L, was fed to 8-year-old ISPAD inoculum and digested at 18 °C. Changes in glucose, VFAs and pH were monitored along with biogas production. The cross-validated coefficient of determination () was used to determine the fit between the model prediction and the experimental values. The ISPAD model was able to strongly predict glucose degradation, VFAs, pH, and methane. However, the model weakly predicted the early CO<sub>2</sub> changes over time, likely because of its water solubility. </p>

The use of microalgae and their culture medium for biogas production in an integrated cycle

2013 ◽  
Vol 69 (5) ◽  
pp. 941-946 ◽  
Author(s):  
E. L. Formagini ◽  
F. R. Marques ◽  
M. L. Serejo ◽  
P. L. Paulo ◽  
M. A. Boncz
Keyword(s):  
Anaerobic Digestion ◽  
Culture Medium ◽  
Biogas Production ◽  
Algal Growth ◽  
Culture Broth ◽  
Strong Tendency ◽  
Stable Operation ◽  
Microalgae Cultivation ◽  
Algae Cultivation ◽  
Batch Tests

Vinasse is a residue produced in large quantities as a sub-product of ethanol production. Anaerobic digestion of vinasse can yield large amounts of biogas, but often difficulties arise in maintaining stable operation, due to the acidity of the material (which has a pH between 3.5 and 5) and a strong tendency to further acidification. Anaerobically digested vinasse can be used as part of a culture medium for microalgae cultivation, for the production of biodiesel and other compounds, whilst the excess CO2 produced in the ethanol fermentation can be used to stimulate algal growth. During algae cultivation, the pH of the culture medium has a strong tendency to increase; therefore, recycling of the spent culture medium or the concentrated algae suspension to the anaerobic digester treating vinasse was considered an option for pH stabilization there. Batch tests, however, showed that alkalinity of the spent culture broth, in spite of its high pH, is too low (only 350 mgCaCO3L−1) to help stabilise the pH of vinasse digestion. Alkalinity of the algae suspension is higher and digestion of a mixture of vinasse and a suspension of algae results in efficient biogas production, but still the alkalinity is insufficient to stabilise the pH in a range suitable for methanogenic microorganisms; hence, the addition of additional alkalinity, for instance as sodium bicarbonate or urea, remains necessary.

scholarly journals Biogas Production from Combined Irish Potato and Poultry Wastes: Optimization and Kinetic Studies

2018 ◽  
Vol 7 (3.36) ◽  
pp. 170
Author(s):  
Umar M. Ibrahim ◽  
Saeed I. Ahmed ◽  
Babagana Gutti ◽  
Idris M. Muhammad ◽  
Usman D. Hamza ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Parameters ◽  
Ph Value ◽  
Biogas Production ◽  
Irish Potato ◽  
Coefficient Of Determination ◽  
Optimum Conditions ◽  
Biogas Yield ◽  
Potato Waste ◽  
Initial Ph

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.  

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>

scholarly journals Elevated biogas production from the anaerobic co-digestion of farmhouse waste: Insight into the process performance and kinetics

2019 ◽  
Vol 37 (12) ◽  
pp. 1240-1249 ◽  
Author(s):  
Spyridon Achinas ◽  
Gerrit Jan Willem Euverink
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Ternary Mixtures ◽  
Batch Reactors ◽  
Process Performance ◽  
Mixing Ratios ◽  
Batch Tests ◽  
Biogas Plants ◽  
The Impact ◽  
Insight Into

The biodegradable portion of solid waste generated in farmhouses can be treated for energy recovery with small portable biogas plants. This action can be done across the Netherlands and all around the planet. This study aims to appraise the performance of anaerobic digestion of different wastes (cow manure, food waste and garden waste) obtained from a regional farmhouse. Batch reactors were established under mesophilic conditions in order to investigate the impact of ternary mixtures on the anaerobic digestion process performance. Different mixing ratios were set in the batch tests. The upshots from the experiments connoted that ternary digestion with cow manure:food waste:garden waste mixing ratio of 40:50:10 yielded higher biogas amount. The kinetics’ results showed quite good congruence with the experimental study. The results from the kinetic analysis appeared to be in line with the experimental one.

The valuation of malnutrition in the mono-digestion of maize silage by anaerobic batch tests

2008 ◽  
Vol 58 (7) ◽  
pp. 1453-1459 ◽  
Author(s):  
L. Hinken ◽  
I. Urban ◽  
E. Haun ◽  
I. Urban ◽  
D. Weichgrebe ◽  
...  
Keyword(s):  
Trace Elements ◽  
Anaerobic Digestion ◽  
Trace Element ◽  
Biogas Production ◽  
Renewable Energy Sources ◽  
Anaerobic Bacteria ◽  
Trace Element Content ◽  
Energy Crops ◽  
Maize Silage ◽  
Batch Tests

Anaerobic digestion is a technology which is used to produce methane from organic solids and energy crops. Especially in recent years, the fermentation of energy crops has become more and more important because of increasing costs for energy and special benefits for renewable energy sources in Germany. Anaerobic bacteria require macro and micro nutrients to grow. Absence of these elements can inhibit the anaerobic process significantly. In particular mono-substrates like maize or certain industrial wastewater often cannot provide all required nutrients. For this reason this research investigates the influence of substrate and trace elements on anaerobic digestion in detail. Different agricultural anaerobic biomasses are analysed with special regard to their trace element content. Based on these results, the influence of three trace elements (iron, cobalt, and nickel) on anaerobic digestion was studied in anaerobic batch tests at different sludge loading rates and for different substrates (maize and acetate). Biogas production was found to be 35% for maize silage and up to 70% higher for acetate with trace element dosage than in the reference reactor.

scholarly journals Techno-economic evaluation of biogas production from food waste via anaerobic digestion

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abeer Al-Wahaibi ◽  
Ahmed I. Osman ◽  
Ala’a H. Al-Muhtaseb ◽  
Othman Alqaisi ◽  
Mahad Baawain ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
Anaerobic Digestion ◽  
Food Waste ◽  
Net Present Value ◽  
Biogas Production ◽  
Cash Flows ◽  
Gas Production ◽  
Economic Feasibility ◽  
Coefficient Of Determination ◽  
Major Constituent

Abstract Food waste is a major constituent in municipal solid wastes and its accumulation or disposal of in landfills is problematic, causing environmental issues. Herein, a techno-economic study is carried out on the potential of biogas production from different types of food waste generated locally. The biogas production tests were at two-time sets; 24-h and 21-day intervals and results showed a good correlation between those two-time sets. Thus, we propose to use the 24-h time set to evaluate feedstock fermentation capacity that is intended for longer periods. Our approach could potentially be applied within industry as the 24-h test can give a good indication of the potential substrate gas production as a quick test that saves time, with minimal effort required. Furthermore, polynomial models were used to predict the production of total gas and methane during the fermentation periods, which showed good matching between the theoretical and practical values with a coefficient of determination R2 = 0.99. At day 21, the accumulative gas production value from mixed food waste samples was 1550 mL per 1 g of dry matter. An economic evaluation was conducted and showed that the case study breaks-even at $0.2944 per cubic metre. Any prices above this rate yield a positive net present value (NPV); at $0.39/m3 a discounted payback period of six years and a positive NPV of $3108 were calculated. If waste management fee savings are to be incorporated, the total savings would be higher, increasing annual cash flows and enhancing financial results. This economic evaluation serves as a preliminary guide to assess the economic feasibility based on the fluctuating value of methane when producing biogas from food waste via anaerobic digestion, thus could help biogas project developers investigate similar scale scenarios .

scholarly journals Effect of Temperature and Organic Load on the Performance of Anaerobic Bioreactors Treating Grasses

Environments ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 82
Author(s):  
Spyridon Achinas ◽  
Gerrit Jan Willem Euverink
Keyword(s):  
Anaerobic Digestion ◽  
Waste Management ◽  
Biogas Production ◽  
Local Level ◽  
Effect Of Temperature ◽  
Organic Load ◽  
Sustainable Waste Management ◽  
Batch Tests ◽  
Management Scheme ◽  
The Impact

The organic residues generated in grasslands can be treated by adopting anaerobic digestion technology. This technology can enhance the efforts for sustainable waste management around the world. In the northern Netherlands, there is a vast amount of ditch clippings and canal grasses that can be used as a renewable source of energy; however, optimal bioenergy production from grasses is still under research and this study aims to evaluate biogas production from grassy residues at the local level in the context of a sustainable waste management scheme. Batch tests were facilitated to investigate the impact of temperature and organic load on the anaerobic digestion performance of grass mixtures (ditch clippings and canal grasses). The results showed that high temperature favors the degradation of high lignocellulosic materials like grasses. Specifically, bioreactors at 55 °C with an organic load of 30 g volatile solids (VS) L−1 reached 360.4 mL g VSsubstrate−1. Moreover, reactors with low organic loads resulted in a lower methane yield. The kinetics study also showed good fitting of the predicted and experimental values.

Full-stream and part-stream ultrasound treatment effect on sludge anaerobic digestion

2010 ◽  
Vol 61 (6) ◽  
pp. 1363-1372 ◽  
Author(s):  
S. I. Pérez-Elvira ◽  
L. C. Ferreira ◽  
A. Donoso-Bravo ◽  
M. Fdz-Polanco ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Full Scale ◽  
Optimum Process ◽  
Capillary Suction ◽  
Biogas Yield ◽  
Batch Tests ◽  
Secondary Sludge ◽  
Pre Treatment ◽  
The Relationship

The use of ultrasound as pre-treatment to improve anaerobic digestion of secondary sludge has been established as a promising technology. There are great differences between lab scale and full-scale devices, regarding the relationship between the disintegration achieved and the energy supplied. Based on economic aspects, most of the full-scale plants use partial-stream instead of the full-stream sonication, which affects biogas production and digestate dewatering characteristics. A laboratory scale operation combining ultrasound and anaerobic digestion (batch tests) has been performed, determining the relationship between the ratio of sonicated sludge fed and the methane production, SCOD removal and capillary suction time after 20-day anaerobic biodegradation, in order to check the possible benefits of part-stream versus full-stream sonication. Additional incubation was also evaluated, searching for an optimum process combining ultrasound and 24-h incubation pretreatment. Results showed that by sonicating fresh WAS at 25,700 kJ/kg TS biogas yield increased linearly with the percentage of sonicated WAS in the substrate, from 248 (control reactor) to 349 mL CH4/g VS (41% increase in full-stream sonication). By incubation (24 h, 55°C), 325 mL CH4/g VS were obtained (31% increase), but the digestion of the soluble compounds generated during incubation of sonicated sludge appeared to be less degradable compared to those solubilised by ultrasound or incubation alone, which showed no benefit in combining both treatments. Post-digestion dewatering deteriorated for both part-stream and full-stream sonication, and CST values were constant (74% higher than the control digestate) from 30% to 100% sonicated sludge.

scholarly journals Influence of combined sulfachloropyridazine sodium and zinc on enzyme activities and biogas production during anaerobic digestion of swine manure

2018 ◽  
Vol 77 (11) ◽  
pp. 2733-2741
Author(s):  
Ranran Zhang ◽  
Jie Gu ◽  
Xiaojuan Wang ◽  
Li Zhang ◽  
Xiaxia Tuo ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Dehydrogenase Activity ◽  
Volatile Fatty Acids ◽  
Urease Activity ◽  
Biogas Production ◽  
Raw Materials ◽  
Swine Manure ◽  
Dry Weight ◽  
Strongly Correlated ◽  
Batch Tests

Abstract In order to study the influence of different concentrations of zinc and sulfachloropyridazine sodium (SCPS) on anaerobic digestion (AD) during biogas production, we determined the levels of urease, dehydrogenase activity, and volatile fatty acids (VFAs) in batch tests. The experiments were conducted in small AD devices at a temperature of 37 °C using swine manure and wheat straw as raw materials. Four digestion trials were performed using different zinc and SCPS contents: control digestion with no additives (CK), SCPS at 630 mg kg−1 dry weight (S), SCPS at 630 mg kg−1 with zinc at 500 mg kg−1 dry weight (SL), and SCPS at 630 mg kg−1 with zinc at 5,000 mg kg−1 dry weight (SH). The biogas accumulation under S was 1.7 times that with CK, while SL and SH produced 78% and 35% of that under S, respectively. Correlation analysis showed that the accumulated biogas was significantly negatively correlated (p &lt; 0.05) with VFAs, and the urease activity was significantly negatively correlated (p &lt; 0.01) with zinc and significantly positively correlated with VFAs (p &lt; 0.05). The dehydrogenase activity was strongly correlated (p &lt; 0.01) with the biogas accumulated during the AD of swine manure.

scholarly journals Kinetics of Anaerobic Digestion of Unripe Plantain Peels

2020 ◽  
pp. 7-17
Author(s):  
Chinenyenwa Nkeiruka Nweke ◽  
Joseph Tagbo Nwabanne
Keyword(s):  
Anaerobic Digestion ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Growth Yield ◽  
Second Order ◽  
Coefficient Of Determination ◽  
Monod Kinetics ◽  
Order Model ◽  
First Order ◽  
Kinetics Of

This study was carried out to investigate the biogas production obtained from anaerobic digestion of unripe plantain peels (PP) and the kinetics of the digestion process. 400 g of dried and shredded unripe plantain peels were mixed with 200 ml of water and put into 1 L digester and observed for biogas for hydraulic retention time (HRT) of 15 days by the method of downwards displacement. The cumulative biogas volume obtained after digestion was 285 ml. The COD removal efficiency of 72.5% was achieved. The kinetics of PP digestion was evaluated using first order, Monod, Contois and, Grau second-order models. Results showed that the kinetics of anaerobic digestion of PP followed the first-order model with a constant (K) of 0.095 day-1. Monod kinetics was evaluated and the maximum rate of substrate utilization (K), the half velocity constant (KS), endogenous decay coefficient (Kd), biomass growth yield (Y) and, maximum specific microorganism growth rate (µmax) obtained were 0.7615 day-1, 16.20 mg/l, 0.0047 day-1, 0.0112 mgVSS mgCOD-1 and, 0.009 day-1 respectively. These results revealed that inoculation would be required to increase the rate and volume of biogas production. Both first-order and Monod models gave a high coefficient of determination indicating that first order and Monod models can be used to model the digestion of PP. Contois model gave values of µmax and β as 0.011 day-1 and 0.644 mgCOD mgVSS-1 respectively. The result obtained has shown that the digestion of PP did not follow second-order kinetics.

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