scholarly journals Performance and Kinetic Model of a Single-Stage Anaerobic Digestion System Operated at Different Successive Operating Stages for the Treatment of Food Waste

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 600 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Mojtaba Porhemmat ◽  
Biplob Kumar Pramanik

A large quantity of food waste (FW) is generated annually across the world and results in environmental pollution and degradation. This study investigated the performance of a 160 L anaerobic biofilm single-stage reactor in treating FW. The reactor was operated at different hydraulic retention times (HRTs) of 124, 62, and 35 days under mesophilic conditions. The maximum biogas and methane yield achieved was 0.934 L/g VSadded and 0.607 L CH4/g VSadded, respectively, at an HRT of 124 days. When HRT decreased to 62 days, the volatile fatty acid (VFA) and ammonia accumulation increased rapidly whereas pH, methane yield, and biogas yield decreased continuously. The decline in biogas production was likely due to shock loading, which resulted in scum accumulation in the reactor. A negative correlation between biogas yield and volatile solid (VS) removal efficiency was also observed, owing to the floating scum carrying and urging the sludge toward the upper portion of the reactor. The highest VS (79%) and chemical oxygen demand (COD) removal efficiency (80%) were achieved at an HRT of 35 days. Three kinetic models—the first-order kinetic model, the modified Gompertz model, and the logistic function model—were used to fit the cumulative biogas production experimental data. The kinetic study showed that the modified Gompertz model had the best fit with the experimental data out of the three models. This study demonstrates that the stability and performance of the anaerobic digestion (AD) process, namely biogas production rate, methane yield, intermediate metabolism, and removal efficiency, were significantly affected by HRTs.

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3571 ◽  
Author(s):  
Li ◽  
Huang ◽  
Liu ◽  
Huang ◽  
Maurer ◽  
...  

Effects of salt on anaerobic digestion are dosage-dependent. As salt is a widely used condiment in food processing, effects of salt are bound to be considered when food waste is digested. In this study, salt addition effects (0, 2, 4, 6, 9, 12 g∙L−1) on biogas and methane yields and kinetics of biogas production were researched. Meanwhile, component characteristics (food waste featured in carbohydrate, protein and fat, respectively) and fermentation concentrations (5 and 8 gVS∙L−1) were also taken into consideration. Results showed that 2–4 g∙L−1 salt addition was the optimal addition dosage for AD systems as they not only have the maximum biogas and methane yields, but also the maximum vs. removal in most cases. Also, according to the results of a modified Gompertz model, which is used to predict biogas and methane production rates, suitable salt addition can accelerate biogas production, improving the maximum biogas production rate (Rmax). Factorial design (2 × 2) proved that interaction of salt and fermentation concentrations was significant for food waste featured with carbohydrate and with protein (p <0.05). High salt addition and fermentation concentration can break the AD system when the feeding material was food waste featured with carbohydrate, but for food waste featured with protein, interaction of fermentation concentrations and salt addition can alleviate inhibition degrees.


2020 ◽  
Vol 4 (1) ◽  
pp. 44
Author(s):  
Lukhi Mulia Shitophyta ◽  
Gita Indah Budiarti ◽  
Yusuf Eko Nugroho ◽  
Dika Fajariyanto

Biogas telah menjadi bahan bakar alternatif untuk mengurangi kelangkaan bahan bakar fosil. Biogas dapat dihasilkan dari limbah makanan seperti tongkol jagung. Tongkol jagung merupakan biomassa lignoselulosa dan mengandung kandungan total solid (TS) >15%. Produksi biogas dilakukan dengan solid-state anaerobic digestion dengan penambahan co-digestion limbah makanan. Co-digestion berfungsi untuk membantu proses pemecahan tongkol jagung. Tujuan penelitian ini adalah untuk mengkaji pengaruh persentase limbah makanan, reduksi volatile solid (VS), dan model kinetika produksi biogas dari tongkol jagung. Hasil peneltiian menunjukkan bahwa limbah makanan berpengaruh signifikan terhadap yield biogas (p < 0,05). Yield biogas tertinggi sebesar 584,49 mL g-1 VS-1 dan reduksi VS tertinggi sebesar 40% diperoleh pada limbah makanan 20%. Model kinetika produksi biogas dari tongkol jagung dan limbah makanan mengikuti model kinetika orde pertama.Biogas has become an alternative fuel to reduce the lack of fossil fuel. Biogas can be produced from organic wastes such as corn stover. Corn stover is a typical lignocellulosic biomass and contains a total solid (TS) content higher of 15%. Biogas production was conducted by solid-state anaerobic digestion with addition co-digestion of food waste. Co-digestion is useful to help the digestion of corn stover. The purposes of this study were to investigate the effect of the percentage of food waste, volatile solid (VS) reduction, and kinetic model on biogas production from corn stover. Results showed that food waste had a significant effect on biogas yield (p < 0.05). The highest biogas yield of 584.49 mL g-1 VS-1 and the highest VS reduction of 40% was obtained at food waste of 20%. The kinetic model of biogas production from corn stover and food waste followed the first-order kinetic model.


Author(s):  
Kai Schumüller ◽  
Dirk Weichgrebe ◽  
Stephan Köster

AbstractTo tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship.


2018 ◽  
Vol 10 (10) ◽  
pp. 3669 ◽  
Author(s):  
Józef Szlachta ◽  
Hubert Prask ◽  
Małgorzata Fugol ◽  
Adam Luberański

The effect of mechanical pre-treatment of nine different agricultural substrates minced to particle sizes of 1.5 mm, 5 mm and 10 mm on biogas and methane yields and fermentation kinetics was investigated. The results showed, that for five of the nine tested substrates (grass, Progas rye, Palazzo rye, tall wheatgrass, beet), a higher biogas production was obtained for the degree of fragmentation of 10 mm compared to fragmentation of 5 mm and 1.5 mm. For fragmentation of 5 mm, the highest biogas production was achieved for sorghum silage, Atletico maize and Cannavaro maize—649.80, 735.59 and 671.83 Nm3/Mg VS, respectively. However, for the degree of fragmentation of 1.5 mm, the highest biogas production (510.43 Nm3/Mg volatile solid (VS)) was obtained with Topinambur silage. The modified Gompertz model fitted well the kinetics of anaerobic digestion of substrates and show a significant dependence of the model parameters Hmax (biogas production potential) and Rmax (maximum rate of biogas production) on the degree of substrate fragmentation.


2012 ◽  
Vol 485 ◽  
pp. 306-309
Author(s):  
Li Hong Wang ◽  
Qun Hui Wang ◽  
Wei Wei Cai

Solid-state anaerobic digestion (SSAD) of distiller’s grains (DG) and kitchen waste (KW) for biogas was investigated. Six DG to KW ratios of 10/1, 8/1, 6/1, 4/1, 1/0, and 0/1 was used. The results showed that in 48 digestion days the co-digestion with DG to KW ratio of 8:1 obtained the highest methane yield of 159.74mL/gTS, TS and VS reductions of 58.7% and 71.8%, hemicellulase, cellulose and lignin reductions of 46.7%, 45.4% and 4.0%. Compared to mono-digestions of DG or KW, co-digestion of DG and FW had a good synergistic effect. It indicated that SSAD of cellulosic-based waste and food waste could be one of the options for efficient biogas production and waste treatment


2019 ◽  
Vol 118 ◽  
pp. 03022
Author(s):  
Hongguang Zhu ◽  
Jing Yang ◽  
Cheng Xiaowei

The dead pig is an organic waste rich in oil and protein, and is an ideal anaerobic digestion raw material. This study based on single factor ANOVA and Modified Gompertz model. It investigated the effects of the ratio of dead pigs on biogas production by middle temperature co-digestion of pig manure and dead pigs. And the biogas production potential was determined. The results showed that there was no significant correlation between the ratio of dead pigs and the biogas production. The ratio would significantly affect the average methane content and degradation rate. When the addition ratio was in the range of 3 to 15%, the biogas production was between 191.39 and 202.44 (L/kg VS). The average contents of methane were 50.67%, 50.35%, 41.83%, 45.53% and 44.57%, respectively. The time required to reach 80% of the biogas production was 28, 34, 36, 65 and 63 days, respectively. The degradation rate of the raw materials was generally decreased with the increase of the addition ratio. The results of Modified Gompertz model fitting showed that the mixed raw materials had a fully anaerobic digestion with high utilization rate and short hysteresis in the range of 0 ~ 9%. Therefore, a hydraulic retention time (HRT) of 30 days and the addition ratio was in the range of 0 to 6% could be recommended for a continuous digester. It could get a better gas production and higher raw material utilization.


2017 ◽  
Vol 13 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Ádám Nándor Makk ◽  
Tamás Rétfalvi ◽  
Tamás Hofmann

Abstract Fossil fuel depletion has led to an increasing number of research studies and applications focusing on renewable energy, such as different types of biomass. Lignocellulosic biomass represents an abundant source of biomass suitable for energy production in various forms. The present research investigates the application possibility of pedunculate oak bark (Quercus petrea (Matt.) Liebl.) for the production of biogas via anaerobic digestion. This research has significant novelty, as only a few examples on the utilization of tree bark wastes for the production of biogas can be found in the scientific literature. One of the key factors of increasing biogas yield is the efficient hydrolysis of the basic material, which is achieved by different pretreatment methods. In this study, oak bark was pretreated by microwave energy, by extraction, and by the combination of these two methods. The semi-continuous thermophylic anaerobic digestion of untreated oak bark resulted a 76.3 ml/g volatile solid specific methane yield over a 50-day period, which was not significantly lower than methane yield gained from pretreated basic material. Results indicated that oak bark is suitable for the production of biogas even without the application of the investigated pretreatment techniques. As extraction of oak bark does not impair biogas production, the complex biorefinery utilization of oak bark in the form of extraction bark polyphenols and the subsequent anaerobic fermentation of lignocellulosic residue can be accomplished in the future.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 284
Author(s):  
Xiaojue Li ◽  
Naoto Shimizu

To enhance anaerobic fermentation during food waste (FW) digestion, pretreatments can be applied or the FW can be co-digested with other waste. In this study, lipase addition (LA), hydrothermal pretreatment (HTP), and a combination of both methods (HL) were applied to hydrolyze organic matter in FW. Furthermore, the effects of crude glycerol (CG), which provided 5%, 10%, and 15% of the volatile solids (VS) as co-substrate (denoted as CG5, CG10, and CG15, respectively), on the anaerobic digestion of FW were assessed. With an increasing proportion of CG in the co-digestion experiment, CG10 showed higher methane production, while CG15 negatively affected the anaerobic digestion (AD) performance owing to propionic acid accumulation acidifying the reactors and inhibiting methanogen growth. As the pretreatments partially decomposed hard-to-degrade substances in advance, pretreated FW showed a stronger methane production ability compared with raw FW, especially using the HL method, which was significantly better than co-digestion. HL pretreatment was shown to be a promising option for enhancing the methane potential value (1.773 NL CH4/g VS) according to the modified Gompertz model.


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