scholarly journals Batch and Semi-Continuous Anaerobic Digestion of Industrial Solid Citrus Waste for the Production of Bioenergy

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 648
Author(s):  
Erik Samuel Rosas-Mendoza ◽  
Andrea Alvarado-Vallejo ◽  
Norma Alejandra Vallejo-Cantú ◽  
Raúl Snell-Castro ◽  
Sergio Martínez-Hernández ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Continuous Mode ◽  
Citrus Industry ◽  
Batch Mode ◽  
Volatile Solids ◽  
Working Volume ◽  
Plant Level ◽  
Citrus Waste ◽  
Mesophilic Conditions

The aim of this paper is to describe a study of the anaerobic digestion of industrial citrus solid waste (ISCW) in both batch and semi-continuous modes for the production of bioenergy without the elimination of D-limonene. The study was conducted at the pilot plant level in an anaerobic reactor with a working volume of 220 L under mesophilic conditions of 35 ± 2 °C. Cattle manure (CM) was used as the inoculum. Three batches were studied. The first batch had a CM/ISCW ratio of 90/10, and Batches 2 and 3 had CM/ISCW ratios of 80/20 and 70/30, respectively. In the semi-continuous mode an OLR of approximately 8 g total chemical oxygen demand (COD)/Ld (4.43 gVS/Ld) was used. The results showed that 49%, 44%, and 60% of volatile solids were removed in the batch mode, and 35% was removed in the semi-continuous mode. In the batch mode, 0.322, 0.382, and 0.316 LCH4 were obtained at STP/gVSremoved. A total of 24.4 L/d (34% methane) was measured in the semi-continuous mode. Bioenergy potentials of 3.97, 5.66, and 8.79 kWh were obtained for the respective batches, and 0.09 kWh was calculated in the semi-continuous mode. The citrus industry could produce 37 GWh per season. A ton of processed oranges has a bioenergy potential of 162 kWh, which is equivalent to 49 kWh of available electricity ($3.90).

scholarly journals Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

2021 ◽  
Vol 11 (7) ◽  
pp. 3064
Author(s):  
Roberta Mota-Panizio ◽  
Manuel Jesús Hermoso-Orzáez ◽  
Luis Carmo-Calado ◽  
Gonçalo Lourinho ◽  
Paulo Sérgio Duque de Brito
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Organic Substrates ◽  
Biochemical Methane Potential ◽  
Volatile Solids ◽  
Working Volume ◽  
Methane Potential ◽  
Bmp Test ◽  
Cork Industry

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

Temperature effects on the trophic stages of perennial rye grass anaerobic digestion

2011 ◽  
Vol 64 (1) ◽  
pp. 70-76 ◽  
Author(s):  
D. Cysneiros ◽  
A. Thuillier ◽  
R. Villemont ◽  
A. Littlestone ◽  
T. Mahony ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Low Temperature ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Production Performance ◽  
Batch Mode ◽  
Rye Grass ◽  
Long Term Experiment ◽  
Rate Limiting

Continuous Stirred Tank Reactors (CSTRs), operated in batch mode, were used to evaluate the feasibility of psychrophilic (low temperature) digestion of perennial rye grass in a long term experiment (150 days) for the first time. The reactors were operated in parallel at 3 different temperatures, 10, 15 and 37 °C. Hydrolysis, acidification and methanogenesis were assessed by VS degradation, by soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) production, and by methane production, respectively. Hydrolysis was the rate-limiting step at all temperatures and the rates and extent of hydrolysis were considerably lower at 15 and 10 °C, than at 37 °C. The total VS degradation was 53%, 34% and 19% at 37, 15 and 10 °C, respectively. Acidification was not affected by temperature and VFA production and consumption was balanced in all cases, except at 10 °C. Methane yields were 0.215 m3 CH4 kg−1 VS−1 added, 0.160 m3 CH4 kg−1 VS−1 added and 0.125 m3 CH4 kg−1 VS−1 added at 37, 15 and 10 °C, respectively. Methanogenesis was not strongly affected at 15 °C but it became rate-limiting at 10 °C. Overall, the solid degradation and methane production performance under psychrophilic conditions was encouraging and greater than previously reported. Considering the non-acclimated, mesophilic nature of the inoculum, there are grounds to believe that low-temperature anaerobic digestion of grass could be feasible if coupled to efficient hydrolysis of the biomass.

scholarly journals Treatment of dairy waste by anaerobic co-digestion with sewage sludge

2016 ◽  
Vol 23 (1) ◽  
pp. 99-115 ◽  
Author(s):  
Agnieszka A. Pilarska ◽  
Krzysztof Pilarski ◽  
Kamil Witaszek ◽  
Hanna Waliszewska ◽  
Magdalena Zborowska ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Organic Waste ◽  
Cheese Whey ◽  
Oxygen Demand ◽  
Volatile Solids ◽  
Biomethane Production ◽  
Digested Sewage Sludge

Abstract The results of anaerobic digestion (AD) of buttermilk (BM) and cheese whey (CW) with a digested sewage sludge as inoculum is described. The substrate/inoculum mixtures were prepared using 10% buttermilk and 15% cheese whey. The essential parameters of the materials were described, including: total solids (TS), volatile solids (VS), pH, conductivity, C/N ratio (the quantitative ratio of organic carbon (C) to nitrogen (N)), alkalinity, chemical oxygen demand (COD). The potential directions of biodegradation of the organic waste types, as used in this study, are also presented. Appropriate chemical reactions illustrate the substrates and products in each phase of anaerobic decomposition of the compounds that are present in buttermilk and cheese whey: lactic acid, lactose, fat, and casein. Moreover, the biogas and biomethane production rates are compared for the substrates used in the experiment. The results have shown that buttermilk in AD generates more biogas (743 m3/Mg VS), including methane (527 m3/Mg VS), when compared with cheese whey (600 m3/Mg VS, 338 m3/Mg VS for biogas and methane, respectively).

Sludge electrooxidation as pre-treatment for anaerobic digestion

2016 ◽  
Vol 75 (4) ◽  
pp. 775-781 ◽  
Author(s):  
J. A. Barrios ◽  
U. Duran ◽  
A. Cano ◽  
M. Cisneros-Ortiz ◽  
S. Hernández
Keyword(s):  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Treatment Conditions ◽  
Volatile Solids ◽  
Pre Treatment

Anaerobic digestion of wastewater sludge is the preferred method for sludge treatment as it produces energy in the form of biogas as well as a stabilised product that may be land applied. Different pre-treatments have been proposed to solubilise organic matter and increase biogas production. Sludge electrooxidation with boron-doped diamond electrodes was used as pre-treatment for waste activated sludge (WAS) and its effect on physicochemical properties and biomethane potential (BMP) was evaluated. WAS with 2 and 3% total solids (TS) achieved 2.1 and 2.8% solubilisation, respectively, with higher solids requiring more energy. After pre-treatment, biodegradable chemical oxygen demand values were close to the maximum theoretical BMP, which makes sludge suitable for energy production. Anaerobic digestion reduced volatile solids (VS) by more than 30% in pre-treated sludge with a food to microorganism ratio of 0.15 g VSfed g−1 VSbiomass. Volatile fatty acids were lower than those for sludge without pre-treatment. Best pre-treatment conditions were 3% TS and 28.6 mA cm−2.

Anaerobic digestion of mixed microalgae cultivated in secondary effluent under mesophilic and thermophilic conditions

2015 ◽  
Vol 72 (8) ◽  
pp. 1398-1403 ◽  
Author(s):  
Glenda Cea-Barcia ◽  
Gloria Moreno ◽  
Germán Buitrón
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Incubation Temperature ◽  
Secondary Effluent ◽  
Microalgae Culture ◽  
Batch Tests ◽  
Volatile Solids ◽  
Thermophilic Conditions ◽  
Maximum Production Rate ◽  
Mesophilic Conditions

The anaerobic digestion of mixed indigenous microalgae, grown in a secondary effluent, was evaluated in batch tests at mesophilic (35°C) and thermophilic (50°C) conditions. Under mesophilic conditions, specific methane production varied from 178 to 207 mL CH4/g volatile solids (VS) and the maximum production rate varied from 8.8 to 26.1 mL CH4/(gVS day), depending on the type of microalgae culture. Lower methane parameters were observed in those cultures where Scenedesmus represents more than 95% of the microalge. The culture with the lowest digestion performances under mesophilic conditions was studied under thermophilic conditions. The increase in the incubation temperature significantly increased the specific methane production (390 mL CH4/g VS) and rate (26.0 mL CH4/(gVS day)). However, under thermophilic conditions a lag period of 30 days was observed.

scholarly journals Comparison between biodegradable polymers from cassava starch and glycerol as additives to biogas production

2016 ◽  
Vol 37 (4) ◽  
pp. 1827 ◽  
Author(s):  
Paulo André Cremonez ◽  
Armin Feiden ◽  
Joel Gustavo Teleken ◽  
Samuel Nelson Melegari de Souza ◽  
Michael Feroldi ◽  
...  
Keyword(s):  
Biodegradable Polymers ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Cassava Starch ◽  
Swine Wastewater ◽  
Batch Reactors ◽  
Total Volatile ◽  
Swine Waste ◽  
Volatile Solids ◽  
Working Volume

In this study, we compared cassava starch-based biodegradable polymers (PBMs) and glycerol (G) as additives used to increase biogas production from the co-digestion of swine wastewater (ARS). We chose to work with an inoculum comprising 40% (v/v) of the total volume of the reactor; this inoculum was obtained from a Canadian model digester for treating swine waste. In the anaerobic digestion process, batch reactors were used on a laboratory scale with a total volume of approximately 4 L and a working volume of 3.2 L. Three treatments were conducted to compare the efficiency of solid removal, the chemical oxygen demand (COD), and the production of biogas. The first treatment contained only swine waste; the second included the addition of glycerol at 1, 3, and 5% (w/v); and the third treatment included the addition of 1, 3, and 5% (w/v) of PBM residue in relation to the swine wastewater. From the results, it can be concluded that higher yields were obtained for the treatment with 3% PBM and 1% glycerol. Most treatments showed high removal rates of total solids and total volatile solids. Reductions lower than 70% were obtained only for treatments with PBM and glycerol at a ratio of 5%.

Anaerobic digestion of primary sludge from chemical pre-precipitation

1997 ◽  
Vol 36 (6-7) ◽  
pp. 357-365 ◽  
Author(s):  
Wouter Ghyoot ◽  
Willy Verstraete
Keyword(s):  
Anaerobic Digestion ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Municipal Sewage ◽  
Primary Sludge ◽  
Loading Rates ◽  
Volatile Solids ◽  
Feasible Option ◽  
Kjeldahl Nitrogen

Many existing wastewater treatment plants are to be upgraded for phosphorus removal. In our study, ferric chloride was used as a coagulant in pre-precipitation of municipal sewage. Using a Fe/P molar ratio of 0.8, removal efficiencies for suspended solids (64%), chemical oxygen demand (50%), Kjeldahl nitrogen (22%), total phosphorus (43%) and orthophosphate (51%) were obtained. Anaerobic digestion of raw primary sludge yielded a volatile solids (VS) destruction of 35% at VS loading rates of 0.60 to 0.79 kg VS/m3.d. Digestion of chemically enriched primary sludge (CEP-sludge) yielded a VS destruction of 57% at a VS loading rate of 1.36 kgVS/m3.d. Comparison of the methane production per kg VS destroyed (519 to 612 1 CH4/kgVS destroyed for primary sludge, 299 to 395 1 CH4/kgVS destroyed for CEP-sludge) evidenced a change in the composition of the organic material after precipitation with coagulants; the latter sludge was enriched in less reduced compounds. The precipitated phosphorus was not released to the supernatant during anaerobic digestion. No evidence for reduced digester stability was found for digestion of CEP-sludge. These results indicate that retro-fitting a plant by chemical pre-precipitation and subsequent anaerobic digestion of the CEP-sludge is a feasible option.

scholarly journals Mesophilic and Thermophilic Anaerobic Digestion of Organic Fraction Separated during Mechanical Heat Treatment of Municipal Waste

2020 ◽  
Vol 10 (7) ◽  
pp. 2412
Author(s):  
Slawomir Kasinski
Keyword(s):  
Anaerobic Digestion ◽  
Fermentation Process ◽  
Biogas Production ◽  
Municipal Waste ◽  
Organic Fraction ◽  
Thermophilic Anaerobic Digestion ◽  
Volatile Solids ◽  
Thermophilic Conditions ◽  
Potential Impact ◽  
Mesophilic Conditions

The objective of this study was to investigate the effect of process temperature on semi-continuous anaerobic digestion of the organic fraction separated during autoclaving of municipal waste. Tests were carried out in reactors with full mixing. Biogas production was higher in thermophilic conditions than in mesophilic conditions (0.92 L/g volatile solids at 55 °C vs. 0.42 L/g volatile solids at 37 °C, respectively). The resulting methane yields were 0.25-0.32 L CH4/g VS and 0.56–0.70 L CH4/g VS in mesophilic and thermophilic conditions, respectively. In both variants, the methane share was over 70% v/v. This work also discusses the potential impact of Maillard compounds on the efficiency of the fermentation process, which were probably produced during the process of autoclaving of municipal waste. These results indicate that, after autoclaving, the organic fraction of municipal waste can be an effective substrate for anaerobic digestion in thermophilic conditions.

scholarly journals Biogas from slaughter house waste and optimization of the process

2016 ◽  
Vol 51 (3) ◽  
pp. 203-214 ◽  
Author(s):  
MA Rouf ◽  
MS Islam ◽  
T Rabeya ◽  
AK Mondal ◽  
M Khanam ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Stomach Content ◽  
Oxygen Demand ◽  
Gas Production ◽  
Batch Reactors ◽  
Volatile Solid ◽  
Optimum Conditions ◽  
Slaughter House ◽  
Destruction Efficiency ◽  
Volatile Solids

To assess the potential of biogas generation by anaerobic digestion from slaughter house waste (undigested stomach content) and to determine the optimum conditions for biogas generation from the substrate, different proportions of substrate were used in six batch reactors R1, R2, R3, R4, R5 and R6. The reactors were operated with initial volatile solid concentrations of 34.00, 50.80, 67.20, 51.60, 48.10 and 63.36 g/l and corresponding specific gas production obtained was 0.258, 0.200, 0.160, 0.270, 0.201 and 0.170 l/g respectively. The volatile solids (VS) destruction efficiency was 31.71%, 29.15%, 28.26%, 32.29%, 30.56 and 29.08% as well as chemical oxygen demand (COD)  reduction achieved in the test reactors were 40.31%, 44.44%, 49.40%, 53.24%, 48.55% and 51.26% in R1, R2, R3, R4, R5 and R6 respectively. Methane yield in different reactors varied from 72% to 76%. The optimum mix for generation of biogas from the substrate was 75% slaughter waste mixed with 25% cow dung.Bangladesh J. Sci. Ind. Res. 51(3), 203-214, 2016

High-solids anaerobic digestion of cassava pulp in semi-continuous bioreactors

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6723-6736
Author(s):  
Wei Zhao ◽  
Chen-Yu Zhou ◽  
Jun Zhang ◽  
Dun-Qiu Wang
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
High Solids ◽  
Total Solids ◽  
Loading Rates ◽  
Cassava Pulp ◽  
Volatile Solids ◽  
Organic Matter Loading ◽  
Mesophilic Conditions

The effects of two total solids contents (TS) and two inocula were studied for the semi-continuous high-solids anaerobic digestion (HS-AD) of cassava pulp under mesophilic conditions (35 ± 2 °C). In the 1.0-L bioreactors, two TS of 15% and 20% with digestate as a sole inoculum were chosen to run the HS-AD, and two inocula (the digestate from the AD of cassava pulp and sewage sludge) were used separately under TS 20%. All treatments were carried out at the organic matter loading rates (OLRs) of from 3.0 to 10.0 kg volatile solids (VS)/(m3·d), with each phase of 6 days followed by two 3-days phases of no feeding and then low OLR of 6.5 kg VS/(m3·d). Compared with TS 15%, the bioreactors of TS 20% with the digestate had a higher buffering capability to alleviate the rapid acidification and a higher level of the specific methane yields (SMYs) of from 0.212 to 0.233 m3/(kgVSadded) at the OLRs of 4.0 to 6.5 kgVS/(m3·d), while TS 15% obtained the highest SMY of from 0.152 to 0.182 m3/(kgVSadded) at the OLR of 4.0, 6.5, and 8.0 kgVS/(m3·d). In contrast, sewage sludge did not restrain the rapid acidification and only yielded quite small SMYs under TS 20%.

Sign in / Sign up

Export Citation Format

Share Document