scholarly journals Fly ash as stimulant for anaerobic digestion: effect over hydrolytic stage and methane generation rate

2019 ◽  
Vol 80 (7) ◽  
pp. 1384-1391 ◽  
Author(s):  
Lorna Guerrero ◽  
Cristopher Da Silva ◽  
Andrea Barahona ◽  
Silvio Montalvo ◽  
Cesar Huiliñir ◽  
...  
Keyword(s):  
Fly Ash ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Batch Reactors ◽  
Order Kinetic ◽  
Methane Generation ◽  
First Order ◽  
Secondary Sludge ◽  
Order Kinetic Model ◽  
Methane Potential

Abstract Thermoelectric fly ash was used as a micronutrient source for microorganisms in the anaerobic digestion process of thermally pretreated (1 hour, 120 °C) secondary sludge. The obtained results not only suggest that fly ash improves methane generation in the conversion of volatile fatty acids into methane, but also show a new observation, that the fly ash contributes in the particulate organic solubilization. The maximum methane production rate increased from 6.52 mL/L/d to 22.59 mL/L/d when fly ash was added at a dosage of 150 mg/L in biochemical methane potential tests compared with tests with no added ash. Additionally, the kinetic constants of the hydrolysis of particulate organic matter were obtained in both cases (with and without added ash) in batch reactors using a first-order kinetic model; in the case of no addition, the first-order kinetic parameter was 0.019 ± 0.002 d−1, while with ashes this value increased to 0.045 ± 0.000 d−1. Therefore, the addition of fly ash improves methane generation and hydrolytic kinetics in different orders of magnitude.

scholarly journals Evaluation of batch mesophilic anaerobic digestion of raw and trampled llama and dromedary dungs: methane potential and kinetic study

2022 ◽  
Author(s):  
M. J. Fernández-Rodríguez ◽  
J. M. Mancilla-Leytón ◽  
D. de la Lama-Calvente ◽  
R. Borja
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Hydrolysis Rate ◽  
Order Kinetic ◽  
Batch Mode ◽  
First Order ◽  
Volatile Solids ◽  
Order Kinetic Model ◽  
Methane Potential ◽  
Methane Production Rate

AbstractThis research was carried out with the aim to evaluate the anaerobic digestion (AD) of llama and dromedary dungs (both untreated and trampled) in batch mode at mesophilic temperature (35 °C). The biochemical methane potential (BMP) tests with an inoculum to substrate ratio of 2:1 (as volatile solids (VS)) were carried out. The methane yield from trampled llama dung (333.0 mL CH4 g−1 VSadded) was considerably higher than for raw llama, raw and trampled dromedary dungs (185.9, 228.4, 222.9 mL CH4 g−1 VSadded, respectively). Therefore, trampled llama dung was found to be the best substrate for methane production due to its high content of volatile solids as well as its high nitrogen content (2.1%) and more appropriate C/N ratio (23.6) for AD. The experimental data was found to be in accordance with both first-order kinetic and transference function mathematical models, when evaluating the experimental methane production against time. By applying the first-order kinetic model, the hydrolysis rate constants, kh, were found to be 19% and 11% higher for trampled dungs in comparison with the raw dung of dromedary and llama, respectively. In addition, the maximum methane production rate (Rm) derived from the transference function model for trampled llama dung (22.0 mL CH4 g−1 VS d−1) was 83.3%, 24.4% and 22.9% higher than those obtained for raw llama manure and for raw and trampled dromedary dungs, respectively.

Alkaline electro-hydrolysis pretreatment of rice straw for enhanced biogas production under ambient temperature

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gopal P. Naik ◽  
Anil K. Poonia ◽  
Parmesh K. Chaudhari
Keyword(s):  
Ambient Temperature ◽  
Rice Straw ◽  
Biogas Production ◽  
Agricultural Waste ◽  
Batch Reactors ◽  
Order Kinetic ◽  
First Order ◽  
The World ◽  
Combined Pretreatment ◽  
Order Kinetic Model

Abstract Biogas production can supplement the renewable energy target of the world. For this abundantly available agricultural waste like wheat and rice straw can be used. Biogas generation using this waste will curb the stubble burning incidences, reduce greenhouse gases, enhance farmer’s income, and strengthen the energy security of many countries. The recalcitrant nature of rice straw is a barrier to its hydrolysis, which is a prerequisite of the anaerobic digestion (AD) process. Alkaline, electro-hydrolysis, and a combination of both pretreatment (alkaline electrohydrolysis) methods are undertaken in the present study. Batch reactors at ambient temperature were used for AD of rice straw at different inoculums to substrate ratios (ISR) of 0.5, 0.75, and 1.0 to observe the effect on biogas/methane yield. Among these, a higher amount of biogas was obtained for ISR of 0.5 in all sets of experiments. The combined pretreatment method yielded biogas of 315.9 mL/gVS (equivalent to methane of 167.4 mL/gVS). For pretreat-ed rice straw by electro-hydrolysis, alkaline, and combined (alkaline and electro-hydrolysis) respectively, the methane yields were 7.03, 18.13, and 49.82% higher than untreated rice straw. The biogas had approximately 53% of methane content. The use of rice straw for biogas production may prove a viable alternative for clean and sustainable energy. In the studies, a first-order kinetic model is found to fit better the experimental results.

scholarly journals Biogas and Methane Potential of Pre-Thermally Disintegrated Bio-Waste

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3880
Author(s):  
Sylwia Myszograj
Keyword(s):  
Process Parameters ◽  
Alternative Energy ◽  
Biogas Production ◽  
Gompertz Model ◽  
Order Kinetic ◽  
Methane Fermentation ◽  
First Order ◽  
Order Kinetic Model ◽  
Methane Potential ◽  
Kinetics Of

One of the environmental solutions employed in order to achieve circular economy goals is methane fermentation—a technology that is beneficial both for the stabilization and reduction of organic waste and for alternative energy generation. The article presents the results of research aimed at determining the biogas and methane potential of bio-waste which has been pre-thermally disintegrated, and determining the influence of variable process parameters of disintegration on the kinetics of fermentation. A first-order kinetic model was used to describe the fermentation as well as two mathematical models: logistic and Gompertz. It has been found that process parameters such as time (0.5, 1 and 2 h) and temperature (between 55 to 175 °C) have a significant effect on the solubilization efficiency of the bio-waste. The methane fermentation of thermally disintegrated bio-waste showed that the highest biogas potential is characterized by samples treated, respectively, for 0.5 h at 155 °C and for 2 h at 175 °C. The best match for the experimental data of biogas production from disintegrated substrates was demonstrated for the Gompertz model.

scholarly journals Energy Recovery from Anaerobic Digestion of Banana Peels

2019 ◽  
Vol 8 (3) ◽  
pp. 6269-6273
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Kinetic Modelling ◽  
Batch Reactor ◽  
Waste Product ◽  
Banana Peel ◽  
Batch Reactors ◽  
Order Kinetic ◽  
First Order

Bananas are tropical fruits mostly eaten in Malaysia. The banana peels are high in organic, and putrescible caused the odour and leachate problem where it has been a dump. In practice, banana peels considered as a waste product that has been combined with municipal solid waste and dumped into the landfills. However, banana peels are bountiful in organic matter and high with moisture content. Thus, it could be a convincing substrate for biogas production through anaerobic digestion so that the major concerns of environmental protection is achieved aside from producing energy in a sustainable way. Therefore, this study was initiated to estimate the ultimate methane yield from the unripe banana peel (UBP) and ripe banana peel (RBP). Besides that, the assessment on the kinetics of the methane production from UBP and RBP is conducted using Modified Gompertz and first-order kinetic modelling. In this study, the anaerobic digestibility of banana peels measured in a batch reactor for 25 days each fed by UBP and RBP. The batch reactors operated at an inoculum to substrate ratio (I/S) of 1.0 and at a mesophilic temperature (37°C). The ultimate methane yields from UBP and RBP digestion were 847.57mLCH4 /gVS and 1405.31mLCH4 /gVS, respectively. The higher bioavailability (in term of COD, and solid) in RBP resulted in the higher methane production rate. Two first-order and modified Gompertz kinetic models were compared for the prediction of organic degradation, and the results indicated that the first-order kinetic model of the RBP fitted the experiment best. It concluded that ripe banana peels are the most preferable feedstock for the anaerobic digestion.

scholarly journals Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

2021 ◽  
Author(s):  
D. de la Lama-Calvente ◽  
M. J. Fernández-Rodríguez ◽  
J. Llanos ◽  
J. M. Mancilla-Leytón ◽  
R. Borja
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Methane Production ◽  
Methane Yield ◽  
Specific Rate ◽  
Order Kinetic ◽  
Two Phase ◽  
First Order ◽  
Olive Mill Solid Waste ◽  
Olive Mill

AbstractThe biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.

Alkali pre-treatment of Sorghum Moench for biogas production

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Total Phenolic ◽  
Methane Generation ◽  
Pre Treatment ◽  
Alkali Hydrolysis ◽  
Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

Kinetics of bioactive compounds in functional spice Jiangpo during thermal processing

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Xiaoyan Dai ◽  
Chenhuan Yu ◽  
Qiaofeng Wu
Keyword(s):  
Kinetic Parameters ◽  
Bioactive Compounds ◽  
Thermal Processing ◽  
Order Rate Constant ◽  
Heat Processing ◽  
Order Kinetic ◽  
Time Intervals ◽  
First Order ◽  
Order Kinetic Model ◽  
Kinetics Of

Abstract Jiangpo is an increasingly popular East Asian spice which is made from Mangnolia officinalis bark and ginger juice. Since it induces bioactive compounds decomposition and has influence on final flavor and fragrance, cooking is regarded as the key operation in preparation of Jiangpo. To evaluate the bioactive compounds content changes of Jiangpo during thermal processing, kinetic parameters including reaction order, rate constant, T1/2 and activation energy of bioactive markers namely honokiol, magnolol and curcumin were determined. Cooking was set at temperatures 60, 90 and 120 °C for selected time intervals. Results displayed the thermal kinetic characteristics of the three compounds. Thermal degradation of Honokiol and magnolol both followed first order kinetic model and the loss of curcumin fitted second order. A mathematical model based on the obtained kinetic parameters has also been developed to predict the degradation of honokiol, magnolol and curcumin in non-isothermal state. All the information in this paper could contribute necessary information for optimizing the existing heat processing of Jiangpo.

scholarly journals Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  
Keyword(s):  
Reaction Time ◽  
Color Removal ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Fenton Process ◽  
Solution Ph ◽  
Leachate Treatment ◽  
First Order ◽  
Order Kinetic Model ◽  
Better Than

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

Performance of poly-o-phenylenediamine and its carbon dot composite electrode in the removal of Cu2+ from its aqueous solution

2021 ◽  
pp. 2151037
Author(s):  
Yu Meng ◽  
Qing Zhong ◽  
Arzugul Muslim
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Reduction ◽  
Composite Electrode ◽  
Reduction Process ◽  
Order Kinetic ◽  
Carbon Dot ◽  
First Order ◽  
Oxidation Reduction ◽  
Order Kinetic Model ◽  
Optimal Ph

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.

scholarly journals Enhanced photocatalytic activity of wool-ball-like TiO2 microspheres on carbon fabric and FTO substrates

2018 ◽  
Vol 38 ◽  
pp. 02014
Author(s):  
Yu Zhang ◽  
Jian Gu ◽  
Mengqi Zhang
Keyword(s):  
Hydrothermal Method ◽  
Order Kinetic ◽  
Carbon Fabric ◽  
Facile Hydrothermal Method ◽  
Sem Images ◽  
First Order ◽  
Good Crystallinity ◽  
Degradation Rate Constant ◽  
Order Kinetic Model ◽  
Pseudo First Order

The wool-ball-like TiO2 microspheres on carbon fabric (TiO2-CF) and FTO substrates (TiO2-FTO) have been synthesized by a facile hydrothermal method in alkali environment, using commercial TiO2 (P25) as precursors. The XRD results indicate that the as-prepared TiO2 have good crystallinity. And the SEM images show that the wool-ball-like TiO2 microspheres with a diameter of 2-3 μm are composed of TiO2 nanowires, which have a diameter of ~50 nm. The photocatalytic behavior of the wool-ball-like TiO2 microspheres, TiO2-CF and TiO2-FTO under ultraviolet light was investigated by a pseudo first-order kinetic model, using methyl orange (MO) as pollutant. The wool-ball-like TiO2 microspheres obtained a degradation rate constant (Kap) of 6.91×10-3 min-1 . The Kap values of TiO2-FTO and TiO2-CF reach 13.97×10-3 min-1 and 11.80×10-3 min-1, which are 2.0 and 1.7 times higher than that of pristine wool-ball-like TiO2 microspheres due to the “sum effect” between TiO2 and substrates. This study offers a facile hydrothermal method to prepare wool-ball-like TiO2 microspheres on CF and FTO substrates, which will improve the recyclability of phtocatalysts and can be extended to other fields.

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