scholarly journals Optimizing anaerobic co-digestion of goat manure and cotton gin trash using biochemical methane potential (BMP) test and mathematical modeling

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Harjinder Kaur ◽  
Raghava R. Kommalapati

AbstractAnaerobic co-digestion is widely adopted to enhance process efficacy by balancing the C/N ratio of the feedstock while converting organic wastes to biomethane. Goat manure (GM) and cotton gin trash (CGT) were anaerobically co-digested in triplicate batch bioreactors. The process was optimized and evaluated utilizing mathematical equations. The liquid fraction of the digestate was analyzed for nitrate and phosphate. The co-digestions with 10 and 20% CGT having the C/N ratios of 17.7 and 19.8 yielded the highest and statistically similar 261.4 ± 4.8 and 262.6 ± 4.2 mL/gvs biomethane, respectively. The biodegradability (BD) of GM and CGT was 94.5 ± 2.7 and 37.6 ± 0.8%, respectively. The BD decreased proportionally with an increase in CGT percentage. The co-digestion having 10% CGT yielded 80–90% of biomethane in 26–39 d. The modified Gompertz model-predicted and experimental biomethane values were similar. The highest synergistic effect index of 15.6 ± 4.7% was observed in GM/CGT; 30:70 co-digestion. The concentration of nitrate and phosphate was lower in the liquid fraction of digestate than the feedstocks, indicating that these nutrients stay in the solid fraction. The results provide important insights in agro-waste management, further studies determining the effects of effluent application on plants need to be conducted.

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1952
Author(s):  
Ayobami Orangun ◽  
Harjinder Kaur ◽  
Raghava R. Kommalapati

The improper management of goat manure from concentrated goat feeding operations and food waste leads to the emission of greenhouse gasses and water pollution in the US. The wastes were collected from the International Goat Research Center and a dining facility at Prairie View A&M University. The biochemical methane potential of these two substrates in mono and co-digestion at varied proportions was determined in triplicates and processes were evaluated using two nonlinear regression models. The experiments were conducted at 36 ± 1 °C with an inoculum to substrate ratio of 2.0. The biomethane was measured by water displacement method (pH 10:30), absorbing carbon dioxide. The cumulative yields in goat manure and food waste mono-digestions were 169.7 and 206.0 mL/gVS, respectively. Among co-digestion, 60% goat manure achieved the highest biomethane yields of 380.5 mL/gVS. The biodegradabilities of 33.5 and 65.7% were observed in goat manure and food waste mono-digestions, while 97.4% were observed in the co-digestion having 60% goat manure. The modified Gompertz model is an excellent fit in simulating the anaerobic digestion of food waste and goat manure substrates. These findings provide useful insights into the co-digestion of these substrates.


Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 26 ◽  
Author(s):  
Pengfei Li ◽  
Wenzhe Li ◽  
Mingchao Sun ◽  
Xiang Xu ◽  
Bo Zhang ◽  
...  

There is a lack of literature reporting the measurement and prediction of biochemical methane potential (BMP) of vegetable crop residues (VCRs) and similarly, the kinetic assessment on the anaerobic digestion process of VCR is rarely investigated. In this paper, the BMP tests of five different vegetable (snap bean, capsicum, cucumber, eggplant, and tomato) crop residues were conducted at feed to inoculum ratio (F/I) of 2.0 under mesophilic (36 ± 1 °C) conditions. A series of single-variable and multiple-variable regression models were built based on organic components (hemicellulose, cellulose, lignin, total fat, total sugar, and crude protein) for BMP prediction. Three kinetic models, including the first-order kinetic model, the Chen and Hashimoto model, and the modified Gompertz model, were used to simulate the methane yield results of VCR and obtain valuable model parameters simultaneously. As a result, the BMPs and volatile solids (VS) degradation degree of different VCRs were respectively in the range of 94.2–146.8 mL g−1 VS and 40.4–49.9%; the regression prediction models with variables lignin (R2 = 0.704, p = 0.076), variables crude protein and lignin (R2 = 0.976, p = 0.048), and variables total fat, hemicellulose, and lignin (R2 = 0.999, p = 0.027) showed the best performance on BMP prediction among the single-factor, two-factor, and three-factor models, respectively. In addition, compared to the other two kinetic models, the modified Gompertz model could be excellently fitted (R2 = 0.986–0.998) to the results of BMP experiment, verification deviations within 0.3%.


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

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.


2014 ◽  
Vol 70 (4) ◽  
pp. 599-604 ◽  
Author(s):  
Bing Wang ◽  
Ivo Achu Nges ◽  
Mihaela Nistor ◽  
Jing Liu

In this work, biochemical methane potential (BMP) tests with cellulose as a model substrate were performed with the aid of three manually operated or conventional experimental setups (based on manometer, water column and gas bag) and one automated apparatus specially designed for analysis of BMP. The methane yields were 340 ± 18, 354 ± 13, 345 ± 15 and 366 ± 5 ml CH4/g VS obtained from experimental setups with manometer, water column, gas bag, and automatic methane potential test system, which corresponded to a biodegradability of 82, 85, 83 and 88% respectively. The results demonstrated that the methane yields of cellulose obtained from conventional and automatic experimental setups were comparable; however, the methane yield obtained from the automated apparatus showed greater precision. Moreover, conventional setups for the BMP test were more time- and labour-intensive compared with the automated apparatus.


2013 ◽  
Vol 67 (2) ◽  
pp. 410-417 ◽  
Author(s):  
M. A. De la Rubia ◽  
V. Fernández-Cegrí ◽  
F. Raposo ◽  
R. Borja

Due to the chemical and physical structure of a lignocellulosic biomass, its anaerobic digestion (AD) is a slow and difficult process. In this paper, the results obtained from a batch biochemical methane potential (BMP) test and fed-batch mesophilic AD assays of sunflower oil cake (SuOC) are presented. Taking into account the low digestibility shown during one-stage experiments the methane yield decreased considerably after increasing the organic loading rate (OLR) from 2 to 3 g VS L−1 d−1, SuOC was subjected to a two-stage AD process (hydrolytic-acidogenic and methanogenic stages), in two separate reactors operating in series where the methanogenic stage became acidified (with >1,600 mg acetic acid L−1) at an OLR as low as 2 g VS L−1 d−1. More recently, BMP assays were carried out after mechanical, thermal, and ultrasonic pre-treatments to determine the best option on the basis of the methane yield obtained.


2012 ◽  
Vol 66 (7) ◽  
pp. 1416-1423 ◽  
Author(s):  
C. P. Pabón Pereira ◽  
G. Castañares ◽  
J. B. van Lier

A protocol was developed for determining the biochemical methane potential (BMP) of plant material using the OxiTop® system. NaOH pellets for CO2 absorption and different pretreatment methods were tested for their influence in the BMP test. The use of NaOH pellets in the headspace of the bottle negatively affected the stability of the test increasing the pH and inhibiting methanization. Sample comminution increased the biodegradability of plant samples. Our results clearly indicate the importance of test conditions during the assessment of anaerobic biodegradability of plant material, considering BMP differences as high as 44% were found. Guidelines and recommendations are given for screening plant material suitable for anaerobic digestion using the OxiTop® system.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 921 ◽  
Author(s):  
Jameson Filer ◽  
Huihuang H. Ding ◽  
Sheng Chang

Biochemical methane potential (BMP) tests are widely used for characterizing a substrate’s influence on the anaerobic digestion process. As of 2018, there continues to be a lack of standardization of units and techniques, which impacts the comparability and validity of BMP results. However, BMP methods continue to evolve, and key aspects are studied to further eliminate systematic errors. This paper aims to update these key aspects with the latest research progress both to introduce the importance of each variable to those new to BMP measurements and to show the complexity required to design an accurate BMP test.


2017 ◽  
Vol 68 (11) ◽  
pp. 2614-2617
Author(s):  
Adrian Eugen Cioabla ◽  
Gabriela Alina Dumitrel ◽  
Ioana Ionel

Anaerobic digestion is a complex process that allows the conversion of organic wastes into biogas with minimal costs and benefits for the environment. The goal of this study is to evaluate the anaerobic digestion potential of two common agricultural biomass wastes (degraded corn and degraded wheat) used as single substrates or as co-substrates together with wastewater from a waste water treatment plant. The results reveal that the co-digestion is an improved solution, both in terms of biogas amount produced and its methane concentration. Two kinetic models (modified Gompertz model and logistical growth model) were applied to study the methane production. For each case, the kinetic parameters were estimated. One demonstrates that the modified Gompertz model fitted very well the measured methane potential, for all studied cases.


Author(s):  
Zuhaib Siddiqui ◽  
N.J. Horan ◽  
Kofi Anaman

Biomethane production from processed industrial food waste (IFW) in admixture with sewage sludge (primary and waste activated sludge: PS and WAS) was evaluated at a range of C:N ratios using a standard biochemical methane potential (BMP) test. IFW alone had a C:N of 30 whereas for WAS it was 5.4 and thus the C:N ratio of the blends fell in that range. Increasing the IFW content in mix improves the methane potential by increasing both the cumulative biogas production and the rate of methane production. Optimum methane yield 239 mL/g VSremoved occurred at a C:N ratio of 15 which was achieved with a blend containing 11 percent (w/w) IFW. As the fraction of IFW in the blend increased, volatile solids (VS) destruction was increased and this led to a reduction in methane yield and amount of production. The highest destruction of volatile solids of 93 percent was achieved at C:N of 20 followed by C:N 30 and 15. A shortened BMP test is adequate for evaluating optimum admixtures.


2021 ◽  
Vol 924 (1) ◽  
pp. 012071
Author(s):  
N A Rohma ◽  
S Suhartini ◽  
I Nurika

Abstract Production of biogas from lignocellulosic biomass by anaerobic digestion (AD) has attracted much interest. Oil palm empty fruit bunches (OPEFB), one of lignocellulosic biomass, is highly abundant in Indonesia and has potential as feedstock for bioenergy production such as biogas or methane. Yet, pre-treatments are needed to improve biogas production due to its complex crystalline structures. Chemical pre-treatments with acid or alkaline solution were reported to increase cellulose or highly reduce the lignin content of OPEFB. This study aimed to evaluate the effect of acid and alkaline pre-treatments on the characteristics of OPEFB and methane potential. The acid pre-treatment experimental design was used factor of H2SO4 concentration (1, 1.3, and 1.6 (%v/v)) and NaOH concentration (1.8, 2.8, and 3.8 (%w/v)). Methane potential evaluation was carried out using the biochemical methane potential (BMP) test with the Automatic Methane Potential Test System (AMPTS) II under mesophilic condition (37°C), operated for 28 days. The results showed that both dilute acid and alkaline pre-treatment positively impact altering the characteristics of OPEFB, hence the specific methane potential. Alkaline pre-treatment with NaOH 3.8 (%w/v) gave the highest average SMP value of 0.161 ± 0.005 m3 CH4/kgVSadded.


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