scholarly journals Impact of Operational Factors, Inoculum Origin, and Feedstock Preservation on the Biochemical Methane Potential

2021 ◽  
Vol 8 (11) ◽  
pp. 176
Author(s):  
Audrey Lallement ◽  
Aline Siaud ◽  
Christine Peyrelasse ◽  
Prasad Kaparaju ◽  
Blandine Schraauwers ◽  
...  

Anaerobic digestion for the valorization of organic wastes into biogas is gaining worldwide interest. Nonetheless, the sizing of the biogas plant units require knowledge of the quantity of feedstock, and their associated methane potentials, estimated widely by Biochemical Methane Potential (BMP) tests. Discrepancies exist among laboratories due to variability of protocols adopted and operational factors used. The aim of this study is to verify the influence of some operational factors (e.g., analysis frequency, trace elements and vitamins solution addition and flushing gas), feedstock conservation and the source of inoculum on BMP. Among the operational parameters tested on cellulose degradation, only the type of gas used for flushing headspace of BMP assays had shown a significant influence on methane yields from cellulose. Methane yields of 344 ± 6 NL CH4 kg−1 VS and 321 ± 10 NL CH4 kg−1 VS obtained from assays flushed with pure N2 and N2/CO2 (60/40 v/v). The origin of inoculum (fed in co-digestion) only significantly affected the methane yields for straw, 253 ± 3 and 333 ± 3 NL CH4 kg−1 VS. Finally, freezing/thawing cycle effect depended of the substrate (tested on biowaste, manure, straw and WWTP sludge) with a possible effect of water content substrate.

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.


Author(s):  
Supattra Maneein ◽  
John J. Milledge ◽  
Birthe V. Nielsen

AbstractSargassum muticum is a brown seaweed which is invasive to Europe and currently treated as waste. The use of S. muticum for biofuel production by anaerobic digestion (AD) is limited by low methane (CH4) yields. This study compares the biochemical methane potential (BMP) of S. muticum treated in three different approaches: aqueous methanol (70% MeOH) treated, washed, and untreated. Aqueous MeOH treatment of spring-harvested S. muticum was found to increase CH4 production potential by almost 50% relative to the untreated biomass. The MeOH treatment possibly extracts AD inhibitors which could be high-value compounds for use in the pharmaceutical industry, showing potential for the development of a biorefinery approach; ultimately exploiting this invasive seaweed species.


2020 ◽  
Vol 12 (18) ◽  
pp. 7463
Author(s):  
Marie E. Kirby ◽  
Muhammad W. Mirza ◽  
James Davies ◽  
Shane Ward ◽  
Michael K. Theodorou

Chicken manure is an agricultural by-product that is a problematic feedstock for anaerobic digestion due to its high nitrogen content inhibiting methane yields. This research examines a novel pilot-scale method of ammonia stripping, the nitrogen recovery process (NRP) developed by Alchemy Utilities Ltd. The NRP was designed to remove and recover nitrogen from chicken manure and two different operating conditions were examined. Both operating conditions demonstrated successful nitrogen removal and recovery. The biochemical methane potential assays were used to compare the digestibility of the NRP-treated chicken manures to that of a fresh chicken manure control. Overall, the biochemical methane potential assays demonstrated that some NRP-treated chicken manure treatments produced significantly more methane compared to untreated manure, with no inhibition occurring in relation to ammonium. However, some of the NRP-treated chicken manures produced similar or lower methane yields compared to fresh chicken manure. The NRP requires further development to improve the efficiency of the pilot-scale unit for commercial-scale operation and longer-term continuous anaerobic digestion trials are required to determine longer-term methane yield and ammonium inhibition effects. However, these initial results clearly demonstrate the technology’s potential and novel application for decentralised, on-farm nitrogen recovery and subsequent anaerobic digestion of chicken manure.


2017 ◽  
Vol 64 ◽  
pp. 140-148 ◽  
Author(s):  
César Huiliñir ◽  
Paula Pinto-Villegas ◽  
Alejandra Castillo ◽  
Silvio Montalvo ◽  
Lorna Guerrero

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.


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