Anaerobic digestion of Jatropha curcas L. press cake and effects of an iron-additive

2011 ◽  
Vol 29 (11) ◽  
pp. 1171-1176 ◽  
Author(s):  
Thomas Schmidt
Keyword(s):  
Anaerobic Digestion ◽  
Jatropha Curcas ◽  
Loading Rate ◽  
Press Cake ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Biogas Yield ◽  
Jatropha Curcas L ◽  
The Stability

Oil production from Jatropha curcas L. seeds generates large amounts of Jatropha press cake (JPC) which can be utilized as a substrate for biogas production. The objective of this work was to investigate anaerobic mono-digestion of JPC and the effects of an iron additive (IA) on gas quality and process stability during the increase of the organic loading rate (OLR). With the increase of the OLR from 1.3 to 3.2 gVS L−1 day−1, the biogas yield in the reference reactor (RR) without IA decreased from 512 to 194 LN kgVS−1 and the CH4 concentration decreased from 69.3 to 44.4%. In the iron additive reactor (IAR), the biogas yield decreased from 530 to 462 LN kgVS−1 and the CH4 concentration decreased from 69.4 to 61.1%. The H2S concentration in the biogas was reduced by addition of the IA to values below 258 ppm in the IAR while H2S concentration in the RR increased and exceeded the detection limit of 5000 ppm. The acid capacity (AC) in the RR increased to more than 20 g L−1, indicating an accumulation of organic acids caused by process instability. AC values in the IAR remained stable at values below 5 g L−1. The results demonstrate that JPC can be used as sole substrate for anaerobic digestion up to an OLR of 2.4 gVS l−1 day−1. The addition of IA has effectively decreased the H2S content in the biogas and has improved the stability of the anaerobic process and the biogas quality.

scholarly journals Effect of Semi-Continuous Anaerobic Digestion on the Substrate Solubilisation of Lignin-Rich Steam-Exploded Ludwigia grandiflora

2021 ◽  
Vol 11 (10) ◽  
pp. 4452
Author(s):  
Pranshu Bhatia ◽  
Masaaki Fujiwara ◽  
Maria Cecilia D. Salangsang ◽  
Jun Qian ◽  
Xin Liu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Steam Explosion ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Biogas Yield ◽  
Steam Explosion Pretreatment ◽  
The Stability ◽  
Ludwigia Grandiflora

In this study, semi-continuous anaerobic digestion of lignin-rich steam-exploded Ludwigia grandiflora (Lignin = 25.22% ± 4.6% total solids) was performed to understand better the effect of steam explosion on the substrate solubilisation and inhibitors formation during the process. Steam explosion pretreatment was performed at 180 °C for 30 min at a severity factor of 3.8 to enhance the biogas yield of the lignocellulosic biomass. The semi-continuous anaerobic digestion was performed in a continuously stirred tank reactor for 98 days at an initial hydraulic retention time of 30 days and an organic loading rate of 0.9 g-VS L−1day−1. The performed steam explosion pretreatment caused biomass solubilisation, resulting in enhanced biogas production during the process. During the anaerobic digestion process, the average biogas yield was 265 mL g-VS−1, and the pH throughout the operation was in the optimum range of 6.5–8.2. Due to fluctuations in the biogas yield, the hydraulic retention time and organic loading rate were changed on day 42 (50 days and 0.5 g-VS L−1day−1) and on day 49 (40 days and 0.7 g-VS L−1day−1), and 1 M of NaOH was added to the liquid fraction of the steam-exploded L. grandiflora during the latter part of the operation to maintain the stability in the reactor. Therefore, the steam explosion pretreatment helped in the degradation of L. grandiflora by breaking the lignocellulose structure. In addition, changes in the operating conditions of the anaerobic digestion led to an increase in the biogas production towards the end of the process, leading to the stability in the CSTR.

scholarly journals Adjusting Organic Load as a Strategy to Direct Single-Stage Food Waste Fermentation from Anaerobic Digestion to Chain Elongation

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1487
Author(s):  
Vicky De Groof ◽  
Marta Coma ◽  
Tom C. Arnot ◽  
David J. Leak ◽  
Ana B. Lanham
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Loading Rate ◽  
Biogas Production ◽  
Single Stage ◽  
Stirred Tank ◽  
Chain Elongation ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Operating Strategy

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy.

Effect of Organic Loading Rate (OLR) of Slurry on Biogas Production Quality

2015 ◽  
Vol 1115 ◽  
pp. 325-330
Author(s):  
Maizirwan Mel ◽  
Nadiah Mohd Suhuli ◽  
Avicenna ◽  
Sany Izan Ihsan ◽  
Ahmad Faris Ismail ◽  
...  
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Continuous System ◽  
Total Solid ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Feeding Rates ◽  
Organic Loading ◽  
Biogas Yield

In this study, three different concentration of organic loading rate (OLR) were investigated to examine the effect of the change in the organic loading rate on the efficiency of the biogas production. Daily amount of biogas of different type of organic loading rate (OLR), rates of production of biogas, removal efficiencies of chemical oxygen demand (COD), total solid (TS) matter, volatile solids (VS) matter from the slurry were investigated in 30 days retention tyme using 50 L digester. The digester was operated at different organic feeding rates of 25000 mg/L COD, 50000 mg/L COD, and 75000 mg/L COD. The material used in this system is the fruits waste, vegetables waste and cow dung. The system operated in continuous system. The reactor showed stable performance with the highest quality of methane (concentration about70.3% of CH4) and rate of biogas production is 38.1 L/day with COD reduction of 52.1% during organic loading rate 50000 mg/L COD. As the organic loading rate was increased, the COD degradation and biogas yield decreased. Based on this result, the OLR of 50000 mg/L COD is suggested as design criteria for pilot biogas production.

scholarly journals Anaerobic co-digestion of agricultural biomass with industrial wastewater for biogas production

2021 ◽  
Author(s):  
◽  
Edward Kwaku Armah
Keyword(s):  
South Africa ◽  
Industrial Wastewater ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Gravimetric Analysis ◽  
Organic Loading ◽  
Agricultural Biomass ◽  
Biogas Yield ◽  
First Order

With the increasing demand for clean and affordable energy which is environmentally friendly, the use of renewable energy sources is a way for future energy generation. South Africa, like most countries in the world are over-dependent on the use of fossil fuels, prompting most current researchers to seek an affordable and reliable source of energy which is also,a focal point of the United Nations Sustainable Development Goal 7. In past decades, the process of anaerobic digestion (AD) also referred to as monodigestion, has proven to be efficient with positive environmental benefits for biogas production for the purpose of generating electricity, combined heat and power. However, due to regional shortages, process instability and lower biogas yield, the concept of anaerobic co-digestion (AcoD) emerged to account for these drawbacks. Given the considerable impact that industrial wastewater (WW) could provide nutrients in anaerobic biodigesters, the results of this study could apprise decisionmakers and the government to further implement biogas installations as an alternative energy source. The study aims at optimising the biogas production through AcoD of the agricultural biomasses: sugarcane bagasse (SCB) and corn silage (CS) with industrial WW sourced from Durban, KwaZulu-Natal, South Africa. The study commenced with the characterisation of the biomasses under this study with proximate and ultimate analysis using the Fourier transform infrared spectroscopy (FTIR), the thermo gravimetric analysis (TGA), the scanning electron microscopy (SEM) and the differential scanning calorimetry (DSC). The untreated biomass was subjected to biochemical methane potential (BMP) tests to optimise and predict the biogas potential for the selected biomass. A preliminary run was carried out with the agricultural biomass to determine which of the WW streams would yield the most biogas. Among the four WW streams sourced at this stage, two WW streams; sugar WW (SWW) and dairy WW (DWW) produced the highest volume of biogas in the increasing order; SWW ˃ DWW ˃ brewery WW > municipal WW. Therefore, both SWW and DWW were selected for further process optimisation with each biomass. Using the response surface methodology (RSM), the factors considered were temperature (25-55 °C) and organic loading rate (0.5-1.5 gVS/100mL); and the response was the biogas yield (m3 /kgVS). Maximum biogas yield and methane (CH4) content were found to be 5.0 m3 /kgVS and 79%, respectively, for the AcoD of CS with SWW. This established the association that existed among the set temperatures of the digestion process and the corresponding organic loading rate (OLR) of the AcoD process operating in batch mode. Both CS and SCB have been classified as lignocellulosic and thus, ionic liquid (IL) pretreatment was adapted in this study to ascertain their potential on the biogas yield. Results showed that the maximum biogas yield and CH4 content were found to be 3.9 m3 /kgVS and 87%, respectively, after IL pretreatment using 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) for CS with DWW at 55°C and 1.0 gVS/100mL. The IL pretreatment yielded lower biogas but of higher purity of CH4 than the untreated biomass. Data obtained from the BMP tests for the untreated and pretreated biomasses were tested with the existing kinetic models; first order, dual pooled first order, Chen and Hashimoto and the modified Gompertz. The results showed that for both untreated and pretreated biomass, the modified Gompertz had the best fit amongst the four models tested with coefficient of correlation, R 2 values of 0.997 and 0.979, respectively. Comparatively, the modified Gompertz model could be the preferred model for the study of industrial WW when used as co-substrate during AcoD for biogas production. The study showed that higher biogas production and CH4 contents were observed when CS was employed as a reliable feedstock with maximum volume of the untreated and pretreated feedstock reported at 31 L and 20 L respectively.

scholarly journals Opportunities for Green Energy through Emerging Crops: Biogas Valorization of Cannabis sativa L. Residues

Climate ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 142 ◽  
Author(s):  
Carla Asquer ◽  
Emanuela Melis ◽  
Efisio Antonio Scano ◽  
Gianluca Carboni
Keyword(s):  
Anaerobic Digestion ◽  
Loading Rate ◽  
Cannabis Sativa ◽  
Biogas Production ◽  
Gas Production ◽  
Enzymatic Treatment ◽  
Laboratory Scale ◽  
Industrial Plant ◽  
Organic Loading Rate ◽  
Organic Loading

The present work shows the experimental evidence carried out on a pilot scale and demonstrating the potential of Cannabis sativa L. by-products for biogas production through anaerobic digestion. While the current state-of-the-art tests on anaerobic digestion feasibility are carried out at the laboratory scale, the here described tests were carried out at a pilot-to-large scale. An experimental campaign was carried out on hemp straw residues to assess the effective performance of this feedstock in biogas production by reproducing the real operating conditions of an industrial plant. An organic loading rate was applied according to two different amounts of hemp straw residues (3% wt/wt and 5% wt/wt). Also, specific bioenhancers were used to maximize biogas production. When an enzymatic treatment was not applied, a higher amount of hemp straw residues determined an increase of the median values of the gas production rate of biogas of 92.1%. This reached 116.6% when bioenhancers were applied. The increase of the specific gas production of biogas due to an increment of the organic loading rate (5% wt/wt) was +77.9% without enzymatic treatment and it was +129.8% when enzymes were used. The best management of the biodigester was found in the combination of higher values of hemp straw residues coupled with the enzymatic treatment, reaching 0.248 Nm3·kgvolatile solids−1 of specific biogas production. Comparisons were made between the biogas performance obtained within the present study and those found in the literature review coming from studies on a laboratory scale, as well as those related to the most common energy crops. The hemp straw performance was similar to those provided by previous studies on a laboratory scale. Values reported in the literature for other lignocellulosic crops are close to those of this work. Based on the findings, biogas production can be improved by using bioenhancers. Results suggest an integration of industrial hemp straw residues as complementary biomass for cleaner production and to contribute to the fight against climate change.

Optimization of Hydraulic Retention Time and Organic Loading Rate in Anaerobic Digestion of Squeezed Pineapple Liquid Wastes for Biogas Production

2021 ◽  
Author(s):  
Napisa Pattharaprachayakul ◽  
Narumon Kesonlam ◽  
Pongpitak Duangjumpa ◽  
Vilai Rungsardthong ◽  
Worakrit Suvajittanont ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Solid Wastes ◽  
Organic Loading Rate ◽  
Hybrid Reactor ◽  
Organic Loading ◽  
Liquid Wastes

Pineapple wastes are produced in huge amount during the industrial canning process of pineapple; in Thailand over 400,000 tons per annum of canned pineapple exported leaving behind the waste. Besides the pulps and peels as solid wastes, the squeezed pineapple liquid wastes (SPLW) extracted from solid wastes can also be used for anaerobic digestion. In the present study, the anaerobic digestion of liquid squeezed from industrial pineapple peels was carried out using a lab-scale hybrid reactor. The reactor was operated for over 170 days with the hydraulic retention time (HRT) of 20 days decreasing down to 5 days and simultaneous control of organic loading rate (OLR). Under controlled conditions in the hybrid reactor, pH was maintained at 6.5–7.6 by adding alkaline for anaerobic microbial activity. Results showed that the chemical oxygen demand (COD) removal efficiency was at ≥ 90% for all conditions. The biogas production (mL/day) increased thoroughly from longer HRT to shorter HRT, as same as methane production with the maximum values (HRT 5 days, OLR 5 g/COD/ day with recirculation) of 55,130 and 30,322 mL/day, respectively. Moreover, the highest yields of biogas and methane were also investigated under similar conditions with the values of 0.504 and 0.277 L/gCOD, respectively. Interestingly, this optimization of both HRT and OLR of lab-scale anaerobic digestion process could be further practically applied to pilot or industrial scale in canned pineapple factories for biogas production.

scholarly journals Effects of Slurry Reflux on the Stability and Microbial Community Structure of Corn Stalk Anaerobic Digestion System

2021 ◽  
Author(s):  
ling zhao ◽  
yang gao ◽  
jiamin zhao ◽  
jiaixng sun ◽  
zhen wang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
High Throughput Sequencing ◽  
Loading Rate ◽  
Ph Value ◽  
Community Diversity ◽  
System Stability ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
The Stability

Abstract Anaerobic digestion (AD) of corn stalks with slurry reflux and non-reflux was compared and evaluated，to clarify the effects of slurry reflux on AD. It was found that slurry reflux increased cumulative methane production by 45.80% and improved system stability. With the increase of organic loading rate (OLR), pH value and oxidation-reduction potential (ORP) of reflux group remained 7.16±0.23 and -338.71±9.22. High-throughput sequencing results showed that slurry reflux slowed down the decrease of microbial community diversity, and the richness of bacterial community increased by 9.16%. The dominant microorganisms were Bacteroidetes and Methanothrix in reflux group, the relative abundances were 32.41% and 41.75%, respectively. The increase of organic loading rate (OLR) altered the main methane-producing pathway of the AD system, and slurry reflux can delay this trend.

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