Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage

Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George; Naggar, M. Hesham El

doi:10.1016/j.biortech.2012.02.019

Cited by 143 publications

(59 citation statements)

References 29 publications

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“…However, the higher gross energetic potential was due to the higher performance in Total biogas production = 3946 ml Total biogas production = 4220 ml Total biogas production = 4145 ml Total biogas production = 3943 ml Total biogas production = 3819 ml Total biogas production = 3777 ml Total biogas production = 3103 ml Total biogas production = 4072 ml the methanogenic reactor rather than the hydrogen production from the fi rst stage. Nasr et al (2012) estimated the energy balance of two-stage anaerobic digestion of thin stillage, and concluded that optimizing the two-stage anaerobic digestion process can increase the energy balance by 18.5%. Lu et al (2008) reported that a two-stage reactor showed a better energy balance with a surplus of 2.17 kJ/d, as compared to a single stage system for treating sewage sludge.…”

Section: Anaerobic Digestionmentioning

confidence: 99%

Low intensity surplus activated sludge pretreatment before anaerobic digestion

Suschka¹,

Grűbel²

2017

Archives of Environmental Protection

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Sewage sludge (municipal, or industrial) treatment is still a problem in so far that it is not satisfactorily resolved in terms of cost and fi nal disposal. Two common forms of sludge disposal are possible; the fi rst being direct disposal on land (including agriculture) and the second being incineration (ash production), although neither of these methods are universally applied. Simplifying the issue, direct sludge disposal on land is seldom applied for sanitary and environmental reasons, while incineration is not popular for fi nancial (high costs) reasons. Very often medium and large wastewater treatment plants apply anaerobic digestion for sludge hygiene principles, reducing the amount to be disposed and for biogas (energy) production. With the progress in sewage biological treatment aiming at nutrient removal, primary sludge has been omitted in the working processes and only surplus activated sludge requires handling. Anaerobic digestion of waste activated sludge (WAS) is more diffi cult due to the presence of microorganisms, the decomposition of which requires a relatively long time for hydrolysis. In order to upgrade the hydrolysis effects, several different pre-treatment processes have already been developed and introduced. The additional pre-treatment processes applied are aimed at residual sludge bulk mass minimization, shortening of the anaerobic digestion process or higher biogas production, and therefore require additional energy. The water-energy-waste Nexus (treads of) of the benefi ts and operational diffi culties, including energy costs are discussed in this paper. The intensity of pre-treatment processes to upgrade the microorganism's hydrolysis has crucial implications. Here a low intensity pre-treatment process, alkalisation and hydrodynamic disintegration -hybrid process -were presented in order to achieve suffi cient effects of WAS anaerobic digestion. A sludge digestion effi ciency increase expressed as 45% biogas additional production and 52% of the total or volatile solids reduction has been confi rmed.

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Section: Anaerobic Digestionmentioning

confidence: 99%

Low intensity surplus activated sludge pretreatment before anaerobic digestion

Suschka¹,

Grűbel²

2017

Archives of Environmental Protection

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“…On the other hand, in a one-stage process both the acidogenic step and the methanogenic step are mixed in one reactor, which results low process stability due to susceptible to pH and temperature fluctuations, overloading, acid accumulation, etc. Some studies (Vinas et al 1993;Lehtomäki et al 2008;Nasr et al 2012) claimed that a twostage digestion system would result in a greater yield of methane over the one-stage system due to a larger fraction of the substrates being converted to biogas by the more vigorous activity of the acidogenic microbes in the first stage of the two-stage system. Nasr et al (2012) reported a comparative analysis on the efficiency of single-stage and two-stage digestion systems using thin stillage as the substrate and revealed that an improved energy yield of 18.5% was achieved through two-stage systems.…”

Section: Comparison Of Reactor Configurationsmentioning

confidence: 99%

“…Some studies (Vinas et al 1993;Lehtomäki et al 2008;Nasr et al 2012) claimed that a twostage digestion system would result in a greater yield of methane over the one-stage system due to a larger fraction of the substrates being converted to biogas by the more vigorous activity of the acidogenic microbes in the first stage of the two-stage system. Nasr et al (2012) reported a comparative analysis on the efficiency of single-stage and two-stage digestion systems using thin stillage as the substrate and revealed that an improved energy yield of 18.5% was achieved through two-stage systems. Lehtomäki et al (2008) investigated anaerobic digestion of grass silage in leach bed reactors with and without a second stage UASB reactor and found that 66% of the total methane potential in grass silage was obtained in the two-stage process whereas in the one-stage process only 20% of the methane potential was extracted.…”

Section: Comparison Of Reactor Configurationsmentioning

confidence: 99%

Comparison of Reactor Configurations for Biogas Production from Rapeseed Straw

Yuan

2016

BioResources

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To investigate the effects of reactor configurations on the anaerobic digestion performance of agricultural residue rapeseed straw, semicontinuous, one-stage, continuously stirred tank reactors (CSTR) and batch, two-stage, leach bed-upflow anaerobic sludge blanket (UASB) reactors were operated at the same hydraulic retention time (HRT) (30 days) and target organic loading rate (OLR) (3.0 gVS/L.d). In the continuously loaded CSTR, the specific methane yields did not substantially change as the OLR increased from 1.5 gVS/L.d to 3.0 gVS/L.d during the four periods. Conversely, the specific methane yields in the batch-fed leach bed-UASB increased considerably with the increase in OLR. The leach bed reactor contributed 75% of the total yield, while the UASB reactor contributed only 25% of the total yield. The total specific methane yields were 108 mL/gVS and 160 mL/gVS for the leach bed-UASB and CSTR, respectively, while the volatile solid (VS) reductions of the rapeseed straw were 27.1% and 36.6%, respectively. The results indicated that the process performance was more efficient in the CSTR than in the leach bed-UASB for the digestion of rapeseed straw. Biogas production was clearly affected by the reactor configurations.

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“…The separation of the acidogenic step from the methanogenic one results in enhanced stability to the different groups of microorganisms as well as in a better process control [116]. Nasr et al [106] compared one-stage and two-stage anaerobic digestion processes for the treatment of thin stillage. The separation of acidogenesis and methanogenesis allowed a maximum methane yield of 0.33 L/gCOD added and an overall increase of 18.5% in the energy yield.…”

Section: The Combination Of Bioethanol and Biogas Production Processesmentioning

confidence: 99%

Combined Biogas and Bioethanol Production: Opportunities and Challenges for Industrial Application

Cesaro

Belgıorno

2015

Energies

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Abstract:In the last decades the increasing energy requirements along with the need to face the consequences of climate change have driven the search for renewable energy sources, in order to replace as much as possible the use of fossil fuels. In this context biomass has generated great interest as it can be converted into energy via several routes, including fermentation and anaerobic digestion. The former is the most common option to produce ethanol, which has been recognized as one of the leading candidates to substitute a large fraction of the liquid fuels produced from oil. As the economic competitiveness of bioethanol fermentation processes has to be enhanced in order to promote its wider implementation, the most recent trends are directed towards the use of fermentation by-products within anaerobic digestion. The integration of both fermentation and anaerobic digestion, in a biorefinery concept, would allow the production of ethanol along with that of biogas, which can be used to produce heat and electricity, thus improving the overall energy balance. This work aims at reviewing the main studies on the combination of both bioethanol and biogas production processes, in order to highlight the strength and weakness of the integrated treatment for industrial application.

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Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage

Cited by 143 publications

References 29 publications

Low intensity surplus activated sludge pretreatment before anaerobic digestion

Low intensity surplus activated sludge pretreatment before anaerobic digestion

Comparison of Reactor Configurations for Biogas Production from Rapeseed Straw

Combined Biogas and Bioethanol Production: Opportunities and Challenges for Industrial Application

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