Energy balance of a two-phase anaerobic digestion process for energy crops

2010 ◽  
Vol 10 (6) ◽  
pp. 515-519 ◽  
Author(s):  
Simon Zielonka ◽  
Andreas Lemmer ◽  
Hans Oechsner ◽  
Thomas Jungbluth
Keyword(s):  
Anaerobic Digestion ◽  
Energy Balance ◽  
Energy Crops ◽  
Two Phase ◽  
Anaerobic Digestion Process ◽  
Digestion Process

Liquefaction and methanization of solid and liquid coffee wastes by two phase anaerobic digestion process

2003 ◽  
Vol 48 (6) ◽  
pp. 255-262 ◽  
Author(s):  
E. Houbron ◽  
A. Larrinaga ◽  
E. Rustrian
Keyword(s):  
Anaerobic Digestion ◽  
Wash Water ◽  
Organic Loading Rate ◽  
Two Phase ◽  
Experimental Conditions ◽  
Coffee Pulp ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Working Volume ◽  
Acidogenic Reactor

This study attempted to investigate the feasibility of volatile fatty acid (VFA) production from coffee pulp hydrolyse, and further to determine the potential of methanization of both the pre-acidified effluent and the coffee wastewater. The experiments were carried out in 2 completely mixed reactors, each one with a working volume of 4 litres. Coffee pulp was used as substrate in the acidogenic reactor and different mixtures of pulper and wash-water and pre-acidified effluent in the methanogenic one. The acidogenic and methanogenic reactors were operated at an organic loading rate of 5 COD g.l-1.d-1 and 0.5 COD g.l-1.d-1. The total, soluble and VFA's effluent COD concentrations of the acidogenic reactor present average values of 57.75, 17.00 and 13.92 g.l-1 respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 gCOD.l-1.d-1 and the soluble fraction was transformed to VFA's with an acidification efficiency of 82%. Total VFA's concentration reached a value of 13.9 gCOD.l-1, and acetate, propionate, butyrate and valerate represented 52%, 28%, 9% and 11% respectively of the liquid phase COD. In the methanogenic reactor, COD removal and methanization of fresh coffee wastewater, pre-acidified effluent and both combined occur with an efficiency of 85% to 95% respectively, with a characteristic biogas composition of 80% CH4 and 20% CO2. These results show that a humid coffee ‘Beneficio’ processing daily 23 tons of cherry coffee (fresh fruit), equipped with a two stage anaerobic digestion process could generate at least 1,886 CH4 m3.d-1. This represents an increase in methane production by a factor 3 to 5 compared to a ‘Beneficio’ using anaerobic digestion only for the treatment of its wastewater.

The two phase anaerobic digestion process: sludge stabilization and pathogens reduction

2000 ◽  
Vol 42 (9) ◽  
pp. 41-47 ◽  
Author(s):  
A. Huyard ◽  
B. Ferran ◽  
J.-M. Audic
Keyword(s):  
Anaerobic Digestion ◽  
High Efficiency ◽  
Land Application ◽  
Two Phase ◽  
Polio Virus ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Sludge Stabilization ◽  
Volatile Solids ◽  
Solids Content

Regulations for land application of wastewater sludges require the performing of treatment with a high efficiency on pathogens reduction. a reduction of 61% of the Volatile Solids content of the sludge, a reduction of fecal coliform, polio virus and Ascaris egg of 5.5, 4.0 and 2.6 respectively are achieved with a thermmophilic/mesophilic Two Phase Anaerobic Digestion process. According to the EPA 40 CFR 503 regulation, the process produces Class A biosolids and could be recommended as a Process to Further Reduce Pathogens.

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