GC: n
CT: 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 x l(-1) x d(-1) and 0.5 COD g x l(-1) x 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 x l(-1) respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 g COD x l(-1) x 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 g COD x 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 x 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.
S: PubMed – https://goo.gl/uFAzvS (last access: 17 October 2017)
N: 1. From methanize (methane, inflammable colorless and odorless gas, marsh gas, coined from chemical suffix -ane + syllable abstracted from methyl) and the suffix -ation (ending of some nouns of action).
2. A biological process in which organic matter is broken down by bacteria with a total absence of air or of oxygen.
3. This digestion process produces biogas consisting mainly of methane, from which energy can be recovered; and a balanced soil conditioner known as “digestate”.
4. The wastes suitable for methanization are: fats from food industries, sludge from urban and industrial water treatment plants, food industry by-products and agricultural wastes.
5. The advantages of methanization are: production of renewable energy, production of a balanced soil conditioner, less odours, compact plant and a highly favorable carbon balance.
S: 1. ACADEMIC – https://goo.gl/ZvLXcF (last access: 27 October 2017); MW – https://goo.gl/VoJueA (last access: 26 October 2017); OED – https://goo.gl/DjKJiS (last access: 27 October 2017); SEDE – https://goo.gl/2UAmeK (last access: 26 October 2017). 2. TERMIUMPLUS – https://goo.gl/1E88kJ (last access: 27 October 2017). 3. TERMIUMPLUS – https://goo.gl/1E88kJ (last access: 27 October 2017). 4. SEDE – https://goo.gl/2UAmeK (last access: 26 October 2017). 5. SEDE – https://goo.gl/2UAmeK (last access: 26 October 2017)
OV: methanation
S: TERMIUMPLUS – https://goo.gl/CVcge7 (last access: 27 October 2017)
SYN: anaerobic digestion, biomethanization.
S: TERMIUMPLUS – https://goo.gl/1E88kJ (last access: 27 October 2017)
CR: biomethanization plant, methane .
