Methane production from marine, green macro-algae
1983; Elsevier BV; Volume: 8; Issue: 3 Linguagem: Inglês
10.1016/0166-3097(83)90024-x
ISSN2212-4136
Autores Tópico(s)Anaerobic Digestion and Biogas Production
ResumoFermentation studies have been carried out to produce methane from green algae native to Scandinavian waters and suitable for large scale cultivation. Long term semi-continuous fermentations during mesophilic and thermophilic conditions were performed as well as batch fermentations in flasks and syringes. A mixed inoculum was prepared from sediments, rotting seaweed, sewage sludge and rumen contents. Methane production from the seaweed substrate, consisting of ground green algae without any nutrient additions, started immediately in this culture, mesophilicly as well as thermophilicly. Fermentations were carried out with retention times from 27 to 11 days and loading rates from 1.1 to 2.6 g volatile solids (VSadded) per litre per day. In the mesophilic fermentation gas yields were 250–350 ml CH4/g VSadded and the VS-reduction was around 50–55% at all tested retention times and loading rates. The level of volatile fatty acids was very low in this system. In the thermophilic digestor gas yields were somewhat lower although the VS-reduction was around 50% also in this system. The VFA-levels were higher and the culture more sensitive to disturbances. Thus no advantages were found with the thermophilic fermentation. In mesophilic batch fermentations the gas production was rather rapid and almost completed after 12–15 days, in agreement with the continuous fermentations. The gas yields in batch experiments were high, 350–480 ml CH4/9 VSadded.
Referência(s)