Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10294016 | Renewable Energy | 2016 | 10 Pages |
Abstract
Although digestion of micro-algal biomass was first suggested in the 1950s, there is still only limited information available for assessment of its potential. The research examined six laboratory-grown marine and freshwater micro-algae and two samples from large-scale cultivation systems. Biomass composition was characterised to allow prediction of potentially available energy using the Buswell equation, with calorific values as a benchmark for energy recovery. Biochemical methane potential tests were analysed using a pseudo-parallel first order model to estimate kinetic coefficients and proportions of readily-biodegradable carbon. Chemical composition was used to assess potential interferences from nitrogen and sulphur components. Volatile solids (VS) conversion to methane showed a broad range, from 0.161 to 0.435Â LÂ CH4Â gâ1Â VS; while conversion of calorific value ranged from 26.4 to 79.2%. Methane productivity of laboratory-grown species was estimated from growth rate, measured by changes in optical density in batch culture, and biomass yield based on an assumed harvested solids content. Volumetric productivity was 0.04-0.08Â LÂ CH4Â Lâ1 culture dayâ1, the highest from the marine species Thalassiosira pseudonana. Estimated methane productivity of the large-scale raceway was lower at 0.01Â LÂ CH4Â Lâ1Â dayâ1. The approach used offers a means of screening for methane productivity per unit of cultivation under standard conditions.
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Keiron P. Roberts, Sonia Heaven, Charles J. Banks,