Publicação

Biological hydrogen production by Anabaena sp. – Yield, energy and CO2 analysis including fermentative biomass recovery

Detalhes bibliográficos
Resumo:	This paper presents laboratory results of biological production of hydrogen by photoautrotophic cyanobacterium Anabaena sp. Additional hydrogen production from residual Cyanobacteria fermentation was achieved by Enterobacter aerogenes bacteria. The authors evaluated the yield of H2 production, the energy consumption and CO2 emissions and the technological bottlenecks and possible improvements of the whole energy and CO2 emission chain. The authors did not attempt to extrapolate the results to an industrial scale, but to highlight the processes that need further optimization. The experiments showed that the production of hydrogen from cyanobacteria Anabaena sp. is technically viable. The hydrogen yield for this case was 0.0114 kgH2/kgbiomass which had a rough energy consumption of 1538 MJ/MJH2 and produced 114640 gCO2/MJH2. The use of phototrophic residual cyanobacteria as a substrate in a dark-fermentation process increased the hydrogen yield by 8.1% but consumed 12.0% more of energy and produced 12.1% more of CO2 showing that although the process increased the overall efficiency of hydrogen production it was not a viable energy and CO2 emission solution. To make cyanobacteria-based biofuel production energy and environmentally relevant, efforts should be made to improve the hydrogen yield to values which are more competitive with glucose yields (0.1 kgH2/kgbiomass). This could be achieved through the use of electricity with at least 80% of renewables and eliminating the unessential processes (e.g.pre-concentration centrifugation).
Autores principais:	Ferreira, Ana F.
Outros Autores:	Marques, Ana C.; Batista, Ana Paula; Marques, Paula; Gouveia, Luisa; Silva, Carla M.
Assunto:	Cyanobacteria Biohydrogen Photoautotrophic production Energy balance CO2 emissions
Ano:	2012
País:	Portugal
Tipo de documento:	artigo
Tipo de acesso:	acesso aberto
Instituição associada:	Laboratório Nacional de Energia e Geologia, I.P.
Idioma:	inglês
Origem:	Repositório do LNEG

Descrição
Resumo:	This paper presents laboratory results of biological production of hydrogen by photoautrotophic cyanobacterium Anabaena sp. Additional hydrogen production from residual Cyanobacteria fermentation was achieved by Enterobacter aerogenes bacteria. The authors evaluated the yield of H2 production, the energy consumption and CO2 emissions and the technological bottlenecks and possible improvements of the whole energy and CO2 emission chain. The authors did not attempt to extrapolate the results to an industrial scale, but to highlight the processes that need further optimization. The experiments showed that the production of hydrogen from cyanobacteria Anabaena sp. is technically viable. The hydrogen yield for this case was 0.0114 kgH2/kgbiomass which had a rough energy consumption of 1538 MJ/MJH2 and produced 114640 gCO2/MJH2. The use of phototrophic residual cyanobacteria as a substrate in a dark-fermentation process increased the hydrogen yield by 8.1% but consumed 12.0% more of energy and produced 12.1% more of CO2 showing that although the process increased the overall efficiency of hydrogen production it was not a viable energy and CO2 emission solution. To make cyanobacteria-based biofuel production energy and environmentally relevant, efforts should be made to improve the hydrogen yield to values which are more competitive with glucose yields (0.1 kgH2/kgbiomass). This could be achieved through the use of electricity with at least 80% of renewables and eliminating the unessential processes (e.g.pre-concentration centrifugation).