A blog from University of Borås

Monday, May 31, 2010


Hydrogen (H2) is an interesting source of energy. It contain about 3 KWh/m3 energy (lower latent heat), and produces just water while burning. However, H2 is produced today from oil by reforming fossil fuels. There has been many research and development on production of hydrogen by a sustainable methods in the last decades. Biological hydrogen production is of great interest. An interesting recent review compares the three methods of biohydrogen production, i.e. by oxygenic photosynthesis by purple bacteria, dark fermentation by anaerobic bacteria, and microbial enectolysis cells by anode-respiring bacteria. The first method works well in theory, but it has many problems in practice. Dark fermentation works well in practice, but has a low yield (about 17% of the theoretical yield), and the last method needs electricity and has a low kinetic. Although these challenges, it seems a combination of these methods might lead to a promising method for BioH2 production in the future!

Monday, May 24, 2010

Effects of biofuels on greenhouse gases

Ethanol has the largest share in the biofuel market. Its market grew very fast in connection to the more concern on global environment and crisis in energy market. It resulted in many debates if ethanol reduces greenhouse gases or not. Some people were/are optimistic and some pessimistic. There is also similar debates about other biofuels, including biodiesel (RME) and biogas which are avialable in Swedish market. A recent life cycle analysis from Lund University show that all these biofuels results in reducing greenhousue gases by different degrees from 68% up to 148%!

(Reduction of greenhouse gases by using different biofuels. Ref. here)

Sunday, May 16, 2010

Bioenergy bigger than oil in Sweden

While EU has a goal to have 20% renewable energy in 2020, Sweden has the highest goal among these 27 countries with 49% renewable energy in 2020. However, if the current trend keeps going, we might be able to even pass this goal. The recent statistics shows that the share of renewable energy in Sweden in 2009 was 46.3%. The data also shows a share of bioenergy as 31.8%, compares to the share of oil that was 30.9%, according to SVEBIOS.

(Trend in Energy sources in Sweden, Ref. Swedish Energy Agency)