Distinct advanced strategies for the production of H2 from biomass are currently being studied:
• thermal processes like gasification or supercritical water gasification;
• non-thermal (biological or fermentative) processes, which are the issue in HYVOLUTION.
Non-thermal processes have a specific advantage for the efficient conversion of biomass with high moisture content to pure hydrogen. Secondly, fermentative processes do not require large installations for economy of scale. In this way, small-scale installations can be constructed for cost-effective conversion of the locally produced biomass on-site and loss of energy through transport is prevented.
The potential of biologically produced H2 is recognised worldwide. The Netherlands is very active in research on application of bacteria for H2 production from biomass, similar as Sweden, Hungary, Turkey and the UK. Also in Asia and Canada and especially in the USA, biological H2 production is seen as one of the options for renewable H2 production on the longer term, as presented in the US document ‘National Hydrogen Energy Roadmap’. The progress in research on hydrogenase enzymes and basic physiological parameters of hydrogen producing bacteria forms the basis for continuation and expanding the developments in Europe following the approach in The Netherlands.
Most research in this topic has been performed with hydrogen producing bacteria, which have optimum growth and hydrogen production at ambient temperatures. The main drawback of these bacteria is that, besides hydrogen, they produce other reduced intermediates which compete with hydrogen production. As a result, the efficiency of biomass conversion to hydrogen is low.
In a Dutch project, coordinated by A&F, and supported by the EET programme, a joint initiative of the Ministries of Economic Affairs, Education, Culture and Sciences and of Housing, Spatial Planning and the Environment, a conceptual design has been made for the biological production of hydrogen from potato steam peels. The conceptual design was based on hydrogen production rates, regarded feasible after further R&D. The outcome was a cost price of circa 4 Euro/kg H2 (comparable to 30 Euro/GJ) which is about 3–4 times higher than the present price for hydrogen, derived from fossil fuels produced in large-scale installations. The Dutch project identified the bottlenecks, which need to be addressed and improved before the bioprocess can become cost-effective.
The new approach focuses on a combination of a thermophilic fermentation with a photofermentation to enable the complete conversion of biomass to hydrogen with the highest efficiency theoretically possible. The proof of principle of this combined bioprocess has been delivered by the A&F coordinated FP 5 project BIOHYDROGEN.
The consortium for HYVOLUTION also coordinated by A&F, was formed to exploit the acquired knowledge and make a breakthrough with a new taskforce aiming at the development of a hydrogen industry producing H2 at a cost price of 10 Euro/GJ. The necessary advances will be established by a greater critical mass of specialists from different disciplines, representing academia, research organisations, SMEs and industries, in the European Research Area. The price target will be achieved by reducing costs in the biomass pretreatment, by optimizing the efficiency and rate of the fermentations enabling low cost thermo- and photo-bioreactors, by developing dedicated, low-cost gas upgrading procedures and optimum system integration for making economic balances with respect to energy and heat utilisation.