Low temperature hydrogen production from 2nd generation biomass
Key Objectives of the project
The overall objective of ‘HyTIME’ is to accelerate the implementation of an industrial bioprocess for decentral hydrogen production systems using 2nd generation biomass.
The target of this project is to construct a prototype process based on fermentation of biomass for delivering 1-10 kg hydrogen/d and to develop a biohydrogen production system as a stepping stone to pre-commercial application.
The objective of HyTIME is to expand the unique strategy of thermophilic dark fermentation and to add an alternative approach in combining the thermophilic dark fermentation with anaerobic digestion. HyTIME builds on previous results with a focus on thermophilic fermentation to accelerate a breakthrough of fermentative hydrogen production from 2nd generation biomass including waste biomass. The acquired knowledge on biomass availability, logistics and pretreatment and on gas upgrading technology will be fully exploited to develop dedicated systems for an easy to handle biohydrogen production system
- optimal utilization of 2nd generation biomass from sustainable biomass supply chains (grass, straw, residues from food-industry) in tailor-made pretreatment procedures
- developing large scale high rate bioreactors for increased H2 productivity at low nutrient cost
- combining high yield in H2 fermentation with increased quality of biogas from anaerobic digestion
- stimulating production by recovering dissolved H2 from the liquid phase
- optimizing the unit-operations for upgrading H2 at small scale, low pressure and low temperature including development of process monitoring and control devices
- heat and energy integration for increasing the overall energy efficiency
- providing the design for a pre-commercial H2 production plant to enable medium term market implementation
The 9 participants, coming from small and large industries, universities and a research institute are spread over HyTIME addresses the entire value chain from biomass logistics and pretreatment, thermophilic hydrogen production and gas upgrading technologies. The integration of all these components of the hydrogen production system is done to bring progress in HyTIME to beyond the state-of-the-art of current fermentative hydrogen production.
More specifically: for the production of biomass, road side grass, straw and over-date residues from supermarkets will be studied in terms of availability and suitability. Pretreatment and hydrolysis for mobilisation of sugars will be optimized by developing procedures to decrease energy demand, use of chemicals and enzymes, formation of inhibitors, and to increase fermentability, keepability etc. The hydrolysates will be tested for thermophilic fermentation and adjusted with required nutrients for optimum yield. The increase in productivity (kg H2/ time) will be addressed by increasing the concentration of the bacteria through immobilization on carriers or by making bacterial flocs. The approach will be using designed co-cultures of Caldicellulosiruptor species and bacteria from the Thermotogales order in dedicated bioreactors based on a combination of a moving bed and trickle bed system. For removal and capture of hydrogen, the strategy is twofold: upgrading hydrogen in the gas phase by Pressure Swing Adsorption or the application of a membrane contactor combining specific absorption and separation. Besides, hydrogen in the liquid phase will be removed by a membrane unit in an internal loop connected to the bioreactor. To guarantee proper process control and operation and, eventually, automation, dedicated measurement devices will be developed which will allow continuous detection of hydrogen or contaminants like H2S. Finally, the effluent of the hydrogen bioreactor will be tested for methane production in an innovative continuous anaerobic membrane reactor operating at thermophilic conditions. All mass and energy balances and basic engineering data of the separate process units will be integrated and used for modelling and simulation studies to design a hydrogen production unit with maximum product output, minimum energy demand and low cost.
Expected socio and economic impact
In the EU, 118-138 million tons of bio-waste (garden waste, food and kitchen waste and waste from food processing plants) are currently produced on a yearly basis. This bio-waste could be used for methane production with a theoretical production of 2 million ton of methane. Using the same assumptions, the theoretical hydrogen production would be 0.34 million ton hydrogen with additional 1.3 million ton methane when using the technology of HyTIME. If only half of the theoretical amount of hydrogen would be produced, a production 20 PJoule/year would be the result. This would increase because of the 10% increase in bio-waste production foreseen in the EU and because the technology will grow from its infancy to full maturity after 10 years following the start of HyTIME. The impact for the EU is twofold: a significant contribution to the triple 20% by 2020’ objective with green hydrogen and a contribution to improved bio-waste management.