This part will investigate densification options for both woody as well as grassy energy crops. The focus will be on briquetting (and to some extent pelletizing) rather than the conventional baling technologies, which are already available, since briquetting as well as pelletizing are expected to result in denser materials more suitable for industrial use.
In addition, two pre-treatment technologies (torrefaction and Torwash) will be developed and tested on specific crops, both in combination with briquetting as densification step rather than pelletization. Pelletization of these pre-treated materials is already being evaluated in detail in the EU FP7 project SECTOR, which started in 2012.
Therefore, the objectives of this task are to:
- optimize conventional technologies: briquetting for mechanical pre-treatment of energy crops SRC, Miscanthus and giant reed in order to improve storage and transport.
- develop new torrefaction technology for thermochemical pre-treatment of energy crops SRC to improve the briquetting process and as such storage and transport.
- develop new Torwash technology for hydrothermal pre-treatment of energy crops Miscanthus and giant reed to improve the briquetting process and as such storage and transport.
- characterize of the quality of the densified biomass as well as that of process residues.
In 2010 the CEN standards for solid biofuels were largely completed (TC 335), based on the activities performed among others in EU projects Bionorm I and Bionorm II. Simultaneously, the ISO process that should convert the CEN standards into ISO standards has been started. As the CEN standards are of good quality, they will probably be largely taken over by ISO (Bakker and Pels, 2011). A new development that is missing however and which is relevant for the LogistEC project is the development of torrefied fuels. As they are only recently becoming available in small quantities and varying qualities on the market, they are not yet incorporated in the standards. Since torrefied – as well as Torwashed – material is clearly different, it is expected that adjustments to the standards will be needed. Within the EU FP7 project SECTOR – in which LogistEC partners CENER and ECN contribute heavily – these adjustments of standards for torrefied materials are part of the R&D activities. SECTOR will initiate a round robin test on torrefied fuel parameters to validate test methods developed in TC 335 for solid biofuels in particular to the validity for torrefied solid biofuels. European test laboratories are invited within the framework of SECTOR to participate when having experience with the analysis of torrefied biomass and/or with analysis of solid biomass. Taking the 2010 CEN standards for solid biofuels and the round robin testing for torrefied materials within SECTOR into account, the LogistEC will not perform a detailed R&D on the standardization topic but will benefit from and interact with already ongoing activities in CEN and in the EU FP7 project SECTOR.
- Assessment of improved densification technologies
- Preliminary quality characteristics of commoditized energy crops
- Improved densification recipes for raw energy crops
- Assessment of improved pre-treatment technologies
- Improved densification recipes for thermally pre-treated energy crops
- Listing of the various technologies tested for densification and storage in the 3 projects and possible use of each one for the 3 different types of biomass
- Assessment of existing logistics, handling and storage steps for solid carriers derived from energy crops with the densification/pre-treatment options