Thermally Assisted Mechanical Dewatering – DMAT
Sustainable development requires the use of renewables as alternative feedstocks for fuel, chemical and material productions. Currently, share of renewable raw materials runs at best to a few percents but is expected to provide up to 20% by 2030. Herbaceous plants, grasses, leaves, stems are raw materials available in abundance, with a high biomass profit per hectare and a good coupling with agricultural production, and could be considered as an “ideal” feedstock for biorefinery. The common feature of these materials is to be ‘nature-wet’. Their processing requires a preliminary mechanical fractionation. The vegetative biomass is separated into a nutrient-rich liquid fraction - the green juice - and a fiber-rich solid fraction - the press cake. Both fractions have an economic value: the green juice is a raw material for high quality fodder and cosmetic proteins, human nutrition, platform chemicals or biogas production while the press cake can be used directly as silage feed or after thermal drying as fodder or as solid fuel. To date, the economic viability of green biomass fractionation process depended to a large extent on the utilization of the press cake as a high quality ruminant feed, the valorization of the liquid fraction leading to rare specialty chemicals. The emergence of biorefineries, with further alternative processing routes including bulk chemicals production, could significantly improve the economy of the process. In the future, the green juice fraction will contribute more to the value derived from the biomass. As a consequence, mechanical fractionation will be an essential process unit of a green biorefinery plant. A better separation will increase the mass of the liquid fraction, and, simultaneously, reduce the energy consumption and the environmental impact of the press cake valorization process by drying. Intensification of mechanical dewatering processes can take several forms: simultaneous application of a pulsed electric field, superimposition of ultrasounds or with heat supply. Thermal intensification seems the most promising solution: 75 to 80% of the inherent liquid, against 55% with conventional processes, can be removed with a low energy consumption (1/6 of the energy consumption of thermal dryers). One of the technologies, the TAMD process, couples mechanical dewatering at low pressure with a simultaneous moderate heating of the walls of the apparatus in contact with the product.
The TAMD Project joins the RAPSODEE research center of the École des Mines of Albi-Carmaux (FRE 3213) and INRA Transfert, a project management consulting company specialized in the field of innovating technologies arising from agriculture-related research. The scientific and technical objectives of this 24 month project are: (1) to produce a prototype on a pre-industrial scale of the thermally assisted mechanical dewatering process (TAMD process) developed by RAPSODEE; (2) to optimize the operating conditions in order to maximize the dry content of the press cake while preserving the quality of the green juice; (3) to validate a simple model of the prototype, which can be used for the extrapolation of the process on an industrial scale; (4) to evaluate the energy and economic profits resulting from the use of the TAMD in a vegetable bioraffinery.
At the conclusion of the project, a collaboration for final industrial validation, with a company end user and/or an equipment supplier, is expected in order to reach some license agreements on existing patent.
Madame Patricia ARLABOSSE (ECOLE NATIONALE SUPERIEURE DES TECHNIQUES INDUSTRIELLES ET DES MINES D'ALBI-CARMAUX) – firstname.lastname@example.org
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
EMAC - Centre RAPSODEE ECOLE NATIONALE SUPERIEURE DES TECHNIQUES INDUSTRIELLES ET DES MINES D'ALBI-CARMAUX
Help of the ANR 258,145 euros
Beginning and duration of the scientific project: February 2011 - 24 Months