INVESTIGADORES
DIAZ Maria Soledad
congresos y reuniones científicas
Título:
Optimal design of an integrated macroalgal-based biorefinery
Autor/es:
CLAUDIO A. DELPINO; VANINA G. ESTRADA; MARIA SOLEDAD DIAZ
Lugar:
Dalian
Reunión:
Congreso; 3rd International Conference on Sustainable Chemical Product and Process Engineering; 2013
Institución organizadora:
Dalian Univ. of Tech., China; Wayne State Univ., USA
Resumen:
The feasibility of fuel production, using macroalgae biomass as a raw material has been extensively discussed and reviewed. Especially, the fermentation of sugars obtained from such biomass to ethanol has been assesed, with several processing options being proposed. A key differentiating aspect of macroalgae biomass as a source of polysaccharides, which can be directly fermented by special organisms in a simultaneous saccharification and fermentation, or hydrolized into simple sugars fermentable by well known ethanol producing organisms such as Saccharomyces cerevisiae or Zymomonas mobilis, is the absence of lignin. Macroalgae have distinct characteristics which allows clasification in three groups. Those known as "brown" algae, in which polysaccharides are represented by storage molecules like laminarin and mannitol, and alginates and cellulose, which conform the amorphous and fibrillar part of their cell wall, respectively; The so called "red" algae, in which the fermentable polysaccharides involve galactans (which are nowadays used for agar production) and could amount to higher ethanol yields due to their presence, and also cellulose. A biorefinery scheme is proposed and mathematically modeled based on published data and efforts from other sources . The proposed biorefinery main route includes cultivation, harvesting and processing of macroalgae. Cultivation is to be carried out in terrestrial installations, which offer an easier and more precise control of the cultivation (when compared with seafarms), with higher yields, at the expense of higher capital and operating costs. Processing of macroalgal biomass includes both succesive acid and enzymatic hydrolisis of polysaccharides and their posterior fermentation, and an innovative process involving a genetically modified strain mentioned in [4], which would perform said simultaneous saccharification and fermentation of the alginate of brown seaweed. We also allow for the production of agar, as it is a current high value product obtained from some seaweeds, and its a reference to have into account, in order to have an integrated biorefinery or an energetically self sufficient agar production process. We formulate a mathematical model allowing for cost, energy and water need calculations. The model also includes the possibility to allow for several macroalgae species and origins, diverse processing routes, and several products and byproducts. This allows comparison of the different alternatives, and optimization of the economical and energetic performance of the process using mathematical programming techniques. The optimization framework is specially useful for the macroalgae context, where the integration with current algal highvalue products production facilities, or even the production of this highvalue byproducts (i. e. agar) in the integrated biorefinery, is vital for the process economic sustainability. Numerical results provide quantitative information and give useful insights on macroalgalbased biorefineries, allowing for adaptations to local conditions.