Cleaner and sustainable processes for extracting phenolic compounds from bio-waste

D. ZALAZAR GARCÍA; E. TORRES; L. RODRIGUEZ-ORTIZ; Y. DENG; J. SORIA; V. BUCALÁ; R. RODRIGUEZ; G. MAZZA

JOURNAL OF ENVIRONMENTAL MANAGEMENT

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020 vol. 273 p. 1 - 10

0301-4797

The frequent environment-unfriendly treatments ofagro-industrial bio-wastes cause severe pollution through air pollution andthrough residual effluents and hazardous solid waste. These bio-wastes cancontain phenolic compounds, forms of phenolic acids and flavonoids in plants.They are however the most abundant class of many phytochemicals and have beengiven great interest due to their health advantage and high economic value. Aninteresting upgrading of these bio-wastes may consist in obtaining a concentratedextract of phenolic compounds using no-toxic solvents, hence protecting theenvironment and human health. In this work, different alternatives of the extractionprocess were evaluated using an exergetic analysis. The energy and waterconsumptions, CO2 emissions, exergetic yield, wasted and destroyedexergy were calculated. It was found that several alternatives for recyclestreams were convenient (streams with higher chemical exergy were notdischarged into the environment). The energy and water consumption for the bestalternative (ethanol-water ratio1/1 including recycle stream, named E-W 1/1 Rec) were567 MJ/h and 105 kg/h, respectively and the CO2 emission was 105kg/h.The calculated exergy destruction indicated that theevaporation and distillation stages may be optimized towards a more sustainableoperation. It is not advisable to dry the bio-waste if it will be immediatelyprocessed once generated.