School of Mechanical Engineering: Roi Peretz

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SCHOOL OF MECHANICAL ENGINEERING SEMINAR
Monday, January 15, 2020 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Co-conversion of Recycled paper sludge (RPS) to bioethanol and Crystalline Nano Cellulose (CNC) via ozone-based processes

Roi Peretz
PhD Student of Prof. Hadas Mamane

In Israel, more than 1 million tons of paper and cardboard wastes are generated annually, yet only 20% are being recycled, mostly in “Hadera Paper” mill. The waste generated from the recycling process of paper and cardboard results in 31,000 tons of recycled paper sludge (RPS) that is very rich in cellulose fibers (75% dry weight), currently being disposed of in landfills. The high cellulose fiber content makes this waste an ideal source for cellulose-based applications. Efficient means for cellulose recovery and conversion from RPS were examined – by characterization of the RPS, testing and optimization of novel ozonation-based pretreatments and processes, and production of two valuable products: bioethanol and cellulose nano crystals (CNC). CNC serves as a key component in many industrial applications as building blocks, for developing materials including thin films, nanocomposites, biomedicines, water treatment and smart materials. In addition, the RPS remains could be used for sorption of contaminants in water. Results show that up to 35% of the total RPS can be converted to sugars, yielding a total of 15 gr/L of ethanol.  Alternatively, CNC could be produced from the RPS, using weak, recyclable maleic acid hydrolysis. The acid was successfully recovered for repeated use, allowing reduction of acid  costs and generated waste streams. Although the total CNC yield remained relatively low, it demonstrated that ozone can increase the yield, due to it high ability for lignin removal. This research contributes to the waste-to-fuel concept in Israel and globally using RPS, especially given the growing amount of recycled paper, and the amounts of solid-waste being landfilled, following green chemistry and circular economy concepts.