Energy efficient dewatering of far offshore grown green macroalgae Ulva sp. biomass with pulsed electric fields and mechanical press. (January 2020)

• Record Type: Journal Article
• Authors: Prabhu, Meghanath; Levkov, Klimentiy; Levin, Ofir; Vitkin, Edward; Israel, Alvaro; Chemodanov, Alexander; Golberg, Alexander
• Is Part Of: Bioresource technology. Volume 295(2020)
• Publication Date: 2020-01
• Subjects: Offshore biomass production -- Ulva sp. offshore -- Seaweed drying -- Pulsed electric fields -- Macroalgae -- Electroporation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.122229
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Green macroalgae Ulva sp. was cultivated 15 km offshore. A positive growth rate of offshore cultivated Ulva sp. was measured during 7 months of cultivation. A positive yield was measured during 7 months of cultivation. Pulsed electric field dewatering of Ulva sp. saves energy on convective air drying. Abstract: Offshore macroalgae biomass production is a promising, yet challenging, pathway to provide feedstock for biorefineries. In this work, a device and a process for dewatering offshore grown biomass of the green macroalgae Ulva sp. using high-voltage pulsed electric fields (PEF) was developed. Ulva sp. was cultivated attached to fish cages 15 km offshore. Increasing the applied voltage from 250 V to 500 V and invested PEF energy from 9.3 ± 0.4 J g −1 FW to 54.6 ± 0.2Jg −1 FW increased the extracted water from 0.033 ± 0.006 g Water g −1 FW to 0.150 ± 0.031 g Water g −1 FW. The energy consumption to achieve similar moisture content with air convection drying was lower by 78.73 ± 10.41 (JgFW −1 ) for 250 V and 339.31 ± 48.01 (JgFW −1 ) for 500 V, pulse duration 50 µs, pulse number 50, pulse repetition frequency 3 Hz. PEF leads to biomass compression of 8.45 ± 1.72% for 250 V protocol and 25.66 ± 2.53% for 500 V protocol. In addition, PEF leads to the reduction of water diffusivity of 18–19% in the treated biomass, reducing air drying kinetics.