Title: Exergy analysis of an anaerobic digestion system for marine biomass utilisation

Authors: Kana Kuroda; Naoki Nakatani; Koji Otsuka

Addresses: Graduate School of Engineering, Department of Marine System Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan ' Graduate School of Engineering, Department of Marine System Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan ' Graduate School of Engineering, Department of Marine System Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan

Abstract: This study proposes a marine biomass utilisation system and describes an anaerobic digestion system using marine biomass and food waste. Four scenarios are presented where the biomass amount varies and is sourced from different suppliers. Exergy is used for the feasibility evaluation. Various kinds of material and energy overall system are described in terms of exergy; exergy production and consumption is identified. The exergy efficiency of the overall system is introduced, and the efficiency of fossil fuel consumption is compared with the simple incineration of waste biomass. It is found that exergy production is bigger than exergy consumption and that the exergy of organic substances accounts for most of the exergy produced in all cases. From the viewpoint of fossil fuel consumption, the proposed system is more valuable than just the present system of incineration. This study provides a holistic viewpoint using exergy for the feasibility evaluation.

Keywords: seaweed; marine biomass; food waste; anaerobic digestion; feasibility evaluation; exergy analysis.

DOI: 10.1504/IJEX.2016.076865

International Journal of Exergy, 2016 Vol.20 No.2, pp.236 - 253

Received: 26 Jan 2015
Accepted: 31 Jul 2015
Published online: 04 Jun 2016 *

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