From Fishing Gear to Granulates and Recycled Steel – An Eco Innovation Project

Abstract

Plastix A/S, a cleantech company located in Lemvig, Denmark, received in August 2014 funding for the project Retrawl2, which is a part of the EU initiative ECO-Innovation project. Retrawl2 is co-funded by the European Union with the CIP ECO-Innovation initiative of the Competitiveness and Innovation Framework Programme, CIP. The aim of the RETRAWL is to upscale an innovative recycling technology, which transforms used maritime waste into plastic and steel commodities. The plastics are mainly polyamides and polyethylene from nets and trawls, and the steel are mainly carbon steel from taifun wires as parts of the nets and trawls.The suppliers of the used maritime equipment are Danish and other European fishing harbours, where equipment are stored, because it can be a challenge for the fishermen to dispose it. Also ghost nets are collected and delivered for recycling. In order to recycle nets to commodity plastics considerations of the quality of the product has been taken. The nets are made of materials of a high quality, because the abrasion resistance, the tension strength and the chemical resistance need to be high for the use of them in trawl. The quality of the recycled plastics will be high, when they are gently treated under the cutting, separation, washing and extrusion processes. In the processes the gently handling of the polymers is in focus to keep the degree of polymerisation of the polymers, since the strength of the plastics depends on the chain length of the polymers. The quality and the identity of the recycled plastics are verified through infrared spectroscopi, FTIR, differential scanning calorimetry, DSC, measuring the tensile strength and the elongation to break, measuring the melt flow index and the distribution of the grain size. The used fishing nets may have a significant smell of fish from trimethyl amine and rancid smell from oxidized fatty acids. The smell will disappear under the production mainly because of the volatility of trimethyl amine. The fatty acids will be partly degraded under the production, and if there is a remaining part, they will act as plastisizers in polyethylene and polyamide with a minor influence on the strength of the product. In the steel plant the plastic covers of taifun wires are melted off with energy supply from an induction technology. The steel will afterwards be cut in pieces with length up to 1 meter. The capacity of the extrusion line is planned to be 24 ton per day 7 days per week, and on the steel line the capacity is planned to be 8 – 10 ton steel per day 5 days per week. The amount of used fishing equipment for that production will be approximately 40 ton per day. During 2015 another extrusion line will be ready allowing the doubling of the production.