From an environmental perspective, many complex plastic wastes need to be lifted at least one step higher in the recycling hierarchy, i.e. chemical recycling instead of energy recovery. The aim of this project is therefore to develop methods that enable circular material flows in society for the constituents of these complex wastes. High-temperature gasification of plastic waste enables production of synthesis gas that can be used in the manufacture of new plastic raw materials. The project will study gasification of at least three problematic plastic wastes at different operating conditions. The objective is that the yield of useful synthesis gas products (CO and H2) should exceed 75% on an energy basis. In addition, the project will map how halogens and metals are present in the process, thus suggesting appropriate recycling strategies for these. The collaboration project between RISE ETC, Umeå University, Stena Metal and Smurfit Kappa, is proposed to last for two years (2018-2020).