This factsheet has been extracted from D07.3 "Guidelines for the implementation of the Circular Economy models" CC4: Chemicals production based on fiber sludge: CC4 demonstrates the transformation of an industrial waste from the PPI to a functional chemical used as an additive in paint and for applications within the construction sector. Improved cellulose, ethanol derivates and ethyl chloride can be obtained by several chemical processes transforming the PPI rejected fibre sludge waste. These can be employed in several applications, as additives for painting products as Bermocoll®. DOMSJÖ FABRIKER (pulp mill), produces dissolving pulp for viscose applications, ethanol from fiber reject and improved pulp quality suitable for production of cellulose ethers; SEKAB (chemicals), produces ethanol derivatives such as acetic aldehyde and ethyl acetate starting from ethanol, and in addition, ethyl chloride production; NOURYON chemicals (Former AKZONOVEL facility), produces cellulose ether, Bermocoll®, using cellulose and ethyl chloride as raw materials; RISE PROCESSUM (research institute), coordinates the circular case and support scientifically the project. Case achieved user quality requirements for the products. Challenges: scalability requires high investment, safety and environmental constrains for big plants. Environmental benefits avoiding fossil based raw materials and lower CO2 footprint by novel process are high. CC4 process is highly specific. Figure 1 shows the CC4 Circular Case in Sweden. Production chemicals from PPI fiber sludges, Figures 2 to 4 show the industrial scale pilot demonstration, and Tables 1 and 2 the CC Main Items, Key Factos and Lessons learnt.