Objective The pulp and paper industry has a great potential to develop its operation into atruly ecocyclic production system. A higher degree of system closure of thepulping process leads to problems due to the accumulation of different substances. It is therefore necessary to introduce internal separation techniques which clean theliquid flow in the mill. Another issue of great importance is to solve the waterbalance in an reasonable way which means reuse of evaporator condensates. Theoverall objective in this project proposal is by new separation techniques findsolutions to 'bottlenecks' earlier identified in closed-loop manufacture of bleachedchemical pulp. The reach the main objective, the project is divided into four partswith their corresponding objectives :1. Reuse of condensates from the black liquor evaporation : Condensates from the black liquor evaporation have to be reused in a closed-loop process. The smell is a critical parameter in products used in food packages. Bad smell in process water can be transferred to pulp and paper. Consequently, the black liquor condensates need further treatment to remove the smell-creating substances. We intend to develop methods to produce washing water from condensates for use in the bleach plant when filtrates are recycled.2. Handling of accumulating inorganic elements : Inorganic non-process elements, NPE's, will accumulate in a closed-loop process and cause very severe negative effects such as scale, deposits, high content of inerts in lime cycle and negative effects in TCF-bleaching. NPE's such as Al, Si, P, Ca, Ba, Mn, etc can today only be purged in very limited ways or not sufficiently effective. We suggest a technology which enables these elements to be purged in a precipitation/separation-step from a flow of acidic or neutral bleach plant filtrate which would offer an alternative way to solve the water balance from the mill and at the same time purge accumulated substances. However, it is not yet known how a high increase of dry solids content in liquor affects the efficiency of NPE's precipitation and the separation of precipitate. This will be clarified.3. Handling of accumulating organic substances : We will develop and compare two alternative ways to achieve a tight internal closure of a bleaching stage possible - membrane filtration and biological treatment. Today we know that this type of integration of a bleaching stage usually result in high chemical consumptions and a lowered pulp brightness.4. Process integration of separation technologies : The different separation technologies studied in this project proposal will affect the water balances in a closed-loop mill when they are integrated into the process. The main objective is to study these consequences by mass balance calculations with simulation programme, e.g. MOPS, PULPSIM or GEMS. Changes in the water balance, scaling in the evaporation, and build up of organic substance in the bleach plant are examples of consequences which will be illustrated by an analysis of the whole process. Fields of science engineering and technologychemical engineeringseparation technologies Programme(s) FP4-FAIR - Specific research, technological development and demonstration programme in the field of agriculture and fisheries (including agro-industry, food technologies, forestry, aquaculture and rural development), 1994-1998 Topic(s) 1.3.2 - Wood products Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator S.T.F.I. EU contribution No data Address DROTTNING KRISTINAS VÄG, 61 - P.O. BOX 5604 114 86 STOCKHOLM Sweden See on map Total cost No data Participants (3) Sort alphabetically Sort by EU Contribution Expand all Collapse all CENTRE TECHNIQUE DE L'INDUSTRIE DES PAPIERS, CARTONS ET CELLULOSES France EU contribution No data Address DOMAINE UNIVERSITAIRE - B.P. 251 38044 GRENOBLE See on map Total cost No data OY KESKUSLABORATORIO Finland EU contribution No data Address P.O. BOX 70 02151 ESPOO See on map Total cost No data TECH-SEP S.A. France EU contribution No data Address CHEMIN DU PILON, 5 - SAINT MAURICE DE BEYNOST 01703 MIRIBEL See on map Total cost No data