Project: Absolute chlorine free system (ACF) for paper production using recycled fibers

The paper manufacturing is one of the major consumers of water that is mostly used for preparing the paper pulp. Their consumption of fresh water can seriously harm habitat near mills, reduce water levels necessary for fish, and alter water temperature as a critical environmental factor. The processes in paper production are usually performed at higher temperature due to the water circulation, affecting the changes in technological process. Water consumption is therefore an urgent problem from both an economic and ecological point of view. To overcome the problems with high water consumption, closed water circulation in production process is used and they show also some economic and ecological advantages. Normally, those waters shows also increased values of some crucial ecological parameters, such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Closed-loop operations could eliminate all toxicity to aquatic environments by eliminating all discharge into them. It is necessary in paper production to ensure sufficient paper retention to reduce losses and load of technological waters and thus affect the properties of final product, i.e. paper, paperboard or tissue._x000D_The use of recycled fibres as a raw material in the paper manufacturing presents several economic and environmental advantages and therefore the paper producers are interested to use higher percentages of recycled fibers. On the other hand recycled fibers needed various cleaning processes as well chemical additives to remove the contaminants from recycled fibers which influence higher pollution of the environment. Using a new advanced technology (CO2/O3/O2) for water treatment, instead of cleaning processes, chemical additives and all chlorine based chemicals is environmentally more acceptable, more effective and with better economic impact. CO2/O3/O2 technology enables use closed water circuit to reduce fresh water consumption. Advanced technology combination using CO2/O3/O2 is new while each separate technology is already known. There is no information about synergetic effect of such a combination. CO2 and O2 are natural gases of water and their use is completely harmful and environmentally friendly. O3 is toxic but in water decomposed into O2 in few minutes. O3 and O2 are good oxidising agents and they are known to be excellent for detoxification of waters as well for removing BOD and COD (<60%). O3 is also known to replace chlorine based chemicals by conventional paper bleaching processes. CO2 is known to reduce water hardness (reduce calcium ions) as well the microbiological activity._x000D_Experimental work will be performed in real tissue paper manufacture (Gomà-Camps). In this project, an influence of introduction of a new advanced technology (CO2/O3/O2) into tissue paper production line and increased share of recycled fibres (more than 50%), on some crucial process parameters, such as pH value, total hardness, m-alkalinity, COD, retention, consistency, dewatering time, microbiological activity and bleaching effect, will be investigated. An improvement and eventual disadvantages of introduced CO2/O3/O2 will be analysed and discussed. The CO goal of the project is to reduce consumption of chemicals, fresh water consumption and to bleach pulp without chlorine. The aim is also to install proper installation into an existing production line in Gomà-Camps that will be useful for most of the paper manufacturing._x000D_The consortium consist of three companies, ie. IOS, Messer and Gomà-Camps. IOS is the CO participant and they are responsible for the leading the project and COly for the measurements and analytical part of the project. IOS is also responsible for research part. Messer is COly responsible for installation the system into existent production line and Gomà-Camps is more than 200 years old tissue paper manufacture, where all measurements will be performed.

Acronym	ACF system (Reference Number: 6461)
Duration	01/09/2011 - 31/08/2014
Project Topic	Project is dealing with new advanced technology (CO2/O3/O2) for water treatment in the paper industry,which will be more effective with better economic and ecological impact.We will develop closed water circuit with absolute chlorine free technological process and lower amount of chemical additivies
Project Results (after finalisation)	In general experimental investigations have shown that new advanced technology applying different gasses, such as CO2/O3/O2 is efficient, but with certain limitations and origin of the paper pulp wastewater._x000D_CO2 has been useful to treat the water in order to control the scaling. Moreover, it as been useful to improve the sludge drainage._x000D_Two locations in the paper production line,for gas dosing seem to be appropriate: _x000D_(a) CO2 into the process water before showers and vacuum system, where fresh water (optionally) and anti-scaling auxiliaries are dosed;_x000D_(b) CO2 into the sludge, before sludge dewatering system; _x000D_With introduction of CO2 into paper pulp, mineral acids which are commonly used in paper industry as neutralizing agents could be successfully replaced. Also instead of biocides CO2 can be also successfully used for reduction of microorganisms._x000D__x000D_The combined experiments (O2/O3) decrease the COD content and bacteria but are from the economical point of view less appropriate in comparison to ozonation (O3) alone. _x000D__x000D_For ozonation (O3) treatment alone, the results shows that O3 can reduce the COD content at the outlet of the Waste Water Treatment Plant and valid to close the water circuit if this is integrated with a tertiary treatment (e.g. ultrafiltration stage)._x000D_With introduction of O3 as oxidizing agents, chemicals as well chlorine can be partly removed. Therefore the consumption of chemicals will be lower as well the water will be less polluted._x000D__x000D_The results showed that the combination of gases CO2/O3 is the most effective combination for waste water and sludge treatment in the paper industry. The CO contribution and advantage of proposed treatment is that it does not produce additional waste, while it results in treated water of quality, suitable for reuse in technological process and in that way it positively impacts at ecological and economical level. _x000D_
Network	Eurostars
Call	Eurostars Cut-Off 6

Project partner

Number	Name	Role	Country
3	Gomà-Camps S.A.U	Partner	Spain
3	Inštitut za okoljevarstvo in senzorje, d.o.o./Institute for environmental protection and sensors, Ltd.	Coordinator	Slovenia
3	Messer Ibérica de Gases S.A.U.	Partner	Spain