BRUSSELS, Feb. 13, 2012 (RISI) -Dr Salah El Siddique Awadel Karim has a background in chemical engineering with emphasis on pulp and paper science and technology. Following several years of teaching at the University of British Colombia, Canada and work with a number of Canadian biotechnology oriented companies he is now based in Sudan as a freelance pulp and paper expert.
Dr Awadel-Karim has invented a new repulping technology called "System and Method for Repulping of Paper Products and Improvement of Water Quality with Dipolar Solvents and Recovery". The invention has been registered in Canada, United States, and internationally. In 2009 the technology was patented by the World Intellectual Property Organization (WIPO).
Dr Awadel-Karim has already designed a project for developing a prinitng/writing paper mill using waste paper, which is entirely based on the technology which he says is in line with climate change issues, friendly environment and CDM criteria. Furthermore this project may have a significant impact on the social development of poor communities because it will open up remarkable employment opportunities.
Dr. Awedel Karim earned a gold medal in the 3rd International Invention Fair of the Middle East
In November 2010 Dr Awedel-Karim was awarded a Gold Medal in the 3rd International Invention Fair of Middle East (IIFME), Kuwait, Kuwait State.
Dr Awadel Karim has carried out substantial consultancy work at mills in Europe and the Middle East and is currently a partner with Cartoneel Printing and Packaging Company Khartoum, Sudan, in a carton project (flute, test liner and kraft liner) from waste paper. The project is now in the establishment stage. Middle East Paper Co. (MEPCO), Jeddah, Saudi Arabia is also currently using the technology at a commercial scale in its mill.
The technology:System and Method for Repulping of Paper Products and Improvement of Water Quality with Dipolar Solvents and Recovery
PPI: Can you first of all tell us why you think this technology is needed in the paper industry?
Awadel-Karim: I believe dipolar aprotic solvents (DAS) technology, is crucial for the paper industry in particular at this time because the paper industry in general and recycled paper in particular have recently suffered a hard time in generating rewarding returns. This is because conventional repulping technology that is used worldwide in the recycled industry suffers a number of shortcomings. These short comings include low productivity, high production cost, inferior fiber quality and environmental concerns. I believe the DAS technology eliminates all these shortcomings. It is also noteworthy to mention that DAS technology is a multifold climate change related benefits.
*DAS stands for Dipolar Aprotic Solvents family. This family includes dimethylformamide (DMF), dimethylactamide (DMA), dimethylsulfoxide (DMSO), hexamethylphosphorc triamide (HMPT), acetone, and pyridine. These compounds have noticeable effect on hydrogen bonding.
PPI: Can you tell us how the technology actually works?
This technology is designed to provide an enhanced method of repulping paper and improving water quality with a dipolar solvent. This method addresses two parts: first with respect to the repulping of cellulosic material and second with respect to the water quality improvement.
- For the enhancement of the cellulosic material, DAS repulping is capable of offering flexible and responsive cellulose with open hydrogen bond packing (i.e., no less than virgin pulp).
- The primary water quality improvement objects are to increase its reactivity, solvent capacity, carrying efficiency and microbiological stability. This is achieved through the interaction of a dipolar aprotic solvent with the hydroxyl groups of the cellulosic material and offering cellulose with attenuated hydrogen bonds. On the other hand, this dipolar aprotic solvent is capable of restructuring water hydrogen bonding system by offering reactive water with superior qualities characterized by possessing ice crystal-like and small water molecule clusters (six water molecule clusters instead of 400-600 water molecule clusters) with weaken hydrogen bonds.
Also, it is of importance to point out that this invention is designed to work on all types of recycled papers including mixed office waste (MOW), old magazines (OMG), old newspapers (ONP), old corrugated containers (OCC), etc. Thus, it is suitable for production of various end use papers such as printing, writing, newsprint, corrugating, test liner, tissue paper.
What are the benefits/savings/improvements to the production at the mill?
- With regards to DAS technology benefits, as discussed earlier the benefits lie in two parts:
Part 1: Repulping and pulp enhancement
1.High yield of recovered pulp fibers with considerable fiber flexibility can be attained by the effectively uniform interaction of dipolar solvent with both amorphous and crystalline cellulose, i.e., effective breakdown of interfibre bonding of the cellulosic material;
2. Ease of defibrillation and recovery of fibers with attenuated H-bonds, i.e., accessible cellulose;
3. Fibers can be recycled continuously due to open hydrogen bond packing; the recovered fibers are continuously recyclable using the method of the present invention, as the fibers are always in a comfortable H-bonding position. The system and method of this part of invention is thus compatible with sustainable development principles that aim at a rational and effective use of renewable resources, while providing a significant increase in industrial revenue.
4. Dissolution-hydration of hemicellulose (e.g. surface adsorbed xylans) and better degree of hemicellulose retention;
5. Ease of detachment of additives, adhesives, and ink particles due to greater specific molecular surface area exposure to de-additive, de-adhesive, deinking reactions.
6. Energy savings by reduction in other operations (e.g., kneading, soaking, deinking);
7. Ease of bleaching, i.e., greater exposed surface area of fibers for reaction;
8. Better sheet strength properties: The tensile strength, burst strength, stretch and smoothness of paper sheets prepared from the re-pulpled material are improved due to the flexibility of the fibers and the increased amount of hemicellulose attained by the method and system. The flexibility of the fibers and the increased amount of hemicellulose retained by the fibers are directly proportional to the weakening of the hydrogen bonds in the cellulose. The optimizing loops are thus both easy and important to implement for a given repulpable material.
9. Enhanced paper machine operation;
10. Ease of draining; less fines for blocking screens;
11. Smoother paper sheets from re-pulpled material due to fibers being flexible and comfortably in pressed position; no fluffiness on sheets due to no stiff fibers sticking out;
12. Environmentally benign.
Part 2: water quality improvement
1. Increased fibrous material hydration capacity through water-water weaker hydrogen bonds and smaller water molecule clusters interaction with cellulosic material, i.e., better interfiber bonding.
2. Ease of detachment of adhesives, additives and ink particles due to high dissolving power quality of dipolar aprotic solvent treated water (i.e., dissolution of extraneous substances).
3. Improved fibrous mass transfer due to high dissolving quality and greater carrying efficacy of aprotic solvent-water system.
4. Lesser sludge load due to microbiological stability of water, i.e., highly tetrahedral lattice water and small water clusters with no free oxygen for bacteria and enzymes to grow and proliferate.
5. Limited use of biocides.
6. Enhanced fibrous material mixing, i.e., uniform defibration due to lower surface tension, greater carrying efficiency and increased dissolving power of aprotic solvent water.
7. Limitation in the use of sheet strength and sizing agents;
8. Reduced water, electrical and chemical consumption.
- With respect to the savings, the implementation ofDAS technology (invention) for repulping suits both developed and developing countries. Unlike what is happening in the neutral and alkaline repulping methods, the invention (new solvent repulping) is designed to provide an enhanced method of repulping paper and improving water quality with dipolar solvents and recovery and these result in remarkable savings (22% savings, 2007). The considerable savings make both running and newly established mills remarkably viable.
- Concerning the improvements in mill production,DAS technology is capable of delivering high productivity, low production cost, better paper quality and a benign environment.
Will it make any noticeable difference to the carbon footprint at a mill?
Yes, the preposition value of DAS technology includes the reduction of carbon footprint through: forest conservation, reduction of emission, provision of reactive water, reduction of chemical use and it reduces energy consumption. In addition it reduces greenhouse gas (GHG) emissions more than conventional recycling.
How does/will it affect the bottom line in terms of increased profitability? (any case study examples?)
The technology will enable high pulp yield with zero pulp rejects. Also, productivity can be increased by improving paper machine runnability because DAS technology enhances the stretch parameter of the produced paper (vertical increase). In addition, the energy and water consumption are reduced because there is no further technological treatment of pulp rejects and the detachment of ink particles adhesives and additives takes place in the hydropulper. Thus, there is less effort needed to deink and clean. Moreover, DAS technology offers industrial water with superior qualities; increased hydration power, greater dissolving ability, increased carrying efficiency and better microbiological stability. Therefore, there is minimum cost for sludge treatment. Last but not least, through the application of DAS technology, only one dipolar aprotic solvent is used in the repulping process which is less expensive when compared with the total cost of chemicals that are usually used in conventional methods. This profitability is illustrated in Fig. 1 and Table 1. The comparison between production cost of one ton manufactured by conventional method in an Indian mill and new technology was made in 2007.
Table 1 - A comparison between conventional and new technology production cost
|Total cost comparison
||New tech %
||Cost ew method
|Water /cubic meter per ton
|Productivity increase by fiber savings
|Productivity increse by machine runnability
|Net saving percentage
Table 2 - A comparison of physical properties of handsheets produced from conventional and new solvent repulping (NLK-Econotech)
||New solvent repulping
|Basis weight, conditioned
|Tensile energy absorption
|Brightness ISO, top
|Brightness ISO, bottom
Does it improve the quality of the final product?
DAS technology offers reactive cellulose with open hydrogen bond packing (i.e., accessible cellulose), lower curl and kink indices, and fibers with high retention of microfibers (<0.2 mm%). Thus, such characteristics remarkably improve the final product quality.
Has there been any Beta testing? If so, what are the results so far?
DAS technology has been tested in Econotech independent lab, Vancouver, Canada. The results confirmed that all the physical properties are better than those of the conventional technology, Table 2.
As illustrated, even at a higher freeness level, there was an increase in all the strength properties. There was also an increase in the final brightness. Most importantly that these results are repeatable under similar conditions (Econotech independent lab).
How easy is it to apply the new technology, ie: does it involve a pulping/PM shut down? Does it involve the installation of any dedicated machinery? Does the application involve a lot of training?
DAS chemical is a direct replacement for the chemicals in the conventional methods with no changes to capital equipment or the actual process itself other than swapping in the DAS chemical.
Thus the application of DAS technology does not require a machine shutdown or lots of training. However, the DAS technology requires a special course of application.
Can you give us an idea of cost, and if not, could you give an idea on the return on investment involved?
All feasibility studies using DAS technology as a repulping method confirm through payback period, IRR, NPV and other economical parameters, the viability of the business which will certainly encourage the investors. On the other hand, the DAS technology is in line with climate change requirements and it contributes positively to the emission reduction, clean and green technology adoption.
Can the technology be viewed in action anywhere?
The ongoing negotiations with various countries such as China, India, Saudi Arabia, Kenya and Kuwait are good evidence for the technology workability, efficiency and future diffusion. Factually, DAS technology is a real innovation and it will play a revolutionary role in pulp and paper industry worldwide.