With this post I continue the cycle ( one , second ) of articles devoted to waste recycling technologies. The next step is food waste, which can be used in the creation of various new materials. Today I will tell you about an interesting technology for the production of chipboard (chipboard) using bio-glue based on molasses and milk whey. The method developed in Tomsk is based on the process of developing an adhesive base with a specialized strain of microorganisms, and the biotechnology of obtaining an adhesive base itself makes it possible to create a chipboard without the use of toxic formaldehyde resin. At the same time, the price of bio-glue is quite competitive, and ecological chipboard can be obtained practically without changing the usual production technology – after all, the new material has passed the most stringent and serious technical tests. Chemistry and life … I am sure that among the readers there are many specialists in one way or another connected with chemistry and chemical production. Indeed, modern advances in the creation of new materials and unique compounds are impressive. However, in addition to the rapid development of standard chemical technologies, the direction of “green” chemistry is now actively developing . Especially in conjunction with advances in biotechnology. New materials are entering the arena, the production and use of which minimally affects the environment. Ecology in a broad sense – from idea and production – to use and subsequent disposal. But against this background, there are many technologies that have stalled in their development. These include a variety of materials and substances that use phenol-containing compounds and resins. If for specialized industrial materials (polymers, varnishes, adhesives, textolite, getinax, etc.) you cannot do without them, then some materials for household applications can already be made without using such hazardous toxic compounds. First of all, in the production of furniture – after all, most of the budget cabinets, tables, office furniture are made of chipboard. Even in the State Duma, not so long ago, a scandal erupted, due to the fact that in the offices of parliamentarians, the concentration of formaldehyde resin vapors exceeds the MPC several times.
Here is a short (45 sec) video
What can we say about schools, kindergartens and other budgetary institutions, where furniture is supplied at the lowest prices, so its quality and environmental friendliness leaves much to be desired. I think many of you are now reading this article at a table where formaldehyde emissions continue – after all, this process takes about 4 years until the formaldehyde concentration becomes close to the MPC. This is due to the fact that during the production of chipboard it is not possible to completely bind the resin during pressing and uncured phenol-formaldehyde resin can contain up to 11% free phenol . And this is a very dangerous trend. After all, formaldehyde resins are recognized as the strongest carcinogens that cause allergies, metabolic disorders, and the most formidable consequence for a person can be the development of cancer. This danger is understood by Western manufacturers, therefore, in the production of chipboard, it is mandatory to cover with protective films (in the figure on the left) directly at the production site, but this significantly increases the cost of the final product. Unfortunately, most Russian manufacturers do not do this.
Although (by and large) this also does not save the situation. Packed in this way, the resin all remains in the stove and can be much more dangerous.
How is chipboard made?
Let’s talk a little about chipboard production. In fact, the technology is quite simple and well established in many countries. Raw materials (wood, waste wood processing) are crushed into dust, dried, mixed with formaldehyde resin and wax. Then the board is formed and it is pre-pressed at a certain temperature for some time. Technological modes of pressing depend on the thickness of the board, the quality of the feedstock and the concentration of resin.
If there is little resin, pressing is much worse and longer. This leads to significant energy costs and equipment wear. Therefore, resins are sometimes not spared. The pre-formed slabs are subjected to final pressing on a finishing powerful press. The finished slab is cut to size and sent to a ventilated warehouse for weathering for several days. It is prohibited to ship fresh slabs. It is extremely smelly and dangerous. Chipboard production is not environmentally friendly. Talking about the good health of workers in such industries is also not necessary. Although there is a nice video of the chipboard production process in the USA, it was shot very beautifully, in which important points are neatly missed and you will not see a single worker in the board final forming workshop. Everything is automated! Which, in principle, is the most correct for such industries. Alternatives and Prospects As you can imagine, particleboard production is not that difficult. If we imagine the situation that the formaldehyde adhesive base will be replaced by another one, then without changing the technological cycle, the board can be made absolutely environmentally friendly. However, the requirements for the replaced adhesive composition must clearly meet all technological requirements, as is the case with formaldehyde resin. That is, the glue should be the same (as close as possible) in different characteristics – consistency, adhesive ability, density, viscosity, pH, etc. And the most important thing is to be competitive in price. Biotechnologists from Tomsk managed to create such a substance. The substance was obtained as a result of microbiological studies of special strains of microorganisms, which were subsequently studied and described. After research on safety and absence of pathogenicity, the strain was deposited in the All-Russian Collection of Industrial Microorganisms (FSUE GosNII Genetics).
The approximate essence of the technology is as follows. In a special reactor at a temperature of 22 gr. Wastes from the food production of sugar – molasses and cheese whey are loaded. Molasses is the basis of glue, serum is a source of trace elements for the reproduction of microorganisms. A strain of microorganisms is added and within 2 days the biomass of bacteria produces an adhesive substance – destran . It is a complex polysaccharide with a huge molecular weight.
After the completion of the laboratory stage of R&D (with the support, by the way, of the very respected Bortnik Foundation ), the stage of creating a semi-industrial reactor for the production of bio-glue was started, which was successfully completed with the creation of a pilot batch of bio-glue for industrial testing at one of the particle board plants. The figure shows a scheme for obtaining bio-glue.
The tests of the adhesive at an industrial enterprise were successful. Samples of particle board were obtained and tests of the new material were carried out in accordance with GOST RF 10632-2007. New slabs comply with GOST, and even surpass it in some parameters. There were some differences. In particular, the slabs were slightly darker than usual. At the moment of pressing the plates in production, the smell of fresh baked goods began to spread, like in a bakery. And the workers immediately began to say that scientists had come again and would bake pies. Rospotrebnadzor checked the air quality and did not identify any dangers, while the concentration of formaldehyde vapors in the workshop dropped 80 times compared to standard production. Also, the finished slabs are not subjected to microbiological insemination, since they are not hydroscopic and retain low humidity throughout the entire period of human operation.
Test results of plates and technological drains of production
Disposal of food waste is also important in this technology. In particular, whey is the real scourge of dairy production. Despite the fact that many very useful and valuable substances, for example, albumin, are dissolved in this product, the processing of whey is an extremely difficult process. So many dairies are dumping whey down the drain, paying hefty environmental fines in the process. Draining the whey is dangerous and can cause serious biological contamination. The production of bio-glue for chipboard would reduce the environmental burden of dairy production, thereby increasing the production culture and the environmental situation. The bio-glue obtained in Tomsk can also be used for the production of wood pellets, fabrics, and various fertilizers. As for the chipboard plate, it retains its environmental friendliness for the entire period of its operation, and its disposal is not a problem. When it gets into the ground, the slab is destroyed by soil microorganisms within several months, turning into fertilizer. In turn, a formaldehyde plate is toxic for microorganisms, therefore it is difficult for them to utilize it. Technology Prospects At the moment, the project is at the stage of readiness for industrial implementation. Until recent political events, foreign companies operating in the market for the production of environmentally friendly materials showed serious interest in this technology. But these contacts were abruptly terminated. It is difficult to assess the prospects for the development of this technology in Russia now, but the authors of the technology hope that there may be serious investors who will not let another interesting Russian technology fall on the shelf. One way or another, as a popularizer of science and technology, I cannot remain indifferent. I am ready to answer your questions and comments, and if you have any questions that I cannot answer, I will hand them over personally to the team implementing this interesting project.