WO2018151693A1

WO2018151693A1 - Green mdf production technique from sustainable source and energy

Info

Publication number: WO2018151693A1
Application number: PCT/TR2017/050409
Authority: WO
Inventors: Yusuf POLAT; Harun POLAT; Ahmet DALGIN
Original assignee: Polkar Orman Ürünleri̇ Ve Enerji̇ A.Ş
Priority date: 2017-02-15
Filing date: 2017-08-26
Publication date: 2018-08-23

Abstract

Here it is described how the renewable MDF board production technique can be brought into existence without causing any discomfort on the environment, health and commercial acquisition. This technique is relying on a basic principle which is supplying the wood raw material, resin and energy from renewable sources. The realisation of the Green MDF production technique is possible by the preference of the right raw material, the choice of resin without any harmful effect on health and the application of Cogen-w which is a combined power and energy generation procedure.

Description

GREEN MDF PRODUCTION TECHNIQUE FROM SUSTAINABLE SOURCE AND ENERGY

Despite countless technological developments and scientific progress until today realised from the invention of fire, wheel and writing mankind could not achieve to create artificial living conditions yet which is to be alternative to the natural life. Although scientific studies performed to reach this target none of them has attained a promising phase. On the other hand other philosophical debate issue is also that how the potential trial could be reliable, which promises success for the future. This is the reason why there is no alternative other than using industrial production models which supports the unity and sustainability of the life cycle while meeting the demand of the contemporary society at all aspects. Though the inability to grow up such an industrial production model based on this scope comes up as indepent negative factors each other like contamination of soil, air, water and culture, their reflection to the life on earth occurs with very destructive effect called as " global warming".

The words Renewable, Sustainable and Green are the key words for a 100 % environmentalist MDF product and its production techniques and they are substituting to each other.

Likewise the expression formats of Cogen-w and CHP-w are abbreviations symbolizing the

Cogeneration-w energy generation system . Cogeneration-w is containing a different patent application which has been applied to your organisation by the file number 2016/07119-14937.

The stages of the traditional MDF wood based board production and the review of its energy concept; wood and branches are broken into small pieces,

crumbled wood pieces are converted to fibers by cutting them as thin layers in the grinder, fibers are steamed,

Urea formaldehyd resin with E2 or El standard is sprayed to the steamed fibers . Even resin equivalent to E3 norm is preferred in some countries due to its low cost,

• These fibers are dried until they attain 12 % standard moisture content. The 12 % standard moisture content is maintained in order to transmit heat to the interior area which has no direct touch with the press surface. This drying process is realised by hot air flow, • At the end of the drying process steam and fibers are separated by the air separator from each other,

• Fibers accumulated in the bunker are layed and the preliminary pressing is done,

• After the pre-pressing the fiber mass called fiber mat is pressed under high pressure and temperature,

• Following a retention period for the M DF boards the process is finalised by sanding and

dimensioning . MDF boards are constituted by four main components which are wood, resin, energy and technological value added.

• Along this process the power demand of the system is supplied from the grid,

• All cutting wastes and sanding dusts obtained through the conversion of wood branches to fibres and the dimensioning of M DF boards are burned in the boiler to generate the heat energy needed for the production line. • The boiler and hot oil boiler are put together like one is packed inside another. Steam is generated by the enthalpy of the hot oil. Likewise, the heat transfer to the whole system is done through the transmission of the hot oil. As the hot oil should move through the whole system at high speed and uninterrupted, there is the necessity to install high capacity circulation pumps in the system. Any additional pump in the system causes to increase the power consumption.

• In the MDF manufacturing tecnology and production systems until now there is no approach developed intended for dominating the energy efficiency to the whole system until now. Similarly there is no structuring in any stage of the production to support to any energy recovery or to operate to energy more effective. For this reason we can say that there is no study performed until now to audit the whole process flow like any attempt to initiate the reduction of "carbon footprint".

On the contrary it is possible to realise a 100 % environmentalist MDF board production at a reduced cost level compared to the M DF board production in conventional data of quidance and way. This can be accomplished through the right raw material choice in regard to protection of the forests, unusage of emission free resins which has carcinogenic effect, supply of the whole energy demand including power from renewable biomass fuel, using steam instead of hot oil for heat transfer and a general and comprehesive control system with an integrated structural formulation to manage all these subsystems and to check to the energy efficiency at all phases of the production. If we may summarize , it is possible to realise 100 % green, renewable environmentally friendly MDF board production without carcinogenic effect by using the right method and a suitable energy control mechanism.

Except that thin diameter coppices and unqualified logs (tree breeding) MDF/HDF wood-based boards (Medium/High Density Fiber Board) are made by fibers obtained also from the superflous branches broken to planted tree pruning and the sorted logs on the verge of being timber. In accordance with their qualification these kind of raw material sources to which the fiber is obtained do not cause to any negative effect regarding the sustainability of the forestry. Unlikely gaining of qualification of a forest depends on its continous rehabilitation. This is possible only with the planned pruning on the tree body and the dilution method of more than one coppices trying to grow from the same root in the way of being shoot forth. The woody structures provided with fibers are the materials in the form of wood branch which is unqualified, fast renewable and at low value, hence what is reqired to remove regularly from the forest region. As the removal of these materials from the forest is a vitial process which renders possible to enable the tree main body to be qualified and the forest to be preservable against fire hazard and inspect pests etc. The sufficient and qualified log supply to meet the demand of the carpentry and wood processing industry is possible only by pruning the planted trees regularly according to a good planning. Trees that are pruned regularly grow up not only at an accelerated speed, but also comprising of a lot of number of branches accordingly. As a result of this planned pruning process the volume of this renewable raw material source grows up at geometrical progression and it becomes abundant and so more abundant gradually. So this will result in one hand uninterrupted and sustainable supply of this kind of wood material, on the other hand the cost price to turn to bearish prospect in the market.

Industrial wood-based boards that we know under the abbreviations MDF/HDF are produced when the fibers obtained from wood branch species etc. are pressed to each other under high pressure. Different types of resins are available with diverse structural properties which are activated under pressure and temperature and ensuring the adhesion of the fibers to each other. The conventional resins with fomaldehyde basis are the most common used group although these cause to emissions. The emission is an uninterrupted process continuing in the wood-based board along the chemical life of the resin . The same is valid even for the resins proper to the EO standard with the lowest emission group, according to the European Norm ranking from the highest emission value to the lowest with E2, El and EO respectively. Defined in other words the chemical behaviour of the formaldehyde based resins differs to each other in the point inducing to more or less emission value. These resins derived from structurally limited and unsustainable sources such as natural gas and oil are under strict surveillance in many countries due to their emission effect. Even in some countries their usage is forbidden definitely. Due to the carcinogenic impact on the human metabolism the resistance against the usage of formaldehyde component resins is growing continually in parallel to the consciousness of the society. Especially, in Canada and USA the transition to the formaldehyde free resins is realised with a rapid and strong trend. We can aggregate no formaldehyde added resins which are alternatives to the formaldehyde based resins under three main groups;

• Protein-based adhesives obtained from soya bean and slaughterhouse wastes like blood and bones,

• Adhesives called as PMDI (Isocyanate)

· Adhesives called as PVA (Polyvinyl Acetate)

The most widely used formaldehyde component resins in the MDF production are processed at the highest curing temperature range compared to the other resin types as mentioned above. This highest level curing temperature means the acceptance of the superfluous heat energy consumption. On the other hand the completion of the curing of the formaldehyde-based resin is realised after the moisture in the pressed material is converted to steam and leaves the medium completely. However, the reaction process which is continuing along the curing process is not experienced as the same for all resins . The speed and type of the chemical reaction is related to the moisture content in the material and it also depends on the degree of any chemical connection between the resin and moisture . The relation created between resin and moisture is reducing the standard moisture content which should be removed from the medium by evaporation. This is resulting in completion of the curing process in a shorter time and the increase of the board output per unit time. Briefly explained, there are two consequential main issues which are resulted from long pressing time affected by the preference of the urea formaldehyde resin. These are capacity loss and superfluous energy consumption. The sole benefit of the urea formaldehyde resin is its cost advantage at first sight. However, it is possible to increase the board output by decreasing the pressing time with the usage of alternative resins, accomplishing energy saving and using this saving to generate renewable power , if we may define this multivariable equation properly as it will be studied in more details below. In summary the production process related part of the renewable green MDF production technology is depending mainly to the formulation of this alternative equation. Although the excess energy consumed in the press of a traditional plant which can generate its whole heat and steam demand using its own biomass wastes may be evaluated as insignificant, the energy reduction realised by the application of the Cogeneration-w system in the same plant will be meaningful. The reduction of the heat amount which is allocated to the press will result in the increase of the heat allocated for the steam generation and the increase of the renewable power consequently.

The main reason of the preference of urea formaldehyde resin in the MDF board production is its low cost advantage. For the sake of this cost saving the operators are granting the consumption of high heat and time in the press. Regardless of the effects on the environment and health, at the cost of consumption of superfluous heat, the preference of the urea formaldehyde resin in order to utilize to the relative low cost advantage can be simply appeared as a right commercial trend in its integrity, but alternately when a no formaldehyde added resin centered functional equation structure can be defined which is comparable with this simple equation the green MDF production theory is gaining a concrete meaning within the commercial/economic frame by its increased applicability in practice. This functional equation is expressed by a formula where four different variables, using the excess heat which is left from the press process to generate renewable power by CHP-w procedure, the excess cost of no formaldehyde added resin, the heat saving in the press and the production gain per unit time, can be solved together.

Other actions and processes besides the definition of this multivariable equation required to create this 100 % environmentalist product which we call renewable-green MDF wood-based board is also involving the following topics; the definition of the raw material source, the conversion of the main share of this source to the raw material and the rest to the renewable power and the right choice of the other intermediate goods and auxilliary equipment. These issues will be handled in details in the following sentences.

We can observe that the economic advantage of the urea formaldehyde which seems to be attractive at the beginning will disappear after we solve this functional equation within the commercial frame. The stunning increase experienced in the production capacity and the gains of the energy efficiency is turning the indicator towards the preference to no formadehyde added resin alternative.

Biomass is the cleanest fuel known. Its waste gas is called as " Gold Powder". Biomass is dryed to use its total heat potential and so the heat value (HV) of the dried biomass is increased considerably compared to its equivalent with moisture. In parallel to its increased HV the carbon emission and ash values are lowered almost to the zero level. Plants are accumulating carbon through photosynthesis during their life. This accumulated carbon is released to the atmosphere by burning biomass. For this reason the carbon emission generated by biomass burning is neglected due to its natural cyclical effect. The main part of the clean and renewable biomass fuel is obtained during the fiber production through the processing of wooden forest materials used as main raw material of the MDF. The remaining part is provided with sanding waste and side cutting powder. Standard sized wood pieces are dried to the required moisture level and then these are adhered together by pressing them under high pressure in natural way. The new structure after this conversion is a new fuel composition called pellet. According to the type of boiler choice wood pellet can be also used as fuel.

The moisture level of the fuel and the type of the drying are two important factors to determine the calorific value. In addition one of the most important factors which is reducing the combustion efficiency is high moisture level. The heat value of the fuel reveals to increasing or decreasing linearly depending on its moisture content. Nevertheless , we can not avoid another important issue , if we intend to liberate the full heating value contained in the fuel. We have to prevent the escape of volatiles from the biomass material during the drying process. The first measure to ensure this is to keep the moisture level within the 50-60 % range at the start of chipping. Following this it will be possible to prevent the escape of volatiles to the atmosphere when the reduction of the moisture is done under a controlled process only. Besides using low moisture raw material also the long storage time of the chips or wastes at site is causing the spontaneous escape of volatiles from the material. To hinder this the observation of the moisture from the beginning on is crucial and the drying should be done in the drying kiln under strict control . Natural air/sun drying should be avoided definitely. A considerable high energy amount will be recovered as increase in heat Value, increase in combustion efficiencey and finally increase in renewable power generation, if proper techniques are applied. All in all the level of this recovered energy becomes higher than the energy needed for drying.

The conventional MDF plants are producing only the heat and steam required for their own production processes in their boiler-energy centers. They realise it using their own biomass process wastes. These wastes are burned in the boiler without any classification according to their structural type and size and even without any drying process, whereas most of these biomass wastes are obtained from MDF processes like these are grinded specially for burning in the boiler. If these well prepared biomass wastes could be fired after certain rehabilitation processes , we can see a very distinguished fuel combustion efficiency diagram. In the light of this efficiency diagram nearly the all power required for the MDF production can be generated independent from the grid, if the closed cycle thermodynamic system Cogeneration-w method and closed and semi closed energy management systems giving it functionality are applied together instead of the conventional energy generation and production systems applied in the existing M DF plants. In other words the M DF plant becomes the ability to meet its own heat and steam demand and the power demand by using its own biomass wastes only. So the plant has the chance to generate its own power demand at zero cost using a renewable source instead of consuming the power from unknown sources which has an unclear environmental impact level. With this feature a M DF plant can use the wood forest goods (wood branch) to produce its products at an industrial scale and in addition it contributes to the cyclic sustainability and unity of the natural, economic and social life by using the process wastes for renewable power generation. The most important contribution to the formation of the life cycle is taking placing not to interfere to the cyclical functioning and natural balance which has been founded over the billions years by the natural life itself, for the sake of meeting the demand of the social life...

The industrial production model which is supporting the unity and sustainability of the life cycle, using a raw material with % 100 renewable and recyclable character under natural conditions, producing the power and energy demand of the whole system by the wastes of this raw material can realise exactly this, when it is also supported intented for the same aim by other limited and comprehensive components like all other auxiliary supply, material and equipment besides the proper technology and so tecnique used in the production process. In the recent years such an industrial production model has been identified with the intention of the society to limit the interference to the natural life cycle or the call "reduce your carbon footprint" which is accepted as the measuring mechanism for this limitation. The renewable M DF production technique is developed as the result of the adaptation of the industrial production model as we determined framework here to the MDF production processes.

Heat transfer in a MDF plant is realised using a fluid material called oil which is a petroleum derivative . Heat required to generate steam and to heat the surface of the press is obtained through the enthalpy of the hot oil. The hot oil used for heat transfer is deteriorated in time due to the problems related to exposure to high temperature, wear and low circulation speed. The reduced fluidity of this oil will cause irreparable damages in the piping system, if the operation continues. That's why the used oil must be altered to new one in certain time intervals. With the capacity of production line comparatively what is essential to be altered to big amount of petroleum derivative this used oil, whatever the decision is made to bring it to use again, or to dispose it as waste, in both cases it should be converted first using a series of chemical processes. We are exposed to a strict control requirement and serious reponsibility including to risk due to the located classification of the used oil in the hazardous waste. From this point of view we are exposed to this high volume waste oil disposal problem especially in marginal cases where we have to adapt the process flow sheet to the shape of the land. In cases where the distance between the boiler/ heat center and the production process is increased meaningless according to the natural shape of the land, the volume of the oil content in circulation is increased correspondingly. This situation increases to the auditing responsibility of the public and public authority much more who is responsible for inspection on behalf of the public . On the contrary a MDF plant which is able to generate its own power demand by using the

Cogeneration-w system can utilize its excess steam in the hand as an alternative fluid to the conventional hot oil system in order to realise the heat transfer and transport. The only thing to do at this point is to decide to substitute steam to hot oil and to design the new structure and project accordingly. In other words steam is going to be assigned as working fluid to transport heat to the press, to heat the primary air circuit of the boiler, to process the resin, to heat up the boiler feedwater to 104° C and to supply the heat required for fuel and fiber drying.

In M DF plants where the heat transfer to the system is realised through hot oil transfer a

considerable amount of oil is circulated by electric driven pumps at high speed uninterrupted, whereas steam contains to sufficient kinetic energy at the extent of its saturation temperature to transport itself until the point where it release its whole energy by condensation. This property is allowing to save approx. 50 % power compared to the power consumption for the hot oil circulation. In exceptional cases where the distance between the boiler house and production plant is relatively long , the preference of steam will increase the power savings attractively. Another positive result caused by the use of steam instead of hot oil is the avoidance of a fluid like oil which is classified among hazardous wastes.

Use of steam as heat transfer fluid is causing a jumping effect for the renewable power capacity of the CHP-w. This effect is so impressive where the MDF plant can export a considerable amount of power to outside customers beyond meeting its own demand. The major reason of this surprisingly big transition is the allocation of the whole energy for steam production. The importance of this attainment will be understood better, if we remember that the conventional MDF plant is getting sustain to its operations by using purchased power from the grid generated by an unclear source input. Cogen-w will be used as power and energy generation system. Instead of converting the waste heat to power this method which we are expressing as reversible cogeneration or obversely cogeneration is functioning as a closed cycle thermodynamic concept where it uses to the full inner heat content in the boiler except for the unavoidable flue gas discharge in order to generate power first and the energy demanded in the production line is supplied at the required level as an extraction from the turbine in form of steam or liquid fluid.

The strong synergy arised by the right and efficient use of energy reveal itself with a considerable steep increase on the power output curve to induce. This stunning transition experienced in power generation is necessitating to own a conscious monitoring/auditing policy throughout the whole system and to handle the total energy demand of the production line depending on the power generation.

The behaviour of the Cogen-w method like a mechanism controlling to the energy generation at the same time is happening from its feature to centralize the boiler inner heat to generate superheated steam. Thanks to this specialty, the auditing of the energy amount which should be linked to the production line are also ensured as well as the measuring of the foreseen combustion efficiency and boiler efficiency. Along this process the turbine serves like a mechanism where the energy is sorted in itself according to its efficiency.

The controlling of the total system efficiency is at the energy production side ensured by closed circuit thermodynamic concept of CHP-w which gives priority to the power generation, at the consumption side as well by favour of the energy operating system which enables to the CHP-w functional. The feature of this operating system is its treatment to energy in gradual , alternate and cyclical mode within closed and semi-closed circuits . This stringent audit mechanism which is a spontaneous result of the systematic character of CHP-w increases to the power capacity up to the maximum possible level. The expression " reduce your carbon footprint" which became the symbol to pollute the nature at minimum rate without limiting the activities of the society has succeeded to reach an ever increasing number of people in the recent years while the global warming problem that is developing on account of the wasteful consumption of fossil fuels is becoming the black trouble of the world. Although it is a significant development compared to the past, this rate is presenting to a small share in the world population and coming forward as a feature which belongs to the societies at high development level where conscious consumers are living.

Besides the renewable power which you can mainly use in your own production line and sell a considerable amount left to the grid though not being as much used main part as, it is possible to produce a 100 % environmentalist and health friendly M DF product even at a reduced cost at commercial basis by using the green M DF production technique as described above. The first action to do it should be lay the customary methods and techniques on the table and to start to query immediately. However, it is not so easy to make this query under the market conditions where all parameters are accepted as right standards. It is especially more difficult due to the high cost of environmentalist products like no formaldehyde added resins at first sight or the widely accepted perception that these are expensive products. It is not a realistic expectation that these industrial companies may make such an attempt under market conditions where they are operating under severe competition and they attribute this competition to imitation of each other instead of preferring system efficiency and business blindness doesn't allow different viewpoints to flourish.

Actually, the public authority has conducted incentives to support the practise of Cogeneration in order to stimulate the industrial companies to establish energy efficiency policies though indirectly. Nevertheless Cogeneration could not cause the effect at the level as expected from it, beacuse the structure of Cogeneration does not permits to monitor the energy efficiency throughout the entire system and to produce appropriate policies under the light of these appraisals. In principal

Cogeneration produces to commendatory recycling solutions which express that the waste energy is not to be worried about it , not radical solutions pointing to how energy can be used more efficient . Further this is the reason why the efforts of the public authorities are failing to support the industrial companies which generate their own power in developing an energy policy through their

Cogeneration application. Even today there is no general system proposition in the world which has resolved how an energy policy can be brought into existence on a sectoral basis. Here CHP-w is the name of the system which is determining how this can be realised using which kind of methods . Under the circumstances where the pressures from the consumers remain limited and industrial companies hesitate to change to their current position in the prevealing market conditions, how can it be provided with the environment and health friendly renewable products to generalize by using an industrial production model which supports to the unity and sustainability of the life cycle More importantly, using which kind of incentive element could the commercial motivation to enable to succeeding this be placed into the mentality of the industrialist/ industry?

Cogen-w method has the motivation to create such a commercial stimulation due to its structure increasing the power capacity importantly. Set to work by the recognition of boilers in the industrial plants as power plants first of all instead of stoves causing waste heat leads us to two fundamental results. To maximize electricity output these are first to generate power using the whole heat available and then using the remaining-heat from it in the production line and second the necessity to possess a system-wide energy efficiency monitoring and evaluation policy whether you want it any more, or not.

The industrial companies will change their mind , when they can give up to evaluate the power only as a cost item which they can add up to the price of the goods like other cost items and realise that the real cost is not to produce it although they are able to do it . Just after that the monitoring of the energy at the plant basis and developing policies related to it will be possible. Otherwise this black trouble hazard occuring under the name "global warming" can drag our world to the edge of a terrible destruction, which is the sole place in the universe where life conditions are generated according to our knowledge. Unfortunately there is no recognition of the discources which include moral advises or wishes like "do not consume fossil fuels with high carbon emissions or support their usage" and developed towards the restriction of the global warming both in the eyes of consumers and producers . The deficiency of it will come to the daylight when the actual results of the global warming reality will be read carefully.

At least having been known of obvious results for the time being we are causing the real big damage to the nature by preferring nonrenewable fossil fuels for energy generation. Therefore, while meeting the whole demand of the society, the prerequisite of production with an industrial production model which is supporting the unity and sustainability of the life cycle is necessitating to own energy efficiency monitoring and evaluation of policy. The belief that the energy cost from all kind of fuel including to fossil fuels with high carbon emission can be added to the product price by using it uncontrolled only for the sake of production is to miss invisible part of the iceberg and it causes losses of all kinds. Cogen-w constitutes actually foundation to industrial production model which supports to the unity and sustainability of the life cycle by its structural features which uncovers the bottom of the iceberg. These features are;

Its considerable high amounts of power generation potential encourages the commercial stimulation of the industrialist/industry and so motivates them to use this model,

This commercial stimulation triggered by CHP-w pushes the company to own a total energy efficiency monitoring and evaluation of policy to earn more revenue generating power.

It evaluates the different effects of alternative raw materials on the total cost together with their effects on the energy efficiency and attains the total plant production efficiency.

Its conversion of the fuel-energy efficiency on behalf of power by mobilizing the idle power/electricity generation reduces the carbon emission level at a considerable rate.

Claims

S

The invention, it is the green M DF production technique from sustainable source and energy, its feature ; as raw material running wood branch forest-material forms with low cost input in fiber production, to increase the output per unit time , to save heat, to evaluate this saved- heat in renewable power generation, the preference no formaldehye added resin in the manufacturing, which does not has any negative effect on environment and living being, burning biomass wood processings residues following reduction to standart sized particle and drying in kiln dry under control, for heat transfer to main production line and relevant to all intermediate circuits, assigning to steam as fluid which requires power ( electrical energy) only in way back, by Cogen-w method which is a combined power and energy system more renewable power generation than that of required in the production line, at the same time using to Cogen-w as a mechanism which keeps total energy generation under control, keeping the total energy efficiency under control and measuring, while providing to demand of the society using an industrial model supporting to the unity and sustainability of the life cycle, is that consisting of the process steps above,

The invention, it is the first process step in the claim 1, its feature; that being uninterrupted sustainable and fast renewable with geometrical progression,

The invention, it is the second process step in the claim 1, its feature; that comprising of resin species which require to low curing temperature/ heat rate and/ or diminish to standart moisture level down to vapourize by joining to chemical bond to moisture for the completion of the reaction,

The invention, it is the thirth process step in the claim 1, its feature; that embodying burning volatiles in its structure that hold to calorific value high.

The invention, it is the fourth process step in the claim 1, its feature; that having got the kinetic energy of steam at the extent of its saturation temperature to transport itself to the point where it releases its whole energy by condensation.

6. The invention, it is the fifth process step in the claim 1, its feature; that using steam as fluid in heat transfer instead of hot oil.

7. The invention, it is the sixth process step in the claim 1, its feature; that accumulating the boiler inner heat in one hand by generating steam.

8. The invention, it is the seventh process step in the claim 1, its feature; that using to the closed circuit thermodynamic character of Cogen-w in the energy generation, as for that in the consumption the energy operation system that makes Cogen-w functional.

9. The invention, it is the eighth process step in the claim 1, its feature; that using to Cogen-w which is a combined power and energy generation method, in energy generation and measurement of total energy efficiency.