Lignin pellets. Hydrolysis lignin Lignin granules

Lignin - what is it? Not everyone will be able to answer this question, but we will try to figure it out. Lignin is a substance that is part of absolutely all plants on Earth. In addition to it, it is also worth noting such useful components as cellulose and hemicellulose.

The main purpose of lignin is to ensure the tightness of the walls of vessels through which water and nutrients dissolved in it move. Lignin and cellulose, being together in cell walls, increase their strength. Not all plants have the same amount of this compound. Most of it is found in coniferous trees, approximately 40%, but in deciduous trees - only 25%.

Properties of lignin

This substance is dark yellow in color. It is practically insoluble in water and organic solvents. Lignin - what is it from a structural point of view? It will not be possible to answer this question unequivocally, since, being part of various plants, this substance may differ significantly in its structure.

When lignin decomposes, nutrient-rich humus is formed, which plays an important role in nature. Lignin is processed in the natural environment by an army of bacteria, fungi and some insects.

The main advantage of this substance is that there is no need to produce or mine it. Yes, this is almost impossible; lignin is so tightly bound to plant cells that its artificial separation is a complex process.

The lignin produced today is nothing more than ordinary waste from cellulose processing. In this case, a large mass of it is lost, but its chemical activity increases.

Methods for isolating lignin

The process of extracting this substance from wood is carried out for various purposes:

study of the properties of matter;
determination of the amount of lignin in various plants.

Methods for extracting a substance are selected depending on the purpose of its use. If further study is the goal, the isolation methods should have as little effect as possible on the structure and quality of lignin. Although there are practically no methods that would guarantee the receipt of a substance in an unchanged state.

Once isolated, lignin contains several impurities:

extractive substances yield insoluble compounds upon hydrolysis;
sugar humification products;
a mixture of difficult to hydrolyze polysaccharides.

The most suitable conditions for lignin isolation are those under which greatest number substances. In this case, lignin is obtained practically without impurities, and its small losses are observed.

The sulfuric acid method is considered the most common, but the hydrochloric acid method is used much less frequently due to the inconvenience of working with concentrated acid.

Varieties of lignin

The main source of lignin is the industrial production of cellulose. Different enterprises in this area may use different production technologies, therefore the lignin obtained in this way has different qualities and composition.

In the process of producing alkalis or sulfates, sulfate lignin is obtained, while in the production of acids - sulfite.

These types differ from each other not only in composition, but also in the method of disposal. Sulfate lignin is burned, and sulfite lignin is sent for storage in special storage facilities.

Hydrolytic lignin is produced at hydrolysis enterprises.

Properties of hydrolytic lignin

This is a powdery substance with a density of up to 1.45 g/cm³. Its color varies from light beige to various shades of brown. The lignin content in such a substance can range from 40 to 80%.

Hydrolytic lignin has toxic properties and high adsorption capacity, which is the basis for its use in medicine.

If a substance that becomes flammable when dried is sprayed, there may be a risk of explosion. When burned, dry lignin releases a fairly large amount of heat. Its ignition temperature is 195 degrees, and smoldering begins at a temperature of 185°C.

Production of lignin preparations

Lignin is isolated from wood in order to obtain its preparations for various studies. Let's consider the stages of lignin isolation:

grinding wood into sawdust and, in some cases, flour;
treatment with an alcohol-toluene mixture to get rid of extractives;
the use of acid catalysts that prevent lignin from becoming soluble.

The manufacturing process produces some soluble compounds which are precipitated, purified and dried to form a powder.

Applications of hydrolytic lignin

Despite the fact that this substance is quite difficult to recycle due to its complex nature and instability, we can list various industries where lignin is used. The use of the substance has the following directions:

production of fuel briquettes;
as boiler fuel;
production of reducing agents for certain metals and silicon;
filler in plastic production;
fuel gas production;
fertilizer production;
production of herbicides;
as a raw material for the production of phenol, acetic acid;
production of activated carbon;
as a sorbent for the purification of municipal and industrial wastewater;
production of medical products;
brick production and ceramic products.

Reasons for increasing demand for lignin

Hydrolytic lignin is an excellent fuel that, when burned, produces a large amount of energy. In addition, the raw materials for the production of such an energy resource are quite accessible and renewable.

The issue of producing alternative energy sources is currently relevant not only in our country, but throughout the world. There are a number of reasons for this, including the following:

Natural energy carriers - coal, oil and gas require the use of various costly methods for their extraction. This cannot but affect their constantly growing value.
Energy sources that are currently used are exhaustible natural resources, so a time will come when their reserves are practically used up.
The production of alternative energy sources is stimulated by the state in many countries.

Lignin as a fuel

Today, lignin is increasingly used as an alternative fuel. What is it and what does it look like?

The substance is sawdust with a moisture content of up to 70%, which varies in composition depending on the raw material. Their structure is very similar to which also has a large number of tiny pores. The properties of such a substance make it possible to subject it to briquetting and granulation. If you apply high pressure to such a briquette, it turns into a viscous plastic mass.

Granules made from such lignin have high heat transfer, but do not produce much smoke. and pellets are a high-quality material, when burned, a lot of heat is released, and there is practically no soot. From this we can conclude that lignin serves as an excellent raw material for the production of fuel in briquettes.

Use of lignin in powder form

This substance in powder form finds its use as an additive in the production of asphalt concrete. The use of hydrolytic lignin allows:

increase strength, water resistance and resistance to cracking;
save road construction materials;
significantly improve the environmental situation in places where waste is stored;
restore fertility to those lands that are used for dumps.

In the road industry, it is quite profitable to use lignin. Its properties are such that it can significantly improve the quality of the building material. In addition, lignin makes it possible to replace expensive additives.

Lignin derivatives

Derivatives of this substance are lignosulfonates, which are formed during the sulfite method of wood processing. Lignosulfonates have high activity, which allows them to find their application in various industries:

oil industry (regulate properties;
foundry (act as a binding material in mixtures);
concrete production;
construction industry (as emulsifiers in road emulsions);
raw materials for the production of vanillin;
agriculture (soil cultivation to prevent erosion).

Sulfate lignin has high density and chemical resistance. When dry it is a powder brown, which dissolves in ammonia, alkalis, ethylene glycol, dioxin.

Sulfate lignin is non-toxic, non-spraying and non-flammable. It is used:

as a plasticizer in the production of ceramic products and concrete;
as a raw material for the production of plastics and phenol-formaldehyde resins;
as a connecting link in the production of cardboard, wood and paper boards;
as an additive in the production of rubber and latexes.

Now it becomes clear how widely lignin is used. What it is now no one questions, since due to its qualities this substance is in great demand in the modern world.

Medicines based on lignin

As we have already found out, the use of hydrolytic lignin is also possible in the medical field. The following drugs based on it can be listed:

"Lignosorb" is prescribed for gastrointestinal diseases and food poisoning;
"Polifan" has the same recommendations for use;
"Polyphepan" brings relief from diarrhea and dysbacteriosis;
"Filtrum-STI";
"Entegnin."

Application of "Polyphepan"

Another name for this drug is hydrolytic lignin. It is produced in the form of granules, suspensions, powders and tablets. The drug is of plant origin, it is based on lignin. The instructions for use state that such a medicine is able to bind microorganisms well, as well as their waste products.

In addition, under the influence of the drug, toxic substances of various nature are neutralized: heavy metals, radioactive isotopes, ammonia. Hydrolytic lignin detoxifies the body and also has an antioxidant and hypolipidemic effect.

This is the extensive list of merits lignin has! The instructions also say that by taking this drug, you can compensate for the deficiency in the intestines that you are taking active participation during the digestion process, normalize microflora and increase immunity.

Indications for taking "Polyphepan" are:

A drug such as lignin has a fairly extensive list of indications. The instructions also note some contraindications:

hypersensitivity to the drug;
chronic constipation;
gastritis;
diabetes mellitus

In the process of taking lignin, there may be side effects: allergic reaction or constipation.

Methods of using the medicine and its dosage are determined by the doctor depending on the diagnosis and complexity of the condition. Lignin is usually prescribed for a week, but for some problems the duration of therapy can be increased to a month.

Ecology and lignin

This substance is formed in large quantities during the processing of cellulose. It is dumped in large dumps, which contribute to environmental pollution. In addition, cases of spontaneous combustion of lignin are not uncommon.

Today, the issue of using the substance as fuel is acute, since after its combustion a large amount of waste is generated that harms the environment. Lignin finds its application in many industries, so first of all it is important to solve the issue of environmental safety of the environment.

Traditionally, coniferous wood waste is used in the production of wood fuel pellets. However, coniferous wood is an expensive raw material, in demand in the woodworking industry, and its waste is used in a number of other industries. As a result, the resources of coniferous wood are constantly decreasing, and for the production of pellets it is necessary to use low-value and cheap hardwood, which does not find such wide application V industrial production like a conifer.

In relation to pellet production technology, the main difference between hardwood and coniferous species is the low lignin content: 14-25% versus 23-28%. The high temperature and pressure of pressing wood raw materials activate the lignin contained in its cells and bring it into a plastic state. Lignin acts in this process as an internal binder, ensuring the strength of the pellets. Granules made from hardwood are less durable due to the lower lignin content. And to achieve the required strength, various additives or steam treatment of raw materials are used, which will be discussed below.

Also, when producing pellets, the hardness of the wood matters. Harder deciduous wood is more difficult to press into pellets than coniferous wood; high loads are created on the equipment, especially on consumable parts - the matrix and press rollers. But the heat of combustion of some hardwoods, primarily beech and oak, is higher in comparison with this parameter of conifers.

To meet the ever-growing demand for high-quality wood pellets in Europe, hardwoods are increasingly being used for their production. The question is whether such granules comply with ENplus and DIN+ standards.

Active use of hardwood raw materials for the production of pellets would reduce tensions in the market for softwood waste, which is widely used in board production and other industries, which undoubtedly creates very high competition for pellet producers. However, the ash content in hardwood pellets is higher than in softwood pellets, and in most cases corresponds to the ENplus A2 standard (ash content no more than 1.5%). By the way, the change in new version The ENplus A2 standard prescribes an ash content of no more than 1.2% (EN ISO 17225-2). In the future, it is quite possible to further reduce the permissible ash content according to ENplus standards. However, all producers of so-called premium pellets (or household pellets, as they are commonly called in the EU), according to economic reasons They are trying to bring the characteristics of their products up to the ENplus A1 standard (their cost is higher than class A2 and industrial pellets). It is worth noting that the requests for ENplus A2 quality granules in Europe are minimal, since for small boiler houses or mini-thermal power plants, for which this standard was developed, industrial granules are quite suitable, the price of which is lower, production volumes are much higher, and they only differ ash content (up to 1.5%) and, indirectly, color value.

Research in Austria and Germany

To expand the knowledge base on the ash content of pellets made from hardwood, a series of research studies were carried out in Austria to evaluate the feasibility of using hardwood for the production of ENplus pellets. For the largest series of tests, birch, beech, oak and ash were chosen, since these species, along with conifers, are already used in the production of pellets in Austria and Germany. Using a special thermogravimetric analyzer TGA, more than 80 samples were examined for ash content at a temperature of 550°C according to the Austrian standard Önorm EN 14 775. It was found that the ash content of sapwood and other good hardwood timber does not exceed 0.7% (in some cases and when mixing different hardwoods reaches 1-1.5%), and in bark the maximum ash content is up to 10%. Additionally, samples of poplar wood were analyzed; the ash contents were similar.

According to statistics from the German Pellet Institute (DEPI), in Germany, since 2014, the use of hardwood wood has been recorded in the production of pellets, on average up to 10% of the total volume of raw materials (that is, 90% - coniferous, 10% - deciduous). Markus Mann, founder and director of the pellet plant Westerwälder Holzpellets GmbH in Langenbach (Upper Bavaria), experimented in his production with a mixture of 10-15% beech and birch wood and 85-90% coniferous wood. With this ratio, the resulting pellets had an ash content of less than 0.5% and fully complied with ENplus A1 standards. For pelletizing, a matrix with a pressing channel length of 39 mm was used, rather than the standard 45 mm used for coniferous species. To pelletize only beech sawdust, the pressing channel was shortened by another 10 mm - to 29 mm. As a result of experiments, it was found that poplar wood ash low temperature sintering, since poplar usually grows on sandy and clayey soils, its wood, and especially its bark, contains a lot of silicate compounds. This, by the way, is also typical for a number of other deciduous trees, in particular those artificially planted for protection from unfavorable natural and anthropogenic factors.

In this regard, we can mention the Russian company - CJSC AlT-BioT from the Krasnodar Territory, which in 2009 at the international exhibition Interpellets in Stuttgart presented pellets made from deciduous wood (ash, acacia, oak, beech, maple) obtained after sanitary felling of protective forest plantings in the area of the village of Pavlovskaya. With an ash content below 0.7%, the pellets had a high calorific value - 18 MJ/kg. The company's pellet plant was named "Victoria", investments in the enterprise amounted to 600 million rubles. Investor Alexander Dyachenko announced his intention to build at least 20 similar pellet plants in southern Russia by 2015.

The plant never reached its design capacity (10 tons per day, or 70 thousand tons per year), the maximum productivity of 7 tons per hour was achieved. Products were exported mainly to Europe. In two neighboring areas, boiler houses of several schools were converted to use pellets. The then Deputy Prime Minister Viktor Zubkov, who visited the enterprise in 2009, highly appreciated this project and especially the prospect of its replication in other regions of Russia. The author of the article, as part of a delegation that included representatives of a pellet buyer from the Netherlands, visited this pellet plant in 2010. The Dutch highly appreciated both the quality of the granules and the production. But, alas, that same year the plant was shut down, employees were fired, sibling investor Nikolai Dyachenko, head of the regional branch of Rosselkhozbank OJSC in the Krasnodar Territory, who financed the AlTBioTa project, was arrested, and the investor himself went on the run. But that's a completely different story.

Let us return, however, to Austria and Germany. Experts from the Austrian research association BioUP consider the main disadvantage of using hardwood for the production of pellets to be its high ash content compared to coniferous wood. Andreas Haider, a specialist at the Austrian Federal Forestry Research Center, explained that from deciduous wood it is possible to produce not only ENplus A2 and industrial class pellets, but also pellets that fully meet the ENplus A1 and DIN+ standards. It all depends on what part of the hardwood is used as raw material. For example, the ash content of poplar sapwood differs significantly from the ash content of the core of the trunk. The ash content also varies greatly depending on the time of felling and the quality of the soil, that is, on the growing zone of the tree. There is a lot of data on the content of ash substances in wood, but they differ even for the same species. It has been experimentally established that when absolutely dry wood is calcined in a crucible, the average ash residue ranges from 0.3 to 1.0%. Moreover, 10-25% of the residue dissolves in water, these are soda and potash (in the past it was obtained in industrial quantities from wood ash). The most important insoluble components of wood ash are lime and various salts magnesium and iron - make up 75-90%. Haider noticed that in the south of Europe, in the Balkans, especially in the republics former Yugoslavia- Croatia, Montenegro, Serbia and Bosnia and Herzegovina - there are a lot of deciduous trees in the forests. And neighboring Italy today ranks first in the European Union in terms of consumption of premium pellets: more than 3 million tons per year. The geographical location provides favorable conditions (logistics) for the export of pellets from these Balkan countries to Italy. For reference: in Germany, according to data at the beginning of 2018, in 2017, 98.9% of pellets were produced from coniferous wood, and only 1.1% from hardwood.

Research in Belarus and Russia

In 2012, at the Department of Chemical Wood Processing of the Belarusian State Technical University in Minsk, pellets were made in laboratory conditions from the main forest-forming species of the Republic of Belarus: birch, alder and pine. Granule samples were obtained at a pressing temperature of 110°C for 15 minutes. The humidity of the dried sawdust used for the study was 8-11%. The task was set to compare the physical and mechanical characteristics of the resulting granules: humidity, ash content, density, mechanical strength and lower calorific value. It has been established that the lower calorific value of pellets made from birch and alder wood is comparable to the lower calorific value of pine pellets (Table 1). But the ash content of hardwood pellets is 3.5 times higher than the ash content of softwood pellets. The tests carried out confirmed the fundamental possibility of producing pellets from softwood. In terms of ash content, they at least meet the standards for industrial wood pellets (up to 1.5%) and pellets of class ENplus A2. But pellets made from alder and birch wood are characterized by reduced mechanical strength (lower than the strength of pine pellets by 11 and 18%, respectively). To achieve the mechanical strength characteristic of pellets made from softwood, pre-treatment of hardwood raw materials with saturated steam is necessary.

Experimental production of pellets from hardwood treated with saturated steam before granulation was established by Vitebskdrev OJSC. The composition of the raw materials is as follows: birch - 35%, alder - 20%, aspen - 40%, pine - 5%. A matrix with an effective pressing channel length of 33 mm (instead of the usual 45 mm) was used, since heat treatment Deciduous wood takes less time than processing coniferous wood (due to this, energy consumption has decreased). As a result, it was found that the density of pellets from the hardwood composition is comparable to the density of pellets from pine wood (Table 2). It is appropriate to quote here from the test report: “Action saturated steam led to the activation of wood components, the creation of new functional groups that enhance adhesive interactions in the process of pellet formation. Additional moistening of the wood particles occurred, as a result of which the temperature in the press granulator increased from 110 to 120°C. The high pressing temperature contributed to the rapid occurrence of reactions and the accumulation of more and more high-molecular compounds, mainly due to highly reactive hemicellulose. Melted and softened components filled the voids between the fibers and the capillary and submicrocapillary systems of the cell walls. At the same time, the number of cross-links between the molecules of wood components increased, including spatial ones, which ensured the formation of durable products.”

To increase the strength of hardwood pellets, various additives are often used, such as starch and lignin. The Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences of the Russian Federation studied the effect of additives when granulating hardwood. So, soda, lime, fish oil, vegetable oils, coffee grounds improve the properties of pellets or briquettes: they reduce the percentage of dropouts, increase resistance to breakage during transportation and supply to a warehouse or boiler. Crushed charcoal increases the calorific value of pellets and briquettes.

Raw materials for pellet production

In Europe, so-called fast-growing plantation plants are increasingly used for the production of pellets, the ash content of which is often much higher than the ash content of deciduous wood. Expert and consultant of DIN CERTCO - a worldwide accredited German certification center for organizations, services, products, including DIN+ standards; FSC/PEFC, SBP - Erwin Heffele clarified that some fast-growing plantation plants, such as miscanthus and bamboo, are not included in the register of raw materials suitable for the production of wood pellets, since they are not classified as wood, but are classified as grass. That is, it is impossible to obtain ENplus and DIN+ certificates for pellets made from miscanthus and bamboo.

In general, limiting the ash content of raw materials is a purely abstract and relative requirement. For example, at power plants in the Netherlands, Belgium, Denmark, Poland and other countries, pellets from straw and sunflower husks, olive pits, shells of nuts and coffee beans and other biomass, the ash content of which was several times higher than the ash content of wood pellets, were burned together with coal. Another example: the Bionet company from the Arkhangelsk region produces lignin pellets (see LPI No. 3 (133), 2018). This is the first project implemented in Russia for the recycling of hydrolysis production waste - lignin. Lignin granules, in comparison with classic wood granules, are characterized by high calorific value (21-22 MJ/kg), but also by high ash content - 2.4%. This, however, did not prevent Gazprombank, the beneficiary of the project, from starting sales of these pellets to Denmark and France after a presentation in Copenhagen at a business meeting at the Trade Representation of the Russian Federation in Denmark in the spring of 2018.

The high ash content of granules used in low-power boilers requires only frequent extraction of ash from the ash pit, which, as a rule, serves as fertilizer for the garden.

And when pellets are burned together with coal large thermal power plants high strength is not required, since they, like coal, are first passed through crushers and fed into the combustion zone of the boiler in a fine fraction. So the high strength of the granules will only increase energy costs.

As practice shows, it is possible to produce pellets yourself high quality from deciduous wood or a mixture with coniferous wood. Mixed raw materials in a certain proportion allows us to achieve pellet quality that meets ENplus A1 standards. Additives and steam pre-treatment can also be used or omitted. The effect will depend on the quality and type of raw materials used, technological equipment in production and, of course, from the professionalism of the technologist and other specialists.

Sergey Perederi, s.perederi@ eko-pellethandel.de

At the end of 205, an innovative enterprise in the field of alternative energy was launched in Onega - a plant for the production of pellets from hydrolytic lignin. The uniqueness of biofuel is that the raw materials for its production are exclusively industrial waste that has been lying on the ground since the last century.

The first plant in Russia for the production of lignin pellets was commissioned in the Arkhangelsk region. Production was established by JSC Bionet together with specialists from the German company Alligno on the basis of the former Onega hydrolysis plant. The choice of location is not accidental - during the existence of the hydrolysis industry in Onega during the Soviet years, significant reserves of lignin were accumulated, which will allow the plant to produce 150 thousand tons of pellets per year for 10-15 years. The new plant has been under construction since 2013. The total investment in production amounted to about 40 million euros, of which 10 million were equity investments from Gazprombank, and another 30 million euros were additionally attracted by the bank as part of project financing.

Lignin pellets are similar in purpose to traditional wood pellets - they are used as fuel in industrial boiler houses to generate heat or electricity. The uniqueness of the new pellets lies in the innovative technology for processing hydrolytic lignin, which allows us to obtain an export product with high added value and unique physical properties.

The calorific value of lignin pellets is almost a quarter higher than that of conventional wood pellets. The new pellets have a high density, are waterproof and are not subject to spontaneous combustion. This greatly simplifies their storage and transportation.

According to a number of industry economists, pellet production is focused primarily on European markets, where policies are being implemented to reduce the share of fossil raw materials, supported by government subsidy programs for enterprises using biofuels. Bionet has not yet disclosed the buyers, specifying only that companies from Italy, Germany and Slovenia are now showing active interest in the new product.

In addition to the economic component of the project, its social significance for the region is also important.

“When the plant is fully loaded, about two hundred jobs are created. Local budgets will receive additional revenue in the form of taxes. Along with the plant’s activities, it is possible to improve the engineering and communal infrastructure, as well as provide favorable living conditions for plant workers and their families,” said general manager JSC "Bionet" Igor Cheremnov.

As noted by the Minister of Fuel and Energy Complex and Housing and Communal Services of the Arkhangelsk Region, Igor Godzish, the production of biofuel allows us to solve not only the problem associated with lignin dumps and reduce their negative impact on the region, but also to create an innovative export product.

For Gazprombank, this is not the first investment in the real sector of the economy. Gazprombank explained its interest in Bionet OJSC by the fact that historically the energy industry is one of Gazprombank’s key competencies in the field of direct investment. “We have been closely monitoring the bioenergy market in Russia for a long time and are constantly looking for interesting investment opportunities,” said Sergei Grishchenko, deputy head of the direct investment department of Gazprombank and chairman of the board of directors of Bionet. According to him, high level implementation of the project made it possible to attract financing from the German export credit agency Hermes, which generally reduced total cost financing.

Pellets FROM woodworking waste (hydrolytic lignin) and a method for their production

The invention relates to renewable energy sources, bioenergy in particular to the production of biofuel, fuel pellets from waste from the wood processing industry, hydrolytic lignin and intended for use to release thermal energy by combustion in a wide range of thermal power plants with emissions tending to zero when burned.

Previously known methods of producing fuel from lignin of all its varieties by mixing it with additives and impurities having a low ignition and ignition temperature, namely with a list of materials or chemical compounds of the petrochemical industry: oil slag, tar, cracking residue, thermal gas oil, heavy catalytic cracking gas oil, asphalts and extracts of oil production, pyrolysis resin or fuel oil or liquid or paste products of coking and semi-coking of coal, coal tar, pitch, tar slurries or with still remains and waste from organic production in a mass ratio of 9:1 to 1:9, mainly from 2:1 to 1:3. Tar, fuel oil and coal tar pitch are liquefied by heating to 80-150ºС (according to patent RU2129142, class C10L 9/10, C10L 5/14, C10L 5/44 publ. 04/20/99).

The disadvantage of this method of using or using lignin is the negative impact of the resulting fuel (chemical compound) on environment when burning and rendering negative impact in cases of storage and production.

Previously known methods producing fuel briquettes from a plant mixture, including grinding, drying, mixing the components of the mixture and subsequent pressing, characterized in that a mixture of technical hydrolytic lignin with wood waste is used as a plant mixture in the following ratio of components, wt.%: wood waste - 30 - 60 ; technical hydrolytic lignin - the rest (according to patent RU2131912, class C10L 5/44 publ. 06.20.99).

Disadvantage this method is the instability of technical and environmental characteristics, in particular strength and ash content, a product of ash formation as a residual combustion product, due to the inclusion in the composition of briquettes wood waste low quality.

The closest to the proposed solution for granulating hydrolytic lignin can be considered a method of briquetting hydrolytic lignin, including pulping the initial product, neutralizing and enriching the lignin pulp, further dewatering the pulp, drying the dehydrated lignin mass and its subsequent briquetting. The enriched lignin pulp is dewatered by forming lignin slabs with a residual moisture content of no more than 45%. The latter are then dried under the influence of an electromagnetic field and high frequency currents. The disintegrated product, the prepared lignin mass, is transferred to briquette pressing (according to patent RU2132361, class C10L 5/44 publ. 06.27.99).

The difference between this method is the need for additional operations to enrich the raw materials and, as a result, lengthening the time it takes for the input raw materials to pass through technological process. Further crushing of the resulting and formed slabs after drying, which requires the presence additional equipment, implying frequent replacement of working surfaces and low productivity. An important note may be the further use of the resulting product during combustion, which is possible only in specially prepared furnaces of boiler and furnace equipment, using feed transport, usually different from the generally accepted coal ones for boilers operating on pellet products.

The positive techno-economic result of the proposed invention, the production of fuel pellets from hydrolytic lignin, consists in increasing the manufacturability of biofuel production, reducing energy costs, ease of selection of technological equipment, lack of waste, and low emission percentage. Full compliance with the requirements and legislation in matters of energy saving, environmental requirements of areas and localities during further use and intermediate storage of the resulting product as a high-quality biomass-based fuel.

The declared technical result is achieved by the fact that pellets from hydrolytic lignin are made in the form of fuel granules, compressed lignin. Lignin used as a raw material in the production of fuel pellets is obtained by hydrolysis of wood waste, and before processing and before pressing, it undergoes fine cleaning and sorting into fractions with the subsequent removal of mineral elements, non-combustible inclusions and debris, which influence the increase in the percentage of ash residue and low-quality polluting emissions when burned.

In a particular case, hydrolytic lignin is already enriched with derivative residues of hydrolysis production in an amount of 1-20% (wt.). Hydrolysis production waste includes residue from the inverter, hot sludge, cold sludge, organic production sludge waste water, organic compounds, methoxy groups, carboxyl groups, carbonyl groups, phenolic hydroxides and solid hydrocarbons.

The production of pellets from hydrolytic lignin is carried out as follows.

Hydrolytic lignin obtained by hydrolysis using weak solutions of sulfuric acid weakened in the process by lime additives and timber waste is selected mechanically from dumps and storage, then transported to production for processing.

The processing process goes through several stages before preparation.

Preparation and sorting for processing (removal of metal objects, construction inclusions and debris, also non-hydrolyzed wood).

Preparation of hydrolytic lignin for drying. At this stage, a mixture of part of the dry hydrolytic lignin that has passed the drying stage and the hydrolytic lignin entering production with a moisture content of 65% acquired during storage occurs. During mixing, the moisture content of hydrolytic lignin is averaged and equalized to the required technological indicator, which should be equal to 49 - 54%. The moisture content of the input raw materials should be dependent on the biomass, which has a moisture content of less than 14% and is required to equalize the subsequent moisture balance of the raw materials before mixing.

Drying of hydrolytic lignin is carried out in drum-type drying units without direct interaction of the steam involved in the process and completely eliminating the interaction of raw materials with open fire or sources of high temperatures or units and generators.

The supply of dead steam is carried out into bundles of pipes, a characteristic filling of the drying unit used. Drying occurs in the inter-tube sinuses of the drying drum, with methodical, forced mixing, using installed blades and rippers. Drying of hydrolytic lignin is carried out until the moisture content reaches 8-14%.

Fine purification of hydrolytic lignin. Dried hydrolytic lignin (raw material) is fed to the fine purification stage, followed by separation into fractions using pyramidal sets of sieves, using mechanical stimulation and oriented flows for transportation and movement compressed air. The process provides for the removal of mineral inclusions and components from the organic part of the hydrolytic lignin composition. Next, the fractional composition of the sifted material is leveled to a fraction of the finished mixture for transfer to a storage tank for subsequent pressing (granulation). The process of separation into fractional components, through fine purification of raw materials, subsequently affecting the bonding during the formation of the product cylinder, physical characteristics and chemical composition.

Pressing into pellets. The accumulated volume of the prepared homogeneous mass subsequently passes into the stage of preparation for pressing. The preparatory period is short-term and consists of moistening the supplied hydrolytic lignin with its own humidity ranging from 10-16% with tap water without additional preparation at a temperature ranging from 4 – 10ºС. Pressing, as compaction of the prepared mass by means of feeding it into the press granulator, namely into the technological movable cavity between the pressure rollers and the perforated matrix, which is the radius of the working, heavy-duty surface. Pushing the supplied dried and purified material, lignin, into through holes with a theoretically accepted diameter of about 8 mm and a depth of about 8 mm and cutting off the resulting cylinder with an outer knife gives the finished product, lignin granules, fuel pellets.

Next, the resulting product passes through a cooling system and in a specially designed cooler. Cooling is carried out by air flow supplied by a fan. After the cooler, the pellets go through the stage of sifting, separating the resulting fine fraction and substandard product. The resulting screenings are returned to the granulation stage and pressed again.

The sifted finished products are moved to storage silos. The process is complete.

Application - combustion. Lignin pellets do not emit odor when burned; combustion occurs calmly, controlled, in an even carpet on the grate, movable or static. The smoke when burning pellets from hydrolytic lignin is practically colorless, flame entrainment is within the limits of the norms and regulations of thermal power engineering, section on the use and application of solid fuel and solid fuel boiler units. The combustion of lignin fuel pellets is also comparable to the combustion conditions of fuel pellets made from pure wood and coal. Due to low interest rate the sulfur content in hydrolysis pellets, emissions of sulfur dioxide into the atmosphere are low, tending to zero. The combustion of lignin pellets is still qualitatively different from the combustion of classic wood fuel pellets, both in terms of the release of thermal energy. Also environmentally and economically, lignin granules are more advantageous coal, and liquid fuel. The use of lignin pellets allows you to automate the process of loading, feeding into the combustion device and regulate the combustion process. The use of lignin pellets due to their high calorific value equal to 20-21.5 MJ/kg, is higher than a wood product and equal in calorific value to high-quality coal 5100 Kcal/kg. Size (fractional), high density after pressing is characterized by the strength of the resulting product and ranges from 98-99.5%. Bulk density 750 kg/m3, helps reduce the amount of transport containers when moving lignin fuel pellets to the place of burning (use). Pellets can be widely used as fuel for automated boiler houses, both domestic and industrial, without significant changes in design, preliminary modernization and reconstruction of existing models and variants of boiler equipment. Pellets from hydrolytic lignin based on their physical and chemical characteristics have unique abilities and capabilities for accessible storage in various conditions of accessible storage, under current atmospheric conditions without taking into account the time of year, atmospheric precipitation, their type and quantity, without changing their calorific value and maintaining their geometric shape. Another unique ability is their impeccable hydrophobicity, so they do not absorb moisture to the depth of the entire body of the resulting cylinder, but repel it. But another unique property is the restoration of the original humidity after exposure to a humid environment. The initial characteristics stipulated by the technical specifications are acquired by pellets through exposure to changes in ambient humidity or through forced exposure to air mass flows. In a word, drying occurs.

Due to the correct shape, small size and uniform consistency, granules can be poured through the sleeves of vacuum loaders or sleeves without mechanical movement, and along a pre-arranged slope of the chute using the acceleration force of the free fall of bodies under the influence of specific physical weight. This allows not only to automate the loading and unloading processes and also to ensure uniform dosing of fuel during combustion, as well as achieve energy savings when moving.

Today, pellets are comparable in heat cost to coal, but the latter is difficult to implement in automation processes and basic operations - loading/removing slag must be performed using ash selection equipment or manually, depending on the type of boiler equipment. An important aspect is the absence of ash residue, as a consequence, the absence of disposal costs. The formation of slag when using pellets is minimally less than and equal to 3% of the burned mass of lignin granules.

Unlike other types of fuel produced by the method of granulation and pressing, the manufacturing process does not involve third-party additives and additives, chemicals, and therefore does not cause allergic reaction in people.

In terms of their calorific value, ease of use, storage, transportation, use in existing heating equipment, both industrial and domestic, and environmental qualities, pellets are an intermediate link between coal and gas fuel, but more mobile and safe.

1. Pellets from hydrolytic lignin are made in the form of fuel granules, pressed from hydrolytic lignin obtained by hydrolyzing wood waste with sulfuric acid solutions, characterized in that before processing the hydrolytic lignin is enriched with derivative waste from hydrolysis production, and before pressing it undergoes fine cleaning and sorting into fractions with subsequent removal of mineral elements and reduction of ash content.

2. A method for producing pellets from hydrolytic lignin according to claim 1, including cleaning, mixing, drying and pressing and characterized in that before processing, hydrolytic lignin is enriched with derivative waste from hydrolysis production, and before pressing it undergoes fine cleaning with sorting into fractions, followed by removal of mineral elements and reduction of ash content.

3. The method according to claim 2, characterized in that hydrolysis lignin is enriched with derivative waste from hydrolysis production in an amount of 1-20% wt.

Similar patents:

The invention discloses a method for automated control of the process of pressing peat fuel, including measuring humidity, temperature, raw material consumption and subsequent comparison of the measured data with the values set on the microcontroller, and additionally includes automatic measurement and regulation of pressing pressure, movement speed, and holding time material in the matrix (pressing) channel.

The invention describes a long-burning log, which is a monolithic product with a volume of more than 0.5 liters and a weight of more than 500 g, containing paraffin, stearin, wax or mixtures thereof, wood flour, chopped straw, paper no more than 1 mm in diameter or mixtures thereof, wood pellets up to 4 mm in diameter and with a moisture content of no more than 8%, with mass fraction in%: paraffin, stearin, wax 30-40 wood flour, chopped straw, paper 20-60 wood pellets 10-40 The technical result of the claimed invention is to increase the burning time of the log, as well as its unambiguous identification.

The invention discloses a continuous process for producing torrefied densified biomass, comprising the steps of: (a) providing a supply of densified biomass material, (b) immersing the densified biomass material in a flammable liquid, (c) torrefying the densified biomass material in a flammable liquid at or within a temperature range of about 270°C to about 320°C for a period of time from at least 10 minutes to about 120 minutes to form the torrefied densified biomass, (d) transfer the torrefied densified biomass from the flammable liquid into the water bath, and (e) recover the cooled torrefied compacted biomass from a bath of water, wherein the torrefied compacted biomass recovered in step (e) contains no more than about 20% w/w.

The invention relates to a method for producing carbon-enriched biomass material, to the material obtained in this way, as well as to its use. A method for producing carbon-enriched biomass material includes the steps of: (i) providing lignocellulosic material as a feedstock, (ii) subjecting said feedstock to treatment at temperatures ranging from 120°C to 320°C in the presence of a substoichiometric amount of oxygen at a concentration of O2 or equivalents O2 in the range of 0.15-0.45 mol/kg of dried lignocellulosic material, provided that complete combustion of the lignocellulosic material requires a stoichiometric amount of oxygen in a sealed reaction vessel, (iii) open said reaction vessel, and (iv) recover the solid product from the reaction vessel mixtures.

The invention describes a method for producing charcoal fuel briquettes, including grinding, mixing and pressing with preheating of the mixture to 80-100°C at a pressure of 170-200 MPa and humidity 10-12%, characterized by the fact that when preparing the mixture, 5 -10 wt.% sawdust.

The invention discloses a method for producing fuels from biomass, in which the biomass is subjected to heat treatment in a temperature range from 150 to 300°C, a reactor (11) with pressure, increased steam and air, in which the pressure is released upon completion of the treatment, while the increased from the release pressure, the volume of steam and other gases is temporarily accumulated in a container (14) with an adaptive volume, and the steam and other gases are subjected to heat exchange in at least one heat exchanger (13) so that the condensable gases condense and release heat of condensation in at least one heat exchanger ( 13).

The invention describes a method for producing fuel briquettes from wood waste, including loading wood waste, pressing and drying it, and after loading the wood waste, they are additionally compacted with ultrasound, followed by simultaneous pressing and processing of wood waste with a high-frequency electric field.

The invention discloses fuel briquettes from a two-component mixture of wood origin: the first component is crushed wood waste from wood harvesting and/or wood processing enterprises, and the second component is charcoal, while the two-component mixture is presented in the form of a homogenized composite material obtained by compounding a matrix of crushed wood waste and strengthening dispersed particles of charcoal, carried out in two stages: the first stage - by combining the following simultaneously occurring processes: drying of wood waste with the original natural moisture, dispersion of the original charcoal and adsorption of the dispersed charcoal by the matrix; and the second stage - in the process of briquetting the composite material, preferably by extrusion, and the combination of drying, dispersion and adsorption is carried out in a dynamic looped heat flow of a mixture of flue gases with moisture vapor from wood waste released during the drying process, while the charcoal content in the feedstock is maintained at within 5÷30 wt.

The invention describes a method for producing fuel briquettes from wood waste, including grinding, drying to a moisture content of 12-16%, mixing the components of the mixture, including technical hydrolysis lignin, and the preparation of the binder charge is carried out by adding 70-80% sodium carbonate to the technical hydrolysis lignin 5-10 % and further mechanical activation followed by the addition of 15-20% tall tall pitch heated to 90°C, the resulting mixture in an amount of 10-15% is mixed with wood waste, crushed to 1-5 mm in an amount of 85-90%, and briquetting of the mixture is carried out at temperature 90±2°C and pressure 45-50 MPa.

The invention discloses a method for producing fuel granules, including dosing and mixing activated sludge generated at stations biological treatment wastewater, with a dewatering additive, dewatering the resulting mixture and subsequent molding of the mixture, using activated sludge with a water content of 97-99% wt., sludge from thermal chemical water treatment is used as a dewatering additive power station(TES) with a humidity of no more than 3%, dosing and mixing of activated sludge with chemical water treatment sludge of TES is carried out in the ratio (7-10): (1-2)% wt., the resulting mixture is dewatered in two stages, with centrifugation carried out at the first stage for 1-3 minutes until a mixture with a moisture content of 69-74% is obtained, and at the second stage - drying is carried out on a belt dryer at a temperature of 105-115 ° C for 20-40 minutes until a mixture with a moisture content of 40-45% is obtained, then the dehydrated mixture molded by granulation and then the granules are coated with an organic additive, while the fuel granules contain, wt.%: activated sludge - 65-75, thermal power plant chemical water treatment sludge - 6-10, organic additive - the rest.

The invention describes a product made of charcoal containing a cylindrical body and supporting elements, its bottom surface is made in the form of a concave lens, and the supporting elements are separated by air passages-diffusers, which have an arched-curvilinear configuration on the outside and expand inward.

The invention discloses a method for the production of fuel briquettes and granules, including grinding, drying, dosing, feeding, mixing, briquetting, granulating and cooling, characterized in that the briquettes and granules are produced based on a mixture of cut straw with the addition of up to 20-30% of Jerusalem artichoke or sunflower stems and its baskets, or 30-40% dried crushed wood forest or garden waste, or up to 20% sawdust.

The invention discloses a method for producing a dried combustible material, including: a mixing step of mixing a plurality of particles made of a combustible material containing moisture and a dehydrating liquid made of an emulsion containing a synthetic resin to form a mixture in which the surfaces of the particles come into contact with dehydrating liquid; and a drying step to form a synthetic resin coating made from a dehydrating liquid dried on the surfaces of the particles, evaporating moisture from the particles to form coated particles including particles having a reduced percentage of moisture content, and a synthetic resin coating that covers surface of the particles, wherein the synthetic resin contained in the dehydrogenating liquid is an acrylic resin, a urethane resin or a polyvinyl acetate resin, thereby obtaining a dried flammable material, formed from coated particles.

The present invention relates to an environmentally friendly and highly efficient method for producing solid fuel using organic waste with high water content, which includes: (a) a waste mixing step in which organic waste with high water content and municipal solid waste are fed into an Fe-based reactor and mix; (b) a hydrolysis step in which high temperature steam is supplied to the Fe-based reactor to hydrolyze the mixture; (c) a pressure reduction step in which the steam from the reactor is released and the pressure inside the reactor is rapidly so as to ensure low molecular weight organic waste after step (b) or so as to increase the specific surface area of the municipal waste after step (b); (d) a vacuum or differential pressure step to remove water; and (e) a solid fuel production step in which the reaction product from step (d) is naturally dried and compressed to produce a solid fuel having a water content of 10 to 20%. // 2569369

A device for the production of fine-grained fuel from solid or paste-like energy raw materials by means of drying, containing an impact reactor with a rotor and impact elements, wherein said impact reactor is heat-resistant up to 350°C, a device for supplying hot drying gas in the lower part of the impact reactor, a device for supplying solid or paste-like energy feedstock at the top of the reactor, at least one device for releasing a gas stream containing crushed, dried particles of energy feedstock, and a device for separating and discharging crushed, dried particles of energy feedstock from the gas stream discharged from the impact reactor, wherein the drying gas is introduced into the impact reactor near the labyrinth seal and/or through the labyrinth seal located near the rotor shaft of the impact reactor.

The invention describes a method for producing solid fuel, including stages in which a suspension is prepared by mixing powdered low-grade coal and oil; evaporate the moisture contained in the suspension using heat and separate the suspension obtained after the evaporation step into a solid material and a liquid, wherein the evaporation step includes the stages of heating the suspension in the first circulation path and heating the heated suspension in the second circulation path which is different from the first circulation path, wherein the process steam generated in the evaporation step is used as a heat transfer fluid for any one of the preheating stage and the heating step, and the externally introduced steam is used as a heat transfer fluid for the other stage.

The invention discloses pellets from hydrolytic lignin, made in the form of fuel granules, pressed from hydrolytic lignin obtained by hydrolyzing wood waste with sulfuric acid solutions, characterized by the fact that before processing, hydrolytic lignin is enriched with derivative waste from hydrolysis production, and before pressing it undergoes fine cleaning with sorting into fractions with subsequent removal of mineral elements and reduction of ash content. A method for producing pellets from hydrolytic lignin is also disclosed. The technical result consists in obtaining pellets that have optimal characteristics: they have a high calorific value, high mechanical strength, and when they are burned, no ash residue is formed. 2 n. and 1 salary f-ly.

A project for the production of a new type of biofuel - fuel pellets from lignin - was launched in Germany at the Technical University of Cottbus together with the Biomass Research Center in Leipzig and one company producing technological equipment.

According to experts, new project will finally make it possible to produce high-quality fuel granules (pellets) or briquettes from hydrolyzed lignin on an industrial scale.

The pilot project will be launched in June 2013. Funding is provided by EU grants under the environmental protection program.

For many years, hundreds of scientific organizations around the world have been engaged in research and development in the field of utilization of hydrolytic lignin. Many of them are in different years have already been implemented in industry. IN lately These works become relevant due to the increased interest in solving environmental problems and in the industrial use of biomass in general in the energy sector. But without serious government support, most likely “the dump will still be there.”

As for Russia, the reserves of hydrolytic lignin in the Russian Federation, amounting to tens of millions of tons, are comparable to other waste from wood processing - bark, sawdust, etc.

It is interesting that lignin differs from wood waste in its greater homogeneity and, most importantly, in greater concentration (for example, dumps near hydrolysis plants). Due to practically complete absence its disposal creates problems from an environmental point of view and with its storage.

At most hydrolysis and biochemical plants, lignin is disposed of in dumps and pollutes large areas.

Many European experts, visiting such plants, emphasize that nowhere in Europe have they seen such a colossal concentration of unused energy raw materials.

According to the data available in the literature, the use of hydrolytic lignin as a chemical raw material in the CIS does not exceed 5%. And according to the International Lignin Institute, no more than 2% of technical lignins are used in the world for industrial, agricultural and other purposes. The rest is burned in power plants or disposed of in dumps.

Problem

The problem of recycling hydrolytic lignin has been the main one for the industry since the 30s. And although scientists and practitioners have long proven that lignin can be used to produce excellent fuel, fertilizers and much more, for for many years Since the existence of the hydrolysis industry in both the USSR and the CIS, it has not been possible to use lignin in full.

Difficulty industrial processing lignin is due to the complexity of its nature, as well as the instability of this polymer, which irreversibly changes its properties as a result of chemical or thermal effects. The waste from hydrolysis plants does not contain natural lignin, but largely modified lignin-containing substances or mixtures of substances that have high chemical and biological activity. In addition, they are contaminated with other substances.

Some processing technologies, for example, the decomposition of lignin into simpler chemical compounds (phenol, benzene, etc.), with comparable quality of the resulting products, are more expensive than their synthesis from oil or gas.