Kohshin Technology
Technological line KNLL 6000 SHW
The KNLL 6000-SHW composting line is specially designed for the total disposal of manure from animal farms and individual households and the continuous transformation of animal manure into a granulated, stable, hygienic, homogeneous organic fertilizer, highly effective in a single operating cycle, for 32-40 days. Manure fermentation is aerobic and takes place at temperatures of around 70 degrees C, completely sterilizing the product by eliminating germs and parasites and reducing to zero the germination rate of seeds in animal manure. Associated odors, caused by the microbial decomposition of volatile compounds, are eliminated by using odorization systems.
The KNLL 6000-SHW composting line continuously produces about 660 tons/month of natural fertilizer, 2 operations/day (about 8 months per year) and about 330 tons/1 operation/day (4 months per year between November and February). In the operating mode 1.5 cycles per day, the station can produce an average of 495 tons/month of organic fertilizer. The line can process animal manure (pigs, cattle, broilers, laying hens) mixed with organic residues from the slaughterhouse and the sewage treatment plant. The line can process manure from farms raising pigs, cattle, laying hens mixed with material that has a lower moisture content (eg chopped straw with 30% moisture content). The final product is a granulated, stable, hygienic, homogeneous, highly efficient organic fertilizer.The KNLL 6000-SHW line operates continuously and is automated, with an average processing capacity of 66 tons of manure/day for 8 months of the year and 33 tons of manure/day in winter, with approx. 65% humidity at the entrance
1. Area of precomposting, mixing and handling of fresh manure, others degradable materials and / or precomposted mixture.
This consists of a pre-mixing area and an area with 6 polycarbonate covered concrete boxes, measuring 10m x 7.5m and 2m high, with one open side. These speakers are equipped with ventilation systems in the reinforced concrete floor. In the same area, there are 3 similar pits, without aeration system and compressors, used to mix / homogenize the manure before it is stored in the 6 pre-composting pits. For pig and cattle farms, where the manure moisture is above 85%-90%, the station can include the manure dewatering press.
2. The composting area
Aerobic fermentation, consisting of 2 pits with side walls 1.1 m high, 6 m wide and 150 m long, on which the slide rails of the composting equipment are arranged. The equipment is located inside a hall measuring 15 ml (width) and 160 ml (length), with a minimum height at the gutter of 5.3 m. The foundation of the hall is made of reinforced concrete to prevent the infiltration of nitrates into the soil. The construction is made on a structure made of wood, concrete or galvanized metal, resistant to corrosion. The roof is transparent to allow the manure to be exposed to light, which helps and maintains the fermentation process, as well as to keep the internal temperature high. The side closures are made with 3 cm thick polyurethane foam or polycarbonate panels. For good ventilation (which prevents the appearance of condensation inside) at the side closures, openings are provided in the lower part (height 1.5 m from the zero level) and in the upper part (at a height of 0.8 m below the gutter) with automatic or manually operated rollers.
3. The sorting area
Aerobic fermentation, consisting of 2 pits with side walls 1.1 m high, 6 m wide and 150 m long, on which the slide rails of the composting equipment are arranged. The equipment is located inside a hall measuring 15 ml (width) and 160 ml (length), with a minimum height at the gutter of 5.3 m. The foundation of the hall is made of reinforced concrete to prevent the infiltration of nitrates into the soil. The construction is made on a structure made of wood, concrete or galvanized metal, resistant to corrosion. The roof is transparent to allow the manure to be exposed to light, which helps and maintains the fermentation process, as well as to keep the internal temperature high. The side closures are made with 3 cm thick polyurethane foam or polycarbonate panels. For good ventilation (which prevents the appearance of condensation inside) at the side closures, openings are provided in the lower part (height 1.5 m from the zero level) and in the upper part (at a height of 0.8 m below the gutter) with automatic or manually operated rollers.
4. Packaging area
The finished product, organized as an extension of the sorting area, with hall dimensions of 15 ml x 20 ml. The technical characteristics of the building are similar to those of the sorting area. The packaging area can includes a automated packaging line including robot for paletizing for organic fertilizers in 5 to 50 kg bags. The main components of the KNLL 6000-SHW technological line are the composter, the aeration system, the deodorization system (scrubber), the finished product sorting system and the packaging line
Technological Flux
Composting is a process of bio-oxidation of the solid organic substrate and includes a thermophilic phase of decomposition and microbial synthesis of organic substances from residues. The product obtained by aerobic process contains more than 25% relatively stable humus formed mainly from microbial biomass. It is still subject to a weak decomposition, but it is stable enough not to reheat or cause odor or insect breeding problems and has a C:N = 10-15 ratio. Regardless of its origin and nature and depending on the aeration and humidity conditions, the organic matter evolves towards a qualitatively new state, relatively stable compared to biodegradation. Composting is therefore a method of managing the biological oxidation process that converts heterogeneous organic matter into more homogeneous ones, with humus-like particles. Composting means the totality of the microbial, biochemical, chemical and physical transformations that organic, vegetable and animal waste undergo, from their initial state until they reach different stages of humification – qualitatively different from the initial state.
For an efficient composting, both in terms of reducing the impact on the environment, and in order to obtain the best organic fertilizers, three phases of the biological process are followed, respectively:
Phase 1
The mesophilic fermentation stage, which is characterized by the growth of bacteria and temperatures between 25-40 degrees Celsius
Phase 2
The thermophilic stage in which bacteria, fungi and actinomycetes are present (the first level of consumers) at a temperature of 50-60 degrees Celsius, decomposing cellulose, lignin and other resistant materials; the upper limit of the thermophilic stage can be above 70 degrees Celsius and it is necessary to maintain the temperature for at least one day to destroy pathogens and contaminants
Phase 3
The maturation stage, where the temperatures stabilize and some fermentations continue, converting the degraded material into humus through condensation and polymerization reactions; the last objective is to produce a material that is stable with an appropriate C:N ratio; the C:N ratio can decrease from 30 at the beginning of the composting process to 15 in the matured product.
During active composting, aerobic decomposition generates carbon dioxide and water vapor, and active anaerobic decomposition generates carbon dioxide, methane and other fermentation products that create unpleasant odors, reduced pH in the compost pile and inhibit plant growth. Numerous factors affect the generation of odors: the amount of oxygen in the pile, the characteristics of the materials subject to composting, the initial pH of the mixture and the materials used as additives. Even if there is a good supply of oxygen (obtained by diffusion, reshuffling or forced aeration) in the compost heap, there are still some smaller or larger bags in which the process takes place in anaerobic conditions. The products from these anaerobic bags will decompose when they reach aerobic conditions in the compost pile. At pH conditions below 4.5, aerobic microorganisms die, work equipment corrodes and odors appear. Low pH values and the appearance of odors are the best indicators of the need for oxygen. A compost pile is predominantly aerobic if the oxygen concentration in the compost pile is evenly distributed and has values above 5-6%. At oxygen values below 3%, odors appear and the process of anaerobiosis begins. Odors are generated by alcohols and quickly formed volatile organic acids, which lower the pH of the pile. Restoring aerobic conditions through proper aeration and porosity can take from 2 to 6 days.
The microbial organisms necessary for composting occur naturally in many organic materials.
The most common types of sub-materials/additives used to direct composting and improve the quality of the final product are:
- the compost that has not finished ripening and is still rich in microorganisms as the inoculum
- calcium carbonate (correction of calcium deficiency and correction of acid reaction)
- blood and horn meal (nitrogen intake in the absence of manure)
- bone meal (correction of phosphorus and calcium deficiency)
- clayey soil or pure clay (improvement of the formation of clay-humated compounds)
- gypsum (recommended for improving soil texture)
- ground phosphate rock (for the slow release of accessible phosphorus)
- seaweed flour (source of potassium and trace elements)
- specific organisms or biodynamic preparations
- ground rocks (providing microelements or clay)
- herbs, leaves as nitrogen source
- urea as nitrogen amendment (increases composting speed and temperatures)
The ability of the compost heap to heat up and maintain a high temperature depends on 7 factors, respectively:
- the physical and biological composition of the materials subjected to composting
- the accessibility of nutrients, including carbon for the microorganisms that produce composting
- the level of humidity in the materials subjected to composting
- pile structure (particle size, texture and apparent density)
- aeration rate in the pile
- the size of the compost pile
- environmental conditions (temperature, wind, humidity)
In practice, there are several methods of composting, respectively:
A. Passive composting in the open pile: it is suitable for small or moderate farms with less management. The method involves forming the pile of organic materials and leaving it undisturbed until the materials are broken down into stabilized products. These small piles have the advantage of natural air movement. Due to the active fermentation, the pile heats up inside, the hot air rises and is lost on the top surface of the pile, being replaced by the cold air that enters at the base of the pile and on the side, thus refreshing the air in the pile. Depending on the size of the pile, the air currents can refresh the air in the pile faster or slower, activating the fermentation process. For an efficient exchange of air, especially in the summer, and if materials that emit more heat are composted, such as ruminant waste, the height of the pile will be only 0.9 – 1.2 m. The disadvantage of this method is the fact that the pile becomes unmanageable, being too wet, too compacted, and can quickly become anaerobic and very smelly.
B. Flatbed composting in rows or piles using a loader for turning, mixing and handling: Flatbed composting in rows and piles is the most common form of composting. For an active management of the process, the rows and piles are reshuffled with the help of a special machine, which avoids compaction of the pile, improves the air exchange, brings the material from the inside to the surface of the pile and introduces the material from the surface of the pile into the pile. In this way, weed seeds, pathogens and fly larvae can be destroyed by composting, as they end up in the middle of the heap where the temperature is very high. By turning and mixing again during renovations, the materials subjected to composting are fragmented into smaller particles and their biologically active contact surface increases. The excess of rehandling can lead to the reduction of the pile porosity if the particle size becomes too small. The size of the heap (of the string) is given by the characteristics of the equipment that performs the rehandling of the heap. It is preferable for the composting platform to be surrounded by a ditch to collect the runoff. The collected liquid can be used for wetting the pile when reshaping if this is necessary or it can be applied on the agricultural land as a liquid fertilizer in compliance with the environmental norms regarding pollution with nitrites and nitrates.
C. Aerated static pile systems using perforated pipes: it can be developed in open or closed spaces. Perforated pipes for aeration are embedded in the pile at the base. The hot gases inside the pile rise, and the cold air enters through the pipes inside the pile. Forced aeration can also be practiced using an air blower in the pipes at the base of the pile, which makes the air circulation faster. The forced aeration system allows the pile to grow and a better control of the composting process. Negative pressure arrangements (inside perforated pipes) allow air to be exhausted directly through biological filters if odors become a problem. Aerated static piles are based on wood chips, chopped straw or other porous materials. The porous material at the base also incorporates perforated pipes for aeration. The selection and initial mixing of the raw materials subjected to composting are essential, because they must have a good structure to maintain their porosity throughout the composting period. This general requirement is ensured by using a density-maintaining agent, such as straw or wood chips. The initial height of the aerated static pile is 1.5-2.5 m. In winter, larger piles help to maintain heat. A layer of finished compost covers the compost pile. The length of the aerated static pile is limited by the air distribution through the aeration pipes. For aerated static piles, the mixing of the materials deposited in the pile is essential because the pile is formed only once. Mixing the pile is done with the help of a Fadroma type front loader by mixing several times in another pile and then depositing the mixed materials in the final pile. It is recommended that the mixing and pile formation be done on a concrete surface.
D. Pot composting system: involves enclosing active composting materials in a container, building, etc. The container system has the most aggressive management and generally the one with the highest capital investment, but offers the best control of the composting process. Most container methods involve a variety of forced aeration systems and mechanical turning techniques leading to the intensification of the composting process. Some composting systems in containers (a huge bag) include no-return composting materials. The composting system in small containers that are installed for use for about a year are accessible for composting on a variety of farms that generate organic materials including dead birds and manure. Many of these systems combine the attributes of the platform with turning equipment and those of the aerated static pile method.
