Compound Fertilizer Production Line Project Proposal Shandong Tianli R&D Institute July, 2008
1. General 1.1 Introduction According to the fertilizer standard of GB15063-2001, a compound fertilizer is made by chemical method or blending process, containing at least two elements of three major nutrients (nitrogen, phosphorus and potassium) with identified specific weight percentages. The process technology of N-P-K fertilizers is advanced and reliable. According to the compatibility and crossability of the raw materials, N-P-K compound fertilizer in different percentage composition can be manufactured by process of dissolving, mixing, pelleting, drying and screening, applicable for different requirements of soils and crops. Table 1: The technical requirements of the compound fertilizer: Item Total nutrient content: (N+P 2 O 5 +K 2 O)/% Specifications High consistence Mid-consistence Low consistence 40.0 30.0 25.0 Water soluble P /% 70 50 40 Moisture(H 2 O)/% 2.0 2.5 5.0 Granularity (1.00~4.75mm or 3.35~5.60mm) 90 90 80 Cl - /% 3 Appearance Granule, strip or flake,without mechanical impurity 1.2 Application and Market Prospect As the food of plants, fertilizers are vital for yield and quality of crops. At present there is a growing concern that the cultivated land is short of fertilizers and the soil is unbalanced in structure rich in nitrogen while poor in phosphorus and potassium, so the development of compound fertilizer is a more pressing task for the sustainable agriculture. Its aim is to keep agricultural productivity and soil fertility being increased steadily and continuously, keep a harmonious environment and permanent 1
utilization of resources and environment. With the improvement of people s living standard, the demand for quality and quantity of vegetables and fruits is higher than before, so the supply of compound fertilizers is hard to meet the market demand. Therefore, the good-quality compound fertilizers, suitable for a variety of crops with different N-P-K formulas, have a promising bright future in future market. Relying on powerful technical support of Shandong Academy of Sciences, Tianli D & R Institute concentrates a lot of money and labor force on researching and developing compound fertilizer production technology and whole set process equipment. The institute has successfully developed 30000-200000 t/a compound fertilizer whole set technology and has rich experience on key equipment design and manufacture, production technology upgrade and whole set equipment EPC project. The new process technology has arrived at international advanced level with many advantages, such as stable production, reasonable investment, high return rate, environment protection, low energy consumption and etc. Compound fertilizer department of Tianli Company has closely cooperated with cooperation units and undertaken many domestic compound fertilizer projects in recent years, at the same time they has focused on international market development and undertaken the projects for many overseas compound fertilizer production lines. 2.Construction Condition 2.1 Main raw materials of the compound fertilizer 2.1.1 Primary fertilizers Nitrogen fertilizer component: urea, ammonium bicarbonate, ammonium nitrate, ammonium chloride, and etc. Phosphorus fertilizer: single superphosphate, triple superphosphate, ammonium diacid phosphate, diammonium phosphate, calcium magnesium phosphate, nitric phosphate, and etc. Potassium fertilizer: potassium chloride, potassium sulfate, and etc. 2.1.2 Secondary nutrient fertilizer 2
The secondary nutrient fertilizer contains calcium, magnesium and sulfur. It is nourishing and can improve soil fertility. 2.1.3 Trace element fertilizer The trace element fertilizer contains boron, manganese, iron, zinc, copper, molybdenum and chlorine which are absolutely necessary nutrition fertilizer for plant. 2.2 Site area of project: 9080 m2 Workshop: 4000 m2 Product storage area: 2000 m2 Raw material storage area: 2000 m2 Boiler room: 80 m2 Office and other facilities: 1000 m2 2.3 Design of utility Electricity: 1000KVA, transformer 380V±5%, frequency: 50±3%(some changes can be made according to owner s requirements) Boiler: coal-fired (oil-fired, gas-fired) boiler Compressed air: designed according to the requirement of packing machine Water: 0.6 t/h 3. Process and Equipment 3.1 Process 3.1.1 Production process description Compound fertilizer production line contains many processing units: crushing, mixing, granulation, drying, cooling, screening and packing, which are precisely controlled. Crushing process: the material is fed into the double-roller crusher and is crushed by the high-speed roller to reach the required particle size for granulation process. Pulverized and mixed raw materials are transported to the belt weighing feeder via the bucket elevator after leaving the crusher prior to the next stage. Material mixing process: all raw materials in the storage hoppers are discharged at a controlled flow rate by the belt weighing system according to the required ingredient ratio. The material s size distribution was required strictly, no agglomeration and 3
discontinuous operation is allowed during the feeding process. If not, the measurement precision and the final components content of products will be influenced. After being weighed, all the raw materials are collected by a belt conveyor and sent to the third stage. Granulation: the fine materials in the granulation drum are rotated with the drum. In the mean time, certain bond is added proportionally for the granulation. From the basic granule seeds, by coating and agglomeration process the products with the desired size are formed gradually. Depends on the rotating and incline of the granulator, the final granules are discharged and enter into the drying process. Drying: a rotary dryer is used for the drying of granulated compound fertilizer by direct heating. The raw materials are fully mixed with the high temperature flue gas in the dryer by the flight to remove the moisture through vaporization with concurrent flow and slight negative pressure operation. There is a secondary granulation section in the dryer, which can improves the granulation efficiency of whole system. In the drying process, inlet and outlet temperature of the dryer need to be adjusted by means of the adjustment of the temperature in hot-blast furnace and the exhaust. Depending on the process requirement, the secondary dryer is equipped to reach the desired moisture rate. After the drying process, granulated compound fertilizer enters the next stage through the bucket elevator. Cooling: the rotary cooler can cool the hot material down to the ambient temperature rapidly. During the cooling process, the cooled air could also remove some moisture from the products. The cooled material needs rapid packing in time to prevent agglomeration during storage. The counter current flow and slightly negative pressure operation with reliable structure, steady operation and high adaptability improve the working performance. The cooled material is transported to the next stage by the bucket elevator. Product screening: the fine powder and products from the cooler are separated in this process. The separated finer powder returns to the granulator together with the crushed oversized granule which is separated in the former stage. The screened products enter the next stage---coating process. 4
Coating: due to the rotary drum maintained well mixed particle bed, the material could be coated uniformly with the coating agent melted in the agitating tank through the sprinklers mounted within the drum. And the agglomeration is also avoided. Qualified granules enter the next stage packing process. Packing: Through belt conveyor and elevator, the products are transported to the automatic weighing and packing machine. Used the compressed air, the packing machine weighs the material according to the setting weight, then the material is discharged into the packing bag automatically and stitched by the stitching machine, finally transported to the warehouse for sale. Dust collecting: The exhaust from the drying and cooling process is separated by cyclone in first-stage dust collecting system. The separated powder returns to the granulating process. The exhaust is cleaned by venturi scrubber, and finally discharged into the atmosphere through the chimney. 3.1.2 Technology advantages Material measuring: The agglomeration of raw materials will affect the transportation and measurement, so it needs to be crushed. The crushed materials fall into their own measuring bunkers directly. Electronic belt scale is used to indicate measurement report, history record and automatic report of ammonium phosphate, potassium chloride, ammonium chloride and microelement. Granulation process: entering the granulator via electronic belt scale under the buffer hopper, the solid material contacts with steam sufficiently and granulates with incessantly rolling. The buffer hopper and electronic belt scale ensure the material to be fed into the granulator stably at even rate. Drying and cooling process: after being granulated and twice dried, the material enters two rotary screens. The crushed oversized granule together with the separated finer powder returns to the granulator with a higher temperature to reduce the energy consumption. The rotary dryer has automatic cleaner to prevent the material from agglomerating and sticking to the shell of equipment. Dust removal: the main facilities in de-dusting unit are cyclone, venturi tube and wet 5
scrubber. The powder is collected and the off-gas is vented through the chimney. The slurry collected by the wet scrubber will be pumped by a slurry pump. After atmospheric drying, the material returns to the granulator to reduce the loss of material and the production cost. Recovery and use from the cleaning mixture of the wet scrubber can solve the emission problem and reduce the loss of material to increase profitability of the plant. 3.2 Equipment 3.2.1 List of equipments of compound fertilizer production line Name Qty Remark Belt scale 5 IPC2 industrial computer 1 Crusher 1 Return product crusher 1 Rotary drum granulator 1 First stage rotary dryer 1 Second stage rotary dryer 1 Rotary cooler 1 Rolling screener 1 Vibration screener 2 Coating drum 1 Belt conveyor 8 Bucket elevator 4 Packaging machine 1 Urea melting system 1 Ductwork 1 Draught fan 3 Air dehumidification system 1 3.2.2 Key equipments description 3.2.2.1 Rotary drum granulator 6
The rotary drum granulator is one of the key equipments of compound fertilizer production process. It adopts special stainless steel and rubber plate liner and traditional scraper is canceled. The merits of the equipment are as follows: high balling intensity, high yield, high corrosion resistance, high abrasion resisting, low energy consumption, long service life, operating convenience, and so on. 3.2.2.2 Rotary dryer By means of edge driving, flange connection, direct heat exchange, this dryer is suitable for drying granular compound fertilizer. There are many special thrust plates at different angles in the dryer. Because of the thrust plates and the turning of the dryer, the material is fully mixed with gas from the high temperature furnace to remove the moisture. The special plates can prevent the material from sticking to the shell of the equipment. 3.2.2.3 Rotary cooler The fertilizer is fed from inlet end and the cooling air is blown into from outlet end. When the two confront in different direction, the compound fertilizer will transfer the heat to the cooling air and its temperature will drop to a certain degree and ti wil be vented through the outlet. The contact area of compound fertilizer with the cooling air reaches 80% of the total area because of the special thrust plates. It reduces pollution and improves working performance because of a counter current design. 4. Safety and Environment Protection 4.1 Gaseous waste Exhaust gas: Particulate emission < 50 mg / Nm 3 (Emission Standard for Air Pollutants) During the compound fertilizer production, a mass of vapor and a certain amount powder and ammonia is exhausted after the dryer. In order to prevent the flue gas from polluting the agricultural environment, cyclone, venture tube and wet scrubber are provided to collect particulate. 4.2 Liquid waste 7
During the dust collecting system, wet scrubber is used to collect the powder. After the powder being dissolved, the water flows into sedimentation tank. Since water is recycled, wastewater drainage will be zero., 4.3 Solid waste During the compound fertilizer production, all of the solid waste can be recovered. So there is no solid waste. 5. General Layout, Transportation and Storage According to the local natural conditions and site surroundings, we do our best to make reasonable functional divisions. The big power users are located together with the power supply at hand and piping is neatly arranged. Such a concise layout can fully meet the requirements in production, transportation, fire fighting, security, hygiene and environmental protection. 5.1 Layout The factory contains production plant, raw material storage, product storage, substation, office building and duty room. Eatery and dormitory can be added depending on the owner s requirements. 5.2 Features of layout Compact structure, distinct divisions and neatly-arranged pipelines, meet the requirements of production and transportation. 5.3 The roads in plants City concrete roads in orthogonal ring shaped arrangement (width: 9m and 6m). 6. Training Our company has successfully established several compound fertilizer production lines in China. With fully-equipped pilot base and technical engineers, our company can make perfect training plan about process, equipment and on-site operation for the appointed technical staff according to the owners needs and provide one-station service. During the commissioning and start-up in the jobsite, we will instruct the technical personnel from the owner to be familiar with the knowledge concerning the 8
process and equipment and help them acquire the operating skills as soon as possible. 7. Investment and Economic Benefit Analysis Tianli Company has successfully developed a fully-integrated technology of 30000-200000 t/a compound fertilizer. The profit and tax per ton for compound fertilizer is between 120 to 160 RMB, the investment return period is about 1.5-3 years. We can make adjustment in the project investment and make a more reasonable design according to the different production line and production capacity that the owner has chosen, and local conditions and discharge standards. Advanced process, equipment and technology with advantages of stable environment-friendliness and energy conservation are employed in this project, and the product with large consumption has a wide application in market. The enterprises which invest on this project can seize the larger share in market, obtain better economic benefit and lift their image and competitiveness. 9