Straw is the general term for the stems, leaves, and ears of mature crops. Usually refers to the remaining portion of wheat, rice, corn, potatoes, rapeseed, cotton, sugarcane, and other crops (usually coarse grains) after harvesting the seeds. More than half of the products of crop photosynthesis exist in straw, which is rich in nitrogen, phosphorus, potassium, calcium, magnesium, and organic matter. Straw is a versatile and renewable biological resource, and it is also a coarse feed. The characteristic is high crude fiber content (30% -40%) and the presence of lignin, etc. Although lignocellulose cannot be utilized by pigs and chickens, it can be absorbed and utilized by ruminant animals such as cows and sheep.

The main characteristics of straw:

Generally speaking, straw is composed of 80-90% cells and 10-20% inner cavity, with the internal material consisting of 5-10% silica and 5-15% extract, most of which are water-soluble. In terms of molecules, the cell wall of straw is like a woody cell wall, composed of cellulose, hemicellulose, and lignin. Cellulose aggregates in the original fibers surrounded by molecules. Lignin is the “glue” that connects individual cells to form plant tissue and fibers to form cell walls. Straw differs from wood in terms of cellulose, hemicellulose, and lignin content. The cellulose and lignin content of straw is low, but the hemicellulose content is high.

Application of straw pellet production line

Straw pellet line can directly process crop waste such as corn straw, rice straw, cotton straw, soybean straw, flax straw, etc., into pellets, which are mainly used in the fields of feed, biomass fuel, etc. When processing these different types of straw pellets, the process of straw pellet production line is different.

Feed:
After the straw pellet production line makes coarse raw materials such as straw into pellets, it can improve the nutritional content and taste of feed, improve the production performance of livestock, and reduce the cost of feed production.
Biomass fuel:
The straw pellet processing line processes waste crops such as straw into pellets, which can be used to produce biomass pellet fuel, effectively utilize crop waste resources and reduce environmental pollution.
Other applications:
In addition to feed and biomass pellet fuel, straw pellet machines have other application areas, such as organic fertilizer, pharmaceutical intermediates and other fields.

Processing Technology of Straw Pellet Biomass Production Line

Due to its wood like composition, straw can be used to produce straw pulp or converted into straw pellets. According to the particularity of straw, the granulation process of straw can be summarized as follows:

1. Raw material preparation stage:
   Straw usually has a high possibility of dust, which is influenced by the harvesting method. Therefore, straw needs to be screened from pollutants, such as dust and other foreign objects that may affect the quality of straw particles, such as stones, metals, and those that may damage the granulator in the following procedures.

2. Crushing stage:
   Straw biomass is a tubular material with a diameter of 4-8mm and a wall thickness of about 0.3-0.6mm. By adopting a tubular structure, straw can be easily processed and obtain the desired particle size. Usually, the grinding of straw involves cutting and crushing the straw. 3. Drying stage: Usually, straw is transported in the form of air dried bags, with a moisture content of about 15%, suitable for producing straw pellets. Therefore, the drying process of straw particles will be omitted. But if the straw has a high moisture content, the drying step is necessary.
3. Drying stage:Usually, straw is delivered in the form of air-dried bags with a moisture content of about 15%, which is suitable for the production of straw pellets. Therefore, the drying process of straw pellets is omitted. But if the moisture content of straw is large, the drying step is necessary.
4. Conditioning:Straw requires special conditioning to achieve the desired hardness. Straw conditioning includes the application of steam (and/or water) and the addition of binders or additives. Conditioning is required to achieve the necessary temperature and humidity to obtain ductility and melt lignin to act as a binder. Binders are required to enhance the hardness of the pellets and reduce wear during the pelletizing process.
5. Granulation:In the granulation process, it is necessary to consider the influence of factors such as material moisture, density, pellet size, fiber strength, natural adhesive, etc. on the granulation quality. Common problems in the process of straw pelletizing are clogging and breakage of pellet molds, overheating, high energy costs or poor pellet quality, and high maintenance rate of pelletizers. In order to avoid the above problems, a high-quality pelletizer is required.
6. Cooling and screening:The newly extruded straw pellets are hot and soft and need to be cooled to obtain the ideal hardness. At the same time, the screen on the cooler is used to screen out the pellets that do not meet the molding effect.
7. Finished product packaging:The cooled pellets need to be sent to the finished pellet bin by a professional skirt belt conveyor, and then unloaded from the finished pellet bin and packaged with a packaging scale.

How to build a complete straw pellet production line?

1.Are there any preferential policies for the external environment; subsidies for electricity taxes? Inquire with the local environmental protection department about the intensity of coal ban; attitude towards biomass straw pellet fuel; whether there are corresponding official documents?

2.Investigate the quality, price and quantity of raw materials, and also consider the factors of long-term supply (i.e. long-term control). According to the raw materials, we can plan the configuration of the production line and analyze the cost.
3.After determining the raw materials, we must determine the straw pellet plant. The factory building is generally close to the raw materials or convenient for transportation. It is best to have both.
Transformer. The biomass pelletizing industry consumes a lot of electricity. After determining the production capacity, choose to purchase a transformer that matches the production capacity according to the equipment power provided by the equipment manufacturer.
4.When purchasing equipment, you must first understand the product quality of the equipment manufacturer. It is often difficult to distinguish the quality of the product in the network environment.
5.You must go to the manufacturer for on-site inspection and don’t be fooled by the low price. The straw pelletizer is a ZHI invention patent and has now been upgraded to the 4th generation. ZHI Machinery’s strong technical strength will escort you to make pellets.
6.Equipment installation and commissioning: ZHI Machinery provides free installation guidance services and technical support for the entire life cycle of the straw pellet plant equipment.