Biomass pelletization technology

There are already devices that use compacted rice husks as a substitute for coal, but it seems that the technology related to using straw in this regard is not yet fully developed

Manufacturers now produce straw shaping equipment, but its lifespan is too short

It’s a small-scale, workshop-style production method that is widely used among private entities; you can produce fuel in blocks of any size you desire. But as far as I know, the price of such fuel isn’t cheap – it costs around 600 yuan per ton. When used for biomass power generation in power plants, transporting this type of formulated fuel isn’t economical, and it’s quite difficult to achieve profitability

There should be three types: 1. Granulation, 2. Compaction, 3. Rod production

Biomass compaction technology allows biomass to be compressed and densified, making it easier to store and transport. After being compacted, biomass can be used as feed for livestock, or as fuel to replace traditional coal, offering environmental benefits and convenience. Nowadays, the products resulting from biomass compaction are commonly referred to as \"straw coal\" or \"straw feed\".

I have learned about some molding equipment recently; whether it’s ring die or flat die molding, corn and rice straws can be easily molded, while wheat straw is more difficult to mold. Is the wheat straw too dry, or is its composition not suitable for molding?

Similar to briquetted coal, adding some binder during shaping should make it easier to form. Plywood is made in the same way too

It is also different from particleboard, which must be heated and coated with adhesive, then formed through heat pressing. Currently, if this method is used for straw shaping, the cost is relatively high; therefore, shaping can only be achieved by utilizing the heat generated during the extrusion process.

Since the 1980s, significant progress has been made in the development and research of biomass briquetting technology in China, but there are still some limiting factors and technical obstacles. These include a short service life of the main working components, poor coordination among the equipment systems, unstable operation, low production capacity, high energy consumption per unit, and poor reliability of the molding equipment. The development of the biomass briquette fuel industry restricts the large-scale utilization of biomass energy in China, and the performance of biomass solidification equipment forms the foundation for the growth of this industry. Currently, most of the machines sold on the market under the name of straw solidification machinery are actually modified versions of equipment used for compressing forage. Due to inherent structural flaws, such machines generally suffer from a short service life, the density of the products produced being insufficient, as well as high actual operating costs and energy consumption. At present, several domestic companies, with the support of the Ministry of Science and Technology’s innovation funds, have focused on developing key technologies; they have introduced innovations and optimizations to the structure of these machines, resulting in a significant improvement in their performance and the quality of the products produced at the specified output levels. 1. Without increasing energy consumption, it is possible to reduce the crushing rate to below 2%, and during continuous production, the density of the formed fuel can be increased from 0.8 g/cm3 to 1.3 g/cm3 ； 2. Service life of molding equipment: key components > 10,000 hours ； Fragile parts > 1500 hours ； 3. The performance parameters of the manufactured solid fuel products are: ash content < 2% ； Density 1–1.4 g/cm3 ； Moisture <12% ； Breakage rate < 2% ；

Regarding the issue of straw extrusion molding, I would like to explain as follows: The main components of straw are lignin, cellulose, and hemicellulose. Lignin is a molecular structure with aromatic properties; it is a high-molecular compound with a phenylpropane-type structure. All types of biomass contain lignin, although its composition and structure vary. At room temperature, the majority of lignin is insoluble in organic solvents; it is amorphous, has no melting point but does have a softening point, and becomes viscous when the temperature is between 70 and 110°C. Applying a certain amount of pressure at this point allows the various components of the biomass to bond together within the mold cavity to form the desired shape.

Biomass energy has relatively low efficiency; at least, due to the current immature technology, it is difficult to use