Rice husk pellets processing technology and equipment
Characteristics and uses of rice husk
The main components of rice husk vary greatly due to different varieties, producing areas and processing methods. Generally, the water content of rice husk is about 12%, 36% carbon, 0.48% nitrogen, 0.32% phosphorus and 0.27% potassium. Rice husk contains about 40% crude fiber (including lignin fiber and cellulose) and about 20% five-carbon sugar polymer (mainly hemicellulose).In addition, about 20% ash and a small amount of crude protein, crude fat and other organic compounds.Rice husk encyclopedia recommended
Table Compositions of rice husk in % of weight (dry basis) based on ultimate analysis.b
C
(%)H
(%)O
(%)N
(%)S
(%)Ash
(%)HHV
(MJ/kg)40 5 34.8 0.8 0.1 19.5 14.8
b. The determination of the percentage of elements contained in a chemical substance (Encyclopedia, accessed 2016)
The characteristics of rice husk compared with other solid fuels can be summarized as follows:
Its high silica content causes excessive wear to parts of processing machines, such as conveyors or grinders, and hampers digestibility in livestock. The content of volatile matter in the rice husk is higher than in wood and much higher than in coal; whereas, fixed carbon is much lower than in coal. Ash content in the rice husk is much higher than in wood and coal, which causes barriers in energy conversion.
The high content of ash, alkali, and potassium causes agglomeration, fouling, and melting of the parts of combustors or boilers.
Usage: rice husk is a good renewable biomass raw material, processed into fuel pellets through pelleting making machine, converted into rice husk gas through gasification, direct combustion to generate steam or heat, used for power generation, heating and so on.Rice husk can also produce high quality activated carbon, adsorbent, carbon black, silicon dioxide, silicon carbide, potassium silicate and other chemical products.Rice husk is renewable as a biomass resource compared to oil, gas and coal.In 1971 the Food and Agriculture Organization of the United Nations predicted that the most practical use of rice husks would be to provide energy as fuel.
Husk makes up 20% of the weight of rice.Of the 100 million tons of rice husk produced globally each year, 70 percent is underutilized.Demand is expected to reach 780 million tons by 2022, with even more husks to be processed.Learn more about rice International Rice Research Institute.
The advantages of rice husk pellets
After the rice husk is pressed into pelletss, the volume density is greatly increased, which is convenient for mass transportation and storage.
Rice husk pellets burn cleaner.Rice husks leave 15-16% ash when burned before being made into pellets.The ash content after pelleting is only about 6-7%.
Rice husk pellets can be fully and efficiently burned with a calorific value of 3200-3500 kcal, which is moderate and suitable for large boilers
The rice husk pellet machine has brought economic and social benefits to farmers by transforming rice husk into treasure.
| Material | Average diameter | Ash content | Average density | Moisture content |
|---|---|---|---|---|
| Rice husk | 2-3mm | 15-16% | 500kg/m³ | About 12% |
| Rice husk pellet | 8-10mm | 6-7% | 1120kg/m³ | 10-12% |
The principle of rice husk pelleting
pelletizing rice husk is to increase the density of feedstock. Basically, machines that produce pellets could be the ring die (Fig. 1).
Rice husk pellets and briquettes have a density of about 500 to 600 kg per cubic meter, 5 times that of their loose form. This increase in density leads to a reduction in transportation cost and increase in the performance of energy conversion processes. The advantages of using rice husk briquettes and pellets recently stimulate a fast growth of these business models in rice production.
Processing technology of rice husk pelletss
Screening. Removal of impurities in rice husk, such as rock, iron, etc.
Pelleting: the treated rice husk is transported to the silo, through which it is transported to the pellet machine for pellets.
Cooling. After pelleting, the rice husk particles are at a high temperature and need to be cooled by a cooler to maintain their shape.
Packaging. If you are selling rice husk pellets, you will need a packaging machine to pack rice husk pellets.
Processing technology diagram of rice husk pellets:
