Napier Grass Torrefaction & Pelleting Process

By:Mr Evan Wang

Position:Managing Director

Oct 19, 2022

Dry plant materials form lignocellulose, from the combination of the lignin, cellulose and hemicellulose within the plant cells, which is the most abundantly available raw material on Earth for the production of biofuels. It is an important and renewable energy alternative to traditional fossil fuels.

Napier grass is one of the energy crops which are grown with the express purpose of using their biomass energetically in the production of torrefied biomass pellets, at the same time, reducing carbon dioxide emission.

In July 2022, SIMEC R&D division conducted biomass torrefaction and pelleting test program for commercial projects in Asia. Project location & capacity: in confidential against agreement. Feedstock is napier grass chips. The objectives of the tests are to understand mass balance on different processes, and to prove the property of end products and the productivities of biomass leaching, torrefaction and pelleting process.

Leaching Process (standby system, to meet with special market requirement)
1st July, 2022, sample collection and analysis


Raw Napier Chips	Napier Chips after Leaching	Napier Chips after Drying

Lab. Analysis Result:

Sample No.	Moisture Mt %	Ash Content Ad %	Volatile Matter Content Vad %	Fixed Carbon Content Fcad %	High Heating Value Qgrad Cal/g	Low Heating Value Qnetv Cal/g
Raw chips	11.5	6.87	76.32	16.81	4109	3428
After leaching&drying	10.5	3.85	80.43	15.72	4207	3561

Ultimate Analysis of napier grass chips after leaching treatment:

Potassium K	0.06 (%)
Chlorine (Cl)	<0.01 (%)
Sodium (Na)	0.02 (%)
Nitrogen (N2)
Hydrogen (H2)	5.3 (%)
Sulfur (S)	<0.25 (%)
Oxygen (O2)	42.6 (%)

Torrefaction Process (commissioning to process biomass at different torrefaction grades)
4th July, 2022


Torrefied Chips at low, medium and high temperatures

Conversion ratio of torrefaction process: 75-80% dry basis.
Torrefied chips at medium temperature: The brownish color of the torrefied chips is a bit more dark than the photo presents.

Lab. Analysis Result:

Sample No.	Moisture Mt %	Ash Content Ad %	Volatile Matter Content Vad %	Fixed Carbon Content Fcad %	High Heating Value Qgrad Cal/g	Low Heating Value Qnetv Cal/g
L/Torre0704	3.69	9.41	58.4	32.19	5123	4757

The average of mass loss (dry basis) is 20%.
Torrefied napier chips at high temperature, mass loss 25%. More gas phase products were released.

Pelleting Process 12th July, 2022
Make diameter 8mm torrefied pellets from torrefied napier chips.
The test proves that torrefied napier chips can be made to be good quality pellets by SIMEC machines.

Through the tests & commissioning, the optimized torrefaction & pelleting techniques have been proved.

© Copyright of articles and pictures on this site belongs to SIMEC. Any company, media, website or individual are not allowed to reprint, reproduce, repost, modify or use in other ways without permission. Otherwise SIMEC will have the right to pursue legal responsibilities.

Blog

Napier Grass Torrefaction & Pelleting Process