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napier grass, หญ้าเลี้ยงช้าง, หญ้าเนเปีย, ไฟฟ้า

Napier Grass as raw material for gasification process to generate electricity

Napier Grass as raw material for gasification process to generate electricity.


Napier grass is becoming a popular biomass for gasification process to generate electricity in Thailand. Government office also issued the project that subsidizes napier grass as raw material for power plants.

The critical factors for Napier grass for power plants projects are harvesting of the grass, moisture content in the grass, transportation to the preparation factory, and making the dried grass into pellet form or else to be able to use in the reactor of gasification process.

Muddy area can be problem for harvesting and the moisture content in the grass can be as high as 70% (not included the water from rain if the case), causing high cost to dry the grass. Transportation cost and pelletizing cost are also to be considered too. Raw material preparation process includes;

Biomass chipper/cutting
Biomass material: Sugar cane stalks or Napier Grass stalks or similar can be mixed and used in most gasifier. Also woody biomass like wood chips or coconut shells can also be used but they might require a chipping or good cutting technology.

Sample of Output chip/strand size required:
Preferred:    sum of average chip/strand dimensions (L + W + H) at 50 mm
Maximum:     sum of average chip/strand dimensions (L + W + H) at 75 mm
Moisture content input biomass from 50-70% (by weight)
Throughput: minimum 5.0 tph fresh biomass per unit for 1 MWatt power plant size.
Auxilliaries: (i) dust collection system.  (ii) dust storage system.

Biomass Drying Unit
Technology type:  Rotary dryer or Columnar type dryer
Fuel:  Biomass (grass itself, wood chips, waste wood), LPG, also Drying heat source: ambient air diluted hot gen set exhaust. Direct gen set exhaust will be between 430 and 470 Deg C and we will dilute down temperature with air to required dryer operating temperature.

Chip/strand size input:
Expected Average:      sum of average chip/strand dimensions (L + W + H) at 50-75 mm
Expected Maximum:    sum of average chip/strand dimensions (L + W + H) at 100 mm

Moisture content input biomass (maximum 70% moisture content;  target output moisture content at maximum 18-20%

Auxilliaries: (i) feed system  (ii) discharge system.

This is just sample idea about the raw material preparation and gasifier related machines.

Napier grass, elephant grass, Thai Sumi, www.thaisumi.com

หญ้าเนเปีย รูปหญ้า เนเปีย เลี้ยงช้าง พลังงาน napier grass

Is it really economical? –> Napier grass for green energy

Last year (2012), Thai government announced about Napier Grass for generating electric power as follows.
“The government will issue guidelines within the next two months on a policy to promote generation of electricity from Napier grass, Energy Minister Pongsak Ruktapongpisal said yesterday.
Napier grass, originally from Africa, is also known as Uganda grass or elephant grass for being a favourite food of elephants.

Speaking on the sidelines of the “Green Energy Forum: A Balancing Act for Sustainability” held by Krungthep Turakij, Pongsak said Germany had developed 7,000 power stations fuelled by Napier grass that provided 7,000 megawatts, and Thailand could match that production.

The ministry will provide a “feed-in tariff” subsidy of Bt4.50 per kilowatt-hour (unit) for a period of 25 years to power plants that use as feedstock Napier grass supplied by local communities. This grass can be grown in many parts of Thailand, especially in areas currently used as sugar-cane and tapioca plantations in the Northeast and Central regions, provided they are situated not too far from the power grid, he said.

Pongsak said alternative energy currently contributed merely 1 per cent of Thailand’s electricity production, and Napier grass would contribute a significant chunk of the target to increase the contribution of alternative energy to 25 per cent within 10 years.

“Concerning energy security, we are currently depending on natural gas for as much as 67 per cent [of power-generation needs]. Seven new records of peak power loads occurred during the past year, which prompted a call to save energy. While our installed capacity is 32,000MW, the power demand peaked in May at 26,774MW, leaving a power reserve gap of only 16 per cent,” he said.

Pongsak said that if electricity-use growth rates remained at the current level, there could be power-supply issues in the next two years. Investors have often asked him about the government’s plan to boost electricity capacity.

He said the government would negotiate with Myanmar to pursue the 7,000MW Salawin hydropower project as well as putting more emphasis on biomass and biogas, including electricity production from Napier grass.

Considering the Bt6.50-per-unit subsidy for solar farms, promoting more solar plants will place an heavy burden on the public in terms of higher electricity costs, the minister said.

The question is if this project is really economical or not. Many people have heard about some of the Napier grass to feed (“Elephant grass”). Can it be used as a fuel briquette (Briquette) or pellet (pellet)? What are the pros and cons of napier grass?
Napier grass really worth the fuel used to produce energy or not ? Depends on several factors. Particular grass species (Pakchong 1, Emperor, etc. ), which can grow well in the terrain and climate , which is used as fuel. It should be planted so the moisture at the harvest is minimal, enough texture of grass ( 3-4 months , humidity is about 65-70 % by weight). Harvesting (labor, machine) and Transportation to the factory is also a factor to consider too .
The key factors for using Napier grass to make into briquette or pellet form are the preparation of fresh grass into the form ready to be briquetted or pelletized because this process requires a lot of energy. By pressing the water out as the crushing roller, cut the grass into smaller sizes to increase the heat transfer area, the grass still needs drying whice requires a lot of energy, especially to dry grass to reduce moisture from 65-70 % to 15-20 %. First, the grass is being pressed by rollers, which can reduce the initial moisture content down to approximately 35-45 %. Using conventional type rotary drum drier, the required amount of fuel is very high because of low efficiency (in most cases, inevitable to use biomass fuel, i.e. napier grass itself). More efficient process is to use superheated steam, which can dry the grass quickly and the grass does not have chance to catch a fire compared with the conventional hot air type.

หญ้าเนเปีย รูปหญ้า เนเปีย เลี้ยงช้าง พลังงาน napier grass
หญ้าเนเปีย รูปหญ้า เนเปีย เลี้ยงช้าง พลังงาน napier grass

หญ้าเนเปียร์  -004

charcoal briquette making from biomass wastes and sugarcane waste

[QUESTION]: Dear Sir,

I am interested in Machinery to produce charcoal briquett. I intend to start the project in my country. Please do email me a price quote for the whole system including the information (manual) on how to make them. I am specifically interested in making charcoal from coffee husks, rice husks , coconut husks, macadamia husks saw dust and maize cobs.

I don’t know whether your machines can support making charcoal from sugar cane wastes? please let me know.

Thanking you and looking forward to your response.


———- Answer ———-

[ANSWER]:? From the listed raw materials (coffee husks, rice husks , coconut husks, macadamia husks saw dust, maize cobs, and sugar cane waste), in order to make them into charcoal briquette, we would like to classify them into 2 groups which require different process; Hot process and Cold process.

Hot process : coffee husks, rice husks, macadamia husks, sawdust

Cold process : Maize cobs, Coconut husks (coconut shell?), Sugar cane waste

The hot process is more complicated, requires high skilled personals, require 5-6 times higher investment than that of cold process.

The cold process is suitable for above mentioned materials (Maize cobs, Coconut husks (coconut shell?), Sugar cane waste). However, the best quality of charcoal briquette you can get among those three materials is coconut shell, maize cob and sugar case waste respectively.

We would recommend you to start with only maize cobs and coconut shell first because their quality are good.

About machines of cold process, we can supply to you the machine and guarantee that you will be able to produce good quality (high density) briquette.

We will not only provide you the machine but we will also provide to you all related information, document and know-how. You will receive full operating manual, document and necessary know-how with the machine. Please kindly find our machine’s brochure as attachment. The complete unit as quoted comprises 1 crusher, 1 mixer-dispenser (can be used for 2 extruders), and 2 extruders. The production capacity is about 300-400 kg/hour of wood charcoal or any other biomass charcoal. You can add 1 more extruder to the quotation to double the capacity because the mixer and crusher is already designed for 2 extruders. Automatic cutting units are optional. We already give the manual cutting units with the extruders but if you need automatic cuttings, you can purchase as optional unit.

We can also offer the conveyor and other additional unit as per your request too.

Please give us comment about the above suggestion. Then we will get back to you again with further information asap.




Briquette making system for charcoal and Biomass – Correspondences1

Thank you very much for your time yesterday

Please let me summarize again about the options that you have.
1) Biomass briquette making: this process can be used to produce briquette from most of biomass (semi-dry material). The briquette?s density is not very high so it is suitable for being used as direct fuel. Please find photos in our website (link below):-


2) Cold process briquette making: this process can be used to produce charcoal briquette from raw charcoal or charcoal dust. Binder is required for this process which can be starch or molasses. The density of this briquette after drying can be as high as 1.1 g/cm3.
Size of motor for extruder = 10 HP, crusher = 7 HP, mixer = 7 HP (3-phase electrical)

3) Hot process briquette making: this process is suitable for fine and dry biomass such as rice husk, sawdust, crushed biomass. However, the investment cost is very high and the raw material preparation is also required (to reduce size and moisture content to less than 10 wt%.
Size of motor for extruder = 30 HP
All the prices already include major spare-parts and control panel. If without control panel (just direct connector with breaker), the price will be lower.
Please find quotation and photos as attachment. If you need more information or have any question, please feel free to let me know.

Best regards,

DSCF0553 product07


Sent: Monday, July 28, 2008 12:25 AM

To: Anupap Udomsab

Subject: Re: Biuomass and chacaol machine


Dear Mr Anupap Udomsab,

Thank you for your mail,

I have three different client, each one of them plan to use different raw material some of them are looking to mix raw material. To give you little info about raw material founded in my place are rice husk, stalk for each one of rice, Cotton, maize, sugarcane, and normal long grass that grow by itself in. the raw material are as follow as par client

1. Raw material ” Grass that grow in the river or the water ways to rice farm. He want to mix that grass with rice stalk, and cotton stalk” in other word it will be mix of raw material

2. Raw material “rice husk, rice stalk and sugarcane and cotton stalk

3. cotton stalk and sugarcane stalk

Please advice if the mix of the product can be produced. The aim of each client is to produce charcoal briquette as final project, bu client 1 and 2 wish to produce both biomass ” for factory and Bakery maker”.

I need the prices for the whole plant from crushing if needed to charcoal the whole plant. Please send me also the picture, and how many container we need for each plant. Electricity consumption. I would like you also to offer different capacity.

I hope to get a respond from you by tomorrow, my client has got a fund already and I need to act quick.

Thank you

On Sun, Jul 27, 2008 at 11:50 PM, Anupap Udomsab wrote:

Dear ,
First of all, please let us introduce ourselves. We are charcoal producer and charcoal making machine manufacturer based in Ayutthaya Province, THAILAND. We are specialized in Coconut Shell charcoal and some other charcoals as below;
– Coconut shell charcoal and charcoal briquette (100% natural material)
– Mangrove charcoal, Black charcoal and natural wood charcoal (100% natural material)
– Charcoal making equipment, sawdust extruder, etc.
We can supply machine to you and guarantee that you will be able to produce good quality (high density) briquette.Please kindly let us know what type of raw material to make briquette that you have. Then we will get back to you with further information about the machine that suits you case.
If you need more information, please do not hesitate to let us know. We are looking forward to hearing from you soon.
Your sincerely,