Sectors of Pellet Fuel Usage

As a source of energy or wood pellet fuel or pellet fuel can be used in small-scale such as the household to large-scale on power plants. Both quantity and quality pellet are the parameters in its use in relation to equipment that is used. Basically from small-scale to large scale on the use pellet fuel especially related to efficiency factor, easy in operation, safety and gas emission impact (eventhough wood pellet include as renewable fuel that enter the category as carbon neutral) while the use on large-scale the qualityfactor of pellet got a serious attention. Technology that was used to utilize the wood pellet is almost all use combustion technology (direct combustion) to get output in form of heat or electricity.

In small-scale the use pellet fuel for mainly in the four season countries for room/space heating, even for this sector needs premium quality of wood pellet for pellet stove. Pellet stove has not yet been familiar in Indonesia because the wood pellet also still very difficult to get. Other equipment that are to be used in small-scale is boiler and burner. Boiler system will produce steam to source of steam and hot water. While burner can be used for various source of heat.

On the medium-large scale, users mainly for industries and coal-fired power plants. Grate combustor and stoker are equipments that general used in the industry. Pulverized technology system and fluidized bed commonly used in power plant. The percentage of wood pellets this time is still less than 5 percent on the use of cofiring in the coal powerplant. Wood pellet for pulverized while biomass pellet for fluidized bed. The characteristics of both pellet cause of the difference.

Wood Pellet and Briquette For Food and Beverage Industry

Fuels as an energy source in the food and beverage industry is the primary need is always required.  Environmentally friendly fuel, easy handling, cheap and easily available always wanted by the producers of the food and beverage industry. The biomass-based fuel, pellets and briquettes are the ideal choice for those needs it. The advantages of pellets and briquettes are:

1.     Environmentally friendly fuels and renewable

2.     High calorific value is generally more than 4000 kcal / kg

3.     Low ash content and minimum fly ash when burned

4.     Consistent high burning efficiency due to low moisture content

5.     High density thus saving transportation costs

6.     Uniform shape so as to facilitate the transportation, storage, feeding and burning

7.     The burning  is more homogeneous than coal

8.     Pollution is very low due to the sulfur content of nearly zero

9.     The more demanded because of the increase of fossil fuel

A number of industries have done the conversion from fossil fuel or firewood with burning of pellets or briquettes because of the excellences. Here are some types of wood pellet burner with automatic feed burner that is widely used namely:

1.     Stoker burner boiler

Stoker boiler burner boilers are the most simple, which has a small grate mounted directly at the end of the feed auger. In a small stoker boilers burner only comes with a single fan so it is difficult to separate the primary air supply to the grate of the combustion zone above the end of the grate. As a result of overheating and the potential formation of a deposit on the grate is very high, and some boiler makers adding cooling water circuit in the grate as a preventive.

2.     Underfed stoker boiler

In underfed stoker boiler, fuel pushed up through the inverted conical pile formed like a dome where combustion occurs. Almost all stoker boilers have air duct separate primary and secondary air to provide independent control of the combustion zone on the grate and in the end gas combustion.

3.     Moving grate boiler

Moving grate boiler is also known as, stepped grate boiler or inclined grate boiler, allows the greatest flexibility in the design of the boiler. These boilers can use the auger or ram stoker type feeder. As in underfed stoker boiler, moving grate boiler has primary and secondary air duct, and on the largest boiler tertiary air duct was added to ensure the complete combustion of wood gas at all. 

Briquettes have a larger size than the pellets. Therefore the size of the briquettes can be cut into smaller pieces to match the needs of its users. Below is an example of briquettes for boiler applications.

Besides being used in the food and beverage industry, pellets and briquettes can also be used for a variety of industrial fuel (thermal application) include: power generation, ceramic industry, chemical industry and others.