Grass Pellet Mill

Grass pellets have been traditionally produced for animal feed, however there has been a growing interest in grass pellets for the pellet fuel industry. Grass pellet mills can have different features to wood pellet mills. Grass pellet mills generally operate at higher speeds than wood pellet mills. As grass has a lower density than wood, and is easier to gelatinise, higher productivities through higher die speeds can also be achieved, reducing the cost per ton of grass pellets.

In many cases flat die pellet mills are chosen for grass pellet mills. One of the reasons for this is due to the very low cost of many flat die pellet mills from China. Flat die pellet mills work on a vertical design, with raw material entering the mill mainly through gravity. As grass is a low density material it is easier to get the grass into the compression chamber. Ring die pellet mills require a feed system, and therefore generally cost more. However ring die pellet mills have more control over the process and therefore pellet quality.

Grass pellets have very different combustion characteristics to wood pellets for example. Grass pellets in general will produce a much higher ash content, and possibly create a clinker and slag formations. Another aspect of grass pellets that must be looking at before using in a pellet stove or boiler, is the increased risk of corrosion. During combustion many grass pellets will generate at a higher temperature corrosive, chloride. Most pellet stoves and boilers are designed to purely burn premium wood pellets. If grass pellets are used in most pellet stoves and boilers, accelerated corrosion could destroy the unit within a few years, so be very careful.

Hemp Pellets Offer An Alternative