Several of us who earn our living making items from wood look at the mounds of sawdust we generate and question if we can burn sawdust, and what is the best way to do it. We all look at our rising heating costs each year, realizing it is going to cost us more in operation costs, forcing us to work for less or pass the increase on to our customers. At a time when big-box stores and imports are creating tremendous competition for cabinetmakers and furniture builders, we are all looking for ways to control costs and increase profits.
The idea of making our own heating-fuel pellets seems reasonable. In talking directly and online to other woodworkers, cabinetmakers and business owners, all were keen on the idea of a small shop utilizing their own sawdust and wood flour waste to produce heat.
The process for making pellets is, in theory, very simple. Using an extruding machine, moisture-controlled sawdust is fed from a hopper through an extruding screw, forcing the sawdust into a funnel under tons of pressure and heat. The compressed sawdust forms a small round dowel, which breaks apart exiting the extruder to make pellets.
But for a small- to medium-sized woodworking business, the process requires considerable space and money. While a small extruder doesn’t take up much more room than a 24″ planer, its operation requires a large screening process. If your sawdust is too large, it must be broken down with a grinder or hammer mill designed for this purpose. You’ll also have to store the finished products in a dry environment.
In nearly all states, the handling, storage, and use of large amounts of sawdust require permitting and regular inspection from a state government division of waste management. Here in Kentucky, if the sawdust is stored in piles outside, annual water testing is required under the Clean Water Act, a state law requiring that samples from downstream drainage be tested on a routine basis for compliance. If large amounts of oak were present, for instance, you may have tannic acid leaching, resulting in a brown-staining acidic run off, which may result in citations and other environmental control requirements. Some states require air-quality permits due to recent OSHA rulings regarding sawdust and wood flour as potential carcinogens. Local county or city governments may also have their own rules regarding the handling, storage and use of sawdust or wood flour, including nuisance ordinances if the wind blows sawdust onto neighboring properties. Even a thin layer of wood flour on someone’s car can be reason for a complaint and a potential citation.
Covered storage in most areas is a requirement for making wood pellets. There may be additional requirements from local fire marshals or your insurance provider for the production and storage of pellet fuel. The very name “pellet fuel” conjured mental pictures of roaring infernos to my insurance agent over breakfast one morning as we discussed this article.
Another hurdle for the small producer is the cost of electricity. Extruders and the accompanying equipment are power-hungry, and humidity control, materials and air handling add additional costs.
According to David Kaiser, executive director of the Pellet Fuel Institute, the cost and investment of producing pellet fuel is high. “An average investment for small production can easily exceed $500,000, with significant production reaching into millions of dollars.” While it is possible to find used pelletizing machinery, the hard truth is companies must be willing to make large long-term investments with large amounts of moisture-controlled space to produce even small amounts of pellets.
If a company is still interested in producing pellets, there are other products that can be made, such as incense pellets or flavor smoking pellets (for smoking meats and vegetables). The incense and smoking pellet markets usually require specific species of wood such as hickory, apple or mesquite worked separately for continuity of flavor, smoke, and aroma. Incense pellets, which are used in gas fireplaces, outside gas fire pits, or in small incense burners, may require scented oils to be added to the sawdust, with the potential to create other handling and environmental- related expenses.
Perhaps cooperative efforts between a large number of small shops and large wood businesses in a given geographic area may offer potential for the economy of scale to have an operational fuel pellet facility. According to the Pellet Fuel Institute, the number of home heating pellet stoves sold has soared this year due to escalating heating fuel and natural gas costs. The demand for pellets at present is high and growing, but there are only about 50 pellet manufacturing plants in North America.
Other potential options include the development of a small-scale forced-air woodstove or burner, in which dry sawdust is fed into a non-explosive environment, producing a slow smoldering burn. This may offer a more reasonable and economical solution. Large versions of this type of heating are available for large manufacturing and institutional buildings.
For more information regarding wood fuel pellets and commercial production, contact the Pellet Fuel Institute at www.pelletheat.org, or contact them at 703-522-6778.
Link to Pelletheat.org
——————
