Obviously, the main raw material that people think about for fuel pellets is wood. However, many different biomass raw materials can be processed into fuel pellets. Hemp pellets and even cardboard pellets are possible. But what about fuel pellets made from horse manure? Horse stables often have significant disposal costs for manure. Therefore wouldn’t it be amazing to turn this costly raw material into a valuable asset? Well, the answer is obviously yes, but how can you turn horse manure from a cost into a profit?
When it comes to processing and burning manure the first thought for most people is, “But what about the smell?”. Well, odours during combustion can mainly be resolved by making sure the burn is efficient. Therefore that partly means making sure the material is dry before combustion. The video below is of an operation where horse manure is collected, dried and then used in a KSM-Stoker biomass boiler.
Turning Horse Manure from a Cost into an Asset
For many horse owners, the disposal costs of bedding waste can be significant. Therefore making use of the material is an opportunity to turn a cost into a profit. Typically the base bedding material will be straw, hay, shavings or in some cases actually wood pellet bedding. Once the horse manure and bedding is ready for disposal before it can be used for pellet production it needs to be dried.
The video below is of an impressive drying system developed by Organilock. They use their Bio Burner to generate hot water which can then be used to dry the waste. Typically the manure will be at a moisture content around 40% and will need to be dried down below 15% ready for the pellet press. The video below discusses drying various biomass materials, horse manure is also mentioned.
The Organilock drying system uses two large augers. At the end of the first auger, the manure enters a hammer mill with a large screen. This is designed to reduce the particles down so that more effective drying can take place. After the final drying stage has been completed the horse manure can then run through a finer hammer mill screen of 5mm to be ready for the pellet mill.
You may be thinking “why not start with a smaller particle size, the horse manure will dry more quickly?”. Well, trying to hammer mill wet material through a 5mm screen is only going to lead to a blockage of the hammer mill. Now that the horse manure is dry and in small particles it can be compressed through a pellet mill.
Is Burning Horse Manure its most Valuable use?
Horse manure pellets are a high BTU, low ash (compared to grass pellets) and low emission fuel. Therefore they do hold some potential as a locally produced fuel. However, many pellet stoves are designed to only burn premium grade wood pellets. Therefore the potential market for horse manure as fuel is limited.
If you are considering going to the expense of setting up a pellet plant to process horse manure, you should consider selling the pellets as fertilizer and not as fuel. Within the gardening community horse manure pellets are seen as an excellent organic fertilizer and soil conditioner. Selling horse manure pellets in 10kg bags as fertilizer will provide much better profit margins compared to fuel pellets. The same is true for chicken manure/bedding waste.
The Economics of Setting up a Small Pellet Plant
So let’s discuss the economics of setting up a pellet plant to process horse manure into pellets for either fuel or fertilizer. You could probably purchase a budget plant from China for less than $100K. For equipment manufactured in either the US or the EU you’re looking at probably double that. For that sort of money, the plant will be able to produce around 500kg/h of horse manure pellets.
Unless you have a very large stable your not going to be producing sufficient waste to make the plant viable. Therefore you should consider contacting other stables within say a 50-mile radius. You could then look into setting up a cooperative and a pellet plant at a central location. This will keep the delivery costs of the waste to the plant for each member to a minimum. It will also spread the liability of setting up and running the plant.
Conclusions on Processing Horse Manure into Pellets
If you own or operate a horse stable the approach you need to take to address your manure waste issues depends on the scale of your operation. If you are looking after over 20 horses you may be producing sufficient waste to consider purchasing your own dryer and pellet processing equipment. However, if the number of horses is less than that a more realistic option is to group together with other stables and form a collective to deal with the issue. You share the costs and the profits of converting the manure into pellets.
As stated above, you could use the pellets as heating fuel for your own personal use with a suitable pellet stove or boiler which can deal with the ash content. However, the most profitable market for the rest of the horse manure pellets is not as fuel, but as fertilizer.