This is my main post on the subject of how wood pellets are made. Within this post, you will also find links to other posts on the process of making wood pellets. For instance, more details on material preparation, how the pellet mill works etc. It’s best to start with reading this post however as it provides a broad overview of the wood pellet making process. You will learn that while it may appear to involve simply placing wood within a pellet mill, this couldn’t be further from the truth.
Even small changes in the particle size of the wood placed into pellet mill can make a big difference. You will also learn about why controlling the moisture content of the wood plays a crucial role. Consistently producing good quality and durable wood pellets is a challenge. It requires a well prepared raw material and an equally well prepared and maintained pellet mill. If either of these factors is not truly appreciated the results can be a lot of wasted time and frustration.
Not all wood pellets are created equal. Depending on the choice of raw material and how the wood is prepared it can have a significant impact on the quality and grading of the wood pellets. There are various different grades of wood pellets from premium to standard and finally utility grade. With this post, I discuss the various wood pellet certification standards. For instance how the Pellet Standards Institute (PFI) and ENplus provide certificates for various wood pellet grades.
Once you own a pellet mill and the start to try and make wood pellets for the first time it’s more than likely you will run into issues. One of the most common issues is a blocked wood pellet mill die. With this post, I discuss some of the reasons the die can become blocked, and how to avoid it happening again. The die is the most important part of the pellet mill when it comes to making wood pellets. The design of the die and how it is maintained have significant consequences on the process of making wood pellets.
When it comes to making wood pellets there is a lot of discussion and debate around the topic of binders and lubricants. For instance, does a small pellet mill require a pellet binder to make wood pellets? The answer depends on several factors, such as the design and quality of the pellet mill. However, pellet binders and lubricants are actually common in the wood pellet industry. Only small amounts are required which can have a big impact on wood pellet making process. It is possible to make wood pellets without binders, but they can make the process run a lot more smoothly.
You can make wood pellets from practically any source of woody biomass. However, some raw materials will produce wood pellets not fit for purposes depending on their intended use. For instance, the requirements of wood pellets used for heating fuel are very different for those used for animal bedding. Furthermore, wood pellets used in BBQs are also very different than those used for heating fuel or animal bedding. There are also certain raw materials you should not process. Either because it will potentially damage the pellet mill or by using/burning the wood pellets could be a health hazard. There is a lot to think about when choosing the best raw material to make wood pellets from. This includes evaluating how close that raw material is to where you will process it with a pellet mill.
When it comes to making wood pellets, probably the biggest headache comes from the issue of moisture content. If the raw material is too dry or too wet wood pellets will not form. Furthermore, too much moisture can easily lead to a pellet mill die blockage. Then more time needs to be spent to clean the die before you can try again. Therefore trying to figure out what is the perfect moisture content for the raw material to produce wood pellets is one question. The second is how do you get the raw material to that particular moisture content. On a large scale wood pellet plant its fairly straight forward. There are in-line infrared moisture meters and batch mixers to produce a consistent material. On a small scale, however, these luxuries are not viable. Therefore it involves low tech options such as dry weight tests.
You may have a source of logs available or you know of a cheap source of logs and are looking to the process of making wood pellets. What you need to be aware of is that processing logs into wood pellets can present significant challenges. You will need to understand your end users requirements and whether you need to remove the bark from the logs. Removing the bark takes additional time, effort and equipment, but it may be required. In other cases leaving the bark on the wood pellets may even improve the end product.
Getting set up to make wood pellets can be expensive. Therefore its quite understandable that many people consider the purchase of a used pellet mill. However, there are some factors you have to consider before making your used pellet mill purchase. For instance, it may be possible to purchase a new pellet mill for less than a used pellet mill if you look in the right places. Purchasing a used pellet mill from eBay may pay off. However, there may be damage to the pellet press which you cannot easily see. Also, with a used pellet mill you need to consider where you will purchase your spare parts from. As with any pellet mill, at some point, you will need to purchase new dies and rollers as these are consumable parts.
If you are looking to make wood pellets from home, you may be looking to purchase a single phase pellet mill. With this post, I wanted to look at some of the problems you may experience. For instance, does your electrical connection provide sufficient power to be able to run a single phase pellet mill? Also, does the limited productivity of a single phase pellet mill on wood pellets make the project viable? For wood pellets, it takes about 1kW of power to produce 10kgs/h. Is that productivity worth your time and effort? It’s these questions and more you have to ask yourself before purchasing a pellet mill to decide if the project is viable.
There is no doubt then when it comes to small pellet mills, flat die Chinese pellet machines dominate the market. However, while flat die pellet mills are easier to manufacture, they lack some of the benefits of ring die pellet mills. With this post, I explore some of those benefits. I explain why ring die pellet mills produce more consistent quality wood pellets. Also, why ring die pellet mills have reduced roller and die wear. Furthermore, why ring die pellet machines consume less power to produce the same quantity of wood pellets.
If you already own a compact tractor you might be considering the purchase of a PTO pellet mill. However, while PTO pellets mills have the benefit of being portable and using an existing power source, there are some downsides. You need to remember that a pellet mill is only part of the pellet production set up. You will also likely need a chipper, hammer mill and potentially even a drying setup. So while your PTO pellet mill maybe portable, what about the rest of your wood pellet making setup. There is also a significant safety risk with PTO pellet mills that should not be underestimated.
From reading various other websites and forums on how to make wood pellet there seems to be a lot of confusion around the roller and die gap. Many of the forums seem to think that it’s a good idea to ‘clamp’ the pellet mill rollers down against the die. Well, I need to make it clear, that is very bad advice. There should never be any metal to metal contact between the pellet mill rollers and die. However, if that’s the case, how big should the gap be? With this post, I discuss the pellet mill roller and die gap which should be maintained. Maintaining this gap will provide a good balance between wood pellet quality, pellet mill productivity and parts life.
The most common type of pellet mill available on the market today is the flat die pellet mill. However, there are two distinct designs of the flat die pellet mill. Either the die is driven by the motor or the rollers are driven. There are pros and cons to each flat die pellet mill design choice. With this post, I also look at some examples of what can go wrong when trying to make wood pellets with a flat die pellet mill.
First, you may be wondering what exactly a torrefied wood pellet actually is. Don’t worry, most people are unaware of the amazing qualities of torrefied wood pellets. They are essentially a version of man-made coal, but don’t let the term ‘coal’ put you off. Torrefied wood pellets actually burner cleaner and hotter than the best premium grade wood pellets. Torrefied wood pellets also repel water, you could even leave them out in the rain and they would be fine!
Traeger produces some of the most popular BBQ wood pellet grills in the world. Based in the US, Traeger has been producing BBQ wood pellet grills since 1985. Besides making grills, they actually manufacture their own BBQ wood pellets. They offer fuel made from Hickory, Mesquite, Apple, Cherry, Oak, Alder, Pecan, Maple and various other blends. Their BBQ wood pellet production process is very similar to the standard wood pellet fuel process, however, there are some interesting differences.
Fuel pellets can be made from many different forms of biomass including various grasses and energy crops. However, when you compare most other biomass materials to wood the results don’t match up. For instance, there can be issues with high ash contents, clinker formations and corrosion damage. However, there is an exception and its hemp pellets. Fuel pellets made from hemp shiv are actually comparable to wood pellets.
For some people, the idea of being able to make their own wood pellets from home is very appealing. However, the small pellet mills which they can buy are either too expensive or they don’t want to purchase a pellet mill from China for various reasons. Therefore the idea of homemade pellet mill is something quite a few people start to explore. With this post, I want to talk about the videos of homemade pellet mills you may have seen on YouTube. I discuss if and when a homemade pellet mill could be viable to produce wood pellets.
Purchasing wood pellets for your pellet stove or boiler can get expensive. Therefore some people start to look at what other biomass materials could be used for fuel pellets. Lawn clippings are a material many people have access to. Therefore how to make grass pellets from lawn clippings is a topic of interest to many people. The process of turning lawn clippings into grass pellets is actually relatively easy. However, most people are not aware of the downsides of grass pellets, and the significant damage they can cause to a pellet stove or boiler.
It can be really tricky to find a suitable source of dry woody biomass to make wood pellets from. A considerable volume of wooden pallets is shredded every year. Once wooden pallets are too damaged to be used for delivering items they have very little use. Therefore the wooden pallets can be shredded and potentially processed into wood pellets. However, there is a significant issue of metal contamination (nails) which needs to be addressed first. If the metal contamination issue is not completely solved it can cause significant damage to the hammer mill and pellet mill when making wood pellets.
If you have a wood pellet store they are various options to move those wood pellets to your pellet stove or boiler. You can consider fixed or flexible augers. However, they are generally expensive, complicated and can occasionally become blocked. Another alternative is to use a wood pellet vacuum system. The advantages of a wood pellet vacuum system are they are generally cheaper can cover longer distances and tricky tight bends. With this post, we look at an off-the-shelf wood pellet vacuum system and a DIY set up and compare the two.
There are obviously many different uses for wood pellets from fuel, to animal bedding and BBQ pellets. However, I must admit, wood pellets as a growing medium for mushrooms even caught me by surprise. But when I started to look into the subject more, the benefits became clear. To successfully grow mushrooms you require a sterilised material. Typically staw or wood shavings would need to be placed in boiling water for sterilisation. The benefit with wood pellets is that the pellet mill effectively sterilises the wood.
I would encourage anyone to try food cooked with BBQ wood pellets, the flavours are simply amazing. The problem is that full on BBQ wood pellet grills can cost a considerable amount of money. If you have a simple gas BBQ and want to try the smokey flavours from hardwood BBQ pellets, you can try a smoker box. A simple little wood pellet smoker box can be placed in the gas BBQ with a small amount of pellets inside. Once the cast iron pot is up to temperature, wood smoke will come out from around the sides. Its then time to turn down the gas and let the smoke do its magic.
There is a growing demand for portable pellet stoves for various off-grid applications. The Clarry pellet stove was developed over a decade ago for camping. However, since then it has become apparent there is a wider range of demand for portable pellet stoves. For instance, this can include heating green hours and large motorhomes and RV’s. Ove the last decade there has also been a considerable growth in Tiny Houses. It’s in these sorts of applications where a portable pellet stove which does not need electricity to operate can really shine!
There is a significant volume of cardboard waste generated every year. Therefore in terms of recycling cardboard its quite understandable that people are curious about processing cardboard into pellets. Well, from personal experience, while it can be done, it’s not an easy material to process. For instance, with most biomass materials you use a hammer mill for size reduction before the pellet mill. However, when you process cardboard through a hammer mill you end up with a light fluffy mass that looks like candy floss!
Many stable owners have to pay significant fees each year to have horse manure and used bedding disposed of from their stables. Wouldn’t it be amazing if this raw material could be processed somehow to turn a cost into a profit? Well, guess what, pellets to the rescue! With some preprocessing to dry the manure and reduce it into smaller particles, it can be processed in a pellet mill. Horse manure pellets can be used as a fuel, however only certain pellet stoves and boilers can deal with the ash produced. Therefore, the most profitable use for horse manure pellets is as an organic fertilizer product sold to garden centres.