Hi, I’m Chris and welcome to my blog about biomass, feed and wood pellets. I’ve been making, burning and using pellets since 2007. PelHeat.com is an educational resource on wood pellets and other biomass/feed pellets.
I’ve separated the links to my posts under the category headings below. You can click the links below to jump to those particular posts. I hope I’m able to teach you something new about how wood pellets are made, burnt and their other uses! Cheers, Chris.
Making Wood Pellets
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 and how a pellet mill works etc. It’s best to start with reading this post 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.
If you wish to learn the precise details of the wood pellet production process I would very much encourage you to read The Pellet Handbook: eBook and Hardcover – Amazon
Once you own a pellet mill and then 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 the 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 because 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 be able to 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 an important question. The second question is how do you get the raw material to that particular moisture content? On a large scale wood pellet plant it’s 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.
Another useful resource on the wood pellet production process is this book: eBook and Hardcover – Amazon
You may have a source of logs available or you know of a cheap source of logs and you’re looking into 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 a 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, for instance, 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 10kg/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 may be 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.
I myself have often described producing wood pellets as more of an art than a science. This book discusses the difference between the theory of making wood pellets compared to the actual practice of doing so: eBook and Hardcover – Amazon
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 wouldn’t absorb any moisture!
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 etc. I discuss if and when a homemade pellet mill could be viable to produce wood pellets.
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 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.
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.
Burning Wood Pellets
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, standard and 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 the various wood pellet grades.
Not all wood pellets are produced to the same standard. Furthermore, some pellet stoves and boilers can only burn premium grade pellets: Image – Amazon
Most people when they purchase their first pellet stove or boiler order bagged pellets. However, where available you can get a much better deal by purchasing wood pellets lose in bulk. You will need a pellet silo or storage room to accept bulk deliveries. The design of the pipework leading into your storage room is very important to protect the integrity of the wood pellets. With this post, I discuss the benefits of bulk wood pellet deliveries and provide examples of various companies in the US and the UK who offer bulk wood pellet deliveries.
If you have never used pellets before you may be curious about how long they last and if they have a shelf life? A typical question that many people have is ‘do wood pellets go bad?’ Well, if you don’t protect pellets from moisture or you don’t handle them with care, yes they can ‘go bad’. With this post, I discuss how to stop pellets going bad and how to make sure they have an unlimited shelf life. I also discuss a fact many people ignore, some wood pellets are just bad to begin with. Poor quality control means some pellets are just not up to grade. I show how you can test to see if a wood pellet is bad.
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 stove boiler corrosion damage. However, there is an exception and its hemp pellets. Fuel pellets made from hemp shiv are actually comparable to standard grade wood pellets.
If you are not aware of the history around industrial hemp in the US and around the world I would very much encourage you to watch this free documentary on Prime: Video – Amazon
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.
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 vs a DIY set up and compare the two.
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!
There’s 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 Greenhouses, large motorhomes and RV’s. Over 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!
Clarry was one of the first non-powered/gravity pellet stoves on the market. However, there are now other options such as this QStove above: Image – Amazon
BBQ Wood Pellets
Over the last couple of years, the popularity of BBQ wood pellets and pellet grills has really taken off. Previously cooking with hardwood was only the realm of the barbeque professional. However, with hardwood grill/smoker pellets the average homeowner has the ability to get some of that excellent wood smoke taste into their food. This could be by using a smoke pot on a propane gas BBQ or with a full-on pellet grill from Traeger for example. With this post, I discuss who are currently the top brands of wood pellets for grills/smokers.
There is an incredibly wide range of different wood species/flavours available as BBQ wood pellets: Image – Amazon
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 pellet 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.
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 number 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.
I like pizza, who doesn’t? Well, I think it’s pretty universally agreed that wood-fired pizza is the best there is. Now, there are lots of websites which show you how to build your own DIY clay pizza oven. However, realistically, most people don’t have the time for such a project, and it can take up quite a bit of space. That doesn’t mean you should deprive your self of that excellent wood-fired pizza taste. Now you can enjoy wood-fired pizza at home easily with the Ooni 3 and Ooni Pro.
There is a growing range of small/portable wood pellet pizza ovens coming onto the market: Image – Amazon
Other Wood Pellet Uses
There are obviously many different uses for wood pellets from fuel, to animal bedding and BBQ pellets. However, I must admit, wood pellets being an ideal 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 during production.