Hi, one guy locally used to make wood pellets for the stoves. He was buying
shavings from the sawmills that were dressing kiln dry lumber. He had to
run them through a hog to get them finer. Many were too dry to work
properly so he would wet them down a little with a garden hose. He had an
old feed pellet machine. Many feed mills have some old ones in the corner
but when the dies get worn out, the holes are too big thus reducing the
space of solid metal between the holes and they will break easy. These are
a drum full of small holes with a roller on the inside at the bottom which
squeezes the wood particles through the die. If I remember right the dies
were worth around $6,000 10 yrs ago. He did not use any additive and he did
not heat the wood particles, just the heat created from compression was
enough to melt the resins so binding would happen.

We did have a sawmill that had built a log plant, they used the hardwood
chips from their sawmill, hog them, dry them and then press them in a die.
It would compressed around 12 inches of fine wood particles into 1/2" and a
lot of heat was created from this compression. The outfeed was about 40 ft
long to allow cooling so they would not break up. There was no additives of
any kind. If you broke the logs into the 1/2 inch pieces they worked fine
in a barbecue and burned very clean. If the particles were too wet the
pressure in the die head would get so high that the head would fly apart (a
safety feature) and it sure would scare the hell out of you.

One has to factor the wood species in too. Pine has a lot of resin so it
would bind easy. Many small briquette machine were sold in the US and I
believe these were made in Finland. The market was for fireplaces in the
winter and campfires in the summer.

Have fun
Eric