I have several ovens running on alternative fuels other than timber. We have one running on pelletized wood waste; however, this is a commercial oven using a sophisticated control system to deliver forced draft to the combustion chamber. The other fuel we have in use and works very well are hardwood shaving and sawdust made into briquettes. This fuel delivers a very good heat and is much improved if you can mix it with a little amount of softwood sticks. The sticks seam to have the effect of drawing more oxygen through the briquettes and increasing the heat of the fire.
Briquettes unfortunately are very expensive and very a great deal in quality so if you need to use them make surd they are made from wood rather than paper / cardboard waste
Alf |