Process & Operations


Process: ROI has designed the ENVIROSAVER™ and CARBONATOR™ carbonizing system to strike a balance between high-volume conversion of wood and vegetative debris, reduced greenhouse gas emissions and the ability to produce a high-quality end-product, biochar.

Both high or low moisture debris can be fed, and no grinding or chipping is required or suggested. However, in cases where the material is already processed, the ROI ENVIROSAVER™ 400 model can combust ground material, as it has a feed hopper which will meter in the product below the top above chamber air curtain and a live floor in the pyrolysis chamber to advance the material during the carbonizing process.

The system’s primary combustion chamber is designed to sustain consistent temperatures exceeding 2,500°F (1,370°C) throughout operation. The systems rugged thermal-ceramic walls, designed specifically for this environment, sequester heat energy through the combustion of the debris. This sequestering of energy is then released and re-distributed throughout the entire combustion chamber, equalizing temperatures, rapidly evaporating the water and other small molecules of the debris being introduced.

A high velocity curtain of air across the entire top of the primary combustion chamber seals the chamber from the atmosphere. The release of smoke particulates made of tiny combustible solids that would normally be present igniting beneath the above chamber curtain instead of being emitted to the atmosphere. Combustion efficiency is additionally assisted by a pre-heated under-chamber air and sufficient oxygen throughout the entire primary combustion chamber.

As new debris are continually added in to the primary combustion chamber, previous loads begin to carbonize or char as debris temperatures increase by way of pyrolysis. Through several patented techniques the char is passed down through the grate to the char-pan. Further combustion is prevented through cooling, oxygen starvation and quenching processes to produce the highest value end product. Discharge augers continually discharge the biochar at easily adjustable rates.

By sequestering the carbon in the wood through pyrolysis, the release of Carbon Dioxide (CO2) into the atmosphere is drastically reduced over other processes that requires complete combustion, and conversion throughput is increased. Additional benefits of the ROI system: ROI’s Carbonizers will operate without having to be shut down, again, significantly increasing throughput over inferior and outdated designed burning devices, called air curtain burners or air curtain destructors, that lack ROI’s control features, recycling capabilities, and overall performance.

ROI’s design allows for operator flexibility in manufacturing a desired end product by simply swapping out the quick interchangeable grate(s) in the bottom of the primary combustion chamber.



Operations: Once the clean wood and vegetative debris are loaded inside the primary combustion chamber or Fine Debris Hopper, the ENVIROSAVER™ or CARBONATOR™ is ready to be ignited for continual carbonizing.

Taking approximately 7-10 minutes for the debris in the combustion chamber to become completely engulfed in flames the above chamber air curtain and pre-heated under-fire air is turned on and increased in increments to full velocity, utilizing the operator interface control panel.

The desired rate of loading debris for maximum performance is to load the combustion chamber continually for the remainder of operation. Keeping all of the debris beneath the over-chamber air curtain is required for the debris to carbonize most efficiently. Depending on the model ENVIROSAVER™ or CARBONATOR™, along with options chosen, end-product handling may differ based on the customer’s desires.

Shutting down the ENVIROSAVER™ or CARBONATOR™ is based on overall material mass. The shut-down process requires the operator to halt loading approximately 30-45 minutes before departing the site. Debris in the primary combustion chamber will continue carbonizing and eventually reduce and fall beneath the grates into the char-pan. Once all char has been extracted and quenched, surrounding areas must be checked to ensure site and equipment safety.