Torrefaction apparatus and process

A torrefaction system including

• an upstream airlock;
• a fast heater leading from the upstream airlock;
• a slow heater downstream from the fast heater;
• a torrefaction reactor in communication with the slow heater;
• a feedstock;
• a paddle conveyor within the reactor, the conveyor moving the feedstock anaerobically through the reactor to emerge as biocoal, the paddle conveyor including a shaft with paddles extending therefrom, the paddles receiving and transporting the feedstock to be conveyed there through, the paddle conveyor also including bulges extending from the shaft to promote heat transfer;
• a mass measuring system within the reactor;
• a control device that receives signals from the mass measuring system and sends signals to the conveyor so as to influence mass loss from the feedstock by changing rotational and thus translational speed and residence time of the feedstock;
• and
• a downstream airlock.

A torrefaction system including

• an upstream airlock;
• an adiabatic torrefaction reactor with a vertically placed moving bed having a paddle conveyor with a shaft and paddles extending therefrom;
• a feedstock;
• a mass measuring system within the torrefaction reactor;
• a control device that receives signals from the mass measuring system and sends signals to the conveyer so as to influence mass loss from a feedstock by changing rotational and thus translational speed and residence time of the feedstock;
• and
• a downstream airlock.

A manufacturing apparatus for producing a torrefied biomass that at least partially replaces coal in coal-fired processes, the apparatus comprising

• a feeder for receiving carbonaceous mineral-bearing feedstock,
• a dryer that desiccates the feedstock at least partially anaerobically to produce dried feedstock, the dryer including a heater that warms the feedstock to produce heated, dry feedstock;
• and
• a torrefaction subassembly for treating the heated, dry feedstock to produce a biocoal having an average particle size between 30 and 1000 microns, the torrefaction subassembly having
• a paddle conveyor located within the torrefaction sub assembly for conveying the feedstock uniformly and smoothly, the conveyor imparting a centrifugal and translational force to the feedstock, the paddle conveyor having paddles that extend from a shaft and bulges that promote heat transfer;
• a mass measuring system within the torrefaction sub assembly,
• a control device that receives signals from the mass measuring system and sends signals to the conveyer so as to influence mass loss from the feedstock by changing rotational and thus translational speed and residence time of the feedstock
• a fast heater that heats the heated, dry feedstock to a temperature of or about 200 degree Celsius;
• a slow heater, downstream from the fast heater, that further heats the heated, dry feedstock to a temperature of between 280 and 320 degrees Celsius;
• and
• a reactor that is filled to 95% of its volume.

A process for producing a torrefied biomass that at least partially replaces coal in coal-fired processes, the process comprising the steps of:

• I) ingesting carbonaceous mineral-bearing feedstock into a feed bin for receiving, buffering and for conveying modified feedstock uniformly and smoothly;
• II) drying the modified feedstock at least partially anaerobically to produce dried feedstock, the dryer including a heater that warms the dried feedstock to produce heated, dry feedstock;
• III) torrefying the heated, dry feedstock to in a torrefaction reactor produce a biocoal having an average size of particles;
• IV) controlling the residence time of the feedstock in the reactor in response to upstream and downstream mass measurements to ensure that mass loss from the feedstock occurs within an acceptable range;
• V) downsizing the particles to prepare biocoal with a reduced size of particles of between 30 and 1000 microns and a mineral content;
• VI) separating minerals from the reduced particles with a mineral content to produce a mineral-denuded biocoal;
• and
• VII) compacting the mineral-denuded biocoal by applying pressure between 2000 and 4000 bar to biocoal particles for a compaction time of between 1 and 30 seconds, wherein the biocoal particles being compacted have a temperature between 150 and 250 degrees Celsius,
• at least some of steps I)-VII) including conveying the feedstock by a paddle conveyor with paddles mounted on a shaft within a tube so that the feedstock fills up to 80 percent of a surrounding vessel.