US-12618009-B2 - Pyrolysis system for converting carboneous materials into biochar and method for operating same

US12618009B2US 12618009 B2US12618009 B2US 12618009B2US-12618009-B2

Abstract

There is described a pyrolysis system for converting carboneous materials into biochar including a kiln, a retort, and a gas recovery system including a combustor supplying hot air to the kiln, a conduit fluidly connected between the retort and the combustor, the conduit conveying the pyrolysis gas and residues from a chamber of the retort to the combustor, and a filter cartridge fluidly connecting the chamber of the retort to the conduit for filtering the pyrolysis gas and the residues conveyed from the chamber of the retort to the combustor, the filter cartridge removably located inside the conduit and extending at least partially inside the chamber of the retort. Methods for operating the pyrolysis system are also described. The pyrolysis system and methods described herein produce biochar with improved resistance to self-heating.

Inventors

SIMON LANGLOIS
Antoine Langlois
Dominic LORD

Assignees

XYLO-CARBONE INC.

Dates

Publication Date: 20260505
Application Date: 20230712

Claims (15)

1 . A pyrolysis system for converting carboneous materials into biochar, comprising: a kiln adapted for containing hot air; a retort located inside the kiln and affixed to the kiln, the retort including an inlet for filling a chamber of the retort with the carboneous materials, and an outlet located vertically below the inlet for emptying the biochar from the chamber of the retort through gravity, the retort defining a port fluidly connected to the chamber for conveying pyrolysis gas and residues out of the retort; and a gas recovery system including a combustor supplying the hot air to the kiln via a hot air line fluidly connected from the combustor to the kiln; a conduit fluidly connected between the port of the retort and the combustor, the conduit conveying the pyrolysis gas and residues from the chamber of the retort to the combustor; and a filter cartridge fluidly connecting the chamber of the retort to the conduit for filtering the pyrolysis gas and the residues conveyed from the chamber of the retort to the combustor, the filter cartridge removably located inside the conduit and extending through the port at least partially inside the chamber of the retort.
2 . The pyrolysis system of claim 1 , wherein the retort comprises an inlet valve on the inlet and an outlet valve on the outlet, and during pyrolysis, hot air flowing in the kiln is isolated from the carboneous materials, the pyrolysis gas and the residues inside located inside the chamber of the retort.
3 . The pyrolysis system of claim 1 , wherein the retort is configured for indirect heat transfer from the hot air flowing inside the kiln to the carboneous materials located inside the chamber of the retort.
4 . The pyrolysis system of claim 1 , wherein the kiln has an inner wall, the retort has an outer wall spaced inwardly from the inner wall of the kiln, the inner wall of the kiln and the outer wall of the retort defining a hot air plenum between the inner wall of the kiln and the outer wall of the retort.
5 . The pyrolysis system of claim 4 , further comprising a sleeve connected between the inner wall of the kiln and the outer wall of the retort, and the filter cartridge extends from the chamber of the retort, through the sleeve, and out of the kiln such that the filter cartridge is removable from the gas recovery system from outside the kiln.
6 . The pyrolysis system of claim 4 , wherein the retort further includes a transversal member extending across the chamber of the retort, the transversal member being hollow and adapted to allow flow of the hot air therethrough to fluidly connect a first side of the hot air plenum with a second side of the hot air plenum.
7 . The pyrolysis system of claim 6 , wherein the transversal member is located vertically below the filter cartridge, the filter cartridge is a first filter cartridge and the pyrolysis system further includes a second filter cartridge located vertically offset of the first filter cartridge, and the transversal member is located vertically below the second filter cartridge.
8 . The pyrolysis system of claim 6 , wherein the transversal member has a first outer diameter, the filter cartridge has a second outer diameter, and the first outer diameter is greater than the second outer diameter.
9 . The pyrolysis system of claim 6 , wherein the filter cartridge extends along a filter cartridge axis, and the transversal member extends along a transversal member axis, the filter cartridge axis being parallel to the transversal member axis and vertically offset the transversal member axis.
10 . The pyrolysis system of claim 1 , wherein the filter cartridge has at least one wall defining a plurality of holes, the plurality of holes defined on the at least one wall of the filter cartridge having a combined area corresponding between 20% and 40% of an area of the at least one wall.
11 . The pyrolysis system of claim 1 , wherein the retort has an upper portion and a lower portion, and the filter cartridge extends in the lower portion proximate the outlet.
12 . The pyrolysis system of claim 11 , wherein the upper portion is cylindrically shaped, and the lower portion is frustoconically shaped with a narrower end proximate the outlet.
13 . The pyrolysis system of claim 12 , wherein an angle defined between a longitudinal axis of the retort and a wall of the lower portion is comprised between 35° and 70°.
14 . The pyrolysis system of claim 11 , wherein the port is a first port, the filter cartridge is a first filter cartridge, the first filter cartridge extends in the lower portion of the retort, and the retort further includes a second port located vertically higher than the first port, and a second filter cartridge located vertically higher than the first filter cartridge, the second filter cartridge extending in the upper portion of the retort.
15 . The pyrolysis system of claim 1 , further comprising a valve fluidly connected to the port of the retort for isolating the filter cartridge from the conduit.

Description

CROSS-REFERENCE The present application claims priority to U.S. Patent Application Ser. No. 63/389,404 titled “Process for Producing Biocoal Integrating A Gas Recovery System” and filed on Jul. 15, 2022, the contents of which is incorporated-by-reference herein in its entirety. TECHNICAL FIELD The present technology relates to systems for converting carboneous materials into biochar and to methods for operating the same, and more particularly to systems for producing biochar with a gas recovery system. BACKGROUND There exists a wide variety of systems for producing biochar, also known as biocoal. Typically, these systems heat batches of carboneous materials, such as wood chips, into kilns until the carboneous materials are turned into biochar with the desired properties. These batch-type systems require the handling of relatively large retorts that need to be placed and heated up in a kiln with low oxygen concentration, and then withdrawn and cooled down, which leads to increased production downtime. Other systems for producing biochar use a horizontally-extending rotary auger screw for feeding the carboneous materials into a horizontal kiln, and allows for continuous production of biochar. However, moving parts of the system, such as the auger screw, are exposed to highly acidic conditions from the tarry by-products generated during the pyrolysis cycle and are likely to undergo thermal fatigue due to the high temperature of 300° C. up to 900° C. necessary for controlling the thermo-conversion by pyrolysis of the carboneous materials into biochar. Therefore, in spite of previous efforts, there seems to be some room for improvement in the art for systems and methods for producing biochar that reduces the aforementioned drawbacks. SUMMARY In one aspect, there is provided a pyrolysis system for converting carboneous materials into biochar including a kiln adapted for containing hot air, a retort located inside the kiln and affixed to the kiln, the retort including an inlet for filling a chamber of the retort with the carboneous materials, and an outlet located vertically below the inlet for emptying the biochar from the chamber of the retort through gravity, the retort defining a port fluidly connected to the chamber for conveying pyrolysis gas and residues out of the retort, and a gas recovery system including a combustor supplying the hot air to the kiln via a hot air line fluidly connected from the combustor to the kiln, a conduit fluidly connected between the port of the retort and the combustor, the conduit conveying the pyrolysis gas and residues from the chamber of the retort to the combustor, and a filter cartridge fluidly connecting the chamber of the retort to the conduit for filtering the pyrolysis gas and the residues conveyed from the chamber of the retort to the combustor, the filter cartridge removably located inside the conduit and extending through the port at least partially inside the chamber of the retort. In one embodiment, the retort includes an inlet valve on the inlet and an outlet valve on the outlet, and during pyrolysis, hot air flowing in the kiln is isolated from the carboneous materials, the pyrolysis gas and the residues inside located inside the chamber of the retort. In one embodiment, the retort is configured for indirect heat transfer from the hot air flowing inside the kiln to the carboneous materials located inside the chamber of the retort. In one embodiment, the kiln has an inner wall, the retort has an outer wall spaced inwardly from the inner wall of the kiln, the inner wall of the kiln and the outer wall of the retort defining a hot air plenum between the inner wall of the kiln and the outer wall of the retort. In one embodiment, the pyrolysis system further includes a sleeve connected between the inner wall of the kiln and the outer wall of the retort, and the filter cartridge extends from the chamber of the retort, through the sleeve, and out of the kiln such that the filter cartridge is removable from the gas recovery system from outside the kiln. In one embodiment, the retort further includes a transversal member extending across the chamber of the retort, the transversal member being hollow and adapted to allow flow of the hot air therethrough to fluidly connect a first side of the hot air plenum with a second side of the hot air plenum. In one embodiment, the transversal member is located vertically below the filter cartridge, the filter cartridge is a first filter cartridge and the pyrolysis system further includes a second filter cartridge located vertically offset of the first filter cartridge, and the transversal member is located vertically below the second filter cartridge. In one embodiment, the transversal member has a first outer diameter, the filter cartridge has a second outer diameter, and the first outer diameter is greater than the second outer diameter. In one embodiment, the filter cartridge extends along a filter cartridge axis, and the transvers