# US 10,865,356 B1 · Torrefaction process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,356 B1 - Document ID: US10865356B1 - Status: Granted - Kind: B1 - Application number: 16/994,540 - Filed: 2020-08-14 - Granted: 2020-12-15 - Earliest claimed: 2020-08-14 - Assignees: Komax Systems, Inc. - Applicants: Komax Systems Inc. - Inventors: Nolan Smith; Seungsuk Lee; Hayden Smith - Web page: https://patentgrep.com/patent/US10865356B1 ## CPC - C10L 9/083: {Torrefaction} - B01J 19/243: {spirally, concentrically or zigzag wound} - B01J 19/244: {Concentric tubes} - C10B 49/14: with hot liquids, e.g. molten metals - C10B 53/02: of cellulose-containing material (production of pyroligneous acid C10C5/00) - C10L 5/442: {Wood or forestry waste} - C10L 5/445: {Agricultural waste, e.g. corn crops, grass clippings, nut shells or oil pressing residues} - B01J 2219/0077: inclined - C10L 2290/06: Heat exchange, direct or indirect - C10L 2290/24: Mixing, stirring of fuel components - C10L 2290/56: Specific details of the apparatus for preparation or upgrading of a fuel - Y02E 50/10: Biofuels, e.g. bio-diesel - Y02E 50/30: Fuel from waste, e.g. synthetic alcohol or diesel - C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C10B: DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS (cracking oils C10G; underground gasification of minerals E21B43/295) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method of converting cellulosic feedstock to bio coal. The cellulosic feedstock in a carrier of process fluid is introduced within a conduit having substantially linear portions connected by curved portions creating a serpentine structure. The substantially linear portions are surrounded by tubular sleeves creating annular spaces between the tubular sleeves and substantially linear portions for carrying a high temperature fluid for transferring thermal energy to the cellulosic feedstock and process fluid. The cellulosic feedstock is maintained in an oxygen-free environment. The method is continuous as the cellulosic feedstock in process fluid is subjected to a plurality of mixing elements characterized as having no edges perpendicular to the longitudinal axes of the plurality of substantially linear segments and which are sized and positioned within the plurality of substantially linear segments such no mixing elements are in contact with one another resulting in an open region of travel for fluids passing from the conduit inlet to conduit outlet. ## Claims ### Claim 1 A method of converting cellulosic feedstock to bio coal comprising: Providing a conduit comprising a plurality of linear segments having a linear segment diameter, longitudinal axes and circular circumference, said conduit further having an inlet and an outlet and a plurality of curved segments creating a serpentine structure; providing a plurality of tubular sleeves around said linear segments and having longitudinal axes coincident with said longitudinal axes of said linear segments of said conduit creating a plurality of annular spaces, said plurality of tubular sleeves being in fluid communication and having a tubular sleeve inlet and tubular sleeve outlet; providing a plurality of mixing elements within a plurality of said linear segments, said plurality of mixing elements having no edges perpendicular to said longitudinal axes of said plurality of linear segments and are sized and positioned within said plurality of linear segments such that no mixing elements are in contact with one another, and are free of nooks and crotches which would otherwise result in fluid hangup and which results in an open region of travel for fluids passing from said conduit inlet to said conduit outlet; feeding a cellulosic feedstock carried by a process fluid to said conduit inlet; feeding a heating fluid to said tubular sleeve inlet causing said heating fluid to pass within said annular spaces; facilitating heat transfer between said heating fluid and said cellulosic feedstock; and maintaining said cellulosic feedstock and process fluid as a substantially oxygen-free fluid stream for a sufficient time to convert said cellulosic feedstock to said bio coal. ### Claim 2 (depends on 1) The method of claim 1 wherein said mixing elements are provided in said linear segments in complementary pairs, wherein adjacent mixing elements cause said cellulosic feedstock and process fluid passing therein to rotate in opposite directions. ### Claim 3 (depends on 1) The method of claim 1 wherein each mixing element located within each of said linear segments is seated at an angle between approximately 25° to 45° to said longitudinal axes. ### Claim 4 (depends on 1) The method of claim 1 wherein said mixing elements are in the form of primarily circular segments wherein each mixing element is characterized as being widest in profile at its midpoint and narrowest at its longitudinal endpoints. ### Claim 5 (depends on 4) The method of claim 4 wherein each mixing element is of a height equal to approximately D/10 where D is the diameter of said linear segments. ### Claim 6 (depends on 1) The method of claim 1 wherein said heating fluid is any fluid capable of flowing at temperatures over 1000° F. and having boiling points in excess of 1000° F. ### Claim 7 (depends on 6) The method of claim 6 wherein said heating fluid comprises molten salt. ### Claim 8 (depends on 1) The method of claim 1 wherein said cellulosic feedstock comprises a member selected from the group consisting of wood chips and nut shells. ### Claim 9 (depends on 1) The method of claim 1 wherein said feedstock in said process fluid moves counter currently within said conduit to said heating fluid traveling within said annular spaces. ### Claim 10 (depends on 1) The method of claim 1 further comprising mixing elements within said annular space for increasing turbulence and for improving uniform temperatures of said heating fluid passing therein. ### Claim 11 (depends on 10) The method of claim 10 wherein said mixing elements within said annular space are provided in complementary pairs, wherein adjacent mixing elements cause said heating fluid passing therein to rotate in opposite directions. ### Claim 12 (depends on 1) The method of claim 1 wherein said mixing elements positioned within said linear segments are sized such that cellulosic feedstock carried by process fluid having a size of at least 40% of the linear diameter passes there through.