METHOD FOR EXTRACTION OF SUGAR

20110041838

12/602483

May 30, 2008

A method for extraction of sugar from a sugar containing biomass is disclosed, wherein the sugar containing biomass a) is introduced in an extraction device (1), b) is treated with steam having a temperature of between 103 and 124° C., c) is treated in one or more steps with hot water having a temperature of 65-85° C., and d) is subjected to one or more compression steps, wherein a sugar containing solution is extracted from the sugar containing biomass in each of the steps c) and d) in the extraction device (1) and is removed from the extraction device (1), said method being continuously performed at an overpressure of 0.2-1.5 bar in the extraction device (1).

Wallin, Lars Göran (Laholm, SE); Wallin, Jonas (Laholm, SE)

SILECO HB (Laholm, SE)

1. A method for extraction of sugar from a sugar containing biomass, wherein the sugar containing biomass a) is introduced in an extraction device, b) is treated with steam having a temperature of between 103 and 124° C., c) is treated in one or more steps with hot water having a temperature of 65-85° C., and d) is subjected to one or more compression steps, wherein a sugar containing solution is extracted from the sugar containing biomass in each of the steps c) and d) in the extraction device and is removed from the extraction device, said method being continuously performed at an overpressure of 0.2-1.5 bar in the extraction device.

2. The method according to claim 1, wherein said overpressure is 0.4-1.2 bar.

3. The method according to claim 1, wherein said steam has a temperature of between 109 and 120° C.

4. The method according to claim 1, wherein said sugar containing biomass is introduced in the extraction device via an inlet sluice valve device, preferably a drum having wings defining four compartments, and having a sealing action between the interior of the extraction device and the outside atmosphere.

5. The method according to claim 1, wherein the sugar containing biomass during the steam treatment is fed on a web downwardly inclined from the inlet sluice valve device (2) towards the extraction device, wherein said web preferably is a slide surface or a conveyor belt.

6. The method according to claim 5, wherein said sugar containing biomass is treated with steam introduced in the extraction device through one or more steam nozzles arranged close to the web.

7. The method according to claim 6, wherein the steam nozzles are arranged above and under said web and spray the steam on the sugar containing biomass fed on said web, and wherein said web is liquid permeable.

8. The method according to claim 1, wherein the steam treated sugar containing biomass fed to the extraction device is subjected to i) a first hot water treatment step, wherein hot water is sprayed on the sugar containing biomass through one or more hot water nozzles, ii) an intermediate compression step, wherein the sugar containing biomass is brought to pass an intermediate compression device, preferably a belt press or a roller press containing one or more rolls, iii) a second hot water treatment step, wherein hot water is sprayed on the sugar containing biomass through one or more hot water nozzles, and iv) a hard compression step, wherein the sugar containing biomass is brought to pass a hard compression device, preferably a roller press or a belt press containing one or more rolls, wherein the sugar containing biomass in the steps i)-iv) above is fed on a transport device, and wherein a sugar containing solution is extracted from the sugar containing biomass in each of the steps i)-iv).

9. The method according to claim 8, wherein each sugar containing solution is collected in the bottom of the extraction device and are removed from the extraction device (1) via an outlet valve port (10).

10. The method according to claim 8, wherein said one or more hot water nozzles, are arranged above and under the transport device feeding the sugar containing biomass, and wherein said transport device is liquid permeable.

11. The method according to claim 1, wherein the sugar containing biomass is subjected to a final compression step, wherein the sugar containing biomass is brought to pass a final compression device, which also acts as an outlet sealing device in the outlet end of the extraction device, wherein a sugar containing solution is extracted from the sugar containing biomass in the final compression step and is collected in the bottom of the extraction device, and wherein a sugar containing pulp with a reduced sugar content, preferably molasses, is obtained as a by-product and is removed through the outlet end of the final compression device in the extraction device.

12. The method according to claim 11, wherein the sugar containing solution extracted from the final compression step is brought to pass a filter device, preferably a strainer, before it is collected in the bottom of the extraction device.

13. The method according to claim 1, wherein the sugar containing biomass is sugar-beets, sugar canes, beetroots, fodder beets, bananas, or pineapples, or a mixture of two or more thereof, preferably sugar-beets.

14. The method according to claim 1, wherein the sugar in the sugar containing solution extracted from the sugar containing biomass and removed from the extraction device is sucrose, glucose or fructose, or a mixture of two or more thereof, preferably sucrose.

15. The method according to claim 1, wherein the sugar containing biomass is fed into the extraction device in the form of chips, cossettes or slices.

16. The method according to claim 1, wherein the overpressure in the extraction device throughout the process is controlled and regulated with one or more pressure sensors and one or more pressure regulation valves, or with a valve device having both the pressure sensoring and regulating functions.

17. The method according to claim 1, wherein the process time is 1-10 min, preferably 3-6 min.

18. The method according to claim 1, wherein the feed rate in the process is 20-60 tons of sugar containing biomass per hour, preferably 35-40 tons of sugar containing biomass per hour.

19. The method according to claim 5, wherein the sugar containing biomass is fed on a web downwardly inclined from the inlet sluice valve device towards a central part of the extraction device.

20. The method according to claim 8, wherein the sugar containing biomass is subjected to a final compression step, wherein the sugar containing biomass is brought to pass a final compression device, which also acts as an outlet sealing device in the outlet end of the extraction device, wherein a sugar containing solution is extracted from the sugar containing biomass in the final compression step and is collected in the bottom of the extraction device, and wherein a sugar containing pulp with a reduced sugar content, preferably molasses, is obtained as a by-product and is removed through the outlet end of the final compression device in the extraction device.

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edspap.20110041838