Method for converting agricultural biomass or industrial bio waste into biofuel

Abstract

A method for converting agricultural biomass or industrial bio waste into biofuel using concentrated radiated energy is disclosed. Biomass or bio waste is stored inside a batch reactor in either solid or semisolid state. Unwanted moisture and unwanted oxygen are removed from the stored agricultural biomass or industrial bio waste. Concentrated radiated energy is directed towards the biomass or bio waste through a radiated energy concentrator that focuses the concentrated radiated energy. Biomass or bio waste is kept within the depth of focus of the concentrated radiated energy during the conversion operation. Due to substantial matching of the absorption peak of biomass or bio waste with the emission peak of the concentrated radiated energy, the biomass or bio waste that is within the depth of focus instantaneously decomposes into biofuel. The biofuel thus generated is at ambient temperature with higher energy density.

Claims

1. A method for converting agricultural biomass into biofuel comprising the steps of; storing agricultural biomass in a batch reactor, substantially removing moisture and oxygen from the stored agricultural biomass; utilizing a concentrated radiant energy source to convert the agricultural biomass stored inside the batch reactor into biofuel by directing concentrated radiant energy towards the agricultural biomass using a radiating energy concentrator such that the agricultural biomass is within the depth of focus of the concentrated radiated energy.

2. The method of claim 1, wherein an absorption wavelength of the stored agricultural biomass is in a range of 2 microns to 12 microns.

3. The method of claim 1, wherein the absorption peak of the stored agricultural biomass substantially matches an emission peak of the concentrated radiant energy.

4. The method of claim 1, wherein the concentrated radiant energy source comprises a CO, CO.sub.2 or Fiber laser.

5. The method of claim 1, wherein a density of the concentrated radiant energy is selected according to a desired rate of biofuel generation.

6. A method for converting industrial bio waste into biofuel comprising the steps of: storing industrial bio waste in a batch reactor; substantially removing moisture and oxygen from the stored industrial bio waste; utilizing a concentrated radiant energy source to convert the industrial bio waste stored inside the batch reactor into biofuel by directing concentrated radiant energy towards the industrial bio waste using a radiating energy concentrator, such that the industrial bio waste is within the depth of focus of the concentrated radiated energy.

7. The method of claim 6, wherein an absorption wavelength of the stored industrial bio waste is in a range of 2 microns to 12 microns.

8. The method of claim 6, wherein the absorption peak of the stored industrial bio waste substantially matches an the emission peak of the concentrated radiant energy.

9. The method of claim 6, wherein the concentrated radiant energy source comprises a CO, CO.sub.2 or Fiber laser.

10. The method of claim 6 wherein a density of the concentrated radiant energy is selected based on a desired rate of biofuel generation.

11. The method of claim 1 wherein the radiating energy concentrator comprises an optical focusing device.

12. The method of claim 1 wherein the agricultural biomass stored inside the batch reactor is converted into biofuel without heating the biomass.

13. The method of claim 1 wherein the conversion of the agricultural biomass stored inside the batch reactor into biofuel occurs at ambient temperature.

14. The method of claim 6 wherein the radiating energy concentrator comprises an optical focusing device.

15. The method of claim 6 wherein the industrial biomass stored inside the batch reactor is converted into biofuel without heating the biomass.

16. The method of claim 6 wherein the conversion of the industrial biomass stored inside the batch reactor into biofuel occurs at ambient temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The present invention is illustrated in the accompanying drawing. FIG. 1 shows the general arrangement of the components that the method in accordance with the present invention requires to generate biofuel (90) from biomass (10).

(2) As shown in FIG. 1, agricultural biomass (10) or industrial bio waste is stored in a batch reactor (20). The batch reactor (20) can be, for example, an airtight enclosed metallic or ceramic structure. Agricultural biomass (10) or industrial biowaste can be solid or semisolid.

(3) Outlet (40) connects the batch reactor (20) with a vacuum chamber (not shown). Using vacuum pressure applied through outlet (40), the unwanted moisture and unwanted oxygen are removed from the batch reactor (20). A presence of moisture or oxygen causes an undesirably higher level of carbon dioxide and carbon monoxide generation in addition to the desired level of methane generation. To avoid generation of unwanted carbonaceous gases, moisture and oxygen are removed as much as possibledesirably, 100%. At 3 atmospheric pressure, system can become nearly if not entirely 100% air-free (including all oxygen and moisture; any trace presence of other gases is also desirably removed).

(4) A source of concentrated radiated energy (30), which generally is either a CO or CO.sub.2 or Fiber laser, is used, but the type of radiant energy source is not limited to a laser or the particular types of lasers. For example, Continuous Wave (CW) or Pulsed Laser can be used. Quasi Continuous Wave (QCW) can also be used. In some embodiments, average output power (laser power) greater than 20 W is suitable. Any other focused light beam can also be used, such as high power LED, if available.

(5) The density of the concentrated radiated energy (30) or laser depends on the required rate of biofuel (90) generation. The type and wavelength of the concentrated radiated energy source (30) depends on the absorption wavelength of agricultural biomass (10) or industrial bio waste. In general, biomass contains three basic constituents which are: cellulose, hemicellulose, and lignin. Absorption peaks of these three constituents are well described in prior arts or discoverable by persons of ordinary skill in the field. Fourier-Transform Infrared Radiation (FTIR) Spectroscopy is also available for determining absorption wavelength of biomass or bio waste in practical. According to the major absorption peak of biomass or bio waste, the specific radiant energy source is selected. For example, if a biomass or bio waste sample is high in lignin content, then CO.sub.2 laser operating at 10.6 m is selected due to the broad absorption peak of lignin around 10.4 m.

(6) Concentrated radiated energy (30) is directed towards the agricultural biomass (10) or industrial bio waste through a radiated energy concentrator (35) which is essentially a focusing device (e.g., a focusing lens or mirrors) that focuses the concentrated radiated energy (30). The method in accordance with the present invention ensures that agricultural biomass (10) or industrial bio waste remains within the depth of focus of the concentrated radiated energy (30) during the conversion operation. The biomass or bio waste gets converted into biofuel on contact with laser or other concentrated radiant energy. At any given time during conversion operation, a presence of biomass or biowaste within the depth of focus is ensured by letting the biomass or bio waste fall due to gravity. Depth of focus of the radiated energy can be adjusted by adjusting the position of mirrors and focusing lens so that any remaining biomass or bio waste can also be converted.

(7) The agricultural biomass (10) or industrial bio waste that is within the depth of focus instantaneously decomposes into biofuel (90) in the absence of unwanted moisture and unwanted oxygen. The shape of the depth of focus (DOF) of the laser or other concentrated radiant energy will be more or less like an hour-glass placed horizontally and the depth of focus will be the length of the hour-glass so placed. The focal point of the laser will be in the middle of the length of the hour-glass placed horizontally. The depth of focus can be calculated from the equation written below and can be experimentally verified (e.g., using a reflecting mirror):
DOF=0.5(/NA2)

(8) where, is wavelength of the laser beam and NA is numerical aperture of the lens.

(9) Biofuel (90) so generated can be put to use immediately, or using pump (60) it can be transported through ducting (50) and (70) for storage inside a leak proof vessel (80).

(10) Biofuel (90) generated in accordance with the present invention will always be in a gaseous state and that too at ambient temperature.

BEST METHOD OF PERFORMING THE INVENTION

(11) In the best method of performing the invention, agricultural biomass (10) or industrial biomass (10) having absorption wavelength from 2 microns to 12 microns is used. The agricultural biomass (10) or industrial waste is stored inside the batch reactor (20) broken down in particles or powder. An absorption peak of agricultural biomass (10) or industrial bio waste is substantially matched with the emission peak of the concentrated radiated energy (30).

(12) The concentrated radiated energy (30) is directed towards the agricultural biomass (10) or industrial bio waste through a radiated energy concentrator (35) which is essentially an optical focusing device that focuses the concentrated radiated energy (30). The method in accordance with the present invention ensures that agricultural biomass (10) or industrial bio waste remains within the depth of focus of the concentrated radiated energy (30) during the conversion operation.

(13) Due to substantial matching of the absorption peak of agricultural biomass (10) or industrial bio waste with the emission peak of the concentrated radiated energy (30), the agricultural biomass (10) or industrial bio waste that is within the depth of focus instantaneously decomposes into biofuel (90) in the absence of unwanted moisture and unwanted oxygen.

(14) As a person skilled in the art will readily understand from the detailed description of the present invention, merely because some changes may be made to the method described herein above without departing from the spirit and scope of the present invention, so modified method should not be construed to fall outside the scope of the present invention as disclosed and claimed herein. All matters disclosed hereinabove or as shown in the accompanying drawing ought to be interpreted as illustrative and not in a limiting sense.

(15) The following claims are intended to cover all of generic and specific features of the present invention described herein above and all the statements of scope of the present invention regardless of grammatical or linguistic variations might be said to fall there between.