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EP-4735393-A1 - A METHOD FOR PRODUCING FOAM GLASS

EP4735393A1EP 4735393 A1EP4735393 A1EP 4735393A1EP-4735393-A1

Abstract

Disclosed is a method for producing foam glass (1). The method comprises the steps of:  grinding a glass material (2) into glass powder (3),  grinding a waste composite material (4) comprising fiberglass (5) and resin 5 (6) into a composite powder (8), wherein the waste composite material has an ultimate tensile strength above 20 MPa,  mixing said glass powder (3), said composite powder (8) and a foaming agent (9) to form a foam glass feedstock (7), and  heating said foam glass feedstock (7) to a temperature of at least 600⁰C.10

Inventors

  • BARSØE, Søren
  • JENSEN, Christian Ocksen
  • ØSTERGAARD, Martin Bonderup

Assignees

  • Recinnovate ApS

Dates

Publication Date
20260506
Application Date
20240628

Claims (20)

  1. 1. A method for producing foam glass (1), said method comprising the steps of: • grinding a glass material (2) into glass powder (3), • grinding a waste composite material (4) comprising fiberglass (5) and resin (6) into a composite powder (8), wherein said waste composite material has an ultimate tensile strength above 20 MPa, • mixing said glass powder (3), said composite powder (8) and a foaming agent (9) to form a foam glass feedstock (7), and • heating said foam glass feedstock (7) to a temperature of at least 600°C.
  2. 2. A method according to claim 1, wherein said glass material (2) is grinded into glass powder (3) having a particle size of between 10 and 900 microns, preferably between 30 and 600 microns, and most preferred between 50 and 300 microns.
  3. 3. A method according to claim 1 or 2, wherein said waste composite material (4) is grinded into composite powder (8) having a particle size of between 10 and 900 microns, preferably between 30 and 600 microns, and most preferred between 50 and 300 microns.
  4. 4. A method according to any of the preceding claims, wherein said method further comprises screening said glass powder (3) before mixing said glass powder (3), said composite powder (8) and said foaming agent (9).
  5. 5. A method according to any of the preceding claims, wherein said method further comprises screening said composite powder (8) before mixing said glass powder (3), said composite powder (8) and said foaming agent (9).
  6. 6. A method according to any of the preceding claims, wherein said foam glass feedstock (7) comprises between 40% and 97%, preferably between 50% and 94%, and most preferred between 60% and 90% glass powder (3) by weight before said foam glass feedstock (7) is heated.
  7. 7. A method according to any of the preceding claims, wherein said foam glass feedstock (7) comprises between 3% and 60%, preferably between 7% and 50%, and most preferred between 10% and 40% composite powder (8) by weight before said foam glass feedstock (7) is heated.
  8. 8. A method according to any of the preceding claims, wherein said foam glass feedstock (7) comprises between 0.2% and 10%, preferably between 0.5% and 8%, and most preferred between 1% and 5% foaming agent (9) by weight before said foam glass feedstock (7) is heated.
  9. 9. A method according to any of the preceding claims, wherein said foam glass feedstock (7) is heated to a temperature of between 600°C and 1600°C, preferably between 700°C and 1500°C, and most preferred between 800°C and 1400°C.
  10. 10. A method according to any of the preceding claims, wherein said waste composite material (4) comprises between 1% and 80%, preferably between 4% and 70%, and most preferred between 10% and 60% resin (6) by weight.
  11. 11. A method according to any of the preceding claims, wherein said waste composite material (4) comprises Per- and polyfluoroalkyl substances (PF AS).
  12. 12. A method according to any of the preceding claims, wherein said glass material (2) comprises Per- and polyfluoroalkyl substances (PF AS).
  13. 13. A method according to any of the preceding claims, wherein said glass powder (3), said composite powder (8) and a foaming agent (9) is mixed so that said resulting foam glass feedstock (7) comprises between 1% and 50%, preferably between 3% and 40%, and most preferred between 5% and 30% resin (6) by weight.
  14. 14. A method according to any of the preceding claims, wherein said method further comprises determining the resin (6) content of said waste composite material (4), said composite powder (8) and/or of said foam glass feedstock (7) before heating said foam glass feedstock (7).
  15. 15. A method according to any of the preceding claims, wherein said method further comprises determining the calorific value of said waste composite material (4), said composite powder (8) and/or of said foam glass feedstock (7) before heating said foam glass feedstock (7).
  16. 16. A method according to any of the preceding claims, wherein said method further comprises obtaining said waste composite material (4) from wind turbine blade parts formed by a fiberglass (5) and resin (6) material before grinding said waste composite material (4) into a composite powder (8).
  17. 17. A method according to any of the preceding claims, wherein said method further comprises obtaining at least a portion of said glass material (2) from solar panels before grinding said glass material (2) into glass powder (3).
  18. 18. A method according to any of the preceding claims, wherein said resin (6) comprises polyester resin, polyurethane resin, vinyl ester resin and/or epoxy resin.
  19. 19. A method according to any of the preceding claims, wherein said foaming agent (9) comprises a sulphate or a carbonate, such as CaCO3.
  20. 20. A method according to any of the preceding claims, wherein said waste composite material (4) being grinded has an ultimate tensile strength between 20 and 5000 MPa, preferably between 30 and 4500 MPa, and most preferred between 40 and 4000 MPa.

Description

A METHOD FOR PRODUCING FOAM GLASS Background of the invention The invention relates to a method for producing foam glass by adding a foaming agent to a glass material, and foam glass produced by means of this method. Description of the Related Art Foam glass - also called cellular glass - is a porous glass foam material. Its advantages as a building material include its light weight, high strength, and thermal and acoustic insulating properties. Foam glass is made by heating a mixture of crushed or granulated glass and a chemical foaming agent (also called a blowing agent). Near the melting point of the glass, the foaming agent releases a gas, producing a foaming effect in the glass. After cooling the mixture hardens into a rigid material with gas-filled closed-cell pores or sometimes open-cell pores forming a large portion of the foam glass’s volume. Even though foam glass is moisture-proof, fireproof, and anti-corrosive, and given the foam glass material has many advantages particularly in relation to long-term use performance, it is not used particularly often in the building industry or other industries and one of the main reasons for this is the cost, in that it takes much energy to melt the glass. From the international patent applications WO 2012/139550 Al and WO 2020/242407 Al it is known to make the foam glass by means of a waste glass mixture which could reduce the cost of foam glass. However, the production costs are still too high. From the Chinese patent application CN 102643013 A it is known to use waste glass fiber reinforced phenolic resin molding compound to produce foam glass. The glass fiber reinforced phenolic resin molding compound is subjected to heat treatment up to 500°C before being crushed and pulverized. The carbonized powder phenolic resin is then mixed with waste glass powder, a foaming agent, a stabilizing agent, a fluxing agent, a binder and other before the mixture is heated to up to 1000°C to form foam glass. However, this method is still not particularly cost- and energy effective. An object of the invention is therefore to provide for a more cost-efficient method for producing foam glass. The invention The invention provides for a method for producing foam glass. The method comprises the steps of: • grinding a glass material into glass powder, • grinding a waste composite material comprising fiberglass, and resin into a composite powder, wherein said waste composite material has an ultimate tensile strength above 20 MPa, • mixing the glass powder, the composite powder and a foaming agent to form a foam glass feedstock, and • heating the foam glass feedstock to a temperature of at least 600°C. Grinding the waste composite material directly from its original state where it has an ultimate tensile strength above 20 MPa - i.e., without first embrittling the waste composite material through heat treatment or similar - is advantageous in that the full heating value or calorific value of the waste composite material is hereby preserved. Most resins - like polyester resin, polyurethane resin, vinyl ester resin or epoxy resin - has a heating value or calorific value of around 30 MJoule per kg. Compared to this wood has a heating value of around 15 MJoule per kg and coal has a heating value of around 25 MJoule per kg and carbonized composite material will inevitably have a significantly lower calorific value than uncarbonized composite material because some of the combustible components in the composite material will combust or evaporate during the carbonization process thereby inevitably reducing the calorific value of the composite material. Thus, adding a composite powder comprising fiberglass and resin - made from composite material with an ultimate tensile strength above 20 MPa, i.e., composite material which has not been embrittled through heat treatment - to the foam glass feedstock, before the heating process, is advantageous, in that resin is flammable and highly energy dense and the resin hereby is a thermal energy source that will at least aid in driving the heating process in which the glass material and the fiberglass is heated during the manufacturing of the foam glass. Hereby a much more cost- and energy effective way of heating the foam glass feedstock is provided. The energy contribution from the uncarbonized resin also enables that the cost of the foam glass manufacturing plant can be reduced in that the demand for external heating means such as gas heaters, electrical heaters or other for generating the foam glass can be severely reduced. And the cost and complexity of the overall foam glass manufacturing process is reduced because the manufacturing process only includes a single heating step - i.e., the step in which the foam glass feedstock is heated to a temperature of at least 600°C to form the foam glass. Furthermore, waste composite material is problematic because it is very expensive and complicated to reuse it, and because waste composite material ofte