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US 12,214,392 B2Granted
Methods for landfill volume reduction
Assignee3P Projects LLC
InventorJudith P. Oppenheim
Life of this patent
Estimating the term…
Abstract
Systems and methods for reducing the volume of construction and demolition (C&D) debris waste are described. The systems include a torrefaction unit that reduces the hardness of the waste while degrading it into volatiles and particles having a range of sizes. The variation in particle size allows for a more efficient compaction due to minimal void space and the imparted softness allows for increased compressibility. This results in the processed debris having a much smaller volume than had it not undergone the presently described methods, which reduces landfill tipping fees and extends the life of the landfill.
Claims12
A method for reducing a volume of a construction and demolition debris feedstock comprising:
- a) separating construction and demolition debris into a recycle stream, a reject stream, and a construction and demolition debris feedstock comprising concrete;
- b) reducing a size of said construction and demolition debris feedstock using a size reduction unit to produce a particle size distribution diameter between about 0.1 and 10 mm;
- c) torrefying said construction and demolition debris feedstock in a torrefaction vessel having a temperature of 100-400° C. for at least 0.5 hours, wherein said torrefying evaporates moisture and volatile compounds from said construction and demolition debris feedstock;
- d) removing said moisture and volatile compounds from said torrefaction vessel using a heated sweep gas;
- e) transferring said torrefied construction and demolition debris feedstock to a heat exchanger to produce a cooled torrefied construction and demolition debris feedstock, wherein heat from said torrefied construction and demolition debris feedstock is used to heat said sweep gas in step d);
- f) transferring said cooled torrefied construction and demolition debris feedstock to a landfill, wherein a volume of said cooled torrefied construction and demolition debris feedstock is reduced by at least 40% compared to construction and demolition debris feedstock that is not torrefied.
3 more elements
A method for reducing a volume of a construction and demolition debris feedstock comprising:
- a) separating construction and demolition debris into a recycle stream, a reject stream, and a construction and demolition debris feedstock,
- b) reducing a size of said construction and demolition debris feedstock using a size reduction unit to produce a particle size distribution diameter between about 0.1 and 10 mm;
- c) torrefying said construction and demolition debris feedstock in a torrefaction vessel having a temperature of 100-400° C. for at least 0.5 hours, wherein said torrefying evaporates moisture and volatile compounds from said construction and demolition debris feedstock;
- d) removing said moisture and volatile compounds from said torrefaction vessel using a heated sweep gas;
- e) transferring said torrefied construction and demolition debris feedstock to a heat exchanger to produce a cooled torrefied construction and demolition debris feedstock, wherein heat from said torrefied construction and demolition debris feedstock is used to heat said sweep gas in step d);
- f) splitting said cooled torrefied construction and demolition debris feedstock into two streams wherein a first stream comprises larger particles than a second stream and is returned to said size reduction unit to undergo steps b) to e) one or more times and said second stream is transferred to the landfill,
- wherein a volume of said cooled torrefied construction and demolition debris feedstock is reduced by at least 40% compared to construction and demolition debris feedstock that is not torrefied.
4 more elements
A method for reducing a volume of a construction and demolition debris feedstock comprising:
- a) separating construction and demolition debris into a recycle stream, a reject stream, and a construction and demolition debris feedstock,
- b) reducing a size of said construction and demolition debris feedstock using a size reduction unit to produce a particle size distribution diameter between about 0.1 and 10 mm;
- c) torrefying said construction and demolition debris feedstock in a torrefaction vessel having a temperature of 100-400° C. for at least 0.5 hours, wherein said torrefying evaporates moisture and volatile compounds from said construction and demolition debris feedstock;
- d) removing said moisture and volatile compounds from said torrefaction vessel using a heated sweep gas;
- e) transferring said torrefied construction and demolition debris feedstock to a heat exchanger to produce a cooled torrefied construction and demolition debris feedstock, wherein heat from said torrefied construction and demolition debris feedstock is used to heat said sweep gas in step d);
- f) splitting said cooled torrefied construction and demolition debris feedstock into two streams, wherein a first stream comprises greater than 0 to about 60% of said cooled torrefied particles and a second stream comprises remaining cooled torrefied particles, wherein said first stream is returned to said size reduction unit to undergo steps b) to e) one or more times and said second stream is transferred to said landfill, wherein a volume of said cooled torrefied construction and demolition debris feedstock is reduced by at least 40% compared to construction and demolition debris feedstock that is not torrefied.
3 more elements
Dependencies are inferred from the claim text.