Engineering the End of Sludge

What is DRACO?

DRACO is a HydroThermal Carbonization (HTC) solution for sludge volume reduction. It reduces sludge volume by 80% and up to 90% with a dryer preventing sticky phase reducing overall energy costs.

When combined with an anaerobic digestor, DRACO system increases biogas production by over 30% .

DRACO can also be integrated with heat-generating plants such as incinerators, coal-fired power plants, and cement plants. By utilizing waste steam from these facilities as a heat source, it operates without the need for external energy input.

In addition, DRACO retrofits existing sludge dryer process, eliminating sticky phase issues, stabilizing dryer operation, and reducing 70% of energy costs.

Don’t be surprised — DRACO can operate as either THP or HTC, depending on your objectives and configuration. It’s designed to adapt, not compromise.

  • Less Sludge, More Biogas

    Details

  • Sludge Reduction, Zero Energy Bill

    Details

  • Retrofit Your Dryer: From Old to Optimal

    Details

System Configuration

DRACO is a patented HTC system using a batch process with stepwise heating, pressurizing, cooling, and depressurizing of biosolids

Components:

  • Hopper

  • Pre-heating Tank

  • Reactors

  • Decompression Tank

  • Heat Exchanger

  • Filter Press

DRACO exposes sludge to heat & pressure, breaking open cell walls and simplifying complex organic matter.

Hydrolysis, Dehydration, Decarboxylation

Flexible Configuration: THP & HTC

DRACO THP DRACO HTC
Primary Objective Boost Biogas Production Maximize Sludge Volume Reduction &
Boost Biogas Generation
Application Pre-Anaerobic Digestion
  • Post Anaerobic Digestion
  • With Dryer
  • With Waste Heat
Operation Temperature < 170 °C > 190 °C
Pressure 7 Bars 12 Bars
Reaction Time 20 min 30 min
Sludge Characteristics Input Dried Solid > 20% > 20%
Output Dried Solid - ~ 66%
Performance Increased Biogas Generation
(Compared to AD without DRACO)		 ~ 50% ~ 30%
Sludge Volume Reduction (%) - ~ 80%
(~ 90% with dryer)

Inside the reactors

3D CFD (Computational Fluid Dynamics) Analysis using a supercomputer

DRACO can process sludge regardless of water content through effective mixing and high heat transfer efficiency, using a patented multi-point steam injection technology

  • Improved contact between sludge & steam through the use of an agitator

  • Enhanced heat transfer efficiency through patented multi-point steam injection technology

  • Uniform heat distribution enables complete reaction of organic waste

  • Heat transfer efficiency validated through 3D flow analysis

Performance: Sludge Volume Reduction

Item Feed DS Cake
(DRACO + F/P)		 SVR Rate
(before drying)		 SVR Rate
(after drying)
Municipal WWTP Primary + WAS 15.3 ~ 21.8% 57.0 ~ 60.1% 76.8 ~ 83.1% 85.0 ~ 90.0%
WAS 17.8 ~ 23.7% 58.0 ~ 66.3% 76.2 ~ 80.6%
Digested Sludge 15.8 ~ 24.0% 53.6 ~ 66.3% 75.9 ~ 81.9%
Co-Digestion Primary + WAS 17.6 ~ 21.3% 51.1 ~ 51.8% 75.0 ~ 79.1%
Livestock WAS 14.8 ~ 18.8% 54.9 ~ 57.7% 79.4 ~ 83.3%

DRACO Pilot Unit

Pilot proven. Scalable by design.

  • 2 tons/day

    • 2 × 20-foot-high cube containers including 3 vertical opening doors

    • All Package System: DRACO SKID, Steam Boiler, Dewatering SKID

    • Decompression Tank: U Stamp in accordance with American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC)

    • Monitoring & Control System: Underwriters Laboratories (UL) Certification & American National Standards Institute (ANSI) Standards

    1. More than 50% Dry Solid (DS) of final cake (achieving more than 80% of SVR)
      ► Including elimination of pathogens under Class A

    2. 30% more biogas production
      ► Evaluate results with Biochemical Methane Potential (BMP) test

FAQs

Is DRACO Hydrothermal Carbonization (HTC) or Thermal Hydrolysis Process (THP)?

DRACO can be both HTC and THP depending on an operation set-up.

HTC: Temp. >190°C / Pressure ~12 bar / ~30 min THP: Temp. <170°C / Pressure ~7 bar / ~20 min

How much solids can DRACO process?

DRACO can process solids up to 23~25% while usual THP or similar systems can process around 12~16%

Does “sticky phase” become a problem within the system?

DRACO + Filter Press process solves the “sticky phase”

Does DRACO destroy PFAS?

DRACO does NOT destroy PFAS.

But DRACO can be an effective and economical pretreatment to PFAS issues. Due to its sludge volume reduction, PFAS can be concentrated into much smaller and drier sludge which enhances efficiency of downstream destruction (e.g., pyrolysis, gasification)

Is pre-treatment necessary?

It is case-specific but most of the time, No

DRACO Reference

Operation Annual capacity
(tons DS/yr)		 Location
(City, Country)		 Application type/Purpose
2019 7,300
(100 wet tons/d @ 20% DS)		 Gimhae, Korea HTC - Operating
Sludge volume reduction (w/o AD).
Mixed municipal sludge and slaughterhouse waste
2025 5,840
(100 wet tons/d @ 16% DS)		 Seosan, Korea HTC - Operating
Application as a pretreatment to improve drying performance
Municipal sludge volume reduction
2028
(Booked)		 32,522
(495 wet tons/d @ 18% DS)		 Daejeon, Korea THP - Under Construction
Increase biogas production (Pre-AD)
Municipal WAS-only THP
2029
(Booked)		 5,913
(90 wet tons/d @ 18% DS)		 Mokpo, Korea THP - In Design (P3)
Increase biogas production (Pre-AD)
Municipal sludge THP
2029
(Booked)		 2,803
(128 wet tons/d @ 6% DS)		 Gwangju, Korea THP - In Design (P3)
Increase biogas production (Pre-AD)
Municipal sludge THP

DRACO RESOURCES