Engineering the End of Sludge

What is DRACO?

Our customers produce biogas from various organic wastes, including sludge and many began to adopt Thermal Hydrolysis Process (THP) technology to increase biogas production. However, those who utilize THP to obtain more biogas have to use more energy sources like electricity and LNG. Considering the operational costs, facility expenses, and maintenance efforts associated with extra energy input, is it truly beneficial to use THP solely to obtain more biogas?

As a supplier of DRACO THP, Tomorrow Water has been contemplating this question and began exploring ways for this technology to contribute more meaningfully to society. With this approach in organic waste industry, Tomorrow Water discovered that the rising costs of sludge disposal, rather than increasing biogas output, are the biggest pain point for our customers.
Ever since, we have been committed to evolving DRACO into HydroThermal Carbonization (HTC) instead of just sticking with THP technology.

By applying a little more energy to increase temperature and pressure, DRACO HTC can reduce sludge by up to 80% and adding a dryer at the end can cut sludge volume by as much as 90%. It encompasses the hydrolysis stage implemented by THP and extends to dehydration and decarboxylation. As a result, DRACO HTC destroys the cells within the sludge, completely dewatering and removing the water trapped inside, thereby significantly reducing sludge volume. While reducing sludge volume, HTC also enhances biogas production, a feature initially present in THP.
These result in greater economic benefits for our customers.

The DRACO technology that Tomorrow Water possess can realize both THP and HTC.
We constantly reflect on what truly benefits our customers and are always thinking ahead.

Don’t just settle for THP, take a step further and experience DRACO HTC.

DRACO HTC (Hydrothermal Carbonization) has more value than THP when it comes to sludge treatment. DRACI HTC offers sludge volume reduction, less energy consumption when integrated with sludge drying process, no sticky phase and increase in biogas
Tomorrow Water's hydrothermal carbonization (HTC) technology in Korea

DRACO Reactions

DRACO HTC undergoes the same initial hydrolysis phase as DRACO THP, followed by dehydration and decarboxylation to complete the reaction process.

DRACO HTC (HydroThermal Carbonization) undergoes the same initial hydrolysis phase as DRACO THP (thermal Hydrolysis Process), followed by dehydration and decarboxylation to complete the reaction process
DRACO HTC DRACO THP
Primary Objective
  • Sludge Volume Reduction
  • Boost Biogas Generation
  • Less Energy Consumption
  • No Sticky Phase
 Boost Biogas Production
Application
  • Post Anaerobic Digestion
  • With Dryer
  • With Waste Heat
 Pre-Anaerobic Digestion
Operation Temperature > 190 °C < 170 °C
Pressure 12 Bars 7 Bars
Reaction Time 30 min 20 min
Sludge Characteristics Input Dried Solid > 20% > 20%
Output Dried Solid ~ 66% -
Performance Increased Biogas Generation
(Compared to AD without DRACO)		 ~ 30% ~ 50%
Sludge Volume Reduction (%) ~ 80%
(~ 90% with dryer)		 -

DRACO HTC vs. THP

DRACO HTC Applications

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

  • DRACO HTC can reduce sludge and increase biogas production

    Less Sludge, More Biogas

    Details
  • DRACO HTC integrated with a waste-to-energy incinerator, using recovered heat for sludge volume reduction

    Sludge Reduction, Zero Energy Bill

    Details
  • DRACO HTC maximizes sludge drying process' efficiency

    Retrofit Your Dryer: From Old to Optimal

    Details

Seohae Green,
South Korea

One & Only Zero-Energy
Sludge Reduction HTC Facility
in the World

Incinerator in Seohae Green provides waste heat (steam) to DRACO HTC (HydroThermal Carbonization)

Process
DRACO HTC (Sludge Reduction, Zero Energy Bill Application)

Capacity
Sludge Treatment Capacity: 120 ton/day

Steam Usage: 0.21 kg Steam/kg Sludge (21 tons/day)

Steam usage based on the following:
- Feed Sludge Water Content: 84%
- Sludge Temperature: 20°C

** Actual steam consumption may vary depending on the characteristics of the input sludge **

Learn more

DRACO 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

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%
Download Brochure
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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

DRACO pilot which can do both settings of HTC and THP
sludge cake from DRACO process (HTC+Filter PRess)
DRACO Fact Sheet
Request a Pilot

PFAS: Our Future Challenge.

PFAS, often called “forever chemicals,” are one of the toughest challenges in wastewater and sludge management.

Much of today’s sludge is still land-applied, unintentionally reintroducing PFAS back into soils. Research shows these compounds can only be destroyed under extreme thermal conditions, 900°C to 1200°C, far beyond the reach of conventional treatment.

This is where Tomorrow Water’s DRACO HTC plays a critical role. By reducing sludge volume by up to 90% and concentrating PFAS into a smaller, denser residual stream, DRACO HTC makes downstream processes like pyrolysis, gasification, and incineration more energy and cost-effective.

Together with utilities, researchers, and industry leaders, we can build collaborative pathways toward scalable PFAS solutions.

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

Talk to our product owner.

HI I’M
DANIEL
KIM

DRACO Product Owner

dk@tomorrowwater.com

1225 N Patt St
Anaheim, CA 922801

DRACO RESOURCES