Thermal Hydrolysis - High Temperature and Pressure Cell (1).pptx

Thermal Hydrolysis - High Temperature and Pressure Cell (1).pptx

1. Thermal Hydrolysis Process for Enhanced Solids Reduction from Anaerobic Digestion

2. Circular Economy: Resource Recovery & Waste to Wealth Sewage Treatment Plant (STP) – Water Resource Recovery Facility - Recycle & Reuse of treated Wastewater - Sludge to Energy - Sludge to Fertilizer/Soil Conditioner/Amendment – Source of C,N, P, Nutrients - Recovery of Phosphorus - Other

3. VALUE IN SLUDGE (BIOSOLIDS)

4. Sewage Treatment Plant (STP) Sewage Treatment Plant (STP) Treated Water 1. Discharge 2. Recycle, Reuse, Recharge Sludge AD or T HP + AD Biogas to Electricity & Heat Treated Sludge for Fuel/ Incineration Treated Sludge as Soil Conditioner / Fertilizer Biogas to CNG/CBG/RNG AD = Anaerobic Digestion

5. Sludge Regulation for Land Application US EPA Biosolids Rule For Land Application – 3 criteria Concentration Limit of 9 heavy/trace metals provided in Rule Vector attraction Reduction – mim . 38% VS destruction Pathogen Reduction - Sludge from STPs contain pathogens and presents health hazard. Class A or Class B Class B Fecal coliform 20,00,000 MPN/gm of dry solids Anaerobic Digestion most commonly used Class A Density of Fecal Coliform < 1,000 MPN/gm of DS OR Density of Salmonella sp. bacteria < 3 MPN / 4 gm of DS Advanced Anaerobic Digestion (such as THP) most commonly used

6. Temperature Effect on Sludge Digestion Type of Digestion Temperature of digestion o C Digestion Period (Days) Min Normal Max Min Normal Max Unheated Ambient 90 120 150 Mesophilic 27 32 35 25 28 30 Thermophillic 49 51 53 12 13 15

7. Definition Thermal Hydrolysis  is a chemical process in which the organic molecules (in the substrate/ feed material) are split into two parts by adding a molecule of water. The process forces the water molecules between the chemical bonds holding together large tissue molecules such as fats, DNA and proteins. As the name suggests  thermal hydrolysis (TH) uses heat and high pressure to break the cellular tissues down to their original smaller molecular components . This also dramatically  reduces viscosity, destroys all infectious agents , and above all it  hugely increases biodegradability during fermentation .

8. History of Thermal Hydrolysis Thermal Hydrolysis Process (THP) was first applied to improve sludge dewaterability ( Haug et al.,1978), but has since grown into a pre-treatment for anaerobic digestion. THP is the engineered application of temperature (320 to 330°F) and pressure (87 to 130 PSI) to more effectively break down sludge.

9. Cambi - THP Process Definition ▪ 2 - Stage process combining high-pressure boiling of sludge followed by a rapid decompression (steam explosion) ▪ This combined action - Sterilizes the sludge – Class A sludge - Converts insoluble solids to soluble solids - Reduces sludge viscosity by more than 60-80% - Reduced Digester size - Makes sludge more biodegradable - Eliminates hydrolysis step in digester – Reduced digester size - Removes bound water and EPS (extra polymeric substance) - Increases Dewaterability

10. Benefits of Thermal Hydrolysis Increasing treatment capacity, reducing biosolids handling, increasing biogas production to reduce energy utilization, reduce operation cost for biosolids processing, produce renewable bio-fertilizer.

11. Typical Process Flow for the Thermal Hydrolysis Process  10 to 25% higher volatile solids reduction in the digesters  10 to 20% higher methane generation  5 to 15% greater cake solids from dewatering.

12. Benefits: Cambi THP over Conventional Digestion Produces a high-quality Class A nutrient rich biosolids to be used as soil conditioner/fertilizer Increases Biogas production by 20-50% Dewaterability – 18% to 32% solids Reduces Digester volume by 60-70% Volume of sludge to be disposed off by 40-50% Odour drastically Opex for sludge treatment by 40-50% Sludge storage area by 50-60% Sludge treatment area drastically Reduces Carbon footprint Low Lifecycle Cost

13. Benefits: Cambi THP over Conventional Digestion Parameter Units Conventional Digestion THP with Digestion VS destruction % VSR 44% 59% Gas Yield Nm³/TDS 339 454 Digester volume m³ 46,350 14,300 THP size % - 100% Dewatering % DS 21% 32% Cake volume Ton/year 115,000 62,000

14. Potential for Thermal Hydrolysis as a Part of AD Systems There is a huge potential for the introduction of thermal hydrolysis of municipal waste solids. Incorporating thermal hydrolysis in new AD Plants, and retrofitting it to existing plants. For example, it represents an opportunity for Wastewater Treatment Works operators to increase the rate of solid hydrolysis, increase the extent of volatile solids reduction, and boost biogas production. At the same time, the more complete reaction achieved brings benefits to the digestate as a fertilizer. There is an increase in nitrogen (N) and phosphorus (P) solubilization enhancing the availability of these essential components of any fertilizer.

15. Key Takeaways Thermal Hydrolysis Process (TH) : A chemical process using heat and pressure to break down organic materials in anaerobic digestion (AD) systems. It significantly enhances biodegradability, increases biogas production, and facilitates sludge digestion. Biogas and Sludge Benefits : TH increases biogas yields by making more organic matter available for methanogenic organisms. It also improves the dewaterability of sludge, making post-digestion processing more efficient. Pathogen-Free Output : TH eliminates pathogens in the sludge, producing a sterilized, pathogen-free fertilizer that meets international regulatory standards, such as the EU Animal By-Products Regulation. Enhanced AD Performance : TH doubles the solids loading rate in AD reactors, reduces viscosity, and stabilizes plant operations, making the process more efficient. Wider Applications : TH is not limited to large wastewater treatment plants. New low-temperature systems, such as those from Lystek , offer scalable solutions for smaller plants, allowing broader use across various sectors. Industry Adoption : Companies like Cambi and Exelys are pioneers in promoting TH technology for AD plants, with multiple installations worldwide since the 1990s.

16. Companies Offering TH Process Equipment Cambi has long been well-known for their Thermal Hydrolysis Sludge Pre-treatment Technology for enhanced Anaerobic Digestion of municipal and industrial sludges.  Cambi  has been installing thermal hydrolysis as a pre-treatment to anaerobic digestion, around the world since 1995. Exelys is another company actively promoting this technology, which has a TH technology that they describe as representing the next generation of bio-solids thermal hydrolysis. But, these example companies are far from being alone in having spotted a business opportunity in TH within AD Plant Systems.

17. References Next Generation Thermal Hydrolysis Process - High Solids THP - Sudhakar Viswanathan1 *; Chris Thomson1 ; Rich Dimassimo1 ; Ross Garbett 1 ; Wesley Yellin1 ; Dr. Jongmin Kim2 ; Dr. Nicholas Landes3 Mohammad Abu- Orf , PhD AECOM Water North America Biosolids Practice Leader [email protected] CAMBI Thermal hydrolysis Sludge Treatment: Medium to large-scale application - https://www.environmentindex.com/en/article/cambi-thermal-hydrolysis-sludge-treatment-medium-to-large-scale-application-677.aspx