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Reinventing the liquid waste disposal process

Periodic Reporting for period 1 - WAS2VAL (Reinventing the liquid waste disposal process)

Reporting period: 2020-11-01 to 2022-01-31

The treatment of sewage sludge (SS), the by-product generated during wastewater treatment, represents one of the biggest problems for small and medium sized wastewater treatment plants (WWTPs), due to the adoption of stringent rules towards resource valorization and the minimization of adverse effects on the environment. Besides, it entails high costs for the plants. This is pushing WWTPs to seek urgently for cost-efficient, ecological and clean disposal solutions for their SS.

TreaTech has developed a unique SS treatment technology based on catalytic hydrothermal gasification (cHTG) that can convert different types of liquid wastes, that are typically incinerated or landfilled, into useful products including renewable gas, clean water, and mineral salts, which can be further upgraded into e.g. fertilizers (figure 1). The implementation of our technology into the market will contribute to society addressing the following points:

Sustainable and circular economy:
TreaTech is on the path for a sustainable economy, as it transforms liquid waste into high-value products, representing a nearly zero-waste business. Besides, the recovery of the minerals contributes to a circular, biobased economy following the principles of the European Roadmap for Resource Efficiency.

Mitigating climate change:
Alternative clean technologies are crucial to mitigate climate change and address EU goals to reduce at least 50% of GHG emissions by 2030. Our solution produces 17 times less CO2eq emissions than solutions involving anaerobic digestion followed by incineration.

Energy transition:
TreaTech is aligned with the energy transition, since our technology, besides not needing fossil fuels, can produce 80% more renewable energy than anaerobic digestion by converting >99% of the organic matter present in biomass into high-quality renewable gas.

The overall objective of the project is to bring a scalable and validated Industrial HTG technology to the market. Specifically, we aim at:
- The validation of a pilot plant at a research institute
- The design and validation of a new transportable pilot unit at a customer site
- The commercialization and industrialization of the technology
The first reporting period covers the successful transition from commissioning to the efficient operation of the pilot plant at the Paul Scherrer Institute (PSI) by performing troubleshooting, developing a protocol for feedstock preparation and performing R&D on the improvement of the catalyst. Besides, we designed a transportable pilot unit and we worked on pre-commercial activities such as the dissemination of the technology.
Successful commissioning of the plant at PSI [WP1, 10M]
After accomplishing all the required tasks to be able to operate the plant, the commissioning phase concluded with the first successful cHTG test with a 5 wt.% glycerol solution. The plant (figure 2) maintained stable pressure and temperature during the 20 hours test and produced rich-gas containing a high fraction of methane (70 vol.%) with a high rate of carbon conversion (95%).

Development of a feedstock conditioning unit [WP1, 5M]
We developed an improved process for feed preparation for the pilot plant at PSI which included putting in place an efficient sewage sludge supply chain and implementing an improved process for milling and filtering the feedstock.

Improvement of the catalyst lifetime [WP1, 12M]
We performed >30 tests with our lab-scale prototype focused on improving the catalyst lifetime. We now understand the causes of deactivation of the benchmark catalyst, we found new materials that improved the stability of the catalyst resulting in a reduction of the costs and we performed a preliminary research on the regeneration methods for spent materials.

Design of a transportable unit [WP1, 9M]
We have designed a new transportable pilot unit to validate the technology in a real environment with continuous processing of the feed. The design is currently in the basic engineering phase. The P&IDs are drawn and we are working on the 3D drawings before starting the manufacturing process.

Pre-commercial activities [WP3, 15M]
We participated in 2 digital events and 1 physical tradeshow. With the support of our coach we settled our sales strategy and marketing tactics.

TreaTech was 4 times in the news and we produced several communication contents (video, papers, etc.). We received 10+ LOI/MOU from potential customers/partners and performed feedstock testing campaigns for 5 customers which led to planning for future steps.

Finally, with the support of a financial contractor we have developed our financing strategy and planned our Series A.
During the first fifteen months of the project, we have performed the first successful cHTG test at pilot scale with glycerol and we have found new promising configurations for the catalyst resulting in a significant reduction of costs. Those results confirm that we are on the right path towards the industrialization and commercialization of the technology.

During the second part of the project, we expect to validate the technology at a customer site achieving continuous processing of their feedstock. With this purpose we will manufacture and install a transportable pilot unit at a customer location while taking advantage of the maturity of the pilot at PSI for optimizing and testing. Besides, we will continue researching for the optimum catalyst configuration that ensures the profitability of the technology at large scale. Finally, we expect to assemble a well-defined commercial network and achieve a good level of dissemination of the technology which together, will facilitate the industrialization and commercialization phase.

By commercializing the cHTG technology, by 2030, we expect to treat 485'000 tons of dry feedstock (municipal and industrial waste) for 115 customers which will have a socio-economic impact translating into producing 2 million tons of clean water and 1260 GWh of energy which could power 120'000 households. Moreover, by treating 200'000 tons of dry SS we would save 136'193 tons of CO2eq emissions per year compared to anaerobic digestion followed by incineration.

Moreover, the technology has a broader societal implication which derives social and health benefits. It is well known that sludge contains highly varied amounts of organic chemicals, toxic metals, chemical irritants, and pathogens. These substances can cause disease, and people and animals exposed to them may become sick or carriers. The conditions used in our process technology ensure sanitation conditions, eliminating any risk of contamination by all types of virus (including COVID19) and microorganisms. Furthermore, as our technology does not require storage it avoids unpleasant odours providing great benefits to the community.

Finally, we have noticed a growing interest from industrial sectors such as chemical production, oil & gas, food & beverage, among others, incentivized by net zero initiatives and the need of renewable gas to fuel their process. This has led us to prioritize this set of customers whose quick call to action will facilitate unit implementations at scale.
Back view of the HydroPilot plant at PSI
Block diagram of the Catalytic Hydrothermal Gasification process including nutrient recovery