Frequently Asked Questions
What is Hydrothermal Carbonization (HTC)?
What is the difference between HTC, TDH, HTL, HTP?
THP is operated at 160-170 °C. In this process, the organic structures of the feedstock are broken down by the exposure to temperature and pressure, which improves their availability in the subsequent digestion process and increases the digester gas yield.
In HTL, a temperature level of about 250-400 °C is required. In this process, the biomass is almost completely liquefied and can then be further processed into various fuels (kerosene, gasoline, diesel, etc.), among others.
How do hydrothermal processes (HTP) differ from pyrolysis?
Who 'invented' HTC?
What products can be obtained with HTC, what can they be used for
The coal produced can be used as a CO2 neutral fuel to replace fossil coal in the cement industry, power plants and waste incinerators, but cannot be used as barbecue coal. The coal can also be used as a soil conditioner, thus also enabling CO2 sequestration (Carbon Dioxide Capture and Storage – CCS) due to its stabilized carbon structure.
The recovered process water contains high concentrations of C, N and P and can therefore be used as a liquid fertilizer, if permitted, or can increase the digester gas yield by up to 15% when recycled to a digester. Generally, the process water can not directly be discharged into the sewer network and must be treated.
Are HTC products from sewage sludge sanitized and does HTC achieve an End of Waste (EoW)?
HTC products from sewage sludge generally do not reach the end of waste (EoW) according to Section 5 (1) of the German Waste Management Act (KrWG).
Which materials can be treated in a TerraNova Ultra® system, do they have to be pre-conditioned?
For good pumpability, depending on the structure of the biogenic residue, it may be helpful to mechanically pulp the input material before transfer to the input hopper.
What is the purpose of the individual system components in a TerraNova Ultra® system, what is the pressure range?
The area between the feed pump and the slurry outlet is the pressure area of the plant. All other components are outside the pressure range.
Does a TerraNova Ultra® plant operate continuously and automatically?
What exactly can a TerraNova Ultra® system be used for and what are the advantages?
In a TerraNova Ultra® plant, bio waste materials are upgraded with the aim of saving disposal costs, refining the waste materials, or recovering nutrients.
For example, sewage sludge can be dewatered just mechanically after HTC treatment to a dry matter content of about 65 %, which leads to energy savings of 80 % compared to conventional drying. In addition, if the process water is recycled, the digester gas yield can be increased by up to 15 %, which further improves energy efficiency. In addition, 60 – 70% of the phosphorus contained in the sewage sludge can be recovered. The recovered HTC coal can replace fossil coal or be used as a soil conditioner or for CO2 sequestration.
How does phosphorus recovery work?
Phosphorus recovery can be optionally integrated into existing TerraNova Ultra® systems.
What does the economic efficiency of a TerraNova Ultra® system depend on, and what input quantities are necessary for economic operation?
For industrial use, modules with input capacities of 1, 2 or 3 t/h are offered (approx. 7,500 / 15,000 or 23,000 t/a). For processing larger quantities, several such modules are operated in parallel.
Does this take into account revenues that could be generated by HTC products?
Are there smaller plants in addition to industrial modules?
What are typical consumption values for HTC of, for example, sewage sludge and can waste heat flows be used?
By using the separated process water, the digester gas production can additionally be increased by up to 15 %.
The necessary process heat can be provided by a suitable waste heat source, such as a CHP plant.