Pyrolysis Dryer

Capture CO2 with our Pyrolysis Option

Sludge/Biomass Dryer with Pyrolysis

The Jumbo Dryer with Pyrolysis option utilizes biogenic residues which are produced in a wide range of processes. Examples of these are:

  • Digestate from biogas plants
  • Sewage sludge from municipal sewage treatment plants
  • Sewage sludge from the industrial production of foodstuffs
  • Bedding from animal husbandry
  • All types of pomace
  • Residues from forestry and silviculture
  • Residues from landscape conservation

 

The PYRODRY process is based on a biomass drying plant with integrated pelletizing system from Jumbo Group Smart Dry with the addition of a thermal treatment plant for Pyrolysis. The feedstock is pre-dewatered biogenic residue and is further processed in the pyrolysis unit to produce heat for drying leaving a treated carbon containing organically decontaminated product. The produced bio(based)char can be seen as carbon sequestering agent having a CO2 positive balance and helps to fulfill worldwide requested climate goals.

The JUMBO dryer is a high temperature vortex dryer whose thermal energy is provided by the direct exhaust gases from the pyrolysis gas combustion. The hot exhaust gases with approx. 850°C from the thermal reaction of the pyrolysis are mixed with cooling air to approx. 300°C and an oxygen content of approx. 17%. This hot and non-combustible drying gas is evenly fed into three individual drying chambers. Within the drying chambers, the moist biomass is swirled in a cloud of material and exposed to the hot exhaust gas stream. The high-pressure difference between partial pressure and steam saturation pressure results in an immediate aggregate transition from liquid water to gaseous steam. The resulting evaporative cooling reduces the hot exhaust gas to a temperature of approx. 70°C. Due to the hot gas impingement and simultaneous provision of the maximum material surface by the permanent turbulence of the drying material, a drying efficiency close to the physical limit of 650W per litre of water evaporation is achieved. The material throughput is on average only 4.5 minutes to the material exit with a dry substance content of 90%. The dry material is fed in a closed system to a ZRP250 press wheel pelletizer. The dried biomass is pressed into pellets at a compression ratio of approx. 1.2 by two press wheels running slowly into each other. The pelletizing is fully automatically integrated into the process.

After the pelletizing process, the pellets are transferred to the pyrolysis process via a rotary feeder. Inside the thermal pyrolysis system, organic compounds are thermally decomposed at a temperature of about 600-700°C in the absence of oxygen (λ ≈ 0). The process basically produces two fractions – pyrolysis gas and pyrolysis char (Carbonisate). The mass and energy distribution of the products is mainly influenced by three parameters:

  • Composition of the feedstock
  • Temperature
  • Residence time

Pyrolysis is basically an endothermic process to which heat must be supplied. During the heating phase at startup,
the system is heated to the required process temperature with an auxiliary burner (e.g. natural gas). The pyrolysis gas generated is burned directly in the pyrolysis unit. Part of the generated heat is used for the pyrolysis itself, the other part directly heats the dryer by offering drying gas. In this way, valuable and CO2-intensive primary energy (e.g. natural gas) can be replaced by utilizing the feedstock containing heat. Overall, the emission of the whole system can be reduced in a larger range. The produced Carbonisate is discharged at the end of the reactor, cooled and collected e.g. in big bags. During the process, a substantial mass reduction and carbon accumulation takes place in the solid product. This results in a C-sink potential, which plays an increasingly important role in the context of climate crisis management. This nutrient-rich char product (Carbonisate) can possibly be certified as biochar.

Benefits of Pyrolysis

  • Completely continuous and independent operation; state-of-the-art degree of automation; in principle, can be operated unmanned!
  • Modularity of the plant; easily expandable in terms of capacity.
  • Possibility to discharge a thermal utilization product (= carbonate) with high carbon content! Keyword CO2 balance!
  • Solid fraction is thermally converted into biochar.
  • Due to the two-stage combination in one system, it is possible to thermally convert the dried input material in a “gentle” and low-dust way.
  • By combining the thermal utilization in direct form with the dryer, flue gas cleaning takes place at the same time.
  • The high temperatures produce a high-quality Carbonisate – BIOCHAR – Pyrolysis Coke.