Technology

Carbonization

Technology Description (Abstract)

carbonization

Pyrolix technology is a pyrolysis process carried out in intermittent flow reactors heated by closed-loop thermal fluid in a temperature range of 300 – 330 °C. It is a protected technology, with ownership rights belonging to the Federal University of Minas Gerais (UFMG) and partner institutions.

Depending on its properties, it is necessary to process waste in a chopper. The process begins with solid waste being loaded to the system through a conveyor belt to the pyrolysis reactor, which is subjected to indirect heating by thermal fluid. In this initial phase, the process is endothermic, and the energy for heating the thermal fluid is provided by burning biomass (wood chips) in the furnace. Exhaustion gases from the furnace are treated in the secondary scrubber. Alkali solution, stored in the tank, is used on both scrubbers, and also to cool the carbonized waste.


When reactor reaches a certain temperature (approximately 200 °C), pyrolysis reactions begin. These reactions generate heat, which is eventually sufficient for maintaining the process running. In the same way, the gases and vapors generated in the reactor are also used in the furnace as fuel to provide heat to thermal fluid, after treatment in the primary scrubber.

The thermal fluid operates in closed circuit, passing through the reactor and the fluid heater, which maintains the temperature in a suitable level for the process (over 300 °C on the thermal fluid and over 850 °C on the furnace). The carbonized waste is discharged on the cooling reactor with temperatures below 60 °C. Production cycles considering loading, processing and discharging take approximately 2,5 hours.

Important facts:

  • The pyrolysis process demonstrated environmental safety in the treatment of Health services waste;
  • Concentrations of pollutant emissions into the atmosphere below the limits imposed by legislation;
  • Concentration of emissions of dioxins and furans < 0.1 ng. NM-³ (0.0162 ng. NM-³);
  • Municipal solid waste charred presented PCI 24.7 MJ. Kg-1;
  • Gravimetric Yield pyrolysis process of 33%.
  • Reduction in the mass and the volume of the waste processed between 50% and 90%;
  • Elimination of leachate in the processed waste;
  • Biological waste processed Blanketing;
  • Use of auxiliary fuel at low cost;
  • Reduction of area in relation to other waste treatment processes;
  • Modular Plants, with domestic manufacturers.
  • The process presents environmental safety with respect to releases of gases to the atmosphere, with emissions below the limits of current environmental legislation (dioxins and furans, particulate matter, oxides of nitrogen and sulphur, etc.);
  • Possibility of application of carbonized product retrieved from other thermal processes, to be used as solid fuel (thermoelectric power generation, production of clinker);

Electrical Generation

The carbonization it is an endothermic process at the beginning, as it need fuels to start, but it ends as an exothermic process, as it generates fuel – the CWR, Carbonized Waste Residue. Between th heat, gases, and the CWR, there are diferent options for electrical generation: thermal plant, rankine cyccle motor generator, or stirling motor generators. It is the size of the project, caractheristics, type of waste stream, etc, that will determine how the electrical generation will be done.