Continuous Pyrolysis for the Activated Carbon Production Part 2

Activated carbon production can be done in two ways, namely physical and chemical activation. Both physical and chemical activation require pyrolysis (carbonization) in the activated carbon production process. The difference about the sequence, in the use of the pyrolysis unit (carbonization) in the activation process is the physical activation of the pyrolysis unit (carbonization) for charcoal production which is then activated using steam or CO2, while the chemical activation of the pyrolysis unit (carbonization) is used for charcoal production from raw materials previously chemically activated like with H3PO4, ZnCl2, KOH. Other differences in physical activation using temperature for activation are higher, namely the range of 800-1000 C while the chemical activation uses a lower temperature, which is around 150-200 C only. Activated carbon products or yield that are produced chemically are more than those produced physically, which are around 3: 1.

The advantage of using a continuous pyrolysis unit for activated carbon production primarily increases the efficiency of the production process and the quality of the products. Efficiency is very important for a production activity. The efficiency of the production process is derived from the use of pyrolysis by-products that can be used to produce heat and even electricity. As an example of physical activation that uses a high operating temperature, excess syngas can be used to reach that temperature. Biooil produced can produce steam. Charcoal products produced from a continuous pyrolysis (carbonization) unit also do not need to be cooled and can be activated directly, so that their energy needs can be minimized. So that the activated carbon production should be an integration between the pyrolysis unit (carbonization) and its activation unit.

While in the chemical activation process, pyrolysis (carbonization) byproducts can also be used for the production of activated carbon. The activation process that uses a temperature that is quite low at 150-200 C can use excess heat from the pyrolysis process for its heat source. While excess syngas can be used to produce electricity for the production of activated carbon or sold to other parties such as other industries or PLN. Biooil can also be used for burner fuel or purified again for the production of vehicle fuel and so on. Continuous use of pyrolysis (carbonization) will also produce high quality, standard and stable product quality, this is because the operating conditions in the unit can be easily and accurately controlled, such as heating rate, residence time and temperature.

While in charcoal production (carbonization) traditionally operating in batches, in addition to a lot of energy loss also produces a lot of smoke which causes air pollution. The loss of energy during the traditional process of carbonization (pyrolysis) can even reach more than 60% meaning that more than half of the energy is only wasted, for more details can be read here. Of course this is very unfortunate, the activated carbon plant which should be able to operate very efficiently and economically, becomes wasteful and expensive. The effect of this is of course on the depletion of the profits obtained by the business. Within a short time it is expected that activated carbon factories will use continuous pyrolysis (carbonization) to increase efficiency, environmental and economic aspects.