**3. Description of the experimental setup**

The authors have developed and manufactured an experimental plant for the pyrolysis of plant biomass under pressure, which makes it possible to obtain a highly porous carbon material, the parameters of which (sorption capacity, total pore volume, bulk density, elemental composition) meet the requirements for activated carbon.

During the development of the installation, the technological scheme of thermal steam activation was adopted. In this case, the installation consists of three blocks shown in **Figure 9**.

The arrows show the movement of the steam. Each unit is equipped with a pressure relief valve. On block 1 - for 8 atmospheres, on blocks 2 and 3 - for 10 atmospheres (to ensure, first of all, the movement of steam into the pyrolysis chamber and activation). Each block is made in the form of cylinders with an inner diameter of 0.1 m. The blocks (chambers) are interconnected by adapters in the form of tubes with an inner diameter of 0.02 m. The thickness of the walls of the chambers and adapters is 0.005 m.

The installation diagram is shown in **Figure 10**.

The experimental setup works as follows.

At the beginning of work, wood raw material is loaded into basket 15 (see **Figure 10**) and placed into the cavity of the pyrolysis and activation chamber.

After loading the basket, the pyrolysis and activation chamber is hermetically closed by the chamber lid 14, having previously installed a brass O-ring. Water with a volume of 2 liters is poured into the steam generator and hermetically closed with a lid. After that, the serviceability of the devices and the reliability of the fastening of the installation elements are checked. Then the fan 17, the temperature controller "Sosna-002" and the heaters 2, 9 and 13 on the steam generator, superheater and pyrolysis and activation chamber are turned on.

The required pressure in the installation is maintained by valves 6 and 20 installed on the steam generator and cooler.

### **Figure 9.**

*Block diagram of the experimental setup. (1) pyrolysis and activation chamber, (2) superheater, and (3) steam generator.*

*Features of Pyrolysis of Plant Biomass at Excessive Pressure DOI: http://dx.doi.org/10.5772/intechopen.99468*

The general view of the installation is shown in **Figure 11**.

A general view of the loaded basket is shown in **Figure 12**.

To control the pressure level, pressure gauges are installed on the steam generator and cooler.

The temperature regime in the installation is maintained through the use of electric heaters on the steam generator, superheater and pyrolysis and activation chamber. The temperatures in the chambers are controlled using thermocouples 3, 8, 11 and 19 (see **Figure 10**) installed in the steam generator, superheater, in the pyrolysis chamber and in the cooler.

**Figure 11.** *General view of the experimental setup.*

**Figure 12.** *Loading the basket into the pyrolysis chamber and activation.*

**Figure 13.** *General view of the cooler.*

The gaseous products of the conversion, together with the superheated steam during thermal expansion, create an overpressure in the installation. In the case when the pressure exceeds the operating pressure (8 atm), the surplus of gaseous products leaves the unit through the safety valves.

Heavy hydrocarbons released in the pyrolysis and activation chamber during the operation of the unit enter the cooler (**Figure 13**) through the heat exchanger. In the cooler, heavy hydrocarbons and steam are condensed. To remove them, the cooler is equipped with an outlet pipe and a valve.

To intensify the process of cooling the exhaust gaseous products and ensure their condensation, a fan is installed that creates an air flow to enhance heat transfer.
