1. Preparation of the waste to form a "CHO-Fuel"

To ensure maximum energy efficiency for the process, the waste – made up of that portion of material which is rejected during previous sorting operations – has any metal and any inert materials removed, if necessary. It is then coarsely crushed before being conveyed into the gasification unit.

2. Conversion of the "CHO-Fuel" into BioSynGas

A)    Drying the material
First of all, the material is dried at 200°C and then converted into gas at around 600-800°C. This operation is carried out in the absence of air, so that there is no combustion, but instead, the organic material is converted into gas. This is the principle behind gasification.
The design of the gasification unit is based on that of a robust grate furnace, a process that has been in use for over 50 years.

B)    Refining the syngas using plasma torch - TurboPlasma
The crude syngas is mainly composed of carbon monoxide and hydrogen, but also includes tar which makes it unsuitable for use in turbines or engines. The TurboPlasma system is used to ensure complete dissociation of the tar into gas, without it being able to recombine, thus raising the calorific value of the gas. TurboPlasma equipment is patented by Europlasma.
C)    Heat recovery and decontamination of the BioSynGas
Heat is recovered from the BioSynGas in order to supply the gasification unit and a combined-cycle steam turbine.
Depending on the type of waste, a suitable system for treatment of the BioSynGas is used to neutralise acidic components and to filter out heavy metals. The fact that the process involves no combustion means that the volume of gas to be treated is small, and that the equipment is very efficient.

3. Electricity production

Depending on the options involved, the cleaned, refined gas may be supplied as it is. It has a calorific value which is about 1/3rd that of natural gas. The commonest use for the gas is to supply a gas turbine/engine, and to produce electricity which is sold back to the grid. The heat from the engines is recovered to generate steam and additional electricity.
With this process the end-to-end electrical yield is between 35 and 40%.

4. The vitrification unit

Depending on the type of fuel that is introduced into the gasification unit, there may be a non-organic part (metallic or mineral for example) which is not transformed into syngas. If necessary, the residual ash may then be taken to a vitrification kiln which is also equipped with a plasma torch. The ash is made to melt at 1,400°C, and on cooling, forms an inert vitrified material which can be reused. This is the vitrification process.
Europlasma is the world leader in this technology, and this part of the process is based on 15 years’ experience with 6 plants currently equipped with  ash vitrification units.