PROJECT DESCRIPTION
BACKGROUND
The aim of this project is to demonstrate BAT for the process industry for maximising solvent recovery and reuse whilst minimising emissions to the atmosphere. The VOC emissions of interest include those of halogenated solvents. In quantitative terms, the project aims to demonstrate a reduction in VOC emissions from levels of aproximately 500mg/m3 to below 5mg/m3 , which will define a new EU standard for BAT. From this project, information will be available to enable the design of a plant that can be incorporated into the manufacturing lines of the process industries. An integrated solution to the problem of combining solvent capture and recovery with plasma destruction of the remaining VOC in the gas stream is proposed. The non-thermal atmospheric pressure plasma is generated using a patented microwave system. The electric field is intensified to a level where the gas carrying the solvent is ionised. The microwave power then heats the released electrons thus producing more ionisation and also high densities of reactive free radicals. These radicals, together with direct electron impact, destroy the solvent molecules producing compounds that can be easily removed by, for example, standard scrubbing techniques. The project is being performed in two phases. Firstly, a prototype non-thermal plasma system has been designed, constructed and commissioned. Small scale laboratory studies have indicated that this approach can economically oxidise low concentrations of a range of organic materials. Secondly, the system has been installed downstream of a solvent condensor at a pharmaceutical process plant. Trials have been carried out to demonstrate reduced VOC emissions from pharmaceutical processes when the plasma system is operated in conjunction with solvent capture techniques