Processing Magazine

Multiphase biofilter provides alternative for VOC control

August 11, 2009
The biosystem incorporates both air phase and liquid phase approaches, taking advantage of the natural tendency of VOCs to partition into both phases. It uses proprietary media, and enhanced bioremediation techniques to treat high inlet concentrations of VOC with efficiencies up to 98 percent. The system uses permanent, synthetic ceramic biomedia, which is surface-modified to allow accelerated attachment and growth. It has a very high biologically active surface area, and will not clog due to biomass growth or particulate accumulation. The media bed is self-cleaning, and never needs to be replaced. The biofilter system has a small, manageable footprint. It is a single-vessel system that can be sited close to the emission source, sometimes even inside the facility, minimizing long duct runs. The biosystem generates minimal wet and solid waste, and does not create NOx by-products. It also produces much less CO2 because it is not burning natural gas. Its lifecycle environmental impact is much smaller than biofilters, RTO and RCO. Applications that benefit most from Multiphase technology include manufacturers of fiberglass, adhesives, resins, and engineered lumber; also processors who generate emissions from formaldehyde, methanol, turpenes, pinenes, and other VOC species and is ideal for tars, waxes and heavy VOC compounds, according to the manufacturer. It is compatible with high-temperature VOC emissions, such as those from dryers and other hot processes. This is a substantial advantage over biofilters, whose use is limited to processes with low inlet temperatures. In contrast to thermal oxidation, the biofilter system is much less expensive to install and operate over time. There is no perpetual natural gas cost, and consequently no dependence on the unreliable natural gas market. Systems are custom-engineered to the application and are operated like standard industrial equipment. The system is fully instrumented, integrates with the plant control system, and can be rapidly brought on and offline.