PROJECT DESCRIPTION
BACKGROUND
This LIFE project can be linked to Art. 7(f) (Health and Quality of LIFE, Air) of the 6th Action Programme. The European Commission’s Regulation 178/2002 of 28 January 2002 calls for a reduction of salmonella in feed products. Salmonella can be reduced through thermal treatment technology using hot air or steam, but this has the disadvantage of causing noxious odours emissions. Residents in the areas around feed mills have complained about these emissions for some time. A number of methods to reduce the odours have been analysed, including bio filters and bio scrubbers conventionally used in the feed industry. These methods, however, are both subject to high investment and operating costs and low rates of efficiency – below 50 percent in most cases. As a solution to these problems, AGRAVIS (formerly Raiffeisen-Centralgenossenschaft Nordwest eG (RCG)) installed a Non-Thermal Plasma plant (NTP) in two of its compound feed mills to achieve the overall target and reduce odour emissions from the mills by up to 98 percent. Within the new developed NTP technology for the feeding industry a new technique is now available and has been further developed and applied successfully.
OBJECTIVES
The main objective of the project is to reduce the odours emitted by feed mills by up to 98 percent. It was also expected that NTP technology would be transferable across different production lines, such as the production of pig, cattle, poultry and horse feed. The aim of the project was to adapt the NTP process to the specific conditions of feed mills. Emissions of odours increasingly found to be hazardous for the environment are to be reduced both effectively and reliably. To save energy and costs, a control system will be developed for the process. This will be tailored to the needs of the industry.
RESULTS
The project was completed successfully. The technical targets were achieved, with the exception of the development of the “Electronic Nose". The NTP (Non Thermal Plasma) plant in Oldenburg is technically running successfully. Measurements have demonstrated that the odour reduction achieved with the Non-Thermal Plasma Process is between 60-85 percent. The reduction rate was found to be proportional to the concentration of odorous substances. The environmental benefit during the operation of the NTP technology is quite high compared with other odour reduction techniques due to the low levels of energy consumption, waste production, wastewater, fuel emissions and noise emissions. There are almost no secondary emissions produced through use of the technique. The project can be linked with Article 7(f) (Health and Quality of Life, Air) of the 6th Action Programme. Transferability of results: The results are transferable across the European feed and food industries, the aromatics production industry, and disposal plants for recycling, such as composting plants and similar facilities. The NTP method can be effectively combined with biological exhaust-air treatment systems. This synergy allows decomposition of substances that normally are not broken down by plants using biological processes. In the meantime, the results have also been transferred to other unrelated industry sectors and are applied in the chemical industry for the decomposition of organic compounds, which, in the form of phenolic resins or amines, present a considerable olfactory nuisance. Our partners and the producers of the system, Rafflenbeul Ingenieure, Voltstraße 5 in D-63225 Langen, report that the system has now also been employed successfully for purifying the combustion gases of diesel engines, where it has for the first time been possible to achieve substantial soot oxidation. The reaction produced in the exhaust gas of high-capacity diesel engines yielded soot reductions of the order of 50 percent plus. The experiments will be continued with the aim of also removing the NOx, possibly without the use of catalysts. Innovative aspect of the project at a national and international level: In industry, so-called “silent” exhaust-air treatment systems are sometimes used, which operate on a frequency of 50 Hz. For the feed industry, these systems are of limited use, because of their low efficiency in odour reduction. The Non-Thermal Plasma Process, by contrast, offers the decisive advantage that at a frequency of 400 Hz with linearized voltage characteristics, the current yield can be much improved. This fact is demonstrated when analysing the so-called “ethyl acetate index“, according to which less than 120 kWh electrical energy is required for the decomposition of 1kg of ethyl acetate. This compares to energy requirements of 350 to 500 kWh for “silent” methods operating on a service voltage of < 3000 V. In summary, the Non-thermal Plasma Process is an advanced “silent” method. The innovative aspects of the LIFE project can be seen in the linearalized voltage characteristic which helps reduce energy consumption, the use of low-cost discharge modules made from ceramics, and the compact design of the system, as well as the ecological benefits that can be derived from this system.