Biogas facilities

Biogas facilities are an attractive option for the generation of power and heat from organic materials. The power being generated by these facilities is being purchased by the local power company in accordance to statutory law.

Decontamination · Oxidation

Waste water decontamination is the term for all those processes in which toxic substances in the water are transformed into harmless substances that can then be removed from the water flow. These are, in particular, waste water flows containing cyanides, chromates, arsenic or nitrite as well as dissolved complex metal compounds. Around the world, authorities pose increasingly high requirements on the biodegradability of undesired substances contained in water. In some cases very low COD values are demanded.

Ion Exchanger

Ion exchange is the most versatile and proven separation process for water purification and recycling. With this technique, it is possible to desalinate fresh water to the point that it can be used as boiler water in a power station or in combination with membrane separation processes for chip production. Ion exchangers are often used for the circulation of rinsing water because of their robustness and economical advantages for desalination of low salt-containing water. For the waste water treatment, selective ion exchangers are used for the removal or recovery of metals.

Recycling

Because of the EISENMANN policy, reduction and recycling are preferred to disposal, and circulation techniques have priority over waste water treatment. With EISENMANN’s experience in production processes, all options for water saving and water recycling are checked and already incorporated in the design phase. By integration of an evaporator in a pretreatment line zero discharge operation can be achieved. Because waste water no longer discharges into the sewer, a whole series of official regulations and controls are eliminated. Another example of an optimum combination of economy and ecology is the two-step membrane process for printing ink recycling. The wash water from production has traditionally been treated by coagulation, creating a sludge that had to be disposed of. With the recycling process developed by EISENMANN, the ink containing wash water is treated by ultrafiltration so that the printing ink is recovered and can be reused. The second step, the nanofiltration, removes the trace organic substances and heavy metals from the filtrate of the ultrafiltration. The nanofiltrate can then be reused for cleaning or discharged into the sewer. The example described shows that the combination of recovery of valuable substances and waste water treatment leads, even for environmental plants, to interesting amortisation periods.

Regenerative Thermal Oxidation

The Right Technology for Every Use: Thermal Treatment or Adsorption Thermal and regenerative oxidation RTO and adsorption technology are the major methods of exhaust air purification. The decision what method constitutes the most economical solution in each individual case is determined by the following factors: the exhaust air volume, type and concentration of the emitted pollutants, exhaust air temperature, the value of the recovered materials, and especially whether the released energy can be directly recycled into the production process. Regenerative Thermal Oxidation Due to its minimal use of additional energy, and cases where recovered energy cannot be reused, the trend clearly goes towards RTO. A patent protected air distribution system developed exclusively by EISENMANN uses a rotating distributor to continuously control the alternating airflow through the individual heat exchanger sections without expensive control technology. This replaces complicated damper mechanisms and eliminates the pressure shocks associated with dampers.

Thermal and regenerative oxidation RTO and adsorption technology

The Right Technology for Every Use: Thermal Treatment or Adsorption Thermal and regenerative oxidation RTO and adsorption technology are the major methods of exhaust air purification. The decision what method constitutes the most economical solution in each individual case is determined by the following factors: the exhaust air volume, type and concentration of the emitted pollutants, exhaust air temperature, the value of the recovered materials, and especially whether the released energy can be directly recycled into the production process. Thermal Treatment The fastest and safest method to eliminate volatile organic pollutants is oxidation. In this process, the polluted air is heated to the point where the majority of the organic materials oxidize into water and carbon dioxide. Recuperative Thermal Oxidation In cases where the excess energy can be recovered and reused in the production process, recuperative oxidation is unbeatable. This process is known to be robust, safe and universally applicable.

Ultrafiltration

Membrane filtration is the selective separation and concentration of dissolved as well as non-dissolved substances from the aqueous phase under pressure. The size of the particles to be separated determines the pore size (cut-off) of the membrane which has to be chosen for the optimal process. For example, ultrafiltration is suitable for retaining paint pigments and/-or oil droplets, but ultrafiltration can’t retain ions. Consequently, the conductivity of the treated water remains the same. For desalination of water, reverse osmosis membranes are required, which are gaining an increased market share in competition with the established ion exchange processes. Most important for the efficiency of the membrane separation process is among the cut-off and the individual design, the choice of membrane material (ceramic or organic), and module design (hollow fiber, tubular, spiral wound, rotor or plate).

Waste disposal, recycling and energy utilization

For almost 25 years, plants for thermal treatment and energy utilization of different kinds of waste are included in the product range of EISENMANN. These can be waste fractions with high heating value and residues from industrial processes, sewage sludge or recyclable valuable substances.