Systems for the treatment and reduction of odor emissions

We supply systems for the control, reduction, and elimination of odor emissions from different sources, such as industrial processes, wastewater treatment plants, farms, etc.

We design and supply customized systems that adapt to the specific needs and objectives of each case, always complying with the most demanding environmental standards.

Odor emissions are releases of volatile chemical compounds into the air that produce odors detectable by the human sense of smell. These odors can come from a variety of sources, such as industrial processes, wastewater treatment plants, waste handling facilities, chemical plants, animal farms, and more. The presence of odor emissions can cause discomfort and air quality issues for people living or working near these sources.

We supply different technologies for the design and implementation of odor emissions treatment systems.

The choice of the most suitable technology for each case depends on variables such as the source of odor emissions, the concentration and composition of odor compounds, emissions volume, local environmental regulations, as well as the specific factors that come with each case. It is very common to find odor emission treatment systems that combine and integrate various technologies to achieve greater efficiency in odor reduction.

Some of the common technologies used for odor reduction or elimination include:

Scrubbers

Scrubbers are a non-destructive technique whereby the odoriferous components are removed from the air by an absorbent solution. This is efficient for treating air contaminated with polar compounds such as NH3, H2S, amines and some water-soluble VOCs. The absorbent solutions used depend on the contaminants to be removed. In some cases, several washing steps are necessary to achieve high efficiencies. This technique consumes chemical reagents and produces liquid waste that has to be properly treated before discharge. It is a technique applicable for all types of flows.

Activated carbon filters

Adsorption does not destroy the contaminants, but transfers them from the gas phase to the solid phase. The universal adsorbent is activated carbon, although zeolites and alumina can also be used. Adsorbents have a finite capacity and have to be either regenerated or replaced when the adsorbent is saturated. If the adsorbent cannot be regenerated in situ, it is not advisable to treat air flow rates which are high or have a high load. When pollutants are nonpolar, the adsorption efficiency is high.

Biofilters

In this operation the air flow is treated by passing the current through a porous bed filled with plant-based material (e.g. wood chips, bark or coconut fiber), whose surface acts as a support to colonize the microorganisms that consume the contaminants. The emission must be pretreated by incorporating moisture and nutrients that the microorganisms will subsequently need.

This is a technique applicable when the pollutant load is low and biodegradable and the gas flow treated is constant. The use of chemical reagents is not required and no waste is generated. The microorganisms grow attached to the biofilter support and convert the contaminants into harmless products. The investment and operating costs of these processes are low; however, their application is restricted to biodegradable VOCs, moderate loads of hydrogen sulfide or ammoniacal compounds and the emission must not contain toxic or inhibitory substances.

Percolator biofilter system

This consists of circulating the flow through a bed filled with a support where attached microorganisms grow and an aqueous current is recirculated in countercurrent. The contaminants are transferred from the gas phase to the liquid phase and from this to the biofilm where they are consumed by microorganisms. These systems do not consume chemical reagents or produce waste.

They are applicable for all types of air flows and hydrogen sulfide or ammoniacal compound pollutant loads. The removal efficiency is very high, even with low air residence times inside the percolator. Investment costs are of the same order as chemical absorption towers (scrubbers), but with much lower operating costs. Like any biological process, this technique is not applicable when the air contains toxic and/or inhibitory substances.

Regenerative thermal oxidation

This operation oxidizes the VOCs to CO2 and water at high temperatures (760-850ºC). The emission containing the pollutants is heated by a ceramic heat exchanger up to the combustion temperature. The VOCs oxidize to CO2 and water In the combustion chamber. The hot gases then pass over a second ceramic bed to recover the heat. This technique is used to treat high air flows with a moderate/high concentration of VOCs. The efficiency obtained depends on the air residence time and temperature, but can be more than 99%.

Catalytic oxidation

This consists of oxidizing VOCs to CO2 and water using a catalyst, at temperatures lower (250-400°C) than for thermal oxidation. Destruction efficiency is over 95% and depends on the temperature and the catalyst. Although the operating costs are higher than for thermal oxidation, due to the catalyst becoming deactivated and having to be replaced, this is offset by the energy savings of working at lower temperatures. In addition, the risk of oxidation of by-products, such as CO, NOX and dioxins, is reduced by working at lower temperatures.