Environmental sustainability is the only viable path for the future of the industry. The only possible answer is to implement technologies that combine maximum efficiency in eliminating emissions and waste with the highest efficiency in its implementation and use, in order to avoid damaging the productivity of your industrial processes. So here we are going to explain the 7 most widely used technologies for emissions removal.
With regards to air pollution treatment, there are different technologies that are currently used and that can be installed in production plants to reduce pollutant emissions.
In order to facilitate your decision-making process, at Tecam we have compiled in this document the 7 most widely used (and proven) technologies for emissions treatment, most in demand nowadays. We are briefly describing each of them here below.
Regenerative Thermal Oxidizers (RTO):
The advantages of installing a Regenerative Thermal Oxidizer (RTO) lie in the ability to optimise your energy use while maintaining the same level of efficiency for eliminating VOCs. This is due to the fact that the ceramic towers are able to store a large amount of energy during each sequence, which in turn serves to heat the air or gas that is being treated. In fact, thermal efficiency can reach levels of 90-95 %.
This means that under normal operating conditions, fuel gas is not consumed, as the process is autothermal. An autothermal process is one in which the combustion chamber maintains its operating temperature without needing to burn energy from an external source (i.e. fuel). This is because the energy released by the VOCs as they oxidise is sufficient to keep the chamber at a high temperature.
This technology can also come in Electrical RTO, which is the same equipment as a regular RTO, but in this case, there is no flame in the oxidation chamber, and therefore no NOX associated.
Regenerative Catalytic Oxidizers (RCO):
The advantages of installing a Regenerative Catalytic Oxidizer (RCO) system include the ability to efficiently eliminate VOCs at a lower temperature, thanks to the catalytic process.
The lower oxidation temperature translates to a lower consumption of natural gas.
RCO systems are typically used for flows with a low concentration of VOCs (< 0.5 g/Nm3). However, you must bear in mind that these VOCs should not contain heavy metals, sulphur compounds, silicon compounds or phosphorus compounds, as these could poison the catalyst.
Thermal Oxidizer (TO or DFTO):
The main advantage of installing a Direct-Fired Thermal Oxidizer (DFTO) or Thermal Oxidizer (TO) system is that high temperatures are achieved at the outlet of the combustion chamber, meaning that the heat can be used by heat recovery systems in the form of superheated steam, saturated steam or hot water. Even when steam is generated, it can be subsequently used to generate electricity via a turbine.
Gas Scrubbers:
Gas Scrubbers are ideal for the neutralisation of pollutants in an atmospheric system and at ambient temperature. They are highly efficient at eliminating pollutants, as they usually take the form of adsorption with acid-base neutralisation reactions that help to eliminate pollutants. Scrubbers are ideal for treating odours.
Baghouse filters
Baghouse filters are devices that remove the solid particles suspended in gas flows by passing the gas through fabric. They comprise rows of fabric “sleeves” that retain particles and are cleaned automatically by highly pressurised compressed air that is passed through them in a counter-current. The particles transported in the airflow pass radially through the fabric sleeves and are deposited on the outside of them.
At certain intervals, which can be regulated in accordance with how dirty the fabric sleeves are, a counter-current of compressed air is passed through each sleeve so that the dust particles are detached from the fabric and fall onto the hopper below, where they are collected in order to be treated in the appropriate manner.
Active Carbon Filters:
Active carbon filters have a wide range of applications. They can be used to control emissions in paint booths and to eliminate dioxins and furans generated during the incineration of solid urban waste (SUW), VOCs, H2S in biogas plants, NH3, amines, mercury vapour and acidic (lactic, acetic, muriatic) vapour, etc.
The contaminated gas passes through the carbon bed. As it passes through, the pollutants adhere to the surface of the filter, thereby cleaning the process gas. Consequently, over time the active carbon becomes saturated, and when it reaches its maximum adsorption capacity it must be desorbed in order to be used again. In order to avoid halting the process, two adsorption columns are normally used, of which one is performing adsorption while the other is undergoing desorption.
SCR/SNCR:
These DeNOx systems present several advantages. The main advantage of Selective Catalytic Reduction (SCR) is that it reduces NOx by up to 95 % without producing any polluting waste or by-products: it only generates (inert) nitrogen gas and water vapour. It operates at temperatures between 350 °C – 500 °C and can also be used on sources with a low concentration of NOx.
Selective Non-Catalytic Reduction(SNCR) systems offer lower costs in comparison to other technologies, as they require little space and minimal maintenance. They are easy to install and operate and work at high temperatures (850 °C – 1100 °C) without a catalyst. They can also process flows of residual gas with high levels of particulate matter (PM).
We hope that this information was useful to you to start the analysis of the options you have to manage the polluting emissions generated at your production plant.
Please remember that you can count on Tecam specialists at any time to help you select the technology that best suits your case. We will be happy to assist you in the analysis phase and to design a custom installation for your needs.
You can contact us now for further information.
