Gas cleaning and water treatment systems

Eco-Spectrum is a developer and manufacturer of high-tech gas cleaning equipment designed for technological cleaning of the gas-air mixture to the maximum allowable concentration (MAC) of suspended solids, and water treatment systems necessary to prevent the discharge of waste water after the wet gas cleaning system.

According to the requirements of BAT ITS 9-2020 ...

to eliminate the negative impact on the environment and normalize the gas composition, it is necessary to use gas purification equipment, which may contain heavy metals, which are also standardized by MAC values.

In addition to suspended solids and their components, many other substances are standardized in flue gas emissions, for example, nitrogen oxides, sulfur dioxide, hydrogen chloride, carbon monoxide, saturated hydrocarbons, benzapyrene, dioxins and furans, mercury, the level of which in flue gases must be below the MAC, since all these compounds are classified as hazardous pollutants (HPs)

The values of pollutant indicators in flue gas emissions must comply with the requirements of the order of the Ministry of Natural Resources and Ecology of the Russian Federation dated by November 12, 2021 N 844 "On approval of the regulatory document in the field of environmental protection" Technological indicators of the best available technologies for the disposal and disposal of waste, including thermal ways."

  • We develop and manufacture gas cleaning systems. There are a large number of options for the types and components of gas cleaning systems.
  • In order to choose the type of gas cleaning and its configuration, Eco-Spectrum conducts a preliminary calculation of the content of certain pollutants in flue gases, and in some cases makes tests of incinerator with the involvement of an independent accredited laboratory and sampling of emissions to actually determine the concentrations of harmful substances.
  • After obtaining data on pollutants in flue gas emissions and selecting the type and configuration of the gas cleaning system, the development and design of individual parts and assemblies is carried out.

Types of gas cleaning systems are the following:

Dry gas cleaning systems

A dry gas cleaning system is used to clean gases from solid particles of a gas-air mixture and some gaseous impurities. The solution to the issue of reducing suspended particles in flue gases until the concentration of this indicator is brought to the MAC value, where the mass concentration of suspended solids in flue gases should not exceed 10 mg/m3, can be implemented by a dry gas cleaning system accompanied by a cyclone and bag filter.

In addition to cleaning from solid impurities, dry gas cleaning can be used ... (for cleaning from gaseous impurities: sulfur dioxide (dry reagent injection is used), heavy metals, such as mercury (coal adsorber is used). However, it should be noted that the capture of acid gases by dry gas cleaning is performed with less efficiency than by wet gas cleaning system – it’s usually not more than 35%.)

Advantages:

  • Lack of water consumption;
  • No need to use a water treatment system to exclude the discharge of waste liquids;
  • Possibility of using gas cleaning at temperature up to -60 °C.

Wet gas cleaning systems

The principle of operation of the wet gas cleaning system is based on the contact of a dusty gas stream with an irrigating liquid, which makes it possible to achieve purification of flue gases from various pollutants. For example, the task is to bring the level of sulfur dioxide to the requirements of MAC and quench the flue gases to prevent the recombination of dioxins and furans. As a solution, the use of a wet gas cleaning system in the configuration of a Venturi scrubber with water spray and an additional injection of an alkaline reagent will be adopted. For dioxins and furans the presence in flue gases is due to their recombination in a highly dusty gas in the temperature range from 200 to 450 °C. Therefore, in this case, to exclude this process, it is necessary to avoid the stay of the dust-gas-air mixture in this temperature range for more than 0.7 seconds. Rapid cooling of gases (quenching) and dedusting prevent the formation of dioxins and furans, fulfilling the requirement for MAC in emissions of no more than 0.1 ng/m3. This process is carried out by a wet gas cleaning system. For sulfur- and chlorine-containing wastes, there are several options for cleaning flue gases from acid gases (sulfur dioxide and hydrogen chloride), while the efficiency of a wet gas cleaning system is higher - up to 99%.

Advantages:

  • Cleaning efficiency is higher than for dry systems - up to 99% for various pollutants;
  • Hardening of gases by rapid cooling, preventing the recombination of dioxins and furans;
  • Less waste after the gas cleaning system than by dry systems.

Combined gas cleaning systems

The combined gas cleaning system consists of combined parts and units of wet and dry gas cleaning into a single complex. It is used in case of exceeding MAC levels for a number of indicators of pollutants in flue gases in accordance with the requirements of BAT ITS 9-2020. If it is necessary to reduce the concentration of suspended solids, sulfur dioxide, hydrogen chloride, heavy metals with gas quenching to prevent the recombination of dioxins and furans, it is necessary to use gas cleaning equipment accompanied with a battery cyclone, a bag filter, a coal adsorber, a Venturi scrubber with a supply of irrigating liquid.

Advantages:

  • Achievement of efficiency up to 99.9% for various pollutants;
  • Hardening of gases by rapid cooling, preventing the recombination of dioxins and furans;
  • Longer service life of wet scrubbers at scheduled maintenance periods.

Water Treatment System

The water treatment system is necessary for the treatment of waste contaminated water after the wet gas cleaning system. In the process of flue gas spraying in the wet scrubbing system to capture pollutants, waste polluted water is generated, which is either discharged into the environment, which leads to a negative impact, or is sent for further purification to the water treatment system, where polluted water is purified from impurities. To purify water in the water treatment system, special reagents are used that increase the efficiency of removing impurities from water, and after that the purified water is re-sent to the flue gas irrigation in the wet gas cleaning system.

Advantages:

  • Exclusion of the discharge of polluted water into the environment, significantly reducing the negative impact;
  • Reduction of water consumption of the wet scrubbing system, using water in a make-up cycle only as a result of insignificant evaporation;
  • Resource saving in accordance with federal laws.