COMPARISON OF REGENERATIVE SILOXANE REMOVAL SYSTEMS (SGS) AND ACTIVATED CARBON
Activated carbon is a filter material with a large surface area and is a preferred material in various industries. It is frequently used on an industrial scale in all areas where air quality or purification processes are needed, especially in the cosmetics, pharmaceutical and air conditioning sectors.
Activated carbon is a filter material with a large surface area and is a preferred material in various industries. It is frequently used on an industrial scale in all areas where air quality or purification processes are needed, especially in the cosmetics, pharmaceutical and air conditioning sectors. The basis of the plant design with the activated carbon-based treatment process is that the used pollution load of the fluid does not change under certain conditions. In industrial scale activated carbon-based treatments, the pollutant concentrations of the input stream are constant and performance verification can be made by continuous measurement of the output stream. Activated carbon is an adsorbent with high purification performance. Activated carbon types that are claimed to be pretreated or developed tend to adsorb all pollutants in the gas stream, such as H₂S, Siloxane, VOCs, etc.
While activated carbon studies can yield more stable results in biogas plants where the raw materials that cause the formation of biogas do not vary and the pollutant profile also amount of the formed biogas are more prominent; in systems with more than 300 pollutant profiles, such as landfill gas, it is less preferred due to treatment performance, continuity of treatment and operational difficulties. Activated carbon studies in biogas plants where landfill gas is used do not yield healthy results since field studies such as gas extraction from the waste stored area, gas extraction from the lines used far wastewater discharge, etc. directly affect the pollutant concentration in the inlet stream. In the design for the biogas plant, the uncertainty about the determination of the frequency of change of the materials to be used as input causes uncertainty in the input concentration. All types of activated carbons capable of holding siloxane can also hold VOC and H₂S. At this point, any surface treatment, change in material mechanical properties or chemical improvement basically does not provide an improvement for one of these 3 pollutants. Therefore, when designing the system to be used in landfill gas facilities, it is necessary to make a prediction such as estimating the concentrations of 3 variables for a certain period.
Activated carbon and similar adsorbents tend to release the pollutants that they previously held when the pores in their structure are filled. If an activated carbon whose pores are filled with pollutants is continued to be used, an output concentration of pollutants which is higher than the inlet concentration will be formed. The absorption capacity of activated carbons has a threshold value. If this threshold value is exceeded and continued to be used, it will damage the gas engines and the entire system during its use. To prevent damage, threshold points must be determined and kept under control with continuous measurements. This transaction imposes a serious financial burden on the business. in addition, it causes an increase in the frequency of material change during the working period and a serious decrease in performance.
The cumulative accumulation state of pollution in engines means that the threshold value exceeded in any period, or the effects caused by the gas going to the engine without purification are permanent and become more harmful over time. The abrasions, scratches and accumulations caused by siloxane derivatives in the engine begin to affect the engine as soon as they occur, and their effects continue until the relevant parts are replaced.
Engine manufacturers refer to clean gas at two points. The first is the number of pollutants measured in the gas entering the engine, and the second is the variation of the Si parameter in oil analysis over time. However, the oil analysis value does not give direct information about the amount of siloxane in the gas. In systems treated with activated carbon, it is practically not possible to measure both continuously in terms of cost and business continuity. Since the two mentioned parameters cannot be met and the pollution is cumulative, it will exclude the gas from the clean gas class. This will cause problems between the engine manufacturer and the operator.
The ANKA Regenerative Siloxane Removal System, which started as an R&D project supported by the Ministry of industry, has become a regenerative system that eliminates the need for gas analysis at the point it has reached and ensures that the fuel, which is considered as clean gas, is constantly supplied to the system. Unlike activated carbon, the selective feature of the filter materials used in the ANKA Regenerative Siloxane Removal System both ensures an effective purification process and prevents problems such as continuous analysis and frequent material changes, which are not possible and feasible in practice. It is very important for long-term energy savings that the system, which can be easily scaled for any capacity due to its modularity, has a very low pressure drop.
The ANKA Regenerative Siloxane Removal System provides 100% success in meeting the performance criteria given by the engine manufacturers in the purification of gas streams with intense pollutants such as landfill gas and guarantees the continuity of these criteria in terms of both purified gas and oil analysis. Unlike activated carbon systems, the main advantages are that the material change times are certain and that these periods are guaranteed based on both gas and oil analyzes, that the system does not bring additional labor to the facility during its operation, and that the treatment process continues uninterruptedly.
A comparison of Anka-Regenerative Siloxane Removal System(SGS) and activeted carbon is given in Table 1.
The selective filter media components of the ANKA Regenerative Siloxane Removal System are precisely targeted to siloxane derivatives and provide up to 99% treatment performance in the outlet gas compared to the inlet gas. This value is the data of our largest siloxane treatment system, which is in the world’s largest capacity landfill gas power generation facility and similarly made on an industrial scale, and results have been seen and verified through oil analysis.
