Relevance of an organic solvent for absorption of siloxanes

Abstract

A wide range of siloxanes exist but the most abundant in biogas are Hexamethyldisiloxane (L2) and Octamethyltrisiloxane (L3) as linear siloxanes and Octamethylcyclotetrasiloxane (D4) as a cyclic siloxane. In order to remove volatile organic compound from biogas, different processes can be used. A promising process for siloxane removal is their absorption in an organic solvent. In this work, three oils were tested to absorb the selected siloxanes: silicone oil 47V20, Seriola 1510 and Polyalphaolefin. Initially, the characterization of these oils was realized by measuring their viscosities and densities, depending on temperature. The second time, the absorption capacity of the siloxanes by selected oils was characterized through the determination of their Henry's constants, but also owing to the implementation of a wet-wall column. Both Henry's constants and removal efficiencies in continuous regime revealed that silicone oil (47V20) can be considered as the most efficient oil among the three selected siloxanes. Moreover, the cyclic siloxane (D4) showed more affinity with oils than linear siloxanes. Silicone oil 47V20 appeared to be the best oil (intermediate price 14 euro/L, low viscosity, low volatility, chemical inertness (no corrosion) and resistance to high and low temperatures).

Characterization of full-scale carbon contactors for siloxane removal from biogas using online Fourier transform infrared spectroscopy

“…Some of this SiO 2 formed is deposited within the engine, [5] which causes abrasion to the engine, [6,7] valve clogging, [8] and a reduction in conversion efficiency. [9] The estimated cost to industry is around 1.5 p kWh −1 of electricity * Corresponding author.…”

Superhydrophobic and stable mesoporous polymeric adsorbent for siloxane removal: D4 super-adsorbent

“…Recent techniques have been applied to remove siloxane from biogas including absorption, 8 bio-ltration, 9 adsorption, 10 peroxidation, 11 cryogenic separation, 12 membrane ltering 13 and catalytic processing. 14 Siloxane capture by the adsorption method is the most widely used technique over several solid adsorbents.…”

Removal of Siloxanes from Model Biogas by Means of Deep Eutectic Solvents in Absorption Process

“…Amine scrubbers do not show satisfactory efficiency of siloxane removal either. Among the effective absorbents, there are mineral oils, mixtures of glycols, or inorganic acids [ 15 , 16 , 17 , 18 ]. Although the abovementioned absorption methods allow for the recovery of solvents, these methods have a significant disadvantage, which is their energy consumption resulting from the large amount of energy needed to regenerate the absorbent.…”