Determination of chlorine and bromine in automotive shredder residues by oxygen bomb and ion chromatography
An analytical procedure, oxygen bomb combustion-ion chromatography (IC), has been developed for the determination of total chlorine in Automotive Shredder Residues (ASR). Samples of these residues are fired under elevated oxygen pressure (30 atm) and the combustion products are transferred into a Na2 CO3/NaHCO3 absorbent solution containing 1% of H2 O2; the chlorine contents are then evaluated by ion chromatography. The use of the non-suppressed IC determination with a conductivity detector provides a rapid, sensitive and selective method for chlorine determination in ASR, allowing determinations of this heteroatom at levels below 1% in the presence of bromine and sulfur. Moreover, the proposed method allows the simultaneous determination of chlorine, bromine and sulfur which are potential environmental hazards.
Overview on the Chlorine Origin of MSW and Cl-Originated Corrosion During MSW & RDF Combustion Process
Nowadays, the rapidly growing quantity of municipal solid waste (MSW) and severe environmental constraints compel us to sharply focus our attention on evaluating an effective method to dispose the wastage. Incineration seems to be an alternative waste management strategy proposed to replace landfill. However, chlorine as a key element to cause high temperature corrosion during combustion process has a large quantity in both MSW & refuse derived fuels (RDF). In order to predict the combustion behavior and corrosion potential, it is necessary to obtain reliable information about the distribution of chlorine and to identify the main sources of chlorine in MSW and RDF. This paper reviews previous research work with chlorine origins and corrosion potential, especially the deposits formation mechanics, and the influence of operating conditions. Additionally, methods commonly used for analysis of chlorine contents and their characterization are summarized and compared in this paper.
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Abstract A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.