Abstract
The objective of this research was to study the treatment of acetonitrile by catalytic supercritical water oxi-dation in a compact-sized tubular reactor, with an internal volume of 4.71 mL. Manganese dioxide was used as the catalyst and H2O2 was used as the oxidant. The oxidation of acetonitrile in supercritical water was studied at 400-500 oC, 25-35 MPa, the flow rate of 2-4 mL/min, the initial concentration of acetonitrile 0.077-0.121 M and the %excess O2 of 50-200%. As a result, the products were mainly N2, CO2 and CO and acetonitrile can be decomposed > 93 % within a very short contact time (1.45-6.19 s). The oxidation process was carried out with respect to the conversion of acetonitrile by 25 factorial design. Regression models were obtained for correlating the conversion of acetonitrile with temperature and flow rate. The complete oxida-tion can be achieved at a condition as moderate as 400 oC, 25 MPa with the flow rate of 2 mL/min.
Highlights
Laboratory wastes, which contain various types of hazardous chemicals generated from scientific research, have become a serious problem both financially and environmentally
Organic compounds and permanent gases are completely miscible in supercritical water, so the oxidation occurs in a single-phase aqueous environment
Above the critical point of water (374 oC, 22.1 MPa), most organic compounds can be converted into CO2 and
Summary
Laboratory wastes, which contain various types of hazardous chemicals generated from scientific research, have become a serious problem both financially and environmentally. Supercritical water oxidation (SCWO) has been proposed as a promising candidate for the treatment of various organic wastes. Organic compounds and permanent gases (such as oxygen) are completely miscible in supercritical water, so the oxidation occurs in a single-phase aqueous environment. Above the critical point of water (374 oC, 22.1 MPa), most organic compounds can be converted into CO2 and. H2O by SCWO in a very short residence time [1,2,3]. There has been increasing interests in the use of heterogeneous catalysts in SCWO. Many catalysts can increase the oxidation rate, reduce the residence time and temperature requirement, and possibly provide a better selectivity for competing reaction pathways, which is difficult to achieve in noncatalytic processes [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
