Electrochemical Studies of Coal Slurry Oxidation Mechanisms

Abstract

Oxidation of a coal slurry solution at platinum electrodes in strong acidic media has been studied in detail. The results indicate that the iron ions leached out from coal are responsible for major anodic currents. The Fe(II) is electrolytically oxidized to Fe(III) at the anode, which oxidizes coal to various products including CO2 4Fe3++2H2O+C→4Fe2++CO2+4H++normalother productsThe rate constants for the catalytic reaction are determined to be 3.0×10−5 normaland 1.1×10−4 sec−1 for Fe(III) and Ce(IV), respectively. The activation energy for the processes are 13.3 and 7.0 kcal/mol for Fe(III) and Ce(IV). Current efficiencies for CO2 production are 15∼30% .

Electrochemical redox processes involving soluble cerium species

“…The oxidation rates were fast [151], and the redox mediator more suitable than Fe(II) [152]. The large scale oxidation of hazardous liquid organic waste with electrogenerated Ce(IV) was patented [153] and developed under the commercial name of CerOx TM in the late 1990s [13].…”

Removal of Heavy Metal Ions by Electrocoagulation for Continuous Use of Fe2+/Fe3+-Mediated Electrochemical Oxidation Solutions

“…1 Electrochemical methods include electroflotation, 2 electrodeposition, 3 direct/indirect electrochemical oxidation, [4][5][6] and ECG.. 7,8 Among these, ECG is probably the most versatile method in that various polluting materials, including a wide range of ionic species [9][10][11][12][13][14][15] as well as organic materials such as textile dyes, 16,17 phenolic compounds, 18 and polymer latex 19 can be successfully treated. This is possible because ECG utilizes various forms of monomeric and polymeric metal hydroxide complexes which can interact with polluting materials via several routes (electrostatic force, surface adsorption, physical entrapment, and coprecipitation).…”

“…In this regard, when limited to the decomposition of organic wastes, [4][5][6] indirect electrochemical oxidation (MEO) has advantages over ECG since mediators can completely decompose organic hydrocarbons to CO 2 and H 2 O. 5,6,[20][21][22][23][24][25] Reactive and high-valent metal ions which are electrochemically generated from stable and low valent state are utilized as oxidants.…”

“…5,6,[20][21][22][23][24][25] Reactive and high-valent metal ions which are electrochemically generated from stable and low valent state are utilized as oxidants. For economical and environmental reason, the overall MEO system is operated as a closed loop.…”

The Scientific Legacy of Su-Moon Park: a Personal View

“…One of the motivations was to see if coal could be utilized directly as a fuel in an electrochemical cell, without much preprocessing. [48][49][50] This line of research was definitely something novel, and one could just proceed without worrying whether someone else was doing the same thing, but there were also very few guidelines. However, this did not deter Professor Park.…”