The implementation of carbon capture, use, and storage in the cement industry is a necessity, not an option, if the climate targets are to be met. Although no capture technology has reached commercial scale demonstration in the cement sector yet, much progress has been made in the last decade. This work intends to provide a general overview of the CO2 capture technologies that have been evaluated so far in the cement industry at the pilot scale, and also about the current plans for future commercial demonstration.
A study was made to remove Chromium VI (Cr6+), present in large quantities in the rinsing waters from the plating industry, using electrochemical treatment. Large amount of Cr6+ are found. It was found that the reaction rate followed a variable kinetic order at concentrations up to 1700 mg Cr6+/L. It was also noticed that Cr6+ reduction depended on the ferrous ions (Fe2+) released at the anode, the cathode reactions and the acidic corrosion on electrodes. Iron salts produced electrode passivation and it caused a 50% increase in treatment time and power requirements. Eliminating the salt formation at the anode could reduce this effect. Using electrochemical processes it is possible to reuse treated waters in the rising stages of the plating industry owing to the fact that final Cr6+ concentration is less than 0.5 mg/L. Finally, a sludge characterization study revealed that residue generated in the process is not considered dangerous according to Mexican environmental protection standards.
Experimental studies were developed in a batch reactor (16 dm 3 ), to obtain the kinetic model of Cr(VI) removal by means of an electrochemical process. An overall kinetic model was obtained and experimentally validated in a continuous stirred electrochemical reactor (16 dm 3 ) with synthetic and industrial wastewater. To develop the mathematical model of the continuous reactor in relation to the Cr(VI) and Fe(II) concentration in the solution, a classical mass balance procedure was performed. The Cr(VI) concentration in the electrochemically-treated waters was less than 0.5 mg dm
À3. In the electrochemical process the Cr(VI) reduction is caused by the Fe(II) released from the anode due to the electric current applied, by the Fe(II) released for the dissolution (corrosion) of the electrodes due to the acidic media, and by reduction at the cathode. During the process, reduction from Fe(III) to Fe(II) occurs. All of these different reactions cause a diminution in the quantity of sludge generated. Finally, it was found that due to the slow rate of reduction of Cr(VI) during the first part of the process it is necessary to develop a method of control to apply the process in a continuous industrial system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.