CO_(2) mineralization of carbide slag for the production of light calcium carbonates

The production of polyvinyl chloride by calcium carbide method is a typical chemical process with high coal consumption,leading to massive flue gas and carbide slag emissions.Currently,the carbide slag with high CaO content is usually stacked in residue field,easily draining away with the rain and corroding the soil.In this work,we coupled the treatment of flue gas and carbide slag to propose a facile CO_(2)mineralization route to prepare light calcium carbonate.And the route feasibility was comprehensively evaluated via experiments and simulation.Through experimental investigation,the Ca^(2+) leaching and mineralization reaction parameters were determined.Based on the experiment,a process was built and optimized through Aspen Plus,and the energy was integrated to obtain the overall process energy and material consumption.Finally,the net CO_(2)emission reduction rate of the entire process through the life-cycle assessment method was analyzed.Moreover,the relationship between the parameters and the CO_(2)emission life-cycle assessment was established.The final optimization results showed that the mineralization process required 1154.69 kW·h·(t CO_(2))^(-1) of energy(including heat energy of 979.32 kW·h·(t CO_(2))^(-1) and electrical energy of 175.37 kW·h·(t CO_(2))^(-1)),and the net CO_(2)emission reduction rate was 35.8%.The light CaCO_(3)product can be sold as a high value-added product.According to preliminary economic analysis,the profit of mineralizing can reach more than 2,100 CNY·(t CO_(2))^(-1).

Synthesis and Characterization of 1,3-Diisopropoxyaloxanes and Their Modification on Calcium Carbonate Filler

Five 1,3diisopropoxyaloxanes,i.e.,(PriO)RO2AlOAlO2R(OPri)_C18H35(),_C9H16CH=CHC7H15(),_P(OCH2(C2H5)CHC4H9)2(),and_C12H23(),respectively]were synthesized by the hydrolysiscondensation of aluminium isopropoxide with water and exchange reaction with relevant acids.They were characterized by elemental analysis,determination of molecular weight,IR,and 27Al NMR.The results show that the coordination number of Al atom in the compounds is 5 and they exist in monomers in benzene.The analyses of TG/DTG and DTA indicated that both the thermal hydrolysis stability and thermal stability of these compounds are in the following order:<<<.The viscosity determinations of light calcium carbonate(LCaCO3)/liquid paraffin suspension systems demonstrated that they had an excellent modification effect on the surface of LCaCO3 filler and the amount needed to form a monomolecular film on the surface of LCaCO3 particles is in the order.

Carbon Capture from Flue Gas Based on the Combination of Non-Contact Hydrophobic Porous Ceramic Membrane and Bubbling Absorption

A hybrid system combined with a non-contact membrane and bubbling absorption is proposed to capture CO_(2) from flue gas.The non-contact way of membrane and liquid absorbent effectively avoids the reduction of gas diffusion flux through the membrane.High-porosity ceramic membranes in hybrid systems are used for gas-solid separation in fuel gas treatment.Due to the high content of H_(2)O and cement dust in the flue gas of the cement plant,the membrane is hydrophobically modified by polytetrafluoroethylene(PTFE)to improve its anti-water,anti-fouling,and self-cleaning performances.The results show that the diffusion flux of CO_(2) through the membrane is still higher than 7.0×10^(−3) mol/m^(2)s(20%CO_(2) concentration)even under the influence of water and cement dust.In addition,slaked lime selected as the absorbent is cheap and the product after bubbling absorption is nano-scale light calcium carbonate.To sum up,the hybrid system combining non-contact membrane and bubbling absorption is expected to be used to capture carbon dioxide from the flue gas of the cement plant.