Papers by Author: Su Ping Cui

Abstract: Reducing NO using coal and active carbon with and without the addition of catalysts were investigated in a fixed bed reactor at a wide temperature of 250-850 °C. The results indicated that without the catalysts, NO reduction using coal was significantly better than that using active carbon. When coal was used as reducing agent, the addition of catalysts made the NO reduction occurred earlier and the effect of catalysts was temperature-dependent. When active carbon was used to reduce NO, the addition of catalysts was not ideal and only CuO showed a significant positive effect above 700 °C.

Abstract: Municipal solid waste incineration fly ash (MSWIFA) is a kind of hazardous waste. In the recent years, the demand for the disposal of MSWIFA has gradually increased with the increase of its production. The co-processing of MSWIFA in cement kiln has become the future development trend in this field due to the advantages of large disposal capacity, thorough disposal and low secondary pollution. In this paper, the life cycle assessment (LCA) was used to analyze the environmental impact of cement kiln co-processing MSWIFA, and the influence of allocation method of by-products in pretreatment process on calculation results was discussed. The results of analysis on the pretreatment of MSWIFA using the water-washing process showed that the allocation method of by-products will affect the calculation results to a certain extent, especially in the toxicity-related indicators, and for pretreatment process, electricity production process is the key link to causing environmental impact. The environmental analysis for clinker product shows that the contribution ratio of pretreatment process calculated by extended boundary method was 3.33% larger than that of mass allocation method in acidification potential(AP), and 3.32% smaller than that in WCP.

Abstract: Slag is widely used as mineral admixtures in cement-based materials by its potential hydration activity. It has the advantage of saving resources and energy, reducing carbon emission, improving the performance of concrete, and plays an increasingly important role in the building materials industry. But the early strength of slag is low, and the industrialization of useful hydration products also need to be activated, so the utilization rate of slag in high grade cement is restricted. The hydration activity of slag depends not only on the content of vitreous in slag, but also on the structure of vitreous slag. To explore slag glass micro composition and structure of its active role, The slag micro-structure was analyzed from the structure levels, and then the factors affecting the activity of slag was evaluated. The potential advantages and disadvantages of some different methods to active slag were discussed such as physical ways, chemical activation method and compound activation way. The existing problems and development direction of improving the activity of slag were summarized , which could provide a valuable reference for the efficient use of slag.

Abstract: A novel polycarboxylate superplasticizer (PCE) with energy saving preparation was elaborately designed and synthesized by using acrylic acid (AA), hydroxypropyl acrylate (HPA) and isopentenyl polyethylene glycol (IPEG) as monomers. To investigate the effects of the preparation method on the effectiveness of PCE, the PCEs were prepared from energy-saving method and common method respectively, and the hydration heat evolutions of the cement pastes containing these PCEs were comparatively probed. Furthermore, the working mechanisms of the PCEs by different preparations were identified via adsorption behavior, adsorption kinetic and Zeta potential of the PCE on cement surfaces. The results showed that, this novel PCE prepared in an energy saving manner can significantly prolong the hydration process and present a stronger adsorption capacity. In addition, the adsorption of this PCE on cement surface exhibited a characteristic of pseudo first order kinetic equation model. The evaluation in energy conservation showed that, this energy saving preparation can save 1.548×10⁴ kJ per 10 ton production. The aim of this study is to provide a new avenue to synthesize a PCE with economical method which achieves energy-saving preparation. Due to the indispensable application in construction industry, the innovations from this study contribute to the low energy-consumption production and high eco-effectiveness of the novel PCE, which has potential applications in low-emission building materials.

Abstract: The hollow mesoporous SiO₂/dense SiO₂/Fe₃O₄ composite particles with different pore sizes were prepared by a multistep coating technique. TEOS as a silicon source, and P123 were combinated with co-surfactant CTAB as template to coat mesoporous on the dense SiO₂/Fe₃O₄ composite particles. The influence of the pore diameter in the composite particles on the laccase immobilization amount in the composite particles and the catalytic efficiency of 2,4-dichlorophenol on hollow composite particles were researched in detail. When the pore diameter of the hollow composite particles was 4.30 nm, the laccase immobilization amount reached the maximum (234 mg/g). The pH was within 3 ~ 8 range, and the activity of immobilized laccase was obviously higher than that of free laccase molecule. And the relative activity of immobilized lactase was highest when pH was 4. When the temperature was within 303K ~ 353K, the immobilized laccase had higher relative activity than free laccase and the activity of immobilized laccase still remained 28%. The removal rate of 2,4-dichlorophenol of immobilized laccase in the composite particles was about 80%.

Abstract: Using the industrial limestone, fly ash and pure chemical reagents as raw materials, the blast furnace slag was prepared in the simulation condition of the actual slag-making process by three different cooling ways, including air cooling, water cooling and liquid nitrogen cooling. Combined with different test methods such as XRD, SEM, IR, the influence of cooling ways on the structure and hydraulic activity of blast furnace slag was studied in the present in investigation. The relationship between glass content, compressive strength and the phase compositions of blast furnace slag has been obtained. The results showed that, the glass content of water cooling slag or liquid nitrogen cooling slag was slightly higher than that of air cooling slag, there was obviously gehlenite crystal phase in air cooling slag. The 7d and 28d compressive strength of three slags did not present positive correlation with vitreous content, the sequence of 28d compressive strength of three slags was water cooling slag > air cooling slag > liquid nitrogen cooling slag. SEM observation found that crystallization phases in water cooling slag had a small grain and uniform distribution, this kind of structure was advantageous to the latter hydration reaction and strength development of blast furnace slag.

Abstract: The hydration of cement is known to be a complex phenomenon. Although the broad pattern of reactions and microstructural development are known, a number of important questions remain unanswered. How to select the proper techniques is what the research people think of for now. This paper reviewed the domestic and international research progress and presented the advantages and disadvantages of these methods and the application prospects. Nuclear magnetic resonance spectroscopy (NMR), nanoindentation and electron microscopy techniques of cements were expounded in detail. Furthermore, through analyzing the results obtained by different research methods, the paper predicted the development prospect of advanced testing method of cement-based materials.

Abstract: Granulated blast furnace slag (GBFS) is a by-product of manufacturing iron. Samples of GBFS with different ratio of SiO₂/Al₂O₃ were prepared by simulating the actual process of GBFS in laboratory. This study investigated the influence of SiO₂/Al₂O₃ content on structure and hydration activity of GBFS which were characterized by X-ray fluorescence (XRF), powder X-ray diffraction (XRD), infrared radiation (IR) and mechanical testing. It is found that the vitreous content of each sample is above 97% and the hydration activity indexes of 7d and 28d of samples significantly decrease with the increase of SiO₂/Al₂O₃ ratio. The IR characteristic absorption spectrum shows that the silicates mainly exist in [SiO₄]-tetrahedra and the aluminum atoms are in different coordination states and the bonding strengths rise with the increase of SiO₂/Al₂O₃ ratio.

Abstract: Catalysts of Mn/TiO₂ and Mn-Ce /TiO₂ prepared by co-precipitation method for low temperature selective catalytic reduction (SCR) of NO with NH₃ were investigated in this study. The experimental results showed that co-precipitation method after improvement, the NO conversion of Mn-Ce/TiO₂ catalyst increased sharply. Meanwhile, the addition of cerium has significant effects on the catalytic activity. Characterizations of catalysts were carried out by XRD, BET and H₂-TPR. The characterized results indicated that co-precipitation method after improvement, in temperature windows 150 to 300 °C, showed higher NOx conversion.

Abstract: Analyzed and calculated the energy savings of heat reflective coatings applied on multi-storied residential buildings and high-risen commercial buildings in Beijing. Some advices about the application of heat reflective coatings in northern cold region are given. Energy saving effect was evaluated with the building energy simulation in winter and summer while the heat reflective coating is applied on the surface of residential buildings and commercial buildings. Calculating results showed that the energy saving is the most optimal to the multi-storied buildings when the cool roof coatings is coated on the roofs and the glass heat reflective coating is applied on east and west windows. With the high-risen commercial building, the energy saving is noticeable when the glass curtain wall is coated with glass heat reflective coatings. The energy saving rate can reach a maximum of 13%.