Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) - Volume 8, Issue 1, 2015

High pore volume silica materials have attracted growing interest for their increasing applications in various fields such as catalyst carrier, coating additive, adsorbent, etc. It is interesting to both industry and academy for its progress in how large pore volume silica material can be produced and what kinds of approaches have been applied. For this purpose, this review intends to summarize the recent progress about the preparations and applications of high pore volume silica materials using sodium silicate as the main silicon precursor. For support, some basic concepts, including the pores, the chemistry of forming large pore volume, and classification of high pore volume material, are introduced. For prospective development, silica materials with relatively large pore volume and large surface area with good mechanical property including hierarchical porous silica should be desirable.

Currently, the emission amount of nitrogen oxide (NOx) from the cement industry accounts for about 10-12% of total emissions in China, and the cement industry has become the third biggest source of NOx, following thermal power plants and vehicles. Thus, the task for controlling NOx emission from the cement industry is very urgent. Selective non-catalytic reduction (SNCR) denitrification technology has many advantages, such as low investment cost, short construction period, simple facilities and low operating cost, etc. This technology is suitable for the reconstruction of the existing cement production lines and the matching construction of the new cement production lines, and is currently considered to be the best denitrification technique for cement kilns. The basic principle and process of SNCR in cement kilns were analyzed and the key points of SNCR denitrification process in cement kilns were summarized, including the proper reaction temperature window (850~1050°C), mixing of reducing agent and flue gas, NH3/NOx mole ratio, residence time, the control of ammonia escape and the effect of calcium base powder. The current status of SNCR simulation and industrial application in cement kilns were also comprehensively analyzed, together with the future development direction of SNCR denitrification technology in cement industry.

A new patent co-current apparatus for gas purification from SO2 is presented. In comparison with the counter-current gas absorbers the gas velocity in the co-current apparatus increases 5-6 times and as a result the column diameter decreases more than 2 times. The new approach for modeling of the column apparatuses is used for modeling the SO2 absorption in the co-current apparatus. The convection-diffusion model for qualitative analysis and process mechanism identification is used. The average concentration model for quantitative analysis is presented.

A comprehensive analysis of the growth of research activity has been conducted in the field of “Engineering” originating from Arab countries. A bibliometric analysis based on database Scopus was carried out to follow research activities in this field. Both quantitative and qualitative perceptions were taken into consideration. It is a fruitful and an informative study for scholars in disciplines related to engineering. A total of 6,399 documents were published from Arab world. The highest number of articles associated with "engineering" was from Egypt (29.1%), followed by Saudi Arabia (17.3%). The maximum number of citations was 371 for an Egyptian research paper. The most productive journal was AEJ Alexandria Engineering Journal. The study identified 2,730 (42.7%) papers with Arab-foreign country collaborations. The most productive institution was King Fahd University of Petroleum and Minerals, Saudi Arabia. This study will improve the understanding of research trends in disciplines related to engineering. The research trends should be focused and oriented toward serving the development and industries in Arab countries. The authors declare that these results are up to the date of 2012, may be some researchers have more publications but did not appear in the search because not all journals are included in Scopus and some others, and even included in the database, some of its volumes are not included yet.

For rapid construction of hovercraft landing platforms at sea shore various compositions of oxychloride cement (OCC) along with sea sand, melamine formaldehyde resin, guar gum and unsaturated polyester resins were prepared for optimization of the suitable composition with optimum compressive strength and elastic modulus. Based on results obtained further optimization was progressed. The Differential Scanning Calorimetric DSC and Thermo-gravimetric TG Analysis were recorded for Cross-linking Guar gum(CLGG), Melamine Formaldehyde (MF) Polymer, CLGG-MF polymer and CLGG-MF-OCC Composites to determine their thermal stability. Compressive strengths of the specimens prepared using CLGG-MF-OCC composite were determined by UTS machine and compared with other compositions. Polymeric concrete composite (PCC) made of aqueous solution of 2% CLGG-MF resin mixed with 25% magnesium oxychloride cement, 12% Fly ash and 60% Sea sand, was used to prepare platform on sea beach soil and it was found to have compressive strength up to 221.02 kg/cm2. Spraying grade CLGG-MF resin based composites were prepared for stabilization of soil by grouting and vulnerability of their sea sand composites towards encroaching water was studied. After curing, no cracks are developed on the surface. This composite is less expensive and ideally suited to make a rapid landing platform at sea shore and river banks which is not deteriorated by continuous slaps of encroaching water/rains as seen in Trials.

Theory calculation method and cold experiment are introduced based on a new J-type Loop Seal of two chambers internal circulating fluidized bed in the paper. Theory calculation includes equivalent model based on J-type Loop Seal experimental device and setting up correlations of solid particles circulation. Cold experiment includes building the experimental device and measuring related parameters. And relationships between lateral blow and three key parameters determining solid particle circulation are discussed on emphasis in cold experiment. The experimental results show that when the left or right lateral blow is fixed, the height difference of two chambers under operation is in linear relationship with another lateral blow. The dynamic head of feedback valve under operation is only in linear relationship with the left lateral blow, and is hardly affected by the right lateral blow; the resistance coefficient in the feedback valve is in linear relationship with reciprocal of right lateral blow. Experimental values are in good agreement with the theory calculation values for solid particle circulation, with the relative error less than 10%. Thus the theory calculation method and cold experiment provide a reliable reference basis for operation and hot experiment of feedback valve of internal circulating fluidized bed. What’s more, we also discussed few related patents.