Effects of Municipal Sewage Sludge on Fixation of Cr,Ni,Cu,and Zn during Co-processing of Heavy Metal-containing Waste in Cement Kilns

Cement raw meal with MSS and different heavy metals was blended to examine the fixation ratios, chemical species, and cement crystalline phases in clinkers. The results showed that blending MSS could decrease the fixation ratio of Cr, Ni, Cu, and Zn in the produced clinker by 5% to 25%. And Cr, Cu, and Zn were mainly incorporated into clinkers as metal silicates, Ni was mainly solubilized in Mg O to form magnesium nickel oxides, and the transition phases were mainly metal aluminum oxides as indicated by X-ray diffraction. The reduction of fixation ratios was likely attributed to the presence of impure elements, such as sodium and phosphorus in MSS. In addition, high concentrations（eg, 1.7 wt%） of chlorine in MSS led to metal chloride formation that could vaporize Cu, Cr, Ni, and Zn. To summarize, introducing MSS would decrease the fixation ratios of heavy metals due to the presence of impure elements, such as sodium and phosphorus and chlorine.

Co-processing petroleum catalytic slurry with coal

It is studied that reactivity of petroleum catalytic slurry （PCS） and coal with Fe catalyst in 1 L autoclave, the fol- lowing is mainly discussed, coal conversion and asphalt properties, especially related with petroleum cracking slurry （PCS） properties. The results show that co-processing conversion and asphalt yield increase with the increase of PCS ratio. PCS prop- erties have important effect on coal conversion and asphalt properties. One kind of PCS shows negative effect on coal conver- sion. High aromatic PCS can lead to high ductility asphalt with good colloid properties. Coal and the PCS can lead to a strong matching effect.

Co-Processing Sewage Sludge in Cement Kiln in China

Sewage sludge is the by-product from municipal waste water treatment plant and is highly polluted. How to treat the SS in a solid environmental friendly way is strictly concerned in China. In this article, the SS situation and also the treatment methods in China have been introduced. The advantage and some related issues of co-processing SS in cement kiln have been discussed. The technical model and projects of Huaxin cement for co-processing SS in cement kiln also have been introduced.

A Probe into Process for Maximization of Low-carbon Olefins via Co-processing of Methanol and Heavy Oil

From the viewpoint of process specifics and thermodynamics, this article has put forward a route for maximiza- tion of low-carbon olefins via co-processing of methanol and heavy oil. Catalytic cracking experiments on co-processing of methanol and heavy oil at different ratios in a fixed fluidized bed reactor had been conducted. Test results have revealed that when 12.5% of methanol was blended to the heavy oil a good products distribution and relatively higher yield of low-carbon olefins could be obtained. The overall yield of low-carbon olefins could reach 50.16%, with the yield of ethylene, propylene and butylene equating to 5.47 %, 28.93% and 15.76 %, respectively.

A Review of Co-processing of Kitchen Waste and Municipal Residual Sludge

In this paper, the methods of kitchen waste disposal in recent years were summed up, and the advantages and disadvantages of the current treatment methods were analyzed. At the same time, it has been found that the co-processing of kitchen waste and residual sludge not only has dealt with both kitchen waste and residual sludge, but also the carbon and nitrogen ratio and moisture content of the mixture are balanced, and increases the processing efficiency significantly. It has a certain processing advantage. At present, most research is about the anaerobic digestion of kitchen waste and residual sludge, and the process is more mature, but the study of VFAs accumulation is still insufficient. Aerobic composting is still in the early stage of development, and there are few studies on it at home and abroad. Meanwhile, prospects for the kitchen waste recycling were made in this article.

Identification of nitrogen-polyaromatic compounds in asphaltene from co-processing of coal and petroleum residue using chromatography with mass spectrometry

Abstract Asphaltene, from co-processing of coal and petroleum residues is one of the most precious and complex molecular mixtures existing, with tremendous economic relevance. Asphaltene was separated by Soxhlet extraction with methylbenzene and then divided into three parts by distillation. Gas chromatography （GC） and high-performance liquid chromatography （HPLC） were coupled with quadrupole time-of-flight mass spectrometry （Q-TOF MS） to separate and characterize organic nitrogen species in the distillates of asphaltene at molecular level. Molecular mass of compounds was mainly distributed from 150 to 600 ~t. Number of rings plus double bonds （rdb） and synchronous fluorescence spectra indicated that most of the organonitrogen compounds （NPAC） contained heterocyclic aromatic rings, including pyridines, anilines, quinolins, pyrroles, carbazoles and indoles plus various alkyl groups. Constant-wavelength synchronous fluo- rescence spectrometry （CWSFS） indicated NPAC with 2-3 rings were the main structures of organonitrogen compounds and the corresponding structural information was proposed. Some organic nitrogen isomers were separated and identified by atmospheric pressure chemical ionization （APCI） GC-Q-TOF MS and electrospray ionization （ESI） HPLC-Q-TOF MS. The methodology applied here contained chromatographic injection of the diluted sample using conventional columns sets and Data Analysis 4.2 software. Identifying molecular structures provides a foundation to understand all aspects of coal- derived asphaltene, enabling a first-principles approach to optimize resource utilization.

Characterisation of a novel, multifunctional, co-processed excipient and its effect on release profile of paracetamol from tablets prepared by direct compression

Objective: To characterise a novel multifunctional pharmaceutical excipient and investigate its ef ect on paracetamol release from tablets prepared by direct compression.Methods: The excipient was prepared by co-processing gelatinized maize starch with sodium carboxymethyl cellulose and microcrystalline cellulose in a ratio of 2:1:1, dried and pulverized into powder. The excipient formulated was characterized using Fourier transform infrared spectroscopy and dif erential scanning calorimetry. The excipient was used to prepare batches of tablets by direct compression with drug-excipient ratios of 1:1, 1:2, 1:3 and 1:4. Parameters evaluated on tablets include crushing strength, friability and in vitro dissolution studies. Results: Differential scanning calorimetry analysis revealed a crystalline excipient while Fourier transform infrared spectroscopy showed no interaction between the excipient and paracetamol. Tablets from all the batches gave average crushing strength values between 3.47 and 4.88 kp. The 1:1 and 1:2 tablet batches were comparable to each other while 1:3 and 1:4 were also comparable to one another in their dissolution proi les. The dissolution parameters of the 1:4 batch was faster with- m∞(90.5%), t50%(3.5 min), t70%(11.6 min) while that of ratio 1:1 was the least with- m∞(48.6%), m5min(23.8%). Their release kinetics followed a KorsmeyerPeppas model with a super case-II transport mechanism.Conclusions: The drug-excipient ratios of 1:3 and 1:4 gave pharmaceutically acceptable tablets that met the British Pharmacopoeia specii cations. The t50% value of the 1:4 batch of tablets may i nd its usefulness in formulating drugs for which a fast onset of action is desired.

Assessment of popular techniques for co-processing municipal solid waste in Chinese cement kilns

Cement kiln co-processing techniques have been developed in the past 20 years in China,and more than 60 factories now use fermentation,screening,and gasification pre-treatment techniques to coprocess municipal solid waste(MSW).There three complete MSW pre-treatment techniques,coprocessing procedures,and environmental risk assessments have been described in few publications.In this study,we assessed the effectiveness of each technique.The results suggested that the pollutant content released by each pre-treatment technology was lower than the emission standard.To reveal the mechanisms of pollutant migration and enrichment,the substances in the kiln and kiln products are investigated.The input of co-processing materials(Co-M)produced by fermentation caused formation of polychlorinated dibenzo-p-dioxins and dibenzoftiran(PCDD/Fs)in the bypass flue gas(By-gas)in excess of the regulatory standard.The Co-M input produced by the screening and gasifier technologies caused the total organic carbon(TOC)concentration to exceed the standard.In addition,the NOx,TOC,and PCDD/Fs in the By-gas exceeded the regulatory standard.Raw meal was the primary chlorine and heavy metals input stream,and clinker(CK)and cement kiln dust(CKD)accounted for>90%of the total chlorine output stream.Flue gas and CKD were the primary volatile heavy metal(Hg)output streams.Greater than 70%of the semi-volatile heavy metals(Cd,Pb,T1 and Se)distributed in hot raw meal and bypass cement kiln dust.The low-volatility heavy metals were concentrated in the CK.These results indicated that co-processing techniques used in China still require improvement.

Disposal of zinc extraction residues via iron ore sintering process:an innovative resource utilization

Zinc extraction residue,a solid waste generated from the treatment of zinc-containing dust in rotary kilns,is commonly stockpiled in steel companies for extended periods.It poses significant disposal challenges and environmental pollution risks.So far,research on the treatment of zinc extraction residues has been slow,inadequate,and sporadic.For this gap,a novel approach was proposed to effectively treat the zinc extraction residue via the iron ore sintering process.It was feasible to add 1 wt.%of zinc extraction residues to the sintering raw materials.The more adequate mineralization reaction resulted in higher yield and tumbler indexes,despite a slight decrease in sintering speed.Although this may result in a slight decrease in sintering speed,the more complete mineralization reaction leads to improved sintering yield and tumbler index.Interestingly,the addition of zinc extraction residues reduced the CO and NO_(x) concentrations in the sintering flue gas.Thus,the iron ore sintering process provided a viable solution for resource utilization and environmentally friendly treatment of zinc extraction residues.