Overall Kinetics of Heat Treatment of Municipal Solid Waste

A mathematical model of the overall kinetics of heat treatment of municipal solid waste was developed. The model considers the main initial substances and products of the reaction of municipal solid waste treatment at high temperatures (1300–1500°C) in a tubular flow reactor.     

Two-phase methanization of food wastes in pilot scale

A 5 ton/d pilot scale two-phase anaerobic digester was constructed and tested to treat Korean food wastes in Anyang city near Seoul. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert materials such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons, and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 d space time at pH of about 6.5. The second, methanization reactor converted the acids into methane with pH between 7.4 and 7.8. The space time for the second reactor was 15 d. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady-state operation with the maximum organic loading rate of 7.9 kg volatile solid (VS)/m³/d and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about 230 m³ of biogas with 70% (v/v) of methane and 80 kg of humus. This process is extended to full-scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings. Author to whom all correspondence and reprint requests should be addressed.     

城市生活垃圾典型有机组分混合热解特性的研究

利用自行设计的较大物量(约10 g)的热重分析装置对城市生活垃圾典型有机组分（纸屑、木屑、织物、塑料、橡胶、厨余）的混合热解特性进行了实验研究，并用最小二乘法计算得到由若干平行反应组成的热解反应动力学模型，实验结果与模型计算结果吻合较好。在此基础上对城市生活垃圾典型有机组分混合热解中的交互影响和非线性规律进行了分析。结果表明，城市生活垃圾典型有机组分混合热解动力学模型由2个～4个平行反应组成；混合热解中有反应发生合并的现象；热效应和组分比例对混合物综合热解特性有显著影响。     

Optimizing zirconia-based solid electrolyte cell operated as oxidizing reactor and chromatographic sensor

A zirconia-based (0.9ZrO₂ · 0.1Y₂O₃) high-temperature electrochemical reactor with three-electrode connection circuit was shown promising if used as a chromatographic sensor for quantitative organic gas detection as well as an organic gas sample preparation device for carbon isotopic analysis. The optimized parameters and working mode of the herein proposed solid electrolyte reactor provided complete organic gas oxidation to stoichiometric oxides without oxygen addition to the carrier gas flow at the temperature of 900 to 950°C. The maximum hydrocarbon gas sample amount was calculated for complete oxidation in the designed reactor. Due to its simple and reliable design, the solid electrolyte reactor can be used instead of a standard oxidizing reactor in an isotopic mass spectrometer.     

利用焦化工艺处理废塑料技术研究 Ⅰ. 热天平与10 g固定床实验

利用热天平和10 g固定床反应器分别考察了北京市生活垃圾中的废塑料与首钢炼焦配煤的热失重特性及热解产物分布规律。实验研究表明，首钢炼焦配煤主要热分解温度区域为300 ℃～750 ℃，北京市废塑料主要热分解温度区域为300 ℃～550 ℃，二者在相互重叠的失重温度区间产生“协同效应”，且在一定配比范围内，共热解产物出现 “增油减水”现象。首次提出了协同效应强度的概念及其计算式： 和 ，并得出废塑料的添加量为1％时，协同效应强度最大。     

Biodegradation of tobacco waste by composting: Genetic identification of nicotine-degrading bacteria and kinetic analysis of transformations in leachate

The tobacco industry produces large quantities of solid and liquid waste. This waste poses a significant environmental problem, as some major components are harmful and toxic. The aim of this work is to isolate and identify the nicotine-degrading microorganisms in the composting of tobacco waste. The bioremediation process for the detoxification of waste was carried out in a column reactor at an airflow-rate of 0.4 L min^?1 kg^?1. The concentrations of nicotine and number of CFU in the samples taken from reactor were monitored over nineteen days. After nineteen days, 89.8 % of nicotine conversion was obtained. A nicotine-degrading bacterium, strain FN, was isolated from the composting mass and identified as Pseudomonas aeruginosa on the basis of morphology, 16S rDNA sequence, and the phylogenetic characteristics. To confirm that the isolated Pseudomonas aeruginosa FN is the actual nicotine degrader, batch experiments were performed using tobacco leachate. It was confirmed that the strain FN possesses a considerable capacity to degrade nicotine with simultaneous COD removal. The Monod kinetic model for single substrate was applied to obtain the substrate degradation rate and half saturation constant.     

Recent R&D towards Aqueous Reprocessing of FBR Fuels

The mixed Pu-rich carbide spent fuel with a burn up of 155 GWd/t from the Fast Breeder Test Reactor is being reprocessed in a hot-cell facility by PUREX process. Based on the input from the operation of this facility, R&D activities were carried out to improve the recovery, decontamination factors, economy and to reduce the waste volumes. Reduction of uranyl ions in a continuous flow electrochemical reactor and electrolytic as well as chemical reduction of 4M HNO₃ from liquid waste could be accomplished in continuous mode. Using the optimized parameters, suitable electrolytic cells/experimental setups were designed for the plant capacity of 6 L/h. Studies on the extraction kinetics of Ru with 30% TBP in NPH revealed that better decontamination factor with respect to Ru can be achieved using fast contactors like centrifugal extractors (CEs). Towards developing a spent solvent recovery system to reduce organic waste volumes, a pilot plant was set up, which could recover diluent as top product of distillation column and 40% TBP as bottom product from inactive degraded solvent. A solvent recovery system using short path distillation was also developed for installation in hot cells.     

Introduction of a coiled solid‐phase microextraction fiber based on a coating of animal bone waste for chromatographic analysis

We attempt to introduce animal bone waste as a coating material with an organic−inorganic structure for the fabrication of a coiled solid‐phase microextraction fiber for the first time. The coiled fiber was simply prepared with the use of copper wire and coated with bone waste suspension through the dip‐coating method. The bone waste coating was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction analysis. It was applied as new type of solid‐phase microextraction fiber for preconcentration of polycyclic aromatic hydrocarbons before determination by high‐performance liquid chromatography with UV detection. A wide linear range 0.01–99.0 μg/L and limits of detection in the range 3.0–11.1 ng/L were obtained at optimized conditions. The bone waste coated coiled solid‐phase microextraction fiber has promise in sample preparation techniques because it is cost effective, available, stable in aqueous and organic solutions, environmentally friendly, and easy to fabricate and operate.     

Autothermal biodrying of municipal solid waste with high moisture content

To carry out autothermal drying processes during the composting of biomass, a horizontal tubular reactor was designed and tested. A biodrying tunnel of the total capacity of 240 dm³ was made of plastic material and insulated with polyurethane foam to prevent heat losses. Municipal solid waste and structural plant material were used as the input substrate. As a result of autothermal drying processes, moisture content decreased by 50 % of the initial moisture content of organic waste of about 800 g kg⁻¹. In the tested cycles, high temperatures of biodried waste mass were achieved (54–56°C). An appropriate quantity of air was supplied to maintain a satisfactory level of temperature and moisture removal in the biodried mass and high energy content in the final product. The heat of combustion of dried waste and its calorific value were determined in a calorimeter. Examinations of pyrolysis and gasification of dried waste confirmed their usefulness as biofuel of satisfactory energy content.     

Solvent Effects in Acid‐Catalyzed Biomass Conversion Reactions

Reaction kinetics were studied to quantify the effects of polar aprotic organic solvents on the acid‐catalyzed conversion of xylose into furfural. A solvent of particular importance is γ‐valerolactone (GVL), which leads to significant increases in reaction rates compared to water in addition to increased product selectivity. GVL has similar effects on the kinetics for the dehydration of 1,2‐propanediol to propanal and for the hydrolysis of cellobiose to glucose. Based on results obtained for homogeneous Brønsted acid catalysts that span a range of pK_a values, we suggest that an aprotic organic solvent affects the reaction kinetics by changing the stabilization of the acidic proton relative to the protonated transition state. This same behavior is displayed by strong solid Brønsted acid catalysts, such as H‐mordenite and H‐beta.     

Anaerobic bioconversion of municipal solid wastes using a novel high-solids reactor design

Novel, laboratory-scale, high-solids reactors operated under mesophilic conditions were used to study the anaerobic fermentation of processed municipal solid waste (MSW) to methane. Product gas rate data were determined for organic loading rates ranging from 2.99–18.46 g of volatile solids (VS) per liter (L) per day (d). The data represent the anaerobic fermentation at high-solids levels within the reactor of 21–32%, while feeding a refuse-derived fuel (RDF)/MSW feedstock supplemented with a vitamin/mineral/nutrient solution. The average biogas yield was 0.59 L biogas/g VS added to the reactor system/d. The average methane composition of the biogas produced was 57.2%. The data indicate a linear relationship of increasing total biogas production with increasing organic loading rate to the process. The maximum organic loading rate obtainable with high-solids anaerobic digestion is in the range of 18–20 g VS/L·d to obtain 80% or greater bioconversion for the RDF/MSW feedstock. This loading rate is approximately four to six times greater than that which can be obtained with comparable low-solids anaerobic bioreactor technology.     

城市生活垃圾的燃烧特性

选取城市生活垃圾中的九种典型级分进行热重特性试验，根据热失重曲线得出反应动力力学参数及反应速率控制方程，提出燃烧指数表征垃圾的燃烧特性。研究结果表明，垃圾中不同的组分的燃烧特性判别很大，不同的垃圾控制燃烧反应的过程是不同的，废塑料，废纸和废棉布类符合两段燃烧模型，且低温段的动力学参数Ｅ和Ａ远大于高温段，其余六处组分可用一段模型来描述，计算得出的失重关系式能较好地反映垃圾燃烧的失重过程，挥 分高的垃     

Mechanism and Kinetics of Heterogeneous Reactions of Unsaturated Organic Acids on α‐Al2O3 and CaCO3

Heterogeneous reactions have a vital role in the atmosphere due to their significant effects on the evolution of atmospheric aerosols, which in turn contribute to air pollution. However, the mechanism and kinetics of these processes involving unsaturated organic acids, important types of volatile organic compounds, are still unclear. In this work, the heterogeneous uptake of two representative atmospheric unsaturated organic acids (acrylic acid and methacrylic acid) on mineral aerosols including α‐Al₂O₃ and CaCO₃ are investigated using a Knudsen cell reactor and an in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) reactor. The corresponding reaction pathways are proposed from the DRIFTS analysis. In addition, the initial uptake coefficients of unsaturated organic acids and their heterogeneous fate are obtained for the first time. Our results suggest that heterogeneous reactions on α‐Al₂O₃ and CaCO₃ can be important sinks for acrylic acid and methacrylic acid, as well as possible contributors to the organic coating found on atmospheric aerosols, especially in high‐pollution events.     

Biohydrogen Production Based on the Evaluation of Kinetic Parameters of a Mixed Microbial Culture Using Glucose and Fruit–Vegetable Waste as Feedstocks

Hydrogen (H₂) production from the organic fraction of solid waste such as fruit and vegetable waste (FVW) is a novel and feasible energy technology. Continuous application of this process would allow for the simultaneous treatment of organic residues and energy production. In this study, batch experiments were conducted using glucose as substrate, and data of H₂ production obtained were successfully adjusted by a logistic model. The kinetic parameters (μ _max?=?0.101 h^?1, K _s?=?2.56 g/L) of an H₂-producing microbial culture determined by the Monod and Haldane–Andrews growth models were used to establish the continuous culture conditions. This strategy led to a productive steady state in continuous culture. Once the steady state was reached in the continuous reactor, a maximum H₂ production of 700 mL was attained. The feasibility of producing H₂ from the FVW obtained from a local market in Mexico City was also evaluated using batch conditions. The effect of the initial FVW concentration on the H₂ production and waste organic material degradation was determined. The highest H₂ production rate (1.7 mmol/day), the highest cumulative H₂ volume (310 mL), and 25 % chemical oxygen demand (COD) removal were obtained with an initial substrate (FVW) concentration of 37 g COD/L. The lowest H₂ production rates were obtained with relatively low initial substrate concentrations of 5 and 11 g COD/L. The H₂ production rates with FVW were also characterized by the logistic model. Similar cumulative H₂ production was obtained when glucose and FVW were used as substrates.     

Solid-state polymerization of butadienes. Polymerization of salts of 6-amino-2,4-trans,trans-hexadienoic acid

The polymerization of 6-amino-2,4-trans,trans-hexadienoic acid and various of its salts was studied in the solid state. Crystals of the hydrochloride and organic inorganic double halides with cadmium chloride, manganese (II) chloride, and iron(II) chloride were found to polymerize rapidly upon UV or γ irradiation. An erythro-diisotactic polymer is obtained in the form of extended chain crystals. The polymer behaves as an amphoteric polyelectrolyte. The kinetics and the mechanism of the polymerization as well as morphological changes during the solid state reaction are discussed.     

On the application of a ZrO2‐based solid electrolyte in isotope ratio mass spectrometry

The application of a high‐temperature electrochemical reactor based on stabilized zirconium dioxide (0.9 ZrO₂0.1 Y₂O₃) for organic gas sampling in continuous‐flow isotope‐ratio mass spectrometry (CF‐IRMS) has been found to be efficient. This solid electrolyte reactor (SER) can also be used as a chromatographic detector for the quantitative measurements of organic gases. A three‐electrode SER system was studied. Complete stoichiometric oxidation of organic gases has been achieved at 900–950°C due to the large catalytic surface area of the porous platinum coating. At this temperature, the oxygen ions formed from the oxygen of ambient air on the outer surface of the reactor migrate through the solid electrolyte under the action of the applied electric field and allow combustion of gases being analyzed to be effected. It should be noted that oxygen gas was not introduced into the gas‐carrier flow. Similar results for the measurements of carbon isotope ratios were obtained at the oxidation of hydrocarbon gases in both the standard and the solid electrolyte reactors. Copyright © 2009 John Wiley & Sons, Ltd.     

Surface modifications of natural clinoptilolite-dominated zeolite for phenolic pollutant mitigation

A novel carbonized clinoptilolite-rich tuff was studied for phenol removal from water. Zeolite sample carbonization was accomplished in a plasmachemical reactor (pyrolytic chamber) using several types of waste, here specifically waste vegetable residues and starch. Phenol adsorption experiments were performed in the batch system. An industrial activated charcoal and a clinoptilolite-rich tuff hydrofobized with an organic ammonium base were used as the related materials to compare phenol removal efficiency.     

Pilot scale thermolysis of municipal solid waste: Combustibility of the products of the process and gas cleaning treatment of the combustion gases

This paper describes the process of thermolysis of the organic fraction of municipal solid waste in a pilot scale reactor and the results are compared with others obtained under laboratory conditions (semi-pilot scale). The aim of this study was to get the energetic valorisation of the products. Owing to the specific characteristics of the plant, two products were obtained from the process: gas and carbonized solid, no liquid fraction was obtained, so the gas fraction is a greater percentage made up both condensable and non-condensable compounds, while at the laboratory scale were obtained separately. The pilot plant was designed so that the gases produced by thermolysis were burnt continuously in a combustion chamber, while the carbonized fraction was fed in batches for co-combustion. To determining composition and combustibility a chromatographic analysis of the gas fraction was undertaken, the solid fraction also being subjected to analyses. The gas composition, rich in light hydrocarbons, and the carbon present in the carbonized fraction make possible the energetic valorisation of these products. The combustion gases were subjected to a cleaning process and their composition analysed twice: before and after the gas cleaning treatment. An energy production system based on the Rankine cycle is proposed. The study led to a positive assessment of the possible use of the process products as fuel, provided that the combustion gases are treated. The neutralization treatment used was seen to be effective in the cleaning of combustion gases. Electricity production yields would have to be raised by means of a co-generation process.     

A Study of the Hydrolysis of Waste Paper Cellulose with a Vertically Hanging Immobilized Cellulase Reactor and the Reuse of the Immobilized Cellulase

A commercialized cellulase from Trichoderma reesei has been successfully immobilized by using calcium alginate gel in our laboratory. The waste paper cellulose was hydrolyzed with a special design of the reactor to form a vertically hanging immobilized cellulase under the optimum conditions of pH 4.0 and 45 °C. Glucose, cellobiose and xylose are the major hydrolysis products. The glucose production from the hydrolysis with the vertically hanging immobilized cellulase was about 1.73‐fold better than the freely suspended immobilized cellulase. The average diameter of the immobilized cellulase pellets was 4.190 ± 0.291 mm. UV light irradiation deactivates the activity of the immobilized cellulase. The advantage of the vertically hanging immobilized cellulase reactor is an easy recycle and reuse of the immobilized cellulase. Washing and soaking the recycled immobilized cellulase with distilled water for one day can restore its activity to a small extent. Overall, the application of the hanging immobilized cellulase reactor for waste paper cellulose hydrolysis is successful.     

Open tube combustion method of organic samples for stable carbon isotope analysis

A simple and effective method for the conversion of organic carbon into carbon dioxide for analysis of stable carbon isotopes (delta(13)C) in samples of various organic substances, soils, sedimentary rocks, oils and volatile organic liquids is presented. The conversion of organic carbon of the samples is carried out in a quartz reactor connected to a vacuum line for CO(2) freezing and purification. A solid organic sample mixed with CuO is placed at the reactor bottom and the reactor is subsequently filled with granular CuO. One end of the CuO column is preheated to 850 degrees C while the other end of the column in contact with the sample is kept at ambient temperature. Heating of the sample (850 degrees C) and the remainder of the column is then performed. The preheated part of the column provides efficient conversion of carbon into CO(2). The reactor for the conversion of volatile liquid organic compounds is filled with granular CuO. The column of CuO is heated to 850 degrees C. Samples of volatile liquids are introduced into the reactor through a septum using a microsyringe. Complete conversion takes 10 min for solid samples and 3 min for volatile liquids. The precision of the delta(13)C analysis for solid and volatile liquid organic substances is +/-0.1 per thousand and +/-0.04 per thousand, respectively.