Study of the Conversion of Postconsumer Polystyrene on CeO2/HZSM-5 Type Materials

The catalytic conversion of polystyrene (PS) was studied in the presence of the materials type HZSM-5, CeO2, 10% CeO2/HZSM-5 and 20% CeO2/HZSM-5, which were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption at 77K. The catalytic tests were performed via thermogravimetric analysis (TG) at heating rates of 5, 10 and 20˚C min−1 in a temperature range from 30˚C to 900˚C. For the tests, a ratio of 30% by mass of each catalytic material mixed with PS was used and the activation energy of the degradation process was determined by the Vyazovkin method. The obtained results showed that the addition of the catalyst to the PS in general reduced its degradation temperature. The 10% CeO2/HZSM-5 catalyst showed greater efficiency, as it resulted in lower activation energy for PS degradation. Thus, the combination of CeO2 with HZSM-5 resulted in materials with potential for application in the catalytic degradation of polystyrene and the results indicate that the production of a composite material can be a good strategy to generate an increase in catalytic activity and a decrease in energy process activation.

Weatherability Studies on External Insulation Thermal System of Expanded Polystyrene Board,Polystyrene Granule and Polyurethane Foam

Atmospheric exposure tests including two experimental stages of high temperature-spraying water cycle and heating-refrigeration cycle were carried out on three currently used ETIS of expanded polystyrene（EPS） board,polystyrene granule mortar and polyurethane foam in order to study the weatherablility of external thermal insulation system（ETIS）.The change rules of adhesive strength were hereby studied at different time period of atmospheric exposure tests.The experimental results show that the adhesive strength of three kinds of ETIS changes a little during high temperature-spraying water cycle,but the adhesive strength of ETIS with EPS board decreases significantly after heating-refrigeration cycle.The lowering rate of adhesive strength with painting finishes is obviously faster than that of tile finishes for ETIS of EPS board during heating-refrigeration cycle.The weatherability of ETIS with EPS board is worse than the other two,and ETIS of polystyrene granule mortar and polyurethane foam are more suitable than ETIS of EPS board in cold area.

Thermal and Thermo-oxidative Degradation of Flame Retardant High Impact Polystyrene with Triphenyl Phosphate and Novolac Epoxy Resin

Thermal and thermo-oxidative decomposition and decomposition kinetics of flame retardant high impact polystyrene （HIPS） with triphenyl phosphate （TPP） and novolac type epoxy resin （NE） were characterized using thermo-gravimetric experiment. And the flammability was determined by limited oxygen indices （LOI）. The LOI results show that TPP and NE had a good synthetic effect on the flame retardancy of HIPS. Compared with pure HIPS, the LOI values of HIPS/NE and HIPS/TPP only increased by about 5%, and the LOI value of HIPS/TPP/NE reached 42.3%, nearly 23% above that of HIPS. All materials showed one main decomposition step, as radical HIPS scission predominated during anaerobic decomposition. TPP increased the activity energy effectively while NE affected the thermal-oxidative degradation more with the help of the char formation. With both TPP and NE, the materials could have a comparable good result of both thermal and thermal-oxidative degradation, which could contribute to their effect on the flame retardancy.

Dynamic Mechanical and Thermal Properties of Cross-linked Polystyrene/Glass Fiber Composites

Cross-linked polystyrene/glass fiber composites were fabricated using cross-linked polystyrene （CLPS） as matrix and E-glass fiber as the reinforcement. Surfaces of E-glass fibers were modified by vinyl triethoxysilane （VTES）, vinyl trimethoxysilane （VTMS） and γ-methacryloylpropyl trimethoxysilane （MPS）. The treated glass fibers were analyzed by fourier transform infrared spectroscopy （FTIR）. Dynamic mechanical thermal analysis （DMTA） and thermo-gravimetric analysis （TGA） were employed to investigate the effect of glass fibers surface modification on viscoelastic behavior and thermal properties. The morphology of fracture surfaces of various composites was observed by scanning electron microscopy （SEM）. The results revealed that these coupling agents were connected to the surfaces of the fibers by chemical bonding. Dynamic mechanical properties as well as thermal stability of the composites were improved considerablely, but to varying degrees depending on the fiber modification. The diversities of improvement of properties were attributed to the different interfacial adhesion between CLPS matrix and the glass fibers.

A New Kind of Renewable Energy: Production of Aromatic Hydrocarbons Naphtha Chemical by Thermal Degradation of Polystyrene (PS) Waste Plastic

Polystyrene (PS) waste plastic to renewable energy or naphtha grade fuel production through fractional distillation process was applied and PS liquefaction temperature range was 250?C - 430?C and fractional column temperature was 110?C - 135?C for naphtha grade fuel separation. The thermal degradation of PS waste plastic to renewable energy or naphtha grade chemical production was without adding any kind of cracking catalyst and without vacuum system. Polystyrene waste plastic is not bio-degradable and its can remain long period of landfill and creating gas emission for that reason its major cause climate change. For experimental purpose raw sample was use 1 kg of PS waste plastic and experiment was performed under Labconco fume hood and experiment was fully closed system, whole experiment was performed into stainless steel reactor. Produced fuel was analysis by gas chromatography and mass spectrometer, FT-IR and DSC. Analysis result indicate for fuel compounds chemical structure, compound band energy and enthalpy, delta H value. Produced fuel sulfur content less then environmental protection agency (EPA) level and fuel could be use for chemical feedstock refinery for further modification. By using this technology can reduce some foreign oil dependency and boost up renewable energy sector all over the world.

An Effective Green Porous Structural Adhesive for Thermal Insulating,Flame-Retardant,and Smoke-Suppressant Expandable Polystyrene Foam

To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.

STUDY ON LIGHTLY SULFONATED SYNDIOTACTIC POLYSTYRENE IONOMERS

Sulfonated syndiotactic polystyrene ionomers (SsPS) with 1.8 mol% degree of sulfonation have been studied. WAXD shows that the crystallinity of SsPS ionomers was decreased with increasing diameter size of the counter ions and sPS > SsPS-H > SsPS-K > SsPS-Zn. Moreover, SsPS ionomers only have alpha crystal form, while original sPS has two crystal forms: alpha and beta crystal form. TGA shows that the thermal stability of SsPS ionomers is higher than that of the original sPS and SsPS-Zn > SsPS-K > SsPS-H. DSC shows that all the glass transition temperatures (T-g) of SsPS ionomers are higher than that of the neat sPS and SsPS-Zn > SsPS-Na > SsPS-K > SsPS-H. However, the melting temperature (T-m) and crystallization peak temperature (T-p) of SsPS ionomers are lower and SsPS-H > SsPS-Zn > SsPS-K > SsPS-Na, while the crystallinity (X-c) of SsPS-Zn is the lowest. Nonisothermal crystallization kinetics shows that the Avrami index of sPS and SsPS-H are both about 4, suggesting the nucleation growth of SsPS-H with lower degree of sulfonation still keeps its three-dimension form. FTIR spectra of SsPS ionomers show a splitting absorption band for asymmetric stretching vibration of sulfonation group. The CH in-plane bending vibration of benzene ring shifted to higher wavenumber and the symmetric stretching vibration of sulfonation group changed slightly with different counter ion neutralized SsPS ionomers.

Effects of Vibration Technology and Polyvinyl Acetate Emulsion on Microstructure and Properties of Expanded Polystyrene Lightweight Concrete

To prevent expanded polystyrene （EPS） beads from rising up to the surface in the molding process of EPS lightweight concrete, vibration with pressure was applied and the polyvinyl acetate （PVA） emulsion was adopted to improve its mechanical properties. The mechanical properties, thermal properties and durability of EPS lightweight concrete were tested. The microstruetures of EPS lightweight concrete were observed by scanning electron microscope （SEM）. Vibration with pressure reduces the number of small cracks. The 180 d compressive strength and flexural strength increase obviously as a large amount of PVA was added. The mixed amount of PVA has no obvious influence on the thermal performance when it is not more than 10% of the cement. Vibration with pressure and surface modification of EPS beads by PVA improve the combination of EPS beads with cement stone and the mechanical properties of EPS lightweight concrete.

Computational fluid dynamics modeling of rapid pyrolysis of solid waste magnesium nitrate hydrate under different injection methods

This study developed a numerical model to efficiently treat solid waste magnesium nitrate hydrate through multi-step chemical reactions.The model simulates two-phase flow,heat,and mass transfer processes in a pyrolysis furnace to improve the decomposition rate of magnesium nitrate.The performance of multi-nozzle and single-nozzle injection methods was evaluated,and the effects of primary and secondary nozzle flow ratios,velocity ratios,and secondary nozzle inclination angles on the decomposition rate were investigated.Results indicate that multi-nozzle injection has a higher conversion efficiency and decomposition rate than single-nozzle injection,with a 10.3%higher conversion rate under the design parameters.The decomposition rate is primarily dependent on the average residence time of particles,which can be increased by decreasing flow rate and velocity ratios and increasing the inclination angle of secondary nozzles.The optimal parameters are injection flow ratio of 40%,injection velocity ratio of 0.6,and secondary nozzle inclination of 30°,corresponding to a maximum decomposition rate of 99.33%.

A Review of the Life Cycle Analysis for Plastic Waste Pyrolysis

Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the production of new plastic. Nevertheless, while there is a consensus that pyrolysis might be a crucial technology in the years to come, more discussions are needed to address the challenges related to scaling up, the long-term sustainability of the process, and additional variables essential to the advancement of the green economy. Herein, it emphasizes knowledge gaps and methodological issues in current Life Cycle Assessment (LCA), underlining the need for standardized techniques and updated data to support robust decision-making for adopting pyrolysis technologies in waste management strategies. For this purpose, this study reviews the LCAs of pyrolytic processes, encompassing the complete life cycle, from feedstock collection to end-product distribution, including elements such as energy consumption, greenhouse gas emissions, and waste creation. Hence, we evaluate diverse pyrolysis processes, including slow, rapid, and catalytic pyrolysis, emphasizing their distinct efficiency and environmental footprints. Furthermore, we evaluate the impact of feedstock composition, process parameters, and scale of operation on the overall sustainability of pyrolysis-based plastic waste treatment by integrating results from current literature and identifying essential research needs. Therefore, this paper argues that existing LCA studies need more coherence and accuracy. It follows a thorough evaluation of previous research and suggests new insights into methodologies and restrictions.

Insights into Pyrolysis of Nano-Polystyrene Particles: Thermochemical Behaviors and Kinetics Analysis

The thermal degradation kinetics of nano-polystyrene particles with diameters of 60,90,160,and 225 nm were investigated in nitrogen atmosphere using thermogravimetric analysis(TGA).Various kinetic models were employed to determine the thermal degradation mechanism and kinetics.Nano-polystyrene particles have relatively lower thermal stability when compared to micro-polystyrene.Both differential thermo–gravimetric(DTG)data and apparent activation energies indicate that the thermal degradation of nano-polystyrene particles at 60 nm is a two-step reaction process where the second step plays a dominant role,while nano-polystyrene particles with diameter greater than 60 nm exhibit single-step degradation.Similar to most micro/macro polystyrene particles,DTG peaks of nano-polystyrene particles shift towards higher temperatures with increasing heating rates.Thermal degradation of nano-polystyrene particles under nitrogen atmosphere follows the first-order reaction model.However,the apparent activation energies increase(162-181 kJ·mol–1)with the increase of particle sizes(60-225 nm).This study could provide some insights into pyrolysis of nano-polystyrene particles and a safer process of manufacturing,storage and handling of nano-polystyrene particles.

Thermal Decomposition Kinetics of High Impact Polystyrene/ Organo Fe-montmorillonite Nanocomposites

In this article, high impact polystyrene/organo Fe-montmorillonite （HIPS/Fe-OMT） nanocomposites were prepared by melting intercalation. The thermal stability of HIPS/Fe-OMT nanocomposites increased significantly compared to that of HIPS examined in thermal degradation conditions. Kinetic evaluations were performed by Kissinger, Flynn-Wall-Ozawa, Friedman methods and multivariate nonlinear regression. Apparent kinetic parameters for the overall degradation were determined. The resuRs showed that the activation energy of HIPS/Fe-OMT nanocomposites was higher than that of HIPS. A very good agreement between experimental and simulated curves was observed in dynamic conditions. Their decomposition reaction model was a single-step process of an nth-order reaction

The effect of volatile components in oil on evolutionary character- istics of diamondoids during oil thermal pyrolysis

On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(saturated, aromatic, resin, and asphalene fractions). However, little is known about the effect of volatile components in oil on diamondoid generation and diamondoid indices due to the lack of attention to these components in experiments. In this study, the effect of volatile components in oil on diamondoid generation and maturity indices was investigated by the pyrolysis simulation experiments on a normal crude oil from the HD23 well of the Tarim Basin and its residual oil after artificial volatilization, combined with quantitative analysis of diamondoids. The results indicate that the volatile components(≤n C12) in oil have an obvious contribution to the generation of adamantanes, which occurs mainly in the early stage of oil cracking(Easy Ro<1.0%), and influences the variations in maturity indices of adamantanes; but they have no obvious effect on the generation and maturity indices of diamantanes. Therefore, some secondary alterations e.g., migration, gas washing, and biodegradation, which may result in the loss of light hydrocarbons in oil under actual geological conditions, could affect the identification of adamantanes generated during the late-stage cracking of crude oil, and further influence the practical application of adamantane indices.

Techno-Economic Evaluation of Thermal and Catalytic Pyrolysis Plants for the Conversion of Heterogeneous Waste Plastics to Liquid Fuels in Nigeria

Techno-economic potentials of thermal and catalytic pyrolysis plants for the conversion of waste plastics to liquid fuels have been widely studied, but it is not obvious which of the two plants is more profitable, as the existing studies used different assumptions and cost bases in their analyses, thereby making it difficult to compare the economic potentials of the two plants. In this study, industrial-scale thermal and catalytic waste plastics pyrolysis plants were designed and economically analyzed using ASPEN PLUS. Amorphous silica-alumina was considered the optimum catalyst, with 3:1 feed to catalyst ratio. Based on 20,000 tons/year of feed and 20% interest rate, the catalytic plant, having a net present value (NPV) of &#83582208 million, was found to be economically less attractive than the thermal plant, having the NPV of &#83582426.4 million. On the contrary, sensitivity analyses of the two plants at a feed rate of 50,000 tons/year gave rise to a slightly higher NPV for the catalytic plant (&#83589861 million) than the thermal plant having NPV of &#83589838 million, thereby making the former more economically attractive for processing large amounts of waste plastics into liquid fuels. Consequently, as the catalytic plant showed a better scale economy and would produce higher quality liquid fuels than the thermal plant, it is recommended for commercialization in Nigeria.

Pyrolysis Characteristics and Thermal Kinetics of Degradable Films

Developing degradable films is an important means for resolving the problem of film pollution; however, in recent years, there have been only few studies related to the thermal analysis of degradable plastic films. This research detailed the composition and pyrolysis of one kind of ordinary and three kinds of degradable plastic films using the differential thermal analysis （DTA） technique. The results showed that degradable films and ordinary film had similar DTA curves, which reflected their similar compositions; however, small differences were measured, which were due to the added constituents of the degradable films. The pyrolysis reaction orders of each film were about 0.93. The pyrolysis activation energies and pre-exponential factors followed the order of ordinary film 〉 photodegradable film 〉 photodegradable calcium carbonate film 〉 biodegradable film. The results of this research laid the foundation for new theories for harnessing soil pollution caused by plastic films.

Assessment of hydrocarbon generation potential and thermal maturity of the deep offshore Lamu Basin, Kenya

In this study, the secondary well data for Cretaceous to Miocene cutting samples in four deep offshore exploration wells, i.e., Pomboo-1 in the north, Kubwa-1 in the central, Simba-1 and Kiboko-1 in the south of the deep offshore Lamu Basin were assessed for identifying source rock presence and examining thermal maturity of the source rocks. The 2D basin modelling was used to analyse the bulk gas transformation in the basin. Total organic carbon (TOC) content values for the wells range from 0.09 wt % to 2.23 wt % with an average of 0.78 wt %. The average organic richness is higher in the Upper Cretaceous (0.83 wt %) than in the Palaeogene (0.65 wt %), Lower Cretaceous (0.28 wt %) and Upper Jurassic (0.30 wt %). The S_(1) averages for the Upper Cretaceous are 3.76 mg HC/g rock in Pomboo-1 and 0.31mg HC/g rock in Kubwa-1. The S_(2) averages for the Upper Cretaceous are 5.00 mg HC/g rock in Pomboo-1 and 0.72 mg HC/g rock in Kubwa-1. Hydrogen index (HI) values vary between 4 and 512 mg HC/g TOC with an average of 157.09 mg HC/g TOC. Organic matters were identified as mixed types of Ⅱ-Ⅲ (oil and gas prone) and Ⅲ-Ⅳ (gas prone) kerogen in the potential source rocks. The HI and S_(2) yield values are exceptionally high for the observed TOC values in Pomboo-1. The vitrinite reflectance and Tmax values of deep offshore Lamu Basin are in the ranges of 0.38%–0.72% and 360–441 ℃, respectively. It suggests the existence of both immature and mature source rocks. Vitrinite reflectance maturity favours near coastal region in the Upper Cretaceous. These results explain why Pomboo-1, Kubwa-1, Simba-1 and Kiboko-1 wells were dry. The temperatures are still cool for hydrocarbon generation in deep offshore. The critical risk for deep offshore Lamu Basin is charge, primarily source presence, and a lack of definitive evidence of a deep-water marine source rock being present. The four wells penetrate good quality reservoir and seal rocks, but source rock presence and maturity remain the critical play risk in the deep offshore Lamu Basin.

吸入暴露途径下纳米塑料在SD大鼠体内的富集特征研究

为探讨吸入暴露纳米级塑料在生物体呼吸系统以外组织上的富集特征,以100 nm聚苯乙烯微球对SD大鼠进行2 h短期吸入暴露,使用热裂解-气相色谱质谱法测定大鼠肝脏、肾脏、心脏以及脑组织上的聚苯乙烯浓度。结果显示:暴露组大鼠肾脏、心脏和肝脏中的浓度[(0.416±0.143)、(0.633±0.278)和(0.617±0.179)g/g]显著高于对照组大鼠[(0.249±0.020)、(0.070±0.096)和(0.101±0.140)g/g],差异具有统计学意义(P<0.05),但各组织间的相关性不显著(P>0.05);2组大鼠脑组织均未检出聚苯乙烯。研究表明,100 nm聚苯乙烯微球吸入暴露2 h后,可通过肺泡进入血液循环,进而在大鼠肝脏、肾脏、心脏中形成沉积。通过探讨纳米级塑料在生物体内的累积特征,为深入开展吸入纳米塑料对人体的健康影响研究提供数据支撑。

高热故障下变压器油纸绝缘系统的产气机理研究

针对高热故障下超/特高压变压器内部绝缘系统状态变化和产气机理不清晰而严重制约变压器状态分析诊断的问题,本文基于热焓理论与仿真模拟手段相结合的方式对超/特高压变压器高热故障下油纸绝缘系统特征气体的生成路径与油纸绝缘系统的裂解机理开展研究。依据热焓理论得到气体的生成机理,并利用仿真模拟验证本文所提出的产气机理与路径。结果表明:高热故障下油纸绝缘系统中链烷烃要比环烷烃和双环芳香烃更容易发生裂解,各组分裂解生成特征气体的速率从大到小依次为纤维素、链烷烃、环烷烃、双环芳香烃。根据气体生成能可知,特征气体CH_4和C_(2)H_6最容易生成,C_(2)H_(2)最难生成,可通过特征气体在油纸绝缘系统中的生成速率判断高热故障的严重程度。

聚苯乙烯颗粒掺量对混凝土力学性能和保温性能的影响研究

以聚苯乙烯颗粒(EPS)作为掺杂材料,通过不同的表面活性剂对其进行亲水改性,在此基础上将聚苯乙烯颗粒掺入到泡沫混凝土中,研究了亲水改性后的聚苯乙烯颗粒对混凝土力学性能和保温性能的影响。结果表明,未改性的聚苯乙烯属于憎水材料,接触角为112°,三乙醇胺改性后接触角降低至31°,具有优异的亲水性。泡沫混凝土具有多孔特征,孔径分布为20~230μm,凝固时间随聚苯乙烯颗粒掺杂量的增多不断降低,流动度先增大后降低,EPS-0.9%的凝固时间为90 min,流动度最高为17.9 mm。随着EPS颗粒掺杂量的增多,泡沫混凝土的抗压强度持续降低,抗折强度先降低后轻微升高,导热系数和干密度先降低后增大,抗碳化性能持续降低。在28 d龄期时,EPS-1.2%试样的抗压强度达到最低值5.2 MPa,碳化深度达到最大值2.13 mm;EPS-0.6%试样的抗折强度达到最大值0.57 MPa;EPS-0.9%试样的干密度和导热系数达到最低值,分别为357 kg/m^(3)和0.069 W/(m·K),保温性能最优。

发泡聚苯乙烯颗粒流化热解特性的实验研究

基于不同加热速率下的热重测试,计算发泡聚苯乙烯颗粒的热裂解动力学参数,自建可视化流化热解炉研究流化床热解过程,并对产物进行分析。热重实验数据根据阿伦尼乌斯方程用KAS,OFW,CR方法计算活化能和指前因子等热解动力学参数。通过可视化实验观察分析不同温度下发泡聚苯乙烯颗粒热解过程的形态变化,并分析固、液、气三相产物的主要成分。KAS和OFW方法计算的活化能分别为143.55 kJ/mol和147.21 kJ/mol。CR方法计算指前因子为6.79×10^(5)~4.40×10^(8)min^(-1)。发泡聚苯乙烯热解过程中吉布斯自由能为219.30 kJ/mol,反应焓变为137.94 kJ/mol,熵变为-0.12 kJ/K。流化裂解产物主要是苯乙烯、1,3,5-三苯基环己烷、9,9-二甲基萘为主的裂解油、碳黑及甲苯和苯乙烯为主的裂解气。