Catalytic pyrolysis of car tire waste using expanded perlite

In this study, the non-catalytic and catalytic pyrolysis experiments were conducted on the sample of tire waste using expanded perlite as an additive material to determine especially the effect of temperature and catalyst-to-tire ratio on the products yields and the compositions and qualities of pyrolytic oils (NCPO and CPO). Non-catalytic studies, which were carried out under the certain conditions (a nitrogen flow of 100 mL/min and a heating rate of 10 °C/min), showed that the highest yield of pyrolytic oil (NCPO) was 60.02 wt.% at 425 °C. Then, the catalytic pyrolysis studies were carried out at catalyst-to-tire ratio range of 0.05-0.25 and the highest catalytic pyrolytic oil (CPO) yield was 65.11 wt.% at the ratio of 0.10 with the yield increase of 8.48 wt.% compared with the non-catalytic pyrolysis. Lastly, the pyrolytic oils were characterized with applying a various techniques such as elemental analyses and various chromatographic and spectroscopic techniques (GC-MS, ¹H NMR, FT-IR, etc.). The characterization results revealed that the pyrolytic oils which were complex mixtures of C₅-C₁₅ organic compounds (predominantly aromatic compounds) and also the CPO compared to the NCPO was more similar to conventional fuels in view of the certain fuel properties.     

废轮胎热解回收的产业现状与创新技术

废轮胎热解回收处理的方法以其较高的资源回收率和较低的二次污染引起广泛关注.但是废轮胎热解回收循环利用是个比较复杂的过程,尤其是热解炭黑品质和市场应用决定着整个热解过程的经济性,如果延用落后的生产工艺和简陋的热解加工设备,热解炭黑品质较差,达不到使用要求,而且还会对环境造成二次污染.主要从废轮胎热解过程和热解产物上进行了一些探索,通过在实践中改进工艺和设备,使热解炭黑的品质显著提高,旨在从技术上对日益剧增的废轮胎土法炼油有所引导,使之尽快走上工艺技术化、设备规范化的轨道,实现真正意义上的废旧轮胎循环利用.     

Valorization of waste tire by pyrolysis and hydrothermal liquefaction: a mini-review

Journal of Material Cycles and Waste Management - An amount of 1.5 billion waste tires has been generated every year, resulting in serious environmental problems and damaging human health caused by...     

Recycling of waste tire by pyrolysis to recover carbon black: an alternative reinforcing filler

Journal of Material Cycles and Waste Management - Thermal pyrolysis of waste tires is an industrially beneficial method for material and energy recovery. Pyrolytic carbon black (CBp) is considered...     

Evaluation of waste pyrolysis characteristics in a pressurized fluidized bed reactor

To obtain the distribution of fuel components to gas, tar and char in a pressurized fluidized bed waste pyrolyzer, experiments were conducted with a laboratory scale fluidized bed reactor. Waste samples were fed batchwise from the top of the reactor into the fluidized bed of silica sand and pyrolyzed by nitrogen/nitrogen-O2 gas and the effects of pressure, particle size, heating rate and oxygen addition were investigated. In the case of rubber, the char yield tended to increase a little and the tar yield decrease over the pressure of 304-709 kPa. In comparison with the thermogravimetry data it was clearly demonstrated that the char yield from fluidized bed pyrolysis is much lower. A small amount of oxygen addition decreased both tar and char yields but its further increase did not affect them very much.     

Anaerobic digestion combined pyrolysis for paper mill sludge disposal and its influence on char characteristics

Journal of Material Cycles and Waste Management - The disposal of paper mill sludge through anaerobic digestion (AD) combined pyrolysis was investigated. Two paper mill sludge samples, both with...     

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the “Image Pro Plus (v6.3)” digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase – drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design.     

Fly ash reinforced thermoplastic vulcanizates obtained from waste tire powder

Novel thermoplastic composites made from two major industrial and consumer wastes, fly ash and waste tire powder, have been developed. The effect of increasing fly ash loadings on performance characteristics such as tensile strength, thermal, dynamic mechanical and magnetic properties has been investigated. The morphology of the blends shows that fly ash particles have more affinity and adhesion towards the rubbery phase when compared to the plastic phase. The fracture surface of the composites shows extensive debonding of fly ash particles. Thermal analysis of the composites shows a progressive increase in activation energy with increase in fly ash loadings. Additionally, morphological studies of the ash residue after 90% thermal degradation shows extensive changes occurring in both the polymer and filler phases. The processing ability of the thermoplastics has been carried out in a Monsanto processability testing machine as a function of shear rate and temperature. Shear thinning behavior, typical of particulate polymer systems, has been observed irrespective of the testing temperatures. Magnetic properties and percolation behavior of the composites have also been evaluated.     

Experimental research on compressibility characteristics of recycled concrete aggregate: recycled tire waste mixtures

The utilization of processed rubber and construction waste in lieu of soil as a substrate could improve significantly seismic performance, while addressing the pressing environmental issue of how to reutilize and dispose of, i.e., automotive tires and demolition by-products. In this study, a series of laboratory tests explore the influence of recycled tire waste (RTW) and recycled concrete aggregate (RCA) fine particles on the compressibility parameters of RCA–RTW mixtures. The results revealed that the addition of rubber waste to RCA causes an increase in its compressibility and consolidation index (c_v) while prompting a power law decrease in the associated void ratio. It is found that all RCA–RTW mixtures are characterized by higher values of the compression (C_C) and swelling (C_S) indexes when compared to the pure RCA specimens while presenting a primary and secondary constrained modulus of fewer than 42 MPa and 96 MPa, respectively.

     

Bio-oil production from pyrolysis of waste sawdust with catalyst ZSM-5

Journal of Material Cycles and Waste Management - Slow pyrolysis is characterized by a low heating rate and high reaction time. The products are bio-char, bio-oil and bio-gas. In bio-oil, there are...     

Quality improvement of pyrolysis oil from waste rubber by adding sawdust

This work was aimed at improving the pyrolysis oil quality of waste rubber by adding larch sawdust. Using a 1 kg/h stainless pyrolysis reactor, the contents of sawdust in rubber were gradually increased from 0%, 50%, 100% and 200% (wt%) during the pyrolysis process. Using a thermo-gravimetric (TG) analyzer coupled with Fourier transform infrared (FTIR) analysis of evolving products (TG–FTIR), the weight loss characteristics of the heat under different mixtures of sawdust/rubber were observed. Using the pyrolysis–gas chromatography (GC)–mass spectrometry (Py–GC/MS), the vapors from the pyrolysis processes were collected and the compositions of the vapors were examined. During the pyrolysis process, the recovery of the pyrolysis gas and its composition were measured in-situ at a reaction temperature of 450 °C and a retaining time of 1.2 s. The results indicated that the efficiency of pyrolysis was increased and the residual carbon was reduced as the percentage of sawdust increased. The adding of sawdust significantly improved the pyrolysis oil quality by reducing the polycyclic aromatic hydrocarbons (PAHs) and nitrogen and sulfur compounds contents, resulting in an improvement in the combustion efficiency of the pyrolysis oil.     

Feasibility study for thermal treatment of solid tire wastes in Bangladesh by using pyrolysis technology

In this study on the basis of lab data and available resources in Bangladesh, feasibility study has been carried out for pyrolysis process converting solid tire wastes into pyrolysis oils, solid char and gases. The process considered for detailed analysis was fixed-bed fire-tube heating pyrolysis reactor system. The comparative techno-economic assessment was carried out in US$ for three different sizes plants: medium commercial scale (144 tons/day), small commercial scale (36 tons/day), pilot scale (3.6 tons/day). The assessment showed that medium commercial scale plant was economically feasible, with the lowest unit production cost than small commercial and pilot scale plants for the production of crude pyrolysis oil that could be used as boiler fuel oil and for the production of upgraded liquid-products.     

Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition

To obtain detailed information on the pyrolysis characteristics, a thermogravimetric study on the pyrolysis of 14 typical medical waste compositions was carried out in thermogravimetric analysis (TGA) equipment using dynamic techniques in a stream of N(2). An index representing pyrolysis reactivity of waste was presented. Kinetic parameters were obtained by Coats-Redfern method and used to model the TG curve. The results showed that: (a) Plastic, protein, cellulosic material, synthetic fibre, and rubber entered pyrolysis process in succession. (b) There was one decomposition stage in the pyrolysis of one-off medical glove, operating glove, cellulosic waste, absorbable catgut suture and adhesive plaster, while other components had two obvious weight loss stages. (c) The obtained apparent activation energy for second stage pyrolysis was comparably higher than that for first stage. (d) Each stage was controlled by only one kinetic mechanism, in which kinetic parameters were constant. (e) The degradation kinetics of medical waste may be affected by special physical and chemical treatment in the product manufacturing process. (f) Among 13 waste samples, the pyrolysis index of cellulosic matter was the highest, which indicated cellulosic matter had strong pyrolysis reactivity. (g) With increasing heating rate, TG curve and DTG peak shifted to high temperatures and main reaction interval of the sample became longer.     

热解温度对青霉素菌渣热解产物的影响

将青霉素菌渣在400～700℃进行热解,研究了产物中热解炭、热解油及气体的产率,以及热解油的组成变化.实验结果表明:600℃时热解油产率最高,随着温度升高,热解炭的产率降低,气体的产率升高;热解油中含量最高的是含氧化合物,在400℃时质量分数达到最高值69.69％,含氧化合物的含量随着热解温度的升高而降低,酸和醇类是热...     

Solar pyrolysis of scrap tire: optimization of operating parameters

Journal of Material Cycles and Waste Management - Pyrolysis of scrap tire using concentrated solar radiation is a novel way to upgrade feedstock. In this investigation, best operating condition for...     

Water-soluble characteristics of chlorine in char derived from municipal solid wastes

Chlorine in char derived from municipal solid waste (MSW) was characterized and quantified based on its water solubility: easily water-soluble, hardly water-soluble, and non-water-soluble chlorine. For that, a four-cycle process of water-washing, heating or carbonation were carried out. In order to confirm the characteristics of non-water-soluble chlorine, additional thermal treatment and an alkali-acid washing process were applied to washed char. It was found that a large particle size of char (0.5-1.0 mm) significantly contributed to the amount of non-water-soluble chlorine. Pulverization and HNO3-HF digestion were performed to identify a factor to interfere chlorine release from char with a large particle size. Pulverization was proven ineffective for release of non-water-soluble chlorine, whereas approximately 32% of non-water-soluble chlorine was extracted by HNO3-HF digestion. Therefore, the presence of non-water-soluble chlorine is likely to originate from its chemical property rather than simply from its physical one.     

废弃电路板SMD元件热拆除工艺实验研究

废弃电路板元件的分离,一直是废弃电路板回收利用的难点。利用有限元分析软件ANSYS建立表面安装元器件(SMD)的有限元分析模型,通过对加热过程进行仿真,分析出元件分离的必要条件。     

Thermal pyrolysis of fresh and waste fishing nets

Kinetic tests on the pyrolysis of nylon-6 taken from fresh (new) fishing nets and waste fishing nets were conducted using thermogravimetric analysis at heating rates of 0.5, 1.0 and 2.0 degrees C/min. The main region of decomposition of both materials was between 340 and 440 degrees C at each heating rate. The region of decomposition for the nylon-6 from the waste fishing nets was slightly lower than that of the fresh fishing nets. The result shows that the value of activation energies increased from 128 to 433 kJ mol(-1) as the conversion of the pyrolysis reaction increased from 5% to 95%. Nylon-6 from the fresh fishing nets was pyrolyzed in a micro-scale tubing bomb reactor for 60, 80 and 100 min at 440 degrees C. The yield of pyrolyzed gases increased from 3.94 to 5.50 wt% with reaction time. The selectivity to specific hydrocarbons was not detected from the pyrolyzed oil and the carbon number distribution of the pyrolyzed oil was random.     

有机固废热解反应器研究进展

热解技术是一种优秀的有机固废处理技术,其具有环保、减量化、资源化等优点,热解技术的核心是热解反应器。通过介绍不同类型热解反应器的特点及其研究与工程应用的进展,为下一步引进与开发热解工艺提供技术支撑。     

Vacuum pyrolysis of waste tires with basic additives

Granules of waste tires were pyrolyzed under vacuum (3.5-10kPa) conditions, and the effects of temperature and basic additives (Na(2)CO(3), NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 degrees C to 600 degrees C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48wt% was achieved at 550 degrees C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50wt% was achieved at 480 degrees C by adding 3wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) approximately 205 degrees C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na(2)CO(3) addition. Pyrolysis gas was mainly composed of H(2), CO, CH(4), CO(2), C(2)H(4) and C(2)H(6). Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5wt%) was much higher.