Thermal Characteristics of Different Plastics
Thermal decomposition of different plastic through pyrolysis can be achieved at different temperature range. Through TGA analysis of various plastics, including PP, PS, LDPE and HDPE, carried by Lee and Shin [10], it was found that PS has the lowest degradation temperature compared to PP and PE thus will decompose more easily into liquid products. Degradation of PS occurs almost in the range of 350 to 460̊C, similarly to Jude et al. [23] where complete degradation occurred at 400̊C, while PP degradation occurs between 380 to 490̊C. Moreover, LDPE and HDPE decompose in temperature range of 400 to 500 and 550̊C. This is also been determined by Lopez et al [15] in terms of rate of mass loss of PE, PP, PS, PET and PVC. The results showed almost similar temperature range as in [10] for PE, PP and PS. Moreover, maximum degradation showed to occur at 490, 470 and 420̊C for PE, PP and PS. Therefore, it can be determined that temperature in the range of 450 and 500̊C will be suitable for pyrolysis of plastic.
Effect of plastic composition on the pyrolytic oil yield and composition
The role of plastic waste composition on the yield of the pyrolysis end-products was studied in which seven different plastic mixtures were pyrolysed using autoclave at 430̊C with heating rate of 20̊C/min [7]. Plastic mixtures were a combination of three main types of plastic; PE, PP and PS with different fraction resulting in 68PE, 68PP, 68PS, 100PE, 100PP, 100PS and 33 of individual type (numbers indicate the percentage fraction each type in the plastic mixture). Oil analysis showed that plastic sample with 100PS led to highest liquid yield (>90%) while the remaining samples show almost similar yield. PS corre...
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...in the pyrolysis of polyethylene in a conical spouted bed reactor. Applied Catalysis B: Environmental. 102, 224-231
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Fire and thermal properties of PA 66 resin treated with poly-N- aniline- phenyl phosphamide as a flame retardant
Z Qin et al modified ammonium polyphosphate (APP) and compared the effect of modification on flame retardant properties of polypropylene along with dipentaerythritol (DPER). The incorporation of modified ammonium polyphosphate (IMAPP) with dipentaerythritol (DPER) at 25 % loading produced LOI 32% with V-0 rating while unmodified APP had LOI 26% and V-1 rating. IMAPP also significantly decreased the PHRR and THR and contributed to the formation of compact intumescent
The most common form of polyethylene is petroleum based or olefins based; as before mentioned polyethylene compounds have a wide commercial applicability and are made from non-renewable resources (Harding, Dennis, von Blottnitz, Harrison, & S.T.L., 2007). Its manufacturing processes are regarded as energy intensive and release significant amount of CO2 and heat into the atmosphere (Broderick, 2008). Next a little more detailed description of polyethylene’s production processes will be presented, with a focus on the way the material inputs are extracted and synthesized.
XTL (Anything to Liquid) is recently emerging phrase that represented all of technologies intended to convert any source of carbon to liquid hydrocarbons. These processes have at least three main steps: syngas production, Fischer Tropsch Synthesis (FTS) and product finalizing. Syngas production might be different from feed and technology point of view and these differences affect all downstream units partially. In this step, source of carbon converted to syngas which is a mixture of hydrogen and carbon monoxide. Origin of the letter X in the XTL phrase depends on this carbon source since B stands for Biomass, C for Coal (bituminous or non-bituminous), G for (natural) Gas and W for Waste (petrochemical wastes, worn automobile tires and …) [1-4]. Amongst these routes steam reforming in fixed bed reformers and partial oxidation in auto thermal reactors are more attractive in industrial applications (both related to Gas to Liquid (GTL) process) [5]. Although these processes seem completely different form syngas production point of view but they are almost similar in the next step, the heart of any XTL factory, namely FTS. In FTS unit syngas converted to chains of different hydrocarbons such as paraffin, olefin, oxygenated and …, by use of sutiable catalysts of iron or cobalt based. This section is the most important section of any XTL factory and in fact XTL is translation of the classical Fischer Tropsch Synthesis the language of industrial and commercial world. Finally the hydrocarbon products might undergo some finalizing steps to reach the specifications of the market. This is the final step of a XTL process and might be comprised of different units with a variation of complexness depending on the final product quality and perhaps...
9. Vispute, T. P., Zhang, H., Sanna, A., Xiao, R. & Huber, G. W. Renewable chemical commodity feedstocks from integrated catalytic processing of pyrolysis oils. Science 330, 1222–7
Recycling is the process by which a waste material is converted again into reusable process and disposal is a process by which we get rid of something. Polymers are not very reactive so this property makes them very useable for storing food but this property makes it difficult to recycle or dispose of polymer. This difficulty in recycling and disposing of polymer is a major cause of environment hazard. Since the waste of polymer is increasing day by day so proper measurement should be taken to reduce the use of polymer and different method should be made to properly dispose and recycle waste. Following are the process by which a polymer is recycled or disposed.
The Olefins II Unit makes hydrocarbons from naphtha or natural gas using furnaces. After distillation, the p...
In SEM an electron beam is focused into a small probe and is rastered across the surface of a specimen. Several emissions occur as a result of the interaction between the sample and electrons produce various signals like secondary electrons, back-scattered electrons (BSE), characteristic X-rays, light (cathodo-luminescence), specimen current and transmitted electrons. These yield information about the sample composition, and topography.
A. B. Mathur, I. S. Bhardwaj, A. B. Mathur. 2003. ‘Testing and Evaluation of Plastics’. New Delhi: Allied Publishers.
In addition, the plastics have shown to generate more damage to the environment in the long-term than any other sources of energy. So, it becomes our responsibility to preserve the environment creating mass awareness. The practice of bio-plastics are an environment friendly method, which doesn’t use the landfills while recycling and deposition, but it is also not that convenient method because the cost of manufacturing bio-plastics are much higher than ordinary method. This directly indicates that the cost of minimizing the waste, the cost of human health and environmental pollution is much higher than the production of
With up to 150 million tons of plastic being consumed each year since the 1950s, it is clear that this polymer plays a critical role in everyday life (Icpeenvis.nic.in, 2011). A polymer is a substance made from identical monomers (molecules) joined together to form one large molecule (Smith et al., 2006). Plastic is often made from petrochemicals, with thermoplastics and thermosetting polymers being the two forms (Helmenstine, 2016). These are found ubiquitously, from packaging to health care. However, with the production and disposal of plastic at an all-time high, this can have devastating environmental effects. For this reason, a versatile plastic which is biodegradable, and produced from sustainable
German Chemist Hans von Pechmann first synthesized Polyethylene by accident in 1898 by heating diazomethane. His colleagues characterized the waxy substance polyethylene due to the fact that they recognized that it consisted of long ethene chains. It was then first industrially synthesized by accident in 1933 by applying extremely high pressure to ethylene and benzaldehyde. Over the years, development of polyethylene has increased due to the additions of catalyst. This makes ethylene polymerization possible at lower temperatures and pressures.1
Production of polypropylene takes place by slurry, solution or gas phase process, in which the propylene monomer is subjected to heat and pressure in the presence of a catalyst system. Polymerization is achieved at relatively low temperature and pressure and the product yielded is translucent, but readily colored. Differences in catalyst and production conditions can be used to alter the properties of the plastic. Propylene is obtained, along with ethylene, by cracking naphtha (crude oil light distillate). Ethylene, propylene, and higher alkenes are separated by low temperature fractional distillation.[3]
X-ray diffraction is an analytical technique looking at X-ray scattering from crystalline materials. Each material produces a unique X-ray "fingerprint" of X-ray intensity versus scattering angle that is characteristic of its crystalline atomic structure. Qualitative analysis is possible by comparing the XRD pattern of an unknown material to a library of known patterns. The three-dimensional structure of non-amorphous materials is defined by regular, repeating planes of atoms that form a crystal lattice.
Plastic industry has become of vital importance for the comfort and quality of our lives, due to numerous qualities as strength, lightness, low cost and durability. Their downside is the negative impact over the environment, due to the accumulating of millions of tons per year. Therefore, the development of biodegradable plastics seems a key issue for further development.