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•Catalytic hydrotreating of waste plastic pyrolysis oil removed 95% of N and Cl.•NiMo/Alumina catalyst removed most of the olefins in feedstock (98%).•The optimal composition of ...catalyst was 5 wt% Ni and a 10 wt% Mo.•The sulfide species on the catalyst surface increased with rising Mo loadings.
The hydrotreating (HDT) reaction of waste plastic pyrolysis oil (WPPO) was investigated using the sulfide NiMo/Alumina catalysts with a fixed Ni loading of 5 wt% and varying Mo loadings (0, 5, 7, and 10 wt%). The catalysts exhibited an increasing presence of NiMoO4 as the Mo loading increased. The HDT results indicated that the NiMo/Alumina with the highest Mo loading demonstrated optimized reactivity for the HDT reaction. The analysis of WPPO and post-HDT products involved various techniques, including total nitrogen sulfur analyzer, X-ray fluorescence, simulated distillation, gas chromatography mass spectrometry, and nuclear magnetic spectroscopy (NMR). After HDT with the sulfide NiMo/Alumina catalyst, a significant reduction in nitrogen and chlorine content was observed in the WPPO. Furthermore, there was a notable decrease in the olefins portion of naphtha, accompanied by an increase in the paraffins portion. Characterization of the spent catalysts from the HDT reaction using X-ray diffraction and X-ray photoelectron spectroscopy analysis indicated the prevalence of sulfide species, including MoS2, NiMoS, and NixSy, on the catalyst surface. The prominence of these sulfide species correlated with an increase in Mo loading.
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During the last decade, massive production of plastic materials causes a significant amount of waste. This growing trend in waste plastic, and the related negative effect on ...environment raised many concerns leading to propose different solutions for its disposal, recycle and re-use. Among different methods, landfilling, incineration and mechanical recycling are more conventional, however due to their environmental problems or economic issues, they would not be the best solutions for waste plastic management. The paper presents a review of a more effective process to recover the energy contained in these materials, with a focus of their use for producing fuel thorough the pyrolysis process. This conversion process does not only represent an environmentally friendly solution for the management of waste plastics, but also allows producing a liquid product which can be used for several energy-related applications. The focus of this review paper is to identify an optimum approach for production of maximum waste plastic pyrolysis oil with the characteristic similar to diesel fuel through investigation on various previous studies in this area. To reach this target, a review of the recent studies related to pyrolysis of waste plastics was carried out, and the main parameters affecting the liquid product yield were investigated. Then, the quality of several waste plastic oil (WPO) was compared to the conventional diesel fuels, based on the information reported about their physico-chemical properties, and their application in the diesel engine based on the parameters such as combustion, performance, and emission have been studied.
The oil obtained by pyrolysis of waste plastics can be used as an alternate fuel for diesel engine without making any modification to the engine. The WPPO (waste plastic pyrolysis oil) mixed with 5% ...and 10% DEE (diethyl ether) were used as fuels for single cylinder water cooled, DI engine and its performance, emission and combustion characteristics were found. The experimental results indicated the reduction in smoke levels with that of baseline waste plastic pyrolysis oil. The BTE (brake thermal efficiency) increased when compared to pure plastic pyrolysis oil and diesel. The pollutants such as CO (carbon monoxide) and NOx (nitrous oxide) were reduced in the blend. It was observed that addition of oxygenates had improved the combustion process and reduced the emissions. The investigation revealed that blending of DEE with plastic oil increases the Cetane rating which is superior to neat diesel.
•Diethyl ether blended in different proportions with waste plastic oil used as fuel in diesel engine.•The addition of diethyl ether with waste plastic oil improves brake thermal efficiency.•Addition of diethyl ether increases the unburned hydrocarbon emission.•The NOx decreases with increase in percentage of diethyl ether.•Addition of diethyl ether shortens the ignition delay.
Conversion of waste plastics into energy products is an effective waste management technique as they constitute a considerable portion of solid waste at present. In this study, distilled diesel ...fraction of Plastic Pyrolysis Oil (PPO) named Distilled Plastic Diesel (DPD) was hydrotreated named hydrotreated plastic diesel (HPD) and blended with commercial diesel fuel by 15:85 ratio (wt%), defined as HPD15, to experimentally investigate the performance and emission characteristics of a compression ignition (CI) engine. The experiment was done in 4-cylinder, 4-stroke diesel engine with an eddy current dynamometer testbed at full load (100 % engine load) and an engine speed of 1200–2400 rpm with 300 rpm intervals. The results are compared with neat diesel fuel data at the same operating conditions. This study found that HPD15 performed better or comparable with diesel fuel. Overall, the brake power (BP) and brake thermal efficiency (BTE) of HPD15 were higher than diesel fuel by a maximum of about 4.77 % and 3.77 %, respectively. Brake specific fuel consumption (BSFC) of HPD15 was lower at all operating speeds (by a maximum of about 4.66 %) and brake specific energy consumption (BSEC) was lower in most of the operating speeds (by a maximum of about 3.77 %). This study also revealed that CO2 at some operating speeds and NOx emission at all operating speeds for HPD15 are lower than diesel fuel. However, CO and unburnt hydrocarbon (UHC) emission are slightly higher for HPD15 than diesel at all speeds. Overall, HPD15 can be recommended as a suitable alternative for diesel fuel without any engine modification.
The ultimate aim of this paper is to extract from plastic waste by pyrolysis using a novel catalyst of rice husk ash. The extracted WPO were tested and found to have properties identical to gasoline. ...The WPO is blended with commercial petrol in various ratios such as 10%, 20%, 30% and mentioned as WPO10, WPO20 and WPO30. The blends were tested in gasoline engines and the combustion efficiency and emission characteristics of these fuels are investigated and compared with regular commercial petrol. It is observed that the brake thermal efficiency is considerably low for all the WPO blends when compared to gasoline. The difference in Brake thermal efficiency of petrol and WPO10 is 0.77% which is almost closer to petrol and also emits CO of 0.09% by volume, NO
x
of 625ppm and HC of 21 ppm at maximum load. It is concluded that WPO10 is suggested for the best overall results.
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•Plastic pyrolysis oil is the alternative potential fuel for the CI engine.•Al2O3 nanoparticle is the vital additive for waste plastic derived fuel.•Multi-objective RSM is a real and ...efficient tool for optimization.•Engine performance of the CI engine was provocatively improved using the optimized process parameters.
This study provides the prediction that plastic pyrolysis oil (PPO) is equivalent to petroleum diesel in CI engines. The four input parameters have been considered to enhance performance and reduced emissions. The input parameters of engine trials, like fuel blend (PPO and diesel), compression ratio, nanoparticle concentration, and injection timing, were studied with the response surface methodology (RSM) using the central composite rotating design (CCRD) matrix. The main goal is to identify the ideal values of input parameters that will provide the highest achievable brake thermal efficiency (BTE), the lowest possible brake-specific fuel consumption (BSFC), and the lowest possible emission like carbon monoxide (CO), unburnt hydrocarbons (HC) and nitrogen oxides (NOx). The optimal engine output responses for BTE, BSFC, in-cylinder pressure, heat release rate (HRR), and ignition delay, respectively. Along witha composite desirability of 0.89 under optimum operating conditions. After the regression analysis, 16.56% PPO blend ratio, 53.53 ppm Al2O3 nanoparticle concentration, 18.06 compression ratio, and 20.95 °bTDC injection timing were received the optimized engine settings. Optimal engine input parameters were validated through actual engine trials and compared with optimized responses and found satisfactory and acceptable errors (less than 5%). The current study establishes vital input parameters providing the best engine performance, combustion characteristics, and lower emissions during engine trials. So current investigation declared PPO with Al2O3 nanoparticles is potential fuel for the CI engine.
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•Catalytic cracking of chlorinated heavy wax from pyrolysis of plastic wastes.•Fe loaded HY catalyst has a dual function of catalytic cracking and dechlorination.•Fe3/HY yielded a ...light liquid fraction of 66.9 wt.% with low Cl content <200 ppm.•Spent catalyst deposited coke and chlorine was restored by calcination in air.
Catalytic conversion of useless chlorinated heavy wax (chlorine, 0.14 wt%) obtained from pyrolysis of refuse plastic fuel was studied using iron oxide impregnated HY zeolite to produce a useful liquid product. It was found that the largest liquid fraction (gasoline and kerosene/ diesel, 66.9 wt.%) with very low chlorine content was achieved when using Fe3/HY among impregnated HY catalysts. This demonstrated that the Fe impregnated HY catalyst had a dual function of catalytic cracking of HY zeolite and dechlorination of iron oxide. Excessive impregnation of Fe, i.e., Fe20/HY, showed the least cracking activity of heavy wax owing to the catalyst having lowest total acid sites, but yielded liquid product with the lowest chlorine content (60 ppm) among the tested catalysts. The spent catalysts were deposited by a significant amount of soft coke and chlorine, and they were totally restored by thermal treatment in air (700 ℃).
Abstract
Recycling is the retrieval, reclamation, reprocessing or refining process of waste to produce new products. Recycling has always been a top priority in waste management since it enables us ...not only to maintain the health of the environment, but also to reuse garbage profitably. Many techniques are utilised to transform plastic waste into articles that are not present in virgin plastic with distinctive features. Polymers undergo molecular and structural changes in this process leading to simpler basic materials with superior thermal properties than original plastics. While gasification and pyrolysis processes break plastics down, fluid and semi-liquid products are also generated.
Plastic waste is an ideal source of energy due to its high heating value and abundance. It can be converted into oil through the pyrolysis process and utilised in internal combustion engines to ...produce power and heat. In the present work, plastic pyrolysis oil is manufactured via a fast pyrolysis process using a feedstock consisting of different types of plastic. The oil was analysed and it was found that its properties are similar to diesel fuel. The plastic pyrolysis oil was tested on a four-cylinder direct injection diesel engine running at various blends of plastic pyrolysis oil and diesel fuel from 0% to 100% at different engine loads from 25% to 100%. The engine combustion characteristics, performance and exhaust emissions were analysed and compared with diesel fuel operation. The results showed that the engine is able to run on plastic pyrolysis oil at high loads presenting similar performance to diesel while at lower loads the longer ignition delay period causes stability issues. The brake thermal efficiency for plastic pyrolysis oil at full load was slightly lower than diesel, but NOX emissions were considerably higher. The results suggested that the plastic pyrolysis oil is a promising alternative fuel for certain engine application at certain operation conditions.
•High quality oil is produced via fast pyrolysis process using plastics as feedstock.•Oil tested on a DI diesel engine.•Engine was able to operate steadily on high loads with different diesel-oil blend ratios.•Exhaust emissions increased with the addition of oil.
Chemical recycling is an attractive way to address the explosive growth of plastic waste and disposal problems. Pyrolysis is a chemical recycling process that can convert plastics into high quality ...oil, which can then be utilised in internal combustion engines for power and heat generation. The aim of the present work is to evaluate the potential of using oils that have been derived from the pyrolysis of plastics at different temperatures in diesel engines. The produced oils were analysed and found to have similar properties to diesel fuel. The plastic pyrolysis oils were then tested in a four-cylinder direct injection diesel engine, and their combustion, performance and emission characteristics analysed and compared to mineral diesel. The engine was found to perform better on the pyrolysis oils at higher loads. The pyrolysis temperature had a significant effect, as the oil produced at a lower temperature presented higher brake thermal efficiency and shorter ignition delay period at all loads. This oil also produced lower NOX, UHC, CO and CO2 emissions than the oil produced at a higher temperature, although diesel emissions were lower.
•Plastics were pyrolysed at different temperatures.•Oils tested in a four-cylinder DI diesel engine.•Oil that produced at lower pyrolysis temperature performed better.•Plastic oils produced higher exhaust emissions than diesel.
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