scholarly journals Biomass:polystyrene co-pyrolysis coupled with metal-modified zeolite catalysis for liquid fuel and chemical production

Author(s):  
Andrew C. Dyer ◽  
Mohamad A. Nahil ◽  
Paul T. Williams

AbstractBiomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a two-stage fixed bed reactor system to produce upgraded bio-oils for production of liquid fuel and aromatic chemicals. The catalysts investigated were ZSM-5 impregnated with different metals, Ga, Co, Cu, Fe and Ni to determine their influence on bio-oil upgrading. The results showed that the different added metals had a different impact on the yield and composition of the product oils and gases. Deoxygenation of the bio-oils was mainly via formation of CO2 and CO via decarboxylation and decarbonylation with the Ni–ZSM-5 and Co–ZSM-5 catalysts whereas higher water yield and lower CO2 and CO was obtained with the ZSM-5, Ga–ZSM-5, Cu–ZSM-5 and Fe–ZSM-5 catalysts suggesting hydrodeoxygenation was dominant. Compared to the unmodified ZSM-5, the yield of single-ring aromatic compounds in the product oil was increased for the Co–ZSM-5, Cu–ZSM-5, Fe–ZSM-5 and Ni–ZSM-5 catalysts. However, for the Ga–ZSM-5 catalyst, single-ring aromatic compounds were reduced, but the highest yield of polycyclic aromatic hydrocarbons was produced. A higher biomass to polystyrene ratio (4:1) resulted in a markedly lower oil yield with a consequent increased yield of gas.

Author(s):  
Rusmi Alias ◽  
Atiqah Mohd Rafee

The aim of this study is to characterise the liquid oil produced from pyrolysis of waste tyre. In this study, a series of experiment were carried out at various process temperature from 300 °C to 500 °C. The degradation study was carried out by using TGA, meanwhile the pyrolysis process was done using a fixed bed reactor. Liquid oil obtained from the pyrolysis was analysed using FTIR and GC-MS. The oil yield was found to decrease with increasing final pyrolysis temperature and the yield of the gas increased. The highest oil yield was 58.3 wt. %. For pyrolysis at 400 °C. The pyrolysis of waste tyre at atmospheric pressure commenced at about 340 °C and completed at 460 °C. An increase in the aromatic content of the oil was observed with increasing temperature. However, the aliphatic content decreased as the temperature increased from 300 °C to 500 °C. It was observed that the amount of aliphatic fraction in the oil decreased from 7.8 wt. % to 5.4 wt. %. In the meantime, the number of aromatic compounds increased from 37.4 wt. % to 51.2 wt. %. The main aromatic compounds were limonene, xylene, styrene, toluene, trimethylbenzene, ethylbenzene and benzene.


2017 ◽  
Vol 4 (12) ◽  
pp. 171367
Author(s):  
Yi-heng Lu ◽  
Kang Li ◽  
Yu-wei Lu

Methane was directly converted to butene liquid fuel by microwave-induced non-oxidative catalytic dehydrogenation under 0.1–0.2 MPa. The results show that, under microwave heating in a two-stage fixed-bed reactor, in which nickel powder and NiO x –MoO y /SiO 2 are used as the catalyst, the methane–hydrogen mixture is used as the raw material, with no acetylene detected. The methane conversion is more than 73.2%, and the selectivity of methane to butene is 99.0%. Increasing the hydrogen/methane feed volume ratio increases methane conversion and selectivity. Gas chromatography/electron impact ionization/mass spectrometry chromatographic analysis showed that the liquid fuel produced by methane dehydrogenation oligomerization contained 89.44% of butene, and the rest was acetic acid, ethanol, butenol and butyric acid, and the content was 1.0–3.0 wt%.


2017 ◽  
Vol 33 (2) ◽  
Author(s):  
José R.G. Sánchez-López ◽  
Angel Martínez-Hernández ◽  
Aracely Hernández-Ramírez

AbstractCurrently, few processes can be considered practical alternatives to the use of petroleum for liquid fuel production. Among these alternatives, the Fischer-Tropsch synthesis (FTS) reaction has been successfully applied commercially. Nevertheless, many of the fundamentals of this process are difficult to understand because of its complexity, which depends strongly on the catalyst and the reactor design and operating conditions, as the reaction is seriously affected by mass and heat transport issues. Thus, studying this reaction system with transport phenomena models can help to elucidate the impact of different parameters on the reaction. According to the literature, modeling FTS systems with 1D models provides valuable information for understanding the phenomena that occur during this process. However, 2D models must be used to simulate the reactor to correctly predict the reactor variables, particularly the temperature, which is a critical parameter to achieve a suitable distribution of products during the reaction. Thus, this work provides a general resume of the current findings on the modeling of transport phenomena on a particle/pellet level in a tubular fixed-bed reactor.


2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Pious O Okekunle ◽  
Oluwatobi S Awani ◽  
Daniel O Jimoh

The effect of potassium carbonate catalyst on the products distribution from pyrolysis of Milicia excelsa (Iroko) at various temperatures (400, 500 and 600 oC) was investigated. Milicia excelsa sawdust was obtained from a sawmill in Ogbomoso, South-Western Nigeria and was sundried for five days in order to reduce its moisture content. Catalytic pyrolysis of the sawdust was performed with different amounts of catalyst (10, 20, 30 and 40 wt.%). Non-catalytic pyrolysis was also performed for the same temperatures and the products distributions from both batches were compared. Char yield generally increased with increase in catalyst amount for all the temperatures considered. Tar yield did not follow any definite pattern with increasing amount of catalyst as different trends were obtained for different temperatures. Gas yield generally decreased with increase in catalyst amount in the feed. Char yields from non-catalytic experiments were higher than those obtained from catalytic runs, with the highest value of 68% at 400 oC. Tar yields from catalytic pyrolysis were higher than those from non-catalytic process at 400 oC (biomass/catalyst ratio of 90/10) and at 500 oC (biomass/catalyst ratios of 70/70 and 60/40), the highest yield being 29.47% at 500 oC and biomass/catalyst ratio of 60/40. Gas yields from catalytic pyrolysis were higher than those from non-catalytic runs except at 500 oC (biomass/catalyst ratio of 60/40), the highest being 51.3% at 600 oC (biomass/catalyst ratio of 90/10). By making use of appropriate biomass/catalyst ratio and temperature, the yield of liquid fuel from catalytic pyrolysis of Milicia excelsa can be increased.Keywords— Catalyst, potassium carbonate, pyrolysis, biomass, product distribution


2013 ◽  
Vol 712-715 ◽  
pp. 119-123
Author(s):  
Long Guo ◽  
De Min He ◽  
Jun Guan ◽  
Qiu Min Zhang

Pyrolysis of vulcanized rubber (VR) with high total sulfur was carried out in the fixed-bed reactor. The effect of heating temperature and on the formation and distrubtion of tar, gas and char and sulfide in pyrolysis products were investigated.The maximal tar yield can reach 55.79% (wt,dry), water yield 1.30% (wt,dry). With increase in temperature, sulfur in char decreases and more sulfur migrates into gases and sulfur removal varies from 66.08% to 77.39 %, and the contents of H2S, CS2and COS increase. Comparing with COS and CS2, the content of H2S is overwhelming, since sulfur radicals from crack of VR is easier for hydrogenation reaction to produce H2S. GC-FPD (Flame Photometric Detector) was used to determine the sulfides in tar. The result indicates sulfides in tar are mainly present in form of sulfides with aromatic group. When temperature grows, sulfur transfers into pyrolysis gas instead of char and total content of detected sulfides in tar rises and then declines.


Author(s):  
M. Tian ◽  
B. S. Liu ◽  
M. Hammonds ◽  
N. Wang ◽  
P. J. Sarre ◽  
...  

Polycyclic aromatic hydrocarbons (PAHs) are known to be present in many astrophysical objects and environments, but our understanding of their formation mechanism(s) is far from satisfactory. In this paper, we describe an investigation of the catalytic conversion reaction of acetylene gas to PAHs over pyroxene and alumina. Crystalline silicates such as pyroxenes (with general formula [Mg, Fe]SiO 3 ) and alumina (Al 2 O 3 ) are observed astrophysically through their infrared spectra and are likely to promote grain surface chemical reactions. In the experiments reported here, gas-phase PAHs were produced by the catalytic reaction of acetylene over crystalline silicates and alumina using a pulsed jet expansion technique and the gaseous products detected using time-of-flight mass spectrometry. In a separate experiment, the catalytic formation of PAHs from acetylene was further confirmed with acetylene gas at atmospheric pressure flowing continuously through a fixed-bed reactor. The gas effluent and carbonaceous compounds deposited on the catalysts were dissolved separately in dichloromethane and analysed using gas chromatography–mass spectrometry. Among the samples studied, alumina showed higher activity than the pyroxene-type grains for the acetylene reaction. It is proposed that formation of the PAHs relies on the Mg 2+ ions in the pyroxenes and Al 3+ ions in alumina, where these ions act as Lewis acid sites. X-ray diffraction, Fourier transform infrared and high-resolution transmission electron microscopy techniques were used to characterize the structure and physical properties of the pyroxene and alumina samples.


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