Effect Of Co-pyrolysis Research Articles

Product distribution and interactive mechanism during co-pyrolysis of a subbituminous coal and its direct liquefaction residue

Compared with individual pyrolysis of Shendong coal or the direct coal liquefaction residue, co-pyrolysis has an improved tar yield. However, the synergistic mechanism in the integrated process is still controversial. In order to explore the interactive effect in co-pyrolysis of coal and the direct coal liquefaction residue, elemental analysis, gas chromatography, Fourier – transform infrared spectrometer, thermogravimetric simulation distillation, nuclear magnetic resonance and gas chromatograph – mass spectrometer were employed to analyze the structure and chemical composition of products (gas, semi-coke, and tar) obtained in co-pyrolysis at 600°C. The results show that the actual product yields are different from the calculated values and elemental redistribution occurs in co-pyrolysis. Instruments characterization suggests an increased loss of aromatic hydrogen and carbon in co-pyrolysis, in comparison with individual pyrolysis. The increasing tar is mainly composed of heavy components with boiling points higher than 400°C. Co-pyrolysis favors the minimization of the dealkylation of phenolic species. Furthermore, the synergistic mechanism analysis using two-stage reactor indicates that the increase in tar yield should be attributed to the change in the free radical reaction during the pyrolysis of Shendong coal and the direct coal liquefaction residue. In co-pyrolysis, more radicals generated from coal pyrolysis are used to stabilize the radicals generated from the pyrolysis of tetrahydrofuran soluble fraction of the direct coal liquefaction residue.

Determination of synergetic effect in co-pyrolysis of lignite and waste tyre

An attempt was made to investigate potential synergistic activities between waste tyre and lignite during co-pyrolysis. The parameters such as blending ratios of waste tyre and lignite, final pyrolysis temperature, heating rates and reactor types were optimized in the experiments. The characteristics of pyrolysis products were determined by using FTIR, 1H-NMR, GC–MS and elemental analysis. The results indicated that the yields of pyrolysis products are proportional to the percentage of waste tyre/lignite in the mixture. The experimental results were compared with calculated results which were obtained from pure waste tyre and pure lignite samples. Significant amounts of synergetic effects were observed in favour of the pyrolysis oil at blending ratio of 10% lignite, pyrolysis temperature of 500°C and heating rate of 300°Cmin−1 in the well-swept fixed bed reactor (WSFB). It was observed that pyrolysis oil quality was also improved as well as quantity. The comparison of the experimental and calculated results showed that the amount of aromatic compounds increased while that of polar compounds decreased at the optimum conditions. The results in this study also indicated that co-pyrolysis of lignite with waste tyres could be an environmentally friendly method for the conversion of hazardous waste into valuable chemical feedstock such as chemicals and fuels.

Mixed-waste pyrolysis of biomass and plastics waste – A modelling approach to reduce energy usage

Thermal co-processing of waste mixtures had gained a lot of attention in the last decade. This is largely due to certain synergistic effects such as higher quantity and better quality of oil, limited supply of certain feedstock and improving the overall pyrolysis process. Many experiments have been conducted via TGA analysis and different reactors to achieve the stated synergistic effects in co-pyrolysis of biomass and plastic wastes. The thermal behaviour of plastics during pyrolysis is different from that of biomass because its decomposition happens at a high temperature range with sudden release of volatile compared to biomass which have a wide range of thermal decomposition. A properly designed recipe and operational strategy of mixing feedstock can ease the operational difficulties and at the same time decrease energy consumption and/or improve the product yield. Therefore it is worthwhile to study the possible synergistic effects on the overall energy used during co-pyrolysis process. In this work, two different modelling approaches were used to study the energy related synergistic effect between polystyrene (PS) and bamboo waste. The mass loss and volatile generation profiles show that significant interactions between the two feedstocks exist. The results also show that both modelling approaches give an appreciable synergy effect of reduction in overall energy when PS and bamboo are co-pyrolysed together. However, the second approach which allows interaction between the two feedstocks gives a more reduction in overall energy usage up to 6.2% depending on the ratio of PS in the mixed blend.

Co-pyrolysis of Biomass and Plastics waste: A Modelling Approach

Thermal co-processing of waste mixtures had gained a lot of attention in the last decade largely due to certain synergistic effects such as higher quantity and better quality of oil, limited supply of certain feedstock and improving the overall pyrolysis process. Many experiments have been done using the TGA analysis and different reactors to achieve the stated synergistic effects in co-pyrolysis of biomass and plastic wastes. The thermal behaviour of plastics during pyrolysis is different from that of biomass because its decomposition happens at a high temperature range (>450 °C) with sudden release of volatilecompared to biomass which have a wide range of thermal decomposition. Therefore it is worthwhile to study the possible synergistic effects on the overall energy used during co-pyrolysis process. In this work, two different modelling approaches were used to study the energy related synergistic effect between polystyrene (PS) and bamboo waste. The results show that both modelling approaches give an appreciable synergy effect of reduction in overall energy when PS and bamboo are co-pyrolyzed together. However, the second approach which allows interaction between the two feedstocks gives a more reduction in overall energy usage up to 6.2 % depending on the ratio of PS in the mixed blend.

Classification of volatile products evolved at fast co-pyrolysis of Goynuk oil shale with low density polyethylene

Fast co-pyrolysis of Goynuk oil shale (GOS) with low density polyethylene (LDPE) was investigated. The aim of the research was to determine the distribution of volatile products and conversion of blends at different temperatures and time intervals. Pyrolysis of oil shale, LDPE and co-pyrolysis of oil shale-LDPE blend of the total carbon ratio of 1:1 were performed by using the fast pyrolysis method in an isothermal pyrolysis reactor. Volatile organic products eluted from the reactor were collected at different temperatures and time intervals by using a special sampling technique. Fast pyrolysis products were analyzed by capillary gas chromatography. In the aliphatic fraction of pyrolysis products, n-paraffins and 1-olefins were classified by their carbon number. The effect of co-pyrolysis on conversion of total organic carbon into volatile products was identified by determination of the experimental and the hypothetical mean values. Possible synergetic effect was investigated by comparing the results on fast pyrolysis of GOS and LDPE. The effect of co-processing of GOS with LDPE was determined by calculating the difference between experimental and hypothetical mean value of conversion of total organic carbon into volatile products. The experimental conversion of the blend to volatile hydrocarbons was found to be lower than hypothetical mean value of conversion at co-pyrolysis, and thus, no synergetic effect was observed.

CLASSIFICATION OF VOLATILE PRODUCTS EVOLVED AT FAST CO-PYROLYSIS OF GÖYNÜK OIL SHALE WITH LOW DENSITY POLYETHYLENE

Fast co-pyrolysis of Goynuk oil shale (GOS) with low density polyethylene (LDPE) was investigated. The aim of the research was to determine the distribution of volatile products and conversion of blends at different temperatures and time intervals. Pyrolysis of oil shale, LDPE and co-pyrolysis of oil shale-LDPE blend of the total carbon ratio of 1:1 were performed by using the fast pyrolysis method in an isothermal pyrolysis reactor. Volatile organic products eluted from the reactor were collected at different temperatures and time intervals by using a special sampling technique. Fast pyrolysis products were analyzed by capillary gas chromatography. In the aliphatic fraction of pyrolysis products, n-paraffins and 1-olefins were classified by their carbon number. The effect of co-pyrolysis on conversion of total organic carbon into volatile products was identified by determination of the experimental and the hypothetical mean values. Possible synergetic effect was investigated by comparing the results on fast pyrolysis of GOS and LDPE. The effect of co-processing of GOS with LDPE was determined by calculating the difference between experimental and hypothetical mean value of conversion of total organic carbon into volatile products. The experimental conversion of the blend to volatile hydrocarbons was found to be lower than hypothetical mean value of conversion at co-pyrolysis, and thus, no synergetic effect was observed.