Papers by Keyword: Product Distribution

Abstract: In this study, an activated natural dolomite catalyst is used as catalyst for the palm empty fruit bunches (PEFB) pyrolysis to produce bio-oil. The research was conducted in fixed bed reactors operating in batches by varying several parameters, which are temperature (400-600°C) and nitrogen gas flow rate (100-300 mL.min^-1). The results show that the catalytic pyrolysis process using an activated natural dolomite catalyst obtains a maximum liquid yield of 35.87% when using a 500°C catalytic pyrolysis temperature and the rate of nitrogen gas is 100 cm³/minute, while the yield of gas and solids is 53.12% and 11.76%, respectively. The use of the dolomite activation catalyst influences the product distribution of pyrolysis and the bio-oil chemical compounds.

Abstract: The agro-industrial sector of many countries generates considerable quantity of waste biomass and potential exploitation of this reside is necessary for economic and environmental reasons. Pakistan is an agricultural based country with widespread amount of crop residue generated annually. This study utilized rice husk, sawdust and bagasse residues to investigate the effects of microwave absorber loading on process temperature, pyrolysis products, and bio-oil composition using multimode microwave pyrolysis system operated at 300W and 2.54GHz. The results indicated that pyrolysis process temperature depends on the type of waste residue and microwave absorber loading. The maximum bio-oil yield of 22.41wt%, 33.61wt% and 19.1wt% were produced at 75wt% microwave absorber loading from rice husk, sawdust and bagasse, respectively. The D-Allose of 21.95 %area, dodecanoic acid of 71.22 %area and octasiloxane of 74.50 %area under GC-MS in rice husk, sawdust and bagasse bio-oils, respectively suggests potential use as chemical feedstock. Keywords: Waste biomass; microwave absorber; microwave assisted pyrolysis; process temperature; product distribution; bio-oil composition

Abstract: The usability of artificial neural networks (ANN) for the estimation of the product distributions was investigated. The study was performed by following a model catalysis reaction, benzene alkylation with propylene on zeolite MCM-22. The effects of temperature, the ratio of benzene/propylene (B/P) and weight hourly space velocity (WHSV) on the product distributions were studied. Data obtained from different courses were used for training of the ANN and one set of data obtained from another courses was used for testing of the trained network. This network was designed as a Back-Propagation (BP) network with four neurons in the input layer, N neurons in the hidden layer and one neuron in the output layer. The network was trained till the mean square value between the targets and the outputs obtained was 1×10^-4. The product distributions for the isopropylbenzene, di-isopropylbenzene and tri-isopropylbenzene were estimated using the trained network. The regression coefficient of determination showed a good correlation between estimated and experimental data sets for both train and test data sets. There are high correlations between experimental and estimated time course curves and that was another proof of the high performance of ANN for estimation of the product distributions of alkylation reaction.

Abstract: The FT reaction involves the conversion of syngas which is derived from natural gas or coal to different kinds of products according to the operating conditions and the type of the catalyst. In other words, it is a practical way to convert solid fuel (coal) and natural gas to various hydrocarbons (C1-C60) and oxygenates such as alkanes, alkenes etc. The main products of the reaction are naphtha and gasoline. This paper deals with developing a proper product distribution model for FT process using the appropriate kinetic model, optimizing the respective rate constants while applying them in product distribution equations. The results revealed only 8.09% deviations from the olefin experimental data and 10.27% deviations from the paraffin experimental data being acceptable when compared with previous open literature data.

Abstract: The cyanobacteria, salvaged from TaiHu Lake every year, contain high water content and organic matters. Nowadays the problem how to deal with such cyanobacteria has attracted wide attention. In this study, the SCWG is applied to the safety disposal and resource utilization of cyanobaceria to reveal the distributions and forms of carbon, nitrogen and phosphorus in the supercritical products under different reaction conditions. The study results show that SCWG is a good way for the disposal and utilization of cyanobaceria. After SCWG, the C of cyanobaceria exists mainly in the solid residue in the form of coke and heavy oils.High temperature and prolonging reaction time lead to C transfers from s/l phase to gas phase. While N of cyanobaceria is found in liquid phase in the form of NH₃-N, and more than 90% of P can be found in the solid residue.

Abstract: The combustion behavior of fixed carbon in supercritical water was explored by a batch reactor. Effects of reaction parameters such as reaction temperature, time, oxygen stoichiometric ratio and stirring rate were investigated. Fixed carbon was difficult to burn out, even if in a harsh condition the conversion of fixed carbon was only 51%. It is determined that for the temperature below 450°C, the process of oxidation was limited by the reaction rate between oxygen and particle surface. For the temperature above 550°C, the rate of oxygen mass transfer to the particle surface was the rate-limiting step. In the transition zone of temperature, surface reaction was comparable to mass transfer in limiting reaction rate. Only trace amount of carbon monoxide was produced at 500°C, and no carbon monoxide was detected at 600°C.

Abstract: Pyrolysis and hydropyrolysis of Chinese Datong coal was carried out at temperature from 350 to 650°C,under pressure of 2Mpa in a fix-bed reactor. The product distribution was determined, and gas evolution of coal pyrolysis and hydropyrolysis was also studied. The experimental results shows that coal conversion and water yield increase with temperature increasing during both pyrolysis and hydropyrolysis; tar yield increase during hydropyrolysis with temperature from 350 to 650°C, but the highest tar yield during pyrolysis is at temperature of 550°C. At high temperature area, CO、CH₄ and C₂₊ has higher yield in hydropyroly than that in pyrolysis. The products distribution of pyrolysis and hydropyrolysis showed that the effect of H₂ on coal thermal conversion only occurs at high temperature area.