LaFe1-xNix as a Robust Catalytic Oxygen Carrier for Chemical Looping Conversion of Toluene

Chemical looping biomass gasification is a novel technology converting biomass into syngas, and the selection of oxygen carrier is key for efficient tar conversion. The performance of LaFe1-xNix as a robust catalytic oxygen carrier was investigated in the chemical looping conversion of toluene (tar model compound) into syngas in a fixed bed. LaM (M = Fe, Ni, Mn, Co, and Cu) was initially compared to evaluate the effect of transition metal on toluene conversion. LaFe (partial oxidation) and LaNi (catalytic pyrolysis) exhibited better performance in promoting syngas production than other oxygen carriers. Therefore, Ni-substituted ferrite LaFe1-xNix (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) was further developed. The effects of Ni-substitution, steam/carbon ratio (S/C), and temperature on toluene conversion into C1 and H2 were evaluated. Results showed that the synergistic effect of Fe and Ni promoted toluene conversion, improving H2 yield yet with serious carbon deposition. Steam addition promoted toluene steam reforming and carbon gasification. With S/C increasing from 0.8 to 2.0, the C1 and H2 yield increased from 73.9% to 97.5% and from 197.7% to 269.6%, respectively. The elevated temperature favored toluene conversion and C1 yield. LaFe0.6Ni0.4 exhibited strong reactivity stability during toluene conversion at S/C = 1.6 and 900 °C.

Decomposition of Tars on a Nickel Honeycomb Catalyst

Biomass can be considered a renewable energy source. It undergoes a gasification process to obtain gaseous fuel, which converts it into combustible gaseous products such as hydrogen, carbon monoxide, and methane. The process also generates undesirable tars that can condense in gas lines and cause corrosion, and after processing, can be an additional source of combustible gases. This study focused on the processing of tar substances with toluene as a model substance. The effect of discharge power and carrier gas composition on toluene conversion was tested. The process was conducted in a plasma-catalytic system with a new Ni3Al system in the form of a honeycomb. The toluene conversion reached 90%, and small amounts of ethane, ethylene, acetylene, benzene, and C3 and C4 hydrocarbons were detected in the post-reaction mixture. Changes in the surface composition of the Ni3Al catalyst were observed throughout the experiments. These changes did not affect the toluene conversion.

Combination of adsorption – desorption with complete oxidation on the MnCoCe oxide based catalyst for toluene treatment

The Adsorption – desorption is considered as one of the most promising VOCs treatment technologies due to its cheap operational cost and low energy consumption. However, there are a huge amount of adsorbed VOCs released in desorption process. That is the reason why this study focused on the combination of adsorption-desorption with catalytic oxidation to treat completely VOCs as toluene. The adsorption catalyst MnCoCe/AC (metal oxide catalyst MnO2-Co3O4-CeO3 on Actived carbon) and oxidation catalyst Au/MnCoCe (Au supported on metal oxide catalyst MnO2-Co3O4-CeO3) were investigated and characterized by SEM - EDX, BET. The catalytic activity test were carried out on a micro-flow reactor system connected with GC online using a TCD detector.The results shown that Au/MnCoCe is a potential catalyst for the complete oxidation of toluene with the temperature for 100% toluene conversion of 300oC. The combination of adsorption-desorption with catalytic oxidation decreased the temperature for 100% toluene conversion to 250 oC.

Catalytic Steam Reforming of Toluene: Understanding the Influence of the Main Reaction Parameters over a Reference Catalyst

Identifying the suitable reaction conditions is key to achieve high performance and economic efficiency in any catalytic process. In this study, the catalytic performance of a Ni/Al2O3 catalyst, a benchmark system—was investigated in steam reforming of toluene as a biomass gasification tar model compound to explore the effect of reforming temperature, steam to carbon (S/C) ratio and residence time on toluene conversion and gas products. An S/C molar ratio range from one to three and temperature range from 700 to 900 °C was selected according to thermodynamic equilibrium calculations, and gas hourly space velocity (GHSV) was varied from 30,600 to 122,400 h−1 based on previous work. The results suggest that 800 °C, GHSV 61,200 h−1 and S/C ratio 3 provide favourable operating conditions for steam reforming of toluene in order to get high toluene conversion and hydrogen productivity, achieving a toluene to gas conversion of 94% and H2 production of 13 mol/mol toluene.

Unraveling Toluene Conversion during the Liquid Phase Hydrogenation of Cyclohexene (in Toluene) with Rh Hybrid Catalysts

Monitoring hydrogen consumption has allowed studying the progress of the liquid phase hydrogenation of cyclohexene in toluene with Rh SILP (supported ionic liquid phase) catalysts prepared by the immobilization of the [{RhCl(cod)}2] complex on different carbon materials. An excess of hydrogen consumption with respect to the required amount for cyclohexene hydrogenation was registered and related with the solvent (toluene) hydrogenation. The study carried out led to unraveling the extent of toluene hydrogenation and to determining if the rate of this reaction is affected by the properties of the carbon material used as support. The results revealed that the Rh SILP catalysts we prepared showed acceptable toluene conversion, with 100% selectivity to the total hydrogenated product, and that the effect of the carbon support is the same as for cyclohexene hydrogenation.

Pengembangan katalis Ni/Al2o3 untuk steam reforming tar hasil gasifikasi

The development of catalysts Ni/Al2O3 for steam reforming gasification tar This research studied the secondary tar removal in gasification technology through catalytic toluene steam reforming reactions. The objective of this study was to obtain a nickel catalyst that has good performance for steam reforming of tar (toluene) by selecting the -Al2O3 or -Al2O3 supports, and adding promoter to inhibit deactivation due to coke formation. The performance of the catalyst is determined from the activity test in a fixed bed reactor at a temperature of 700 oC, atmospheric pressure, Time on Stream (TOS) 10 hours and stability test indicated by XRD and TGA. The catalyst showed the best performance was the Ni/-Al2O3 catalyst with the average of toluene conversion of 96%. The addition of 2% and 5% by weight of CaO decreased the catalytic activity. Although it proved to inhibit the formation of coke, it did not reduce the rate of deactivation of catalyst. The XRD analysis showed that the Ni/-Al2O3 after 10 hours in operation did not undergo any phase changes, thus the catalyst was still stable. Keywords: tar cracking, steam reforming, nickel catalyst, toluene conversion, stability. AbstrakPenelitian ini merupakan suatu bagian dalam pengembangan teknologi penghilangan tar gasifikasi secara sekunder dengan cara perengkahan katalitik menggunakan reaksi steam reforming toluen. Tujuan penelitian ini adalah mendapatkan katalis berbasis nikel yang memiliki kinerja yang baik untuk steam reforming tar (toluen) dengan memilih penyangga -Al2O3 atau -Al2O3, dan menambah promotor CaO untuk menghambat deaktivasi akibat pembentukan arang. Kinerja katalis ditentukan dari uji aktivitas di dalam reaktor fixed bed pada temperatur 700 oC, tekanan atmosferik, selama 10 jam dan uji stabilitas yang diindikasikan menggunakan XRD dan TGA. Hasil pengujian aktivitas memperlihatkan bahwa katalis Ni/-Al2O3 menghasilkan aktivitas yang paling baik dengan rata - rata konversi toluen 96%. Penambahan promotor CaO 2% dan 5% berat menurunkan aktivitas katalis Ni/-Al2O3 dan menghambat pembentukan arang, tetapi tidak mengurangi laju deaktivasi katalis. Hasil XRD katalis Ni/-Al2O3 setelah reaksi 10 jam menunjukkan tidak adanya perubahan fasa dari -Al2O3 ke -Al2O3, yang berarti katalis masih tetap stabil.Kata Kunci: perengkahan tar, katalis nikel, konversi toluen, stabilitas.