Valorization of scrap tires pyrolysis oil (STPO) through a 2-stage hydrotreating-hydrocracking strategy. Process variables and kinetic modeling

232 p.Con objeto de contribuir a la gestión sostenible de los neumáticos usados y a la producción de combustibles de alta calidad, se ha desarrollado una estrategia de hidroprocesado en dos etapas de un líquido de pirolisis de neumáticos usados (scrap tires pyrolysis oil, STPO). En la primera etapa de hidrotratamiento se ha procesado el STPO, mientras que en la segunda etapa de hidrocraqueo se han tratado los productos de la primera etapa, con objeto de valorizar el STPO en cuanto a su contenido en (i) azufre (mediante hidrodesulfuración, HDS), (ii) gasoil (mediante hidrocraqueo, HC), y (iii) aromáticos (mediante hidrodesaromatización, HDA).Las etapas de hidroprocesado se han llevado a cabo en un reactor de lecho fijo bajo distintas condiciones de: temperatura, 300-500 ºC; presión, 25-65 bar; y tiempo espacial 0-0.5 gcat h gSTPO-1. En la primera etapa de hidrotratamiento se han empleado distintos catalizadores NiMo sobre soportes micro- y mesopororos, correlacionando las distintas propiedades catalíticas con las variables de proceso, mientras que en la segunda etapa se ha utilizado un único catalizador de PtPd soportado sobre silico-alúmina para profundizar en el efecto de las variables de proceso y la desactivación catalítica. Como índices de reacción se han definido conversiones de HDS, HC y HDA, basadas en el contenido de azufre, gasoil y aromáticos, respectivamente. Mediante distintos esquemas cinéticos se han calculado los correspondientes parámetros cinéticos considerando la desactivación, para llevar a cabo una simulación en un amplio intervalo de condiciones de operación, determinando así las condiciones óptimas.Los resultados obtenidos han permitido obtener una amplia perspectiva de las dos etapas de hidroprocesado para la valorización del STPO, así como del efecto de las distintas propiedades catalíticas de varios soportes, la naturaleza de la desactivación por deposición de coque y los mecanismos cinéticos que rigen cada proceso. Cabe reseñar que, a través de este proceso, se ha conseguido eliminar prácticamente por completo la fracción gasoil del STPO, así como reducir su contenido de azufre a niveles por debajo de 15 ppm (cumpliendo así con los requerimientos legales medioambientales) y eliminar más del 50 % de su contenido en aromáticos. La eliminación casi total del azufre ha conseguido evitar la desactivación por envenenamiento. Así, el catalizador se desactiva por deposición de coque, fenómeno que se ha estudiado tanto cuantitativa como cualitativamente empleando diferentes técnicas de caracterización

A Hybrid FCC/HZSM-5 Catalyst for the Catalytic Cracking of a VGO/Bio-Oil Blend in FCC Conditions

The performance of a commercial FCC catalyst (designated as CY) and a physically mixed hybrid catalyst (80 wt.% CY and 20 wt.% HZSM-5-based catalyst, designated as CH) have been compared in the catalytic cracking of a vacuum gasoil (VGO)/bio-oil blend (80/20 wt.%) in a simulated riser reactor (C/O, 6gcatgfeed−1; t, 6 s). The effect of cracking temperature has been studied on product distribution (carbon products, water, and coke) and product lumps: CO+CO2, dry gas, liquified petroleum gases (LPG), gasoline, light cycle oil (LCO), heavy cycle oil (HCO), and coke. Using the CH catalyst, the conversion of the bio-oil oxygenates is ca. 3 wt.% higher, while the conversion of the hydrocarbons in the mixture is lower, yielding more carbon products (83.2–84.7 wt.% on a wet basis) and less coke (3.7–4.8 wt.% on a wet basis) than the CY catalyst. The CH catalyst provides lower gasoline yields (30.7–32.0 wt.% on a dry basis) of a less aromatic and more olefinic nature. Due to gasoline overcracking, enhanced LPG yields were also obtained. The results are explained by the high activity of the HZSM-5 zeolite for the cracking of bio-oil oxygenates, the diffusional limitations within its pore structure of bulkier VGO compounds, and its lower activity towards hydrogen transfer reactions.This work has been conducted with the financial support from the Ministry of Economy and Competitiveness of the Spanish Government (MINECO) (Project RTI2018-096981-B-I00), co-funded with FEDER funds, the Basque Government (Project IT1218-19), and the European Commission (Horizon 2020-MSCA RISE-2018, Contract No. 823745). Idoia Hita is thankful for her postdoctoral grant awarded by the Department of Education, University and Research of the Basque Government (Grant No. POS_2015_1_0035). Álvaro Ibarra is grateful for his PhD grant from the University of the Basque Country (UPV/EHU). Authors would also like to acknowledge Ikerlan/IK-4 for providing the raw bio-oil, as well as Petronor S.A. for providing the VGO and the equilibrated FCC catalyst for this study

Implications of Co-Feeding Water on the Growth Mechanisms of Retained Species on a SAPO-18 Catalyst during the Methanol-to-Olefins Reaction

The dynamics of retained and deactivating species in a SAPO-18 catalyst during the methanol-to-olefins reaction have been followed using a combination of ex-situ and in-situ techniques in differential and integral reactors.The retained species were analyzed using extraction, in-situ FTIR and in-situ UV-vis spectroscopies combined with online product analysis (gas chromatography and mass spectrometry). The composition of the extracted soluble species was determined using gas chromatography-mass spectrometry and that of the insoluble species using high-resolution mass spectrometry. We observe a decrease in the formation and degradation rates of retained species when co-feeding water, whereas the extent of the decreases is the same across the entire spectrum of retained molecules. This indicates that co-feeding water unselectively quenches the formation of active and deactivating species. At the same time, the catalyst has an extended lifetime when co-feeding water due to the diffusion of species (particularly olefins) out of the SAPO-18 crystals, and subsequent growth of heavy polycyclic aromatic structures that imply less deactivation. These conclusions can be extrapolated to other MTO catalysts with relatively similar pore topology such as SAPO-34 or SSZ-13 structures.This work was possible thanks to the financial support of the Ministry of Economy, Industry and Competitiveness of the Spanish Government (Project CTQ2016-79646-P, co-founded with ERDF funds), the Basque Government (Project IT748-13, IT912-16) and the King Abdullah University of Science and Technology (KAUST). J.V. is thankful for his fellowship granted by the Ministry of Economy, Industry and Competitiveness of the Spanish Government (BES-2014-069980). The authors are thankful for technical and human support provided by IZO-SGI SGIker of UPV/EHU and European funding (ERDF and ESF)

A Data-Driven Reaction Network for the Fluid Catalytic Cracking of Waste Feeds

Establishing a reaction network is of uttermost importance in complex catalytic processes such as fluid catalytic cracking (FCC). This step is the seed for a faithful reactor modeling and the subsequent catalyst re-design, process optimization or prediction. In this work, a dataset of 104 uncorrelated experiments, with 64 variables, was obtained in an FCC simulator using six types of feedstock (vacuum gasoil, polyethylene pyrolysis waxes, scrap tire pyrolysis oil, dissolved polyethylene and blends of the previous), 36 possible sets of conditions (varying contact time, temperature and catalyst/oil ratio) and three industrial catalysts. Principal component analysis (PCA) was applied over the dataset, showing that the main components are associated with feed composition (27.41% variance), operational conditions (19.09%) and catalyst properties (12.72%). The variables of each component were correlated with the indexes and yields of the products: conversion, octane number, aromatics, olefins (propylene) or coke, among others. Then, a data-driven reaction network was proposed for the cracking of waste feeds based on the previously obtained correlations.This research was funded by the Ministry of Economy and Competitiveness (MINECO) of the Spanish Government (CTQ2015-67425R and CTQ2016-79646-P), the European Regional Development Funds (ERDF) and the Basque Government (IT748-13). Hita is grateful for her postdoctoral grant awarded by the Department of Education, University and Research of the Basque Government (POS_2015_1_0035). Rodriguez is thankful to the University of the Basque Country UPV/EHU (Zabalduz Programme)

Valorization of scrap tires pyrolysis oil (STPO) through a 2-stage hydrotreating-hydrocracking strategy. Process variables and kinetic modeling

232 p.Con objeto de contribuir a la gestión sostenible de los neumáticos usados y a la producción de combustibles de alta calidad, se ha desarrollado una estrategia de hidroprocesado en dos etapas de un líquido de pirolisis de neumáticos usados (scrap tires pyrolysis oil, STPO). En la primera etapa de hidrotratamiento se ha procesado el STPO, mientras que en la segunda etapa de hidrocraqueo se han tratado los productos de la primera etapa, con objeto de valorizar el STPO en cuanto a su contenido en (i) azufre (mediante hidrodesulfuración, HDS), (ii) gasoil (mediante hidrocraqueo, HC), y (iii) aromáticos (mediante hidrodesaromatización, HDA).Las etapas de hidroprocesado se han llevado a cabo en un reactor de lecho fijo bajo distintas condiciones de: temperatura, 300-500 ºC; presión, 25-65 bar; y tiempo espacial 0-0.5 gcat h gSTPO-1. En la primera etapa de hidrotratamiento se han empleado distintos catalizadores NiMo sobre soportes micro- y mesopororos, correlacionando las distintas propiedades catalíticas con las variables de proceso, mientras que en la segunda etapa se ha utilizado un único catalizador de PtPd soportado sobre silico-alúmina para profundizar en el efecto de las variables de proceso y la desactivación catalítica. Como índices de reacción se han definido conversiones de HDS, HC y HDA, basadas en el contenido de azufre, gasoil y aromáticos, respectivamente. Mediante distintos esquemas cinéticos se han calculado los correspondientes parámetros cinéticos considerando la desactivación, para llevar a cabo una simulación en un amplio intervalo de condiciones de operación, determinando así las condiciones óptimas.Los resultados obtenidos han permitido obtener una amplia perspectiva de las dos etapas de hidroprocesado para la valorización del STPO, así como del efecto de las distintas propiedades catalíticas de varios soportes, la naturaleza de la desactivación por deposición de coque y los mecanismos cinéticos que rigen cada proceso. Cabe reseñar que, a través de este proceso, se ha conseguido eliminar prácticamente por completo la fracción gasoil del STPO, así como reducir su contenido de azufre a niveles por debajo de 15 ppm (cumpliendo así con los requerimientos legales medioambientales) y eliminar más del 50 % de su contenido en aromáticos. La eliminación casi total del azufre ha conseguido evitar la desactivación por envenenamiento. Así, el catalizador se desactiva por deposición de coque, fenómeno que se ha estudiado tanto cuantitativa como cualitativamente empleando diferentes técnicas de caracterización

Insight into structure-reactivity relationships for the iron-catalyzed hydrotreatment of technical lignins

The viability of several technical lignins as a source for biobased platform chemicals was investigated via hydrotreatment using a cheap Fe-based limonite catalyst and without using a solvent. In general, high-quality oils (up to 29 wt% total monomers) with an average relative composition of 55% alkylphenolics and 27% aromatics were obtained. Detailed structural investigations showed that the S-G aromatic unit content of the lignins was the most important factor positively affecting overall oil yields. A second parameter was the lignocellulose processing method. Even though alkaline lignin isolation provides more recalcitrant lignins, their lower aliphaticity and methoxy group content partially limit char and gas formation. Finally, enhanced monomer yields could be obtained irrespective of the ether linkage content, and a high amount of beta-O-4 linkages actually showed a slightly negative effect on monomer yields. Overall, the results demonstrate that this route is particularly suitable for processing residual lignin streams

Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H-2 pressure of 100 bar, 4 h). The best results were obtained at 450 degrees C resulting in 34 wt % of liquefied kraft lignin (lignin oil) on lignin intake. The composition of the lignin oil was determined in detail (elemental composition, GC-MS, GCXGC-FID, and GPC). The total GC-detectable monomeric species amounts up to 31 wt % on lignin intake, indicating that 92 wt % of the products in the lignin oil are volatile and thus of low molecular weight. The lignin oil was rich in low-molecular-weight alkylphenolics (17 wt % on lignin) and aromatics (8 wt % on lignin). Performance of the limonite catalyst was compared to other Fe-based catalysts (goethite and iron disulfide) and limonite was shown to give the highest yields of alkylphenolics and aromatics. The limonite catalyst before and after reaction was characterized using XRD, TEM, and nitrogen physisorption to determine changes in structure during reaction. Catalyst recycling tests were performed and show that the catalyst is active after reuse, despite the fact that the morphology changed and that the surface area of the catalyst particles was decreased. Our results clearly reveal that cheap limonite catalysts have the potential to be used for the depolymerization/hydrodeoxygenation of kraft lignin for the production of valuable biobased phenolics and aromatics