Influence of the Catalyst Particle Size on the Aqueous Phase Reforming of n-Butanol Over Rh/ZrO2

Energy and economic analysis of alternatives for the valorization of hydrogen rich stream produced in the aqueous phase reforming of pyrolysis bio-oil aqueous fraction

Aqueous phase reforming has been explored for renewable H2 production from waste biomass. Promising results have been reported for pyrolysis bio-oil aqueous fractions (AFB), but economical assessments are needed to determine process feasibility, which requires both energy consumption minimization and optimal H2 valorization. This work compares different alternatives using process simulation and economic evaluation computational tools. Experimental results and a specific thermodynamic model are used to set mass balances. An adequate heat integration allows to reduce the process energy demand, covering the 100 % of the reactor duty. Optimal H2 unit cost is achieved if part of the produced H2 is valorized for energy self-covering and the rest is commercialized. Renewable H2 net production of c.a. 3.3 kgH2/m3 of treated AFB at a preliminary 1-2 €/kg unit cost is estimated, which can be considered as competitive with green H2, even though a case of diluted AFB is considered.

A new method for obtaining the magnetic shape anisotropy directly from electron tomography images

A new methodology to obtain magnetic information on magnetic nanoparticle (MNP) systems via electron tomography techniques is reported in this work. The new methodology is implemented in an under-development software package called Magn3t, written in Python and C++. A novel image-filtering technique that reduces the highly undesired diffraction effects in the tomography tilt-series has been also developed in order to increase the reliability of the correlations between morphology and magnetism. Using the Magn3t software, the magnetic shape anisotropy magnitude and direction of magnetite nanoparticles has been extracted for the first time directly from transmission electron tomography.

Highly Active Biphasic Anatase-Rutile Ni-Pd/TNPs Nanocatalyst for the Reforming and Cracking Reactions of Microplastic Waste Dissolved in Phenol

Solvent-based recycling of plastic can offer the main improvement when it is employed for pyrolysis-catalytic steam reforming. In this research, plastic waste dissolved in phenol was used as a feed for catalytic cracking and steam reforming reactions for valuable liquid fuels and hydrogen production, which is gaining the attention of researchers globally. Microplastic wastes (MPWs) are tiny plastic particles that arise due to product creation and breakdown of larger plastics. They can be found mainly in several habitats, including seas and freshwater ecosystems. MPWs harm aquatic species, turtles, and birds and were chosen to recover in this study that can be reacted on the catalyst surface. Biphasic anatase-rutile TiO₂ with spherical-shaped support for Ni and Pd metals with nanosized particles was synthesized via the hydrothermal treatment method, and its chemical and physical properties were characterized accordingly. According to temperature-programmed desorption of carbon dioxide (CO₂-TPD) and temperature-programmed reduction of hydrogen (H₂-TPR) results, the incorporation of Pd into Ni/TNPs enhanced the basicity of the support surface and the redox properties of catalysts, which were strongly linked to the improved hydrogen yield (71%) and phenol conversion (79%) at 600 °C. The Ni-Pd/TNPs nanocatalyst, with remarkable stability for 72 h of time on stream, is a promising catalyst for the MPW-phenol cracking and steam reforming reactions toward H₂ production for clean energy generation and other environmental applications. Besides, this study has also highlighted the opportunities of overcoming the risk of microplastic waste and converting it into valuable fuels such as decamethyltetrasiloxane, phenanthrene, methyl palmitate, benzenepropanoic acid, benzoic acid, azulene, xanthene, anisole, biphenyl, phthalic acid, diisooctyl phthalate, etc.

Kinetics Study of the Hydrodeoxygenation of Xylitol over a ReOx-Pd/CeO2 Catalyst

In this study, we elucidate the reaction kinetics for the simultaneous hydrodeoxygenation of xylitol to 1,2-dideoxypentitol and 1,2,5-pentanetriol over a ReOx-Pd/CeO2 (2.0 weight% Re, 0.30 weight% Pd) catalyst. The reaction was determined to be a zero-order reaction with respect to xylitol. The activation energy was elucidated through an Arrhenius relationship as well as non-Arrhenius kinetics. The Arrhenius relationship was investigated at 150–170 °C and a constant H2 pressure of 10 bar resulting in an activation energy of 48.7 ± 10.5 kJ/mol. The investigation of non-Arrhenius kinetics was conducted at 120–170 °C and a sub-Arrhenius relation was elucidated with activation energy being dependent on temperature, and ranging from 10.2–51.8 kJ/mol in the temperature range investigated. Internal and external mass transfer were investigated through evaluating the Weisz–Prater criterion and the effect of varying stirring rate on the reaction rate, respectively. There were no internal or external mass transfer limitations present in the reaction.

Bioalcohol Reforming: An Overview of the Recent Advances for the Enhancement of Catalyst Stability

The growing demand for energy production highlights the shortage of traditional resources and the related environmental issues. The adoption of bioalcohols (i.e., alcohols produced from biomass or biological routes) is progressively becoming an interesting approach that is used to restrict the consumption of fossil fuels. Bioethanol, biomethanol, bioglycerol, and other bioalcohols (propanol and butanol) represent attractive feedstocks for catalytic reforming and production of hydrogen, which is considered the fuel of the future. Different processes are already available, including steam reforming, oxidative reforming, dry reforming, and aqueous-phase reforming. Achieving the desired hydrogen selectivity is one of the main challenges, due to the occurrence of side reactions that cause coke formation and catalyst deactivation. The aims of this review are related to the critical identification of the formation of carbon roots and the deactivation of catalysts in bioalcohol reforming reactions. Furthermore, attention is focused on the strategies used to improve the durability and stability of the catalysts, with particular attention paid to the innovative formulations developed over the last 5 years.