Aitor Arregi

University of the Basque Country | UPV/EHU · Chemical Engineering

The fast deactivation of the reforming catalyst greatly conditions H2 production from biomass. In order to alleviate this problem, use of conditioning catalysts in a previous conditioning step has been proposed to modify the pyrolysis volatile stream reaching the reforming catalyst. The experimental runs have been conducted in a two-step reactor sy...

The steam pyrolysis of pinewood sawdust has been conducted in a bench scale plant provided with a conical spouted bed reactor (CSBR). This process is of uttermost relevance for the in-line valorisation of pyrolysis volatiles, specifically for their catalytic steam reforming for hydrogen production. The influence of temperature on he product yields...

In recent decades, the production of H2 from biomass, waste plastics, and their mixtures has attracted increasing attention in the literature in order to overcome the environmental problems associated with global warming and CO2 emissions caused by conventional H2 production processes. In this regard, the strategy based on pyrolysis and in-line cat...

Biomass pyrolysis and the in-line catalytic cracking of the pyrolysis volatile stream has been approached in this study. The pyrolysis step was carried out in a conical spouted bed reactor at 500 °C, whereas the inert sand or the cracking catalysts (γ-Al2O3, spent FCC and olivine) were placed in a fixed bed reactor at 600 °C. Product analysis was c...

The environmental problems related with the management of waste plastics require the development of efficient valorization routes. This chapter deals with three different strategies aimed at the selective conversion of plastics to chemicals and hydrogen following the two-step continuous processes. Flash pyrolysis performed in a conical spouted bed...

Based on the promising results of La2O3- and CeO2-promoted Ni/Al2O3 catalysts in the reforming of biomass pyrolysis volatiles, the performance of these catalysts and the non-promoted one was evaluated in the pyrolysis and in-line steam reforming of polypropylene (PP). The experiments were carried out in a continuous bench scale pyrolysis-reforming...

The performance of fixed and fluidized bed reactors in the steam reforming of biomass fast pyrolysis volatiles was compared, with especial attention paying to the differences observed in catalysts deactivation. The experiments were carried out in continuous regime in a bench scale unit provided with a conical spouted bed for the pyrolysis step. The...

The influence of the metal selected as catalytic active phase in the two-step biomass pyrolysis-catalytic reforming strategy has been analyzed. The pyrolysis step was carried out in a conical spouted bed reactor at 500 °C, whereas steam reforming was performed in a fluidized bed reactor at 600 °C. Ni/Al2O3, Co/Al2O3 and two bimetallic Ni-Co/Al2O3 c...

The joint process of pyrolysis-steam reforming is a novel and promising strategy for hydrogen production from biomass; however, it is conditioned by the endothermicity of the reforming reaction and the fast catalyst deactivation. Oxygen addition may potentially overcome these limitations. A thermodynamic equilibrium approach using Gibbs free energy...

The aim of this work was to study fast pyrolysis of three microalgae species in a continuous bench-scale conical spouted bed reactor at 500°C. Bio-gas, bio-oil and bio-char yields have been determined and characterized by using GC, GC/MS, elemental analyzer and SEM. Bio-oil was the main product obtained through pyrolysis of microalgae. The non-cond...

This work pursues the validation of a new reactor for the evaluation of char gasification kinetics. This novel reactor allows continuous gas flow through the fixed bed sample and accurately monitoring the mass loss throughout the reaction. Accordingly, this thermogravimetric flow reactor has a great potential for the analysis of different thermoche...

The effect of La2O3 addition on a Ni/Al2O3 catalyst has been studied in the biomass pyrolysis and in-line catalytic steam reforming process. The results obtained using homemade catalysts (Ni/Al2O3 and Ni/La2O3-Al2O3) have been compared with those obtained using a commercial Ni reforming catalyst (G90LDP). The pyrolysis step has been performed in a...

A study has been carried out of the influence calcination conditions of a Ni/MgO-Al2O3 catalyst have on its performance and stability in the reforming of biomass fast pyrolysis volatiles. Accordingly, the first calcination temperature subsequent to promoter impregnation on the Al2O3 has been modified from 900 to 700 °C. Subsequently, Ni was incorpo...

The performance of a Ni commercial catalyst has been studied under reaction-regeneration cycles in a continuous process consisting of the flash pyrolysis (500 °C) of high-density polyethylene (HDPE) in a conical spouted bed reactor (CSBR), followed by catalytic steam reforming in-line (700 ºC) of the volatiles formed in a fluidized bed reactor. The...

The performance and stability of different Ni supported catalysts have been studied in a continuous bench scale plant fitted with a conical spouted bed reactor for biomass pyrolysis at 500 °C and a fluidized bed reactor for the in line catalytic steam reforming of pyrolysis volatiles at 600 °C. The metal oxides selected as Ni supports have been Al2...

The activity and stability of a Ni/ZrO2 catalyst have been studied in a continuous bench scale plant, in which biomass has been pyrolysed at 500 °C in a conical spouted bed reactor and the outlet volatile stream has been subjected to catalytic steam reforming at 600 °C in a fluidized bed reactor. The influence of space time has been analyzed, and b...

A study has been carried out of the regenerability of a commercial Ni catalyst used in the steam reforming of the volatiles from biomass pyrolysis (gases and bio-oil), determining the evolution of the reaction indices (conversion, product yields and H2 production) in successive reaction–regeneration cycles. The causes of catalyst deactivation (coke...

H2 is regarded as one of the cleanest future energy carrier that can be generated from renewable sources and will give rise to a reduction of CO2 emissions and environmental problems related to the use of petroleum based feedstock. Thus, the thermochemical routes from biomass for sustainable H2 production compared to other biomass treatment routes...

An original kinetic model has been proposed for the reforming of the volatiles derived from biomass fast pyrolysis over a commercial Ni/Al2O3 catalyst. The pyrolysis-reforming strategy consists of two in-line steps. The pyrolysis step is performed in a conical spouted bed reactor (CSBR) at 500 °C, and the catalytic steam reforming of the volatiles...

The valorization of biomass (pine wood) for hydrogen production has been studied in a two-step process, comprising pyrolysis and subsequent steam reforming of the volatiles produced in the first step. This work focuses on the deactivation of the Ni commercial catalyst used in the second step. Pyrolysis of biomass has been performed in a conical spo...

The effect of reforming conditions (temperature, space time and steam/biomass ratio (S/B)) has been studied in the continuous biomass pyrolysis and in-line catalytic steam reforming process in order to establish suitable conditions for attenuating the deactivation of a commercial Ni catalyst by coke deposition. The experiments have been performed i...

Pyrolysis of high density polyethylene (HDPE) has been carried out in a conical spouted bed reactor (500 degrees C) and the volatiles have been reformed in-line over a Ni commercial catalyst in a fluidized bed reactor. The evolution of reaction indices (conversion, H-2 yield and other gaseous product yields) with time on stream has been studied und...

The influence the support has on the performance of Ni catalysts used in the reforming of biomass fast pyrolysis volatiles has been assessed. Accordingly, five catalysts have been prepared by wet impregnation method, namely Ni/Al2O3, Ni/SiO2, Ni/MgO, Ni/TiO2 and Ni/ZrO2. These catalysts have been characterized by nitrogen adsorption/desorption, X-r...

The performance of an original two-step reaction system (pyrolysis and in-line reforming) was assessed in the hydrogen production from different plastics (polyethylene, polypropylene, polyethylene terephthalate and polystyrene) and their mixture. The pyrolysis step was performed in a conical spouted bed reactor at 500 °C, whereas the reforming of p...

The kinetics of the steam reforming of HDPE pyrolysis volatiles is studied on a Ni commercial catalyst in a fluidized bed reactor in-line with the pyrolysis reactor (a conical spouted bed reactor at 500 ºC). Steam reforming reactions have been carried out under the following conditions: 600-700 ºC and space time 0-16.7 gcat min gHDPE-1. Based on th...

Carbonate looping, based on the reversible gas–solid reaction of CaO with CO2, is considered as a promising alternative to amine scrubbing for post-combustion CO2 capture. Solid sorbents suffer however from degradation, mainly due to thermal sintering and elutriation of fine particles due to enhanced attrition rates in fluidized-bed reactors. In th...

The continuous pyrolysis-reforming of pine sawdust and high density polyethylene mixtures (25, 50 and 75 wt% HDPE) has been performed in a two-stage reaction system provided with a conical spouted bed reactor (CSBR) and a fluidized bed reactor. The influence HDPE co-feeding has on the conversion, yields and composition of the reforming outlet strea...

Hydrogen production from polystyrene (PS) has been studied following continuous pyrolysis and in-line steam reforming. The first step was carried out at 500 °C in a conical spouted bed reactor and the subsequent reforming one was performed in a fluidized bed reactor on a commercial Ni catalyst at 700 °C. The effect space time and time on stream hav...

Catalytic steam reforming of n-hexane, 1-hexene, tetradecane and toluene over Ni a commercial catalyst has been carried out in a fluidized bed reactor at 700 °C. These compounds have been selected as model compounds of the volatiles formed in the pyrolysis of waste plastics in order to study in detail the performance of the catalyst in the pyrolysi...

Sewage sludge fast pyrolysis bio-oil, produced in a conical spouted bed reactor (CSBR) in the 450-600 °C range, has been characterized. On the one hand, the effect of temperature on bio-oil composition has been analyzed by means of online chromatography and, furthermore, the ultimate analysis and the higher heating value of each liquid have been de...

The steam gasification of pinewood sawdust derived char has been studied in a conical spouted bed reactor. The effect temperature (in the 800–900 °C range), steam partial pressure (from 0.2 to 1) and sawdust particle size (0.3–1, 1–2 and 2–4 mm ranges) have on the char gasification kinetics has been determined. The pyrolysis step was performed in s...

The continuous fast pyrolysis (500 ºC) of pine wood sawdust has been studied in a conical spouted bed reactor (CSBR) followed by in-line steam reforming of the pyrolysis vapours in a fluidized bed reactor on a Ni commercial catalyst. An analysis has been carried out on the effect reforming temperature in the 550-700 ºC range, space time from 2.5 to...

A continuous process has been developed consisting in the flash pyrolysis (500 °C) of high density polyethylene (HDPE) in a conical spouted bed reactor (CSBR) followed by steam reforming in a fluidized bed reactor (Ni commercial catalyst). The effect reforming temperature in the 600–700 °C range, space time from 2.1 to 20.8 gcat min gHDPE−1 and ste...

Continuous pyrolysis of polystyrene has been studied in a conical spouted bed reactor with the main aim of enhancing styrene monomer recovery. Thermal degradation in a thermogravimetric analyser was conducted as a preliminary study in order to apply this information in the pyrolysis in the conical spouted bed reactor. The effects of temperature and...

Hydrogen production from pyrolysis-catalytic steam reforming of pine sawdust has been investigated using two subsequent reactors: i) a conical spouted bed reactor for biomass pyrolysis at 500 °C, and ii) a fluidized bed reactor for catalytic reforming of volatiles from the pyrolysis step. A commercial Ni reforming catalyst has been used for the ref...

The effect of temperature in the catalytic cracking of HDPE over a spent FCC catalyst on the product distribution has been studied using a two-step reaction system. Thermal pyrolysis of HDPE has been carried out in a conical spouted bed reactor and the volatiles formed (mainly waxes) have been fed in-line into a catalytic fixed bed reactor. An incr...