Call: +34 876555483
Email: abrego@unizar.es
Address: Office 31.080 c/Mariano Esquillor SN Edificio I+D+i, I3A, GPT Zaragoza Aragón
ABOUT ME
Research Interests
Broadly, my research focus is on pyrolysis of organic waste and biomass. I am currently interested in the development of new and/or improved thermochemical processes for biofuels and bioproducts.
Specifically, we are now developing a carbon-negative pyrolysis system with autothermal operation. Operational tests are ongoing. We seek to further develop and scale-up this idea, ideally with an industry partner.
Simultaneously, I work in the development of integrated valorization approaches of various agricultural or animal residues via pyrolysis, and its integration with biomethane production.
I have also collaborated in the development of the Flash Carbonization technology developed by Professor Michael J. Antal at University of Hawai’i as a Visiting Scholar, and worked at Instituto de Carboquímica (Spanish National Research Council), both in postdoctoral positions.
Previously to my PhD research, I also worked in gasification (fluidized bed and downdraft reactors) at demonstration scale.
PUBLICATIONS
2013
Atienza-Martínez, María; Fonts, Isabel; Ábrego, Javier; Ceamanos, Jesús; Gea, Gloria
Sewage sludge torrefaction in a fluidized bed reactor Journal Article
In: Chemical Engineering Journal, vol. 222, pp. 534–545, 2013, ISSN: 13858947.
@article{Atienza-Martinez2013,
title = {Sewage sludge torrefaction in a fluidized bed reactor},
author = {María Atienza-Martínez and Isabel Fonts and Javier Ábrego and Jesús Ceamanos and Gloria Gea},
url = {http://www.sciencedirect.com/science/article/pii/S1385894713002416},
issn = {13858947},
year = {2013},
date = {2013-04-01},
journal = {Chemical Engineering Journal},
volume = {222},
pages = {534--545},
abstract = {Torrefaction of sewage sludge in a lab-scale fluidized bed reactor was studied in order to know if this pre-treatment could enhance the properties of this waste in subsequent thermochemical processing, such as pyrolysis. The influence was studied of two important torrefaction operational parameters, temperature (220–320°C) and solid residence time (3.6–10.2min), on the product distribution and properties. Taking into account the operation conditions evaluated in this work, torrefaction temperature affects solid product properties at long solid residence times (longer than 6.1min) and that the effect of solid residence time is only significant at the highest temperature (320°C). Severe torrefaction conditions result in the release of bonded water which could enhance some properties of the liquid obtained in the ensuing pyrolysis process. However, the torrefaction pre-treatment also implies that part of the extractives is lost from the raw material. Compared to dry raw sewage sludge, the energy density of sewage sludge after torrefaction increases under certain conditions. The removal of H2O and CO2 during the torrefaction step reduces the O/C ratio in the torrefied solid up to 0.12 (66.70% reduction compared to 0.37 in raw sewage sludge) which could be a benefit for subsequent thermochemical treatments. For example, one of the main drawbacks of pyrolysis liquids is their high oxygen content.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Torrefaction of sewage sludge in a lab-scale fluidized bed reactor was studied in order to know if this pre-treatment could enhance the properties of this waste in subsequent thermochemical processing, such as pyrolysis. The influence was studied of two important torrefaction operational parameters, temperature (220–320°C) and solid residence time (3.6–10.2min), on the product distribution and properties. Taking into account the operation conditions evaluated in this work, torrefaction temperature affects solid product properties at long solid residence times (longer than 6.1min) and that the effect of solid residence time is only significant at the highest temperature (320°C). Severe torrefaction conditions result in the release of bonded water which could enhance some properties of the liquid obtained in the ensuing pyrolysis process. However, the torrefaction pre-treatment also implies that part of the extractives is lost from the raw material. Compared to dry raw sewage sludge, the energy density of sewage sludge after torrefaction increases under certain conditions. The removal of H2O and CO2 during the torrefaction step reduces the O/C ratio in the torrefied solid up to 0.12 (66.70% reduction compared to 0.37 in raw sewage sludge) which could be a benefit for subsequent thermochemical treatments. For example, one of the main drawbacks of pyrolysis liquids is their high oxygen content.
Ábrego, Javier; Sánchez, José Luis; Arauzo, Jesús; Fonts, Isabel; Gil-Lalaguna, Noemí; Atienza-Martínez, María
Technical and Energetic Assessment of a Three-Stage Thermochemical Treatment for Sewage Sludge Journal Article
In: Energy & Fuels, vol. 27, no. 2, pp. 1026–1034, 2013, ISSN: 0887-0624.
@article{Abrego2013,
title = {Technical and Energetic Assessment of a Three-Stage Thermochemical Treatment for Sewage Sludge},
author = {Javier Ábrego and José Luis Sánchez and Jesús Arauzo and Isabel Fonts and Noemí Gil-Lalaguna and María Atienza-Martínez},
url = {http://dx.doi.org/10.1021/ef3018095},
issn = {0887-0624},
year = {2013},
date = {2013-02-01},
journal = {Energy & Fuels},
volume = {27},
number = {2},
pages = {1026--1034},
publisher = {American Chemical Society},
abstract = {A three-stage thermochemical process comprising torrefaction, pyrolysis, and char activation is proposed for the treatment of dry sewage sludge or biomass materials. To assess the feasibility of the process, lab-scale experiments were carried out with dried sewage sludge as feedstock, and mass and energy balances were calculated. In the process, 19.3% of the sewage sludge initial weight was transformed into a bio-oil with three distinct phases and reduced water content (66.1% of water content in the aqueous phase compared to 73.8% in a single-step fast pyrolysis). The product gases had a high H2S content but also enough heating value to be combusted. After being activated by the torrefaction vapors, the solid fraction (48.2% of the initial sludge weight) showed certain pore development and might be suitable for adsorption applications. Regarding the energy balance, it was found that the combustion of part of the product gas would provide the necessary heat to drive the process (1019 kJ/kg of dry sewage sludge).
A three-stage thermochemical process comprising torrefaction, pyrolysis, and char activation is proposed for the treatment of dry sewage sludge or biomass materials. To assess the feasibility of the process, lab-scale experiments were carried out with dried sewage sludge as feedstock, and mass and energy balances were calculated. In the process, 19.3% of the sewage sludge initial weight was transformed into a bio-oil with three distinct phases and reduced water content (66.1% of water content in the aqueous phase compared to 73.8% in a single-step fast pyrolysis). The product gases had a high H2S content but also enough heating value to be combusted. After being activated by the torrefaction vapors, the solid fraction (48.2% of the initial sludge weight) showed certain pore development and might be suitable for adsorption applications. Regarding the energy balance, it was found that the combustion of part of the product gas would provide the necessary heat to drive the process (1019 kJ/kg of dry sewage sludge).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A three-stage thermochemical process comprising torrefaction, pyrolysis, and char activation is proposed for the treatment of dry sewage sludge or biomass materials. To assess the feasibility of the process, lab-scale experiments were carried out with dried sewage sludge as feedstock, and mass and energy balances were calculated. In the process, 19.3% of the sewage sludge initial weight was transformed into a bio-oil with three distinct phases and reduced water content (66.1% of water content in the aqueous phase compared to 73.8% in a single-step fast pyrolysis). The product gases had a high H2S content but also enough heating value to be combusted. After being activated by the torrefaction vapors, the solid fraction (48.2% of the initial sludge weight) showed certain pore development and might be suitable for adsorption applications. Regarding the energy balance, it was found that the combustion of part of the product gas would provide the necessary heat to drive the process (1019 kJ/kg of dry sewage sludge).
A three-stage thermochemical process comprising torrefaction, pyrolysis, and char activation is proposed for the treatment of dry sewage sludge or biomass materials. To assess the feasibility of the process, lab-scale experiments were carried out with dried sewage sludge as feedstock, and mass and energy balances were calculated. In the process, 19.3% of the sewage sludge initial weight was transformed into a bio-oil with three distinct phases and reduced water content (66.1% of water content in the aqueous phase compared to 73.8% in a single-step fast pyrolysis). The product gases had a high H2S content but also enough heating value to be combusted. After being activated by the torrefaction vapors, the solid fraction (48.2% of the initial sludge weight) showed certain pore development and might be suitable for adsorption applications. Regarding the energy balance, it was found that the combustion of part of the product gas would provide the necessary heat to drive the process (1019 kJ/kg of dry sewage sludge).
A three-stage thermochemical process comprising torrefaction, pyrolysis, and char activation is proposed for the treatment of dry sewage sludge or biomass materials. To assess the feasibility of the process, lab-scale experiments were carried out with dried sewage sludge as feedstock, and mass and energy balances were calculated. In the process, 19.3% of the sewage sludge initial weight was transformed into a bio-oil with three distinct phases and reduced water content (66.1% of water content in the aqueous phase compared to 73.8% in a single-step fast pyrolysis). The product gases had a high H2S content but also enough heating value to be combusted. After being activated by the torrefaction vapors, the solid fraction (48.2% of the initial sludge weight) showed certain pore development and might be suitable for adsorption applications. Regarding the energy balance, it was found that the combustion of part of the product gas would provide the necessary heat to drive the process (1019 kJ/kg of dry sewage sludge).
2012
Fonts, Isabel; Gea, Gloria; Azuara, Manuel; Ábrego, Javier; Arauzo, Jesús
Sewage sludge pyrolysis for liquid production: A review Journal Article
In: Renewable and Sustainable Energy Reviews, vol. 16, no. 5, pp. 2781–2805, 2012, ISSN: 13640321.
@article{Fonts2012,
title = {Sewage sludge pyrolysis for liquid production: A review},
author = {Isabel Fonts and Gloria Gea and Manuel Azuara and Javier Ábrego and Jesús Arauzo},
url = {http://www.sciencedirect.com/science/article/pii/S1364032112001657},
issn = {13640321},
year = {2012},
date = {2012-06-01},
journal = {Renewable and Sustainable Energy Reviews},
volume = {16},
number = {5},
pages = {2781--2805},
abstract = {The high output of sewage sludge, which is increasing during recent years, and the limitations of the existing means of disposing sewage sludge highlight the need to find alternative routes to manage this waste. Biomass and residues like sewage sludge are the only renewable energy sources that can provide C and H, thus it is interesting to process them by means of treatments that enable to obtain chemically valuable products like fuels and not only heat and power; pyrolysis can be one of these treatments. The main objective of this review is to provide an account of the state of the art of sewage sludge pyrolysis for liquid production, which is under study during recent years. This process yields around 50wt% (daf) of liquid. Typically, this liquid is heterogeneous and it usually separates into two or three phases. Some of these organic phases have very high gross heating values, even similar to those of petroleum-based fuels. The only industrial sewage sludge pyrolysis plant operated to date is currently closed due to some technical challenges and problems of economic viability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The high output of sewage sludge, which is increasing during recent years, and the limitations of the existing means of disposing sewage sludge highlight the need to find alternative routes to manage this waste. Biomass and residues like sewage sludge are the only renewable energy sources that can provide C and H, thus it is interesting to process them by means of treatments that enable to obtain chemically valuable products like fuels and not only heat and power; pyrolysis can be one of these treatments. The main objective of this review is to provide an account of the state of the art of sewage sludge pyrolysis for liquid production, which is under study during recent years. This process yields around 50wt% (daf) of liquid. Typically, this liquid is heterogeneous and it usually separates into two or three phases. Some of these organic phases have very high gross heating values, even similar to those of petroleum-based fuels. The only industrial sewage sludge pyrolysis plant operated to date is currently closed due to some technical challenges and problems of economic viability.
2011
García, Gorka; Cascarosa, Esther; Ábrego, Javier; Gonzalo, Alberto; Sánchez, José Luis
Use of different residues for high temperature desulphurisation of gasification gas Journal Article
In: Chemical Engineering Journal, vol. 174, no. 2-3, pp. 644–651, 2011, ISSN: 13858947.
@article{Garcia2011a,
title = {Use of different residues for high temperature desulphurisation of gasification gas},
author = {Gorka García and Esther Cascarosa and Javier Ábrego and Alberto Gonzalo and José Luis Sánchez},
doi = {10.1016/j.cej.2011.09.085},
issn = {13858947},
year = {2011},
date = {2011-11-01},
journal = {Chemical Engineering Journal},
volume = {174},
number = {2-3},
pages = {644--651},
publisher = {Elsevier},
abstract = {H2S is an important constraint for the final use of gas from coal or biomass gasification. Its content varies depending on the sulphur present in the feedstock raw material. In parallel, char and ash from biomass and coal gasification or combustion usually have significant amounts of metals, some of which have shown activity towards H2S abatement. Thus, these materials could be a feasible and cheap alternative for H2S removal, as they are generated inside the gasification process. This work evaluates the feasibility of using ash and char from several materials (lignite, bituminous coal and sewage sludge) for H2S removal. Experiments were carried out in a fixed bed reactor at 700-900°C, using a synthetic gas with 0.5vol.% of H2S (similar to that obtained by air gasification of sewage sludge).The highest H2S removal was achieved using lignite ash (at all temperatures) and bituminous coal (at T>700°C), obtaining, in these conditions, an outlet gas with less than 0.05vol.% H2S after 2h of experiment. textcopyright 2011 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
H2S is an important constraint for the final use of gas from coal or biomass gasification. Its content varies depending on the sulphur present in the feedstock raw material. In parallel, char and ash from biomass and coal gasification or combustion usually have significant amounts of metals, some of which have shown activity towards H2S abatement. Thus, these materials could be a feasible and cheap alternative for H2S removal, as they are generated inside the gasification process. This work evaluates the feasibility of using ash and char from several materials (lignite, bituminous coal and sewage sludge) for H2S removal. Experiments were carried out in a fixed bed reactor at 700-900°C, using a synthetic gas with 0.5vol.% of H2S (similar to that obtained by air gasification of sewage sludge).The highest H2S removal was achieved using lignite ash (at all temperatures) and bituminous coal (at T>700°C), obtaining, in these conditions, an outlet gas with less than 0.05vol.% H2S after 2h of experiment. textcopyright 2011 Elsevier B.V.
2009
Ábrego, Javier; Arauzo, Jesús; Sánchez, José Luis; Gonzalo, Alberto; Cordero, Tomás; Rodríguez-Mirasol, José
Structural changes of sewage sludge char during fixed-bed pyrolysis Journal Article
In: Industrial and Engineering Chemistry Research, vol. 48, no. 6, pp. 3211–3221, 2009, ISSN: 08885885.
@article{Abrego2009,
title = {Structural changes of sewage sludge char during fixed-bed pyrolysis},
author = {Javier Ábrego and Jesús Arauzo and José Luis Sánchez and Alberto Gonzalo and Tomás Cordero and José Rodríguez-Mirasol},
url = {https://pubs.acs.org/sharingguidelines},
doi = {10.1021/ie801366t},
issn = {08885885},
year = {2009},
date = {2009-03-01},
journal = {Industrial and Engineering Chemistry Research},
volume = {48},
number = {6},
pages = {3211--3221},
publisher = {American Chemical Society},
abstract = {Undigested dried sewage sludge from a wastewater treatment plant was pyrolyzed at temperatures between 300 and 900 °C, with an additional hold time at the highest temperature. A fixed-bed reactor was used with a heating rate of 20 °C/min under an atmosphere of nitrogen. Pyrolysis product distribution, FTIR, XRD, BET, SEM, and ultimate and proximate analyses were used to gain a better understanding of the structural changes occurring during pyrolysis. At low to medium pyrolysis temperatures, major mass loss occurs, and most of the gaseous and liquid products are released with little porous development, whereas at temperatures between 700 and 900 °C, structural changes seem to be triggered by calcium carbonate decomposition. This leads to a second stage of gas evolution, as CaO promotes gasification of the char in the presence of iron sulfides. The subsequent release of CO runs parallel with an increase in the BET surface area. In addition, the aromatic character of the char increases with temperature, and nanotube-like tubular structures can be detected by SEM. textcopyright 2009 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Undigested dried sewage sludge from a wastewater treatment plant was pyrolyzed at temperatures between 300 and 900 °C, with an additional hold time at the highest temperature. A fixed-bed reactor was used with a heating rate of 20 °C/min under an atmosphere of nitrogen. Pyrolysis product distribution, FTIR, XRD, BET, SEM, and ultimate and proximate analyses were used to gain a better understanding of the structural changes occurring during pyrolysis. At low to medium pyrolysis temperatures, major mass loss occurs, and most of the gaseous and liquid products are released with little porous development, whereas at temperatures between 700 and 900 °C, structural changes seem to be triggered by calcium carbonate decomposition. This leads to a second stage of gas evolution, as CaO promotes gasification of the char in the presence of iron sulfides. The subsequent release of CO runs parallel with an increase in the BET surface area. In addition, the aromatic character of the char increases with temperature, and nanotube-like tubular structures can be detected by SEM. textcopyright 2009 American Chemical Society.