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
2020
Atienza-Martínez, María; Ábrego, Javier; Gea, Gloria; Marías, Frédéric
Pyrolysis of dairy cattle manure: evolution of char characteristics Journal Article
In: Journal of Analytical and Applied Pyrolysis, vol. 145, pp. 104724, 2020, ISSN: 01652370.
@article{Atienza-Martinez2020,
title = {Pyrolysis of dairy cattle manure: evolution of char characteristics},
author = {María Atienza-Martínez and Javier Ábrego and Gloria Gea and Frédéric Marías},
doi = {10.1016/j.jaap.2019.104724},
issn = {01652370},
year = {2020},
date = {2020-01-01},
journal = {Journal of Analytical and Applied Pyrolysis},
volume = {145},
pages = {104724},
publisher = {Elsevier B.V.},
abstract = {Livestock manure management constitutes a major challenge at this time. Traditionally, this waste has been used as fertilizer. Excessive application of this residual organic matter on agricultural soils can cause soil quality degradation due to heavy metals accumulation, migration of pathogens to water sources and food, and generation of greenhouse gases. As a promising alternative to land application, pyrolysis of livestock manure allows to obtain biochar, bio-oil and syngas. The goal of this work is to study slow pyrolysis of digested dairy cattle manure (DM) both through one-step and multi-step pyrolysis at increasing temperature in the range 250-600 °C. The non-condensable gases composition was continuously analyzed by gas chromatography. Char properties were characterized by ultimate analysis, heavy metals content, ash content, higher heating value (HHV), pH, electrical conductivity (EC), water holding capacity (WHC), cation exchange capacity (CEC), textural properties (specific surface area, pore volume and average pore width) and Fourier Transform Infrared (FTIR) spectroscopy. The experimental results showed that both the product distribution and the properties of char depended on pyrolysis temperature. Char obtained after the last step of multi-step pyrolysis had similar properties to that obtained in one-step pyrolysis. Thus, the cooling and re-heating of the solid between steps did not have a significant effect on the pyrolysis pathway. Pyrolysis at between 400-550 °C allowed to reach a compromise between char pH and electrical conductivity for its potential use as soil amendment.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Livestock manure management constitutes a major challenge at this time. Traditionally, this waste has been used as fertilizer. Excessive application of this residual organic matter on agricultural soils can cause soil quality degradation due to heavy metals accumulation, migration of pathogens to water sources and food, and generation of greenhouse gases. As a promising alternative to land application, pyrolysis of livestock manure allows to obtain biochar, bio-oil and syngas. The goal of this work is to study slow pyrolysis of digested dairy cattle manure (DM) both through one-step and multi-step pyrolysis at increasing temperature in the range 250-600 °C. The non-condensable gases composition was continuously analyzed by gas chromatography. Char properties were characterized by ultimate analysis, heavy metals content, ash content, higher heating value (HHV), pH, electrical conductivity (EC), water holding capacity (WHC), cation exchange capacity (CEC), textural properties (specific surface area, pore volume and average pore width) and Fourier Transform Infrared (FTIR) spectroscopy. The experimental results showed that both the product distribution and the properties of char depended on pyrolysis temperature. Char obtained after the last step of multi-step pyrolysis had similar properties to that obtained in one-step pyrolysis. Thus, the cooling and re-heating of the solid between steps did not have a significant effect on the pyrolysis pathway. Pyrolysis at between 400-550 °C allowed to reach a compromise between char pH and electrical conductivity for its potential use as soil amendment.
2019
Plaza, Daniel; Artigas, Julia; Ábrego, Javier; Gonzalo, Alberto; Sánchez, José Luis; Dro, Augustin Diomandé; Richardson, Yohan
Design and operation of a small-scale carbonization kiln for cashew nutshell valorization in Burkina Faso Journal Article
In: Energy for Sustainable Development, vol. 53, pp. 71–80, 2019, ISSN: 23524669.
@article{Plaza2019,
title = {Design and operation of a small-scale carbonization kiln for cashew nutshell valorization in Burkina Faso},
author = {Daniel Plaza and Julia Artigas and Javier Ábrego and Alberto Gonzalo and José Luis Sánchez and Augustin Diomandé Dro and Yohan Richardson},
doi = {10.1016/j.esd.2019.10.005},
issn = {23524669},
year = {2019},
date = {2019-12-01},
journal = {Energy for Sustainable Development},
volume = {53},
pages = {71--80},
publisher = {Elsevier B.V.},
abstract = {This paper describes the process of planning, design, building and first operation tests of a carbonization reactor for the valorization of cashew nutshells, obtained as byproduct from small-scale cashew cultivation and processing in Bobo-Dioulasso, Burkina Faso. The main technical requirements for the reactor were: low cost and ease of construction, robustness, autothermal operation, no need for pre or post-treatments for feedstock and products, and readily useable product fractions in a local scale. Design modifications are discussed and justified. Characterization of the raw material, data from the first successful operational tests, as well as product distribution and characterization, are presented. This carbonization prototype allows for the sustainable valorization of an otherwise problematic biomass residue, creating added-value products that would enhance the economic profitability of local processors. The use of the main charcoal product as a fuel substitute for household cooking is preliminarily assessed, and the recovery of potentially valuable cashew nutshell liquid (CNSL) is accomplished.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper describes the process of planning, design, building and first operation tests of a carbonization reactor for the valorization of cashew nutshells, obtained as byproduct from small-scale cashew cultivation and processing in Bobo-Dioulasso, Burkina Faso. The main technical requirements for the reactor were: low cost and ease of construction, robustness, autothermal operation, no need for pre or post-treatments for feedstock and products, and readily useable product fractions in a local scale. Design modifications are discussed and justified. Characterization of the raw material, data from the first successful operational tests, as well as product distribution and characterization, are presented. This carbonization prototype allows for the sustainable valorization of an otherwise problematic biomass residue, creating added-value products that would enhance the economic profitability of local processors. The use of the main charcoal product as a fuel substitute for household cooking is preliminarily assessed, and the recovery of potentially valuable cashew nutshell liquid (CNSL) is accomplished.
Ábrego, Javier; Atienza-Martínez, María; Plou, F; Arauzo, Jesús
Heat requirement for fixed bed pyrolysis of beechwood chips Journal Article
In: Energy, vol. 178, pp. 145–157, 2019, ISSN: 03605442.
@article{Abrego2019,
title = {Heat requirement for fixed bed pyrolysis of beechwood chips},
author = {Javier Ábrego and María Atienza-Martínez and F Plou and Jesús Arauzo},
doi = {10.1016/j.energy.2019.04.078},
issn = {03605442},
year = {2019},
date = {2019-07-01},
journal = {Energy},
volume = {178},
pages = {145--157},
publisher = {Elsevier Ltd},
abstract = {The evaluation of heat of pyrolysis reactions at conditions relevant to the industrial practice is of great importance from the point of view of reactor design. Here, the evolution of heat during the pyrolysis of beechwood chips was experimentally measured in a lab-scale fixed bed pyrolysis system. Wood was heated and pyrolyzed by means of heat transferred from a mass of surrounding inert material (sand) initially heated at temperatures between 400 and 800 °C. Monitoring the evolution of temperatures in the system allowed calculation of heat for pyrolysis (QP) as a function of wood bed temperature. At pyrolysis conditions where slow heating rates of the wood bed are realized, changes in QP were clearly linked to the decomposition of the individual constituents of biomass (cellulose, hemicellulose and lignin), with consecutive exothermic and endothermic stages. When high temperature gradients were present, these stages were simultaneous and QP continuously increased with temperature, reaching 550 kJ kg−1. Under these circumstances, a correlation is provided for QP (T) up to 556 °C. The enthalpy of the pyrolysis reactions ($Delta$HP) was also estimated. Results show good coincidence with previously reported literature values. The proposed experimental system could be useful for determining heat requirements of pyrolysis under different operational conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The evaluation of heat of pyrolysis reactions at conditions relevant to the industrial practice is of great importance from the point of view of reactor design. Here, the evolution of heat during the pyrolysis of beechwood chips was experimentally measured in a lab-scale fixed bed pyrolysis system. Wood was heated and pyrolyzed by means of heat transferred from a mass of surrounding inert material (sand) initially heated at temperatures between 400 and 800 °C. Monitoring the evolution of temperatures in the system allowed calculation of heat for pyrolysis (QP) as a function of wood bed temperature. At pyrolysis conditions where slow heating rates of the wood bed are realized, changes in QP were clearly linked to the decomposition of the individual constituents of biomass (cellulose, hemicellulose and lignin), with consecutive exothermic and endothermic stages. When high temperature gradients were present, these stages were simultaneous and QP continuously increased with temperature, reaching 550 kJ kg−1. Under these circumstances, a correlation is provided for QP (T) up to 556 °C. The enthalpy of the pyrolysis reactions ($Delta$HP) was also estimated. Results show good coincidence with previously reported literature values. The proposed experimental system could be useful for determining heat requirements of pyrolysis under different operational conditions.
2018
Ábrego, Javier; Plaza, Daniel; Luño, Francisco; Atienza-Martínez, María; Gea, Gloria
Pyrolysis of cashew nutshells: Characterization of products and energy balance Journal Article
In: Energy, vol. 158, pp. 72–80, 2018, ISSN: 03605442.
@article{Abrego2018,
title = {Pyrolysis of cashew nutshells: Characterization of products and energy balance},
author = {Javier Ábrego and Daniel Plaza and Francisco Luño and María Atienza-Martínez and Gloria Gea},
doi = {10.1016/j.energy.2018.06.011},
issn = {03605442},
year = {2018},
date = {2018-09-01},
journal = {Energy},
volume = {158},
pages = {72--80},
publisher = {Elsevier Ltd},
abstract = {Cashew cultivation leads to the generation of large amounts of nutshells. In order to determine whether pyrolysis could be a suitable method for the valorization of this agricultural residue, cashew nutshells (CNS) from Burkina Faso were pyrolyzed in the temperature range between 400 and 600 °C in a laboratory-scale fixed bed reactor. The solid, liquid and gaseous fractions were quantified and characterized, with special focus on the solid product. Recovery of the cashew nutshell liquid (CNSL) was accomplished during pyrolysis separately from the pyrolysis liquid. Results suggest that, except for the aqueous fraction, all the products obtained from pyrolysis are suitable for fuel purposes, and that part of the CNSL can be recovered below 200 °C during the heating process. A preliminary energy balance of the process shows that burning the gases can provide the energy necessary for the process at a pyrolysis temperature of 500 °C.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cashew cultivation leads to the generation of large amounts of nutshells. In order to determine whether pyrolysis could be a suitable method for the valorization of this agricultural residue, cashew nutshells (CNS) from Burkina Faso were pyrolyzed in the temperature range between 400 and 600 °C in a laboratory-scale fixed bed reactor. The solid, liquid and gaseous fractions were quantified and characterized, with special focus on the solid product. Recovery of the cashew nutshell liquid (CNSL) was accomplished during pyrolysis separately from the pyrolysis liquid. Results suggest that, except for the aqueous fraction, all the products obtained from pyrolysis are suitable for fuel purposes, and that part of the CNSL can be recovered below 200 °C during the heating process. A preliminary energy balance of the process shows that burning the gases can provide the energy necessary for the process at a pyrolysis temperature of 500 °C.
Atienza-Martínez, María; Ábrego, Javier; Mastral, José Francisco; Ceamanos, Jesús; Gea, Gloria
Energy and exergy analyses of sewage sludge thermochemical treatment Journal Article
In: Energy, vol. 144, pp. 723–735, 2018, ISSN: 03605442.
@article{Atienza-Martinez2018,
title = {Energy and exergy analyses of sewage sludge thermochemical treatment},
author = {María Atienza-Martínez and Javier Ábrego and José Francisco Mastral and Jesús Ceamanos and Gloria Gea},
doi = {10.1016/j.energy.2017.12.007},
issn = {03605442},
year = {2018},
date = {2018-02-01},
journal = {Energy},
volume = {144},
pages = {723--735},
publisher = {Elsevier Ltd},
abstract = {The aim of this research was to provide a methodology for calculating the energy and exergy balances for the thermochemical treatment of sewage sludge. The results of the balances were assessed and compared for three different scenarios (torrefaction, pyrolysis and pyrolysis combined with catalytic post-treatment of the vapors). The balances were calculated based on previously published experimental data and evaluated under different conditions. The results indicated that the endothermicity decreased with the severity of the process. The energy recovery from the products favored the exothermicity of the processes. The three-step process (pyrolysis of torrefied sewage sludge combined with catalytic post-treatment of the hot vapors) was the least exergy efficient scenario.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The aim of this research was to provide a methodology for calculating the energy and exergy balances for the thermochemical treatment of sewage sludge. The results of the balances were assessed and compared for three different scenarios (torrefaction, pyrolysis and pyrolysis combined with catalytic post-treatment of the vapors). The balances were calculated based on previously published experimental data and evaluated under different conditions. The results indicated that the endothermicity decreased with the severity of the process. The energy recovery from the products favored the exothermicity of the processes. The three-step process (pyrolysis of torrefied sewage sludge combined with catalytic post-treatment of the hot vapors) was the least exergy efficient scenario.