@article{Atienza-Martinez2020b,
title = {Functionalization of sewage sludge char by partial oxidation with molecular oxygen to enhance its adsorptive properties},
author = {María Atienza-Martínez and Nurull Nadia {Binti Suraini} and Javier Ábrego and Isabel Fonts and Luisa Lázaro and Hans-Heinrich Carstensen and Gloria Gea},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0959652620352458},
doi = {10.1016/j.jclepro.2020.125201},
issn = {09596526},
year = {2020},
date = {2020-11-01},
journal = {Journal of Cleaner Production},
pages = {125201},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Arauzo2020b,
title = {Combustion Characteristics of Hydrochar and Pyrochar Derived from Digested Sewage Sludge},
author = {Pablo J Arauzo and María Atienza-Martínez and Javier Ábrego and Maciej P Olszewski and Zebin Cao and Andrea Kruse},
url = {https://www.mdpi.com/1996-1073/13/16/4164},
doi = {10.3390/en13164164},
issn = {1996-1073},
year = {2020},
date = {2020-08-01},
journal = {Energies},
volume = {13},
number = {16},
pages = {4164},
publisher = {MDPI AG},
abstract = {

In this paper, hydrochars and pyrochars were produced at 260 °C under different residence times (2 and 4 h) using anaerobic digested sewage sludge (SSL) as initial feedstock. The effect of reaction time on the fuel properties of hydrochars and pyrochars was evaluated. Moreover, the combustion kinetics of raw SSL and the derived pyrochars and hydrochars without coal blending were determined at two different air flows (20 and 90 mL/min) and compared. In the same conditions, the yield of hydrochar was significantly lower than that of pyrochar, confirming the different reaction pathways followed in each process. The results showed hydrochars have lower carbon recovery and energy yield than pyrochars, making the latter more suitable for energy purposes. The thermogravimetric combustion study showed that both thermochemical treatments increased the ignition temperature but decreased the burnout temperature, which results in higher stability during handling and storage. However, raw SSL is better for combustion than hydrochar according to the combustibility index. In addition, the kinetic study showed that the activation energy of the combustion of biochars, especially pyrochar, is lower than that of raw SSL, which is advantageous for their combustion.

},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@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}
}

@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}
}

@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}
}