Xabier Erdocia

• PhD
• Professor (Associate) at University of the Basque Country

Corrosion is an inevitable process that has a significant economic impact globally. Nevertheless, numerous techniques exist to regulate or counteract the effect on metal surfaces. Most coating materials are either pricey or detrimental to the environment, which explains the growing popularity of environmentally friendly inhibitors, also known as gr...

Deep Eutectic Solvents (DESs) have emerged as promising eco-friendly pre-treatment agents for lignocellulosic biomass, offering considerable advantages for the nanofibrillation process. This study investigates the impact of DESs on cellulose fibers morphology, focusing on solubilization phenomena in the amorphous regions that may facilitate cellulo...

The valorization of chitinous biomass from underutilized renewable carbon feedstock offers alternative routes for bioproduct development, reducing our dependence on nonrenewable and nonbiodegradable materials composed of fossil carbon. This work utilizes crustacean waste consisting of inedible shells to isolate chitin and its derivatives, chitin na...

Lignin-activated carbon (AC) composites were employed as electrode active materials to develop more environmentally friendly Supercapacitor (SC) materials with enhanced properties. This way, the hydroquinone/ quinone moieties present in lignin molecules added Faradaic processes to the system, and the capacitance of the active material increased, ma...

Bio-polyols, produced by liquefying lignin with polyhydric alcohols, offer a promising alternative to conventional polyols for polyurethane production. To enhance the sustainability on the production of these bio-polyols, this study proposes the use of crude glycerol and microwave-assisted liquefaction as substitutes for conventional methods and co...

Producing materials from renewable resources is urgent in the current society due to the increment of oil price, environmental concern, and population growth. Lignocellulosic biomass is one of the most abundant renewable resources on earth, and it is composed of cellulose, hemicellulose, and lignin. This third component comprises 15–30% of biomass...

In this work, different lignins were obtained from two different extraction methods (kraft and organosolv) but from the same raw material (Eucalyptus globulus sp.). They were subsequently fractionated to determine the differences of each extraction method and their corresponding physicochemical properties found in fractionation sequence and obtaine...

The depletion of nonrenewable resources highlights the need for sustainable energy production and basic commodities alternatives. Thus, in the last years, several studies have been carried out on the valorization of lignocellulosic biomass in order to be converted into high-added-value products, such as biofuels, chemicals, and biomaterials, which...

Thymol is a renewable substance and has a high antimicrobial efficiency, which indicates that it could be used to produce sustainable biocides. In this study, we used kraft lignin as a partial replacement for a traditional surfactant in order to solubilize thymol in water. In this sense, this article reports an unprecedented method for using a kraf...

Lignocellulosic biomass is described as a three-dimensional polymeric composite material synthesised by plants. It consists mainly of structural components along with other minor non-structural compounds. The structural compounds are formed by three biopolymers: cellulose, hemicelluloses and lignin. The lignocellulosic biomass has been known as an...

In the near future, sustainable and efficient biorefineries would be essential for the production of commodity chemicals and high-added value compounds. Therefore, in this work, six scenarios differing on the delignification steps and cellulose conversion routes were assessed via Life Cycle Assessment methodology in order to study the environmental...

Lignin is the second most plentiful polymer in the nature after cellulose. It is obtained as byproduct during the cellulose extraction for the pulp and paper pulping with around 70 millions tons produced worldwide. However, only about 2% is commerciallized for its utilization as a chemical product. Traditionally, kraft lignin has been burned for en...

The aim of this work was to study the influence of a renewable capping agent (CA) in the production of monomeric compounds from the depolymerization of an organosolv lignin (Pinus radiata) by a base catalyzed depolymerization (BCD) process. After the delignification process of the Pinus radiata sawdust, the lignin contained in the black liquor was...

The whole process of lignin extraction from a lignocellulosic waste streams (almond shell) by sulfur-free methods and its depolymerization by base catalyzed or solvolysis reactions have been addressed in this work. In addition, the influence of avoiding the lignin isolation stage prior to its depolymerization reaction has been studied based on the...

In this work, an integral valorisation of almond shells through a biorefinery approach was studied. The three main components of almond shells were extracted, isolated and characterised. The autohydrolysis process permitted the extraction of the hemicellulosic fraction obtaining a liquor rich in xylooligosaccharides (22.12 g/L). Then, two different...

Agricultural residues (olive tree pruning and almond shell) were subjected to different delignification treatments (organosolv and soda) and the obtained liquors were treated in a high-pressure reactor at 300 °C for 80 min to depolymerize the dissolved lignin. In this way, the step of precipitating lignin from the liquor was avoided. The phenolic o...

Almond shells are waste biomass generated in agro-industrial activities, which represent a resource that can be further valorized upon treatment. The purpose of this work was to assess new value-added products obtained through a novel multi-stage delignification process of almond shells. A comprehensive chemical characterization of the raw material...

Recently, the valorization of the lignin fraction in the biorefinery scheme is getting more and more attention as the use of this component for the production of bio-based chemicals is crucial for the success of the integral development of lignocellulosic biorefinery processes. The present work includes the exergy performance and the economic analy...

A considerable share of final energy consumption in the industrial sector corresponds to thermal energy. Process heating demand is an important part of a large variety of industries. Even if industrial processes work in a wide range of temperatures, there are many systems and unitsthat need low and medium temperatures (up to 250°C). Solar industria...

Among the many oxygen-rich chemicals that can be obtained from biomass, polyols, such as ethylene glycol and propylene glycol, are widely used in industry. Liquid polyols have been used in polyurethane foam preparation and as components of adhesives. Hydrolysis, coupled with hydrogenation and hydrogenolysis allows transformation of biomass or its c...

Biomass wastes (almond shell and olive tree pruning) were used in this work as raw materials for the extraction of high purity lignin by different delignification methods. A pretreatment stage was carried out to remove the major hemicelluloses content in the solid feedstocks. Afterwards, two sulfur-free pulping processes (soda and organosolv) were...

Lignin structure elucidation is one of the main targets for biorefinery related research. Because of its complexity, obtaining reproducible results in a straight-forward way is very important. One of the values that is used to compare different lignins is the syringyl:guaiacyl (S/G) ratio, which has been measured in different ways. The most reliabl...

L ignin structure elucidation is an important but difficult task for biorefinery research. Lignin has a complex structure composed of a variety of substituted aromatic rings and is the only known renewable source of aromatic compounds. When lignin is depolymerized, the obtained products can be valuable as platform chemicals for numerous processes a...

This work is aimed to produce small phenolic compounds from Kraft black liquor. For this purpose, depolymerization reaction is directly carried out over the liquor, without a previous isolation of lignin. In this sense, the intensification of lignin valorization is carried out by the reduction of the total stages of the whole process. Due to the al...

Oxidative depolymerization of lignin obtained from pine and willow can be achieved in a novel system encompassing the ionic liquid (IL) 1-butylimidazolium hydrogensulfate coupled with a vanadium based polyoxometalate (POM) under oxygen rich conditions. Along with an array of phenols and functionalized aromatics, vanillin and syringaldehyde were the...

This work provides an assessment of the exergy performance of the fractionation of olive tree by organosolv process. The process combines a mixer, a heater, a reactor and, finally, a filtration step for the components separation. Flowsheet modeling and exergy analysis were carried out using Aspen Plus® program, after which, an optimization of the p...

Willow biomass was subjected to different pretreatment conditions with triethylammonium hydrogen sulfate as solvent and the produced lignin solutions were treated by oxidation either homogeneously using H2O2 as oxidant, or by heterogeneous catalysis using TiO2. Lignin, residual lignin, oil and the recovered IL were characterized in order to determi...

The development of value-added lignin products from industrial residues of pulping is still a challenge. The present study was aimed to use oil obtained from organosolv lignin by base-catalyzed depolymerization at 300 °C for 40 min as a wood-protecting agent. First, the bio-oil was diluted to 1 wt% into an acetone and water solution, and physicoche...

Organosolv fractionation is a successful process to separate lignocellulosic biomass in its main component for the preparation of multiple products including biofuels, chemicals, and materials. In this study, the exergetic behaviour of the delignification process of olive tree pruning using ethanol-water as solvent media was evaluated. The experime...

Olive tree pruning was delignified by organosolv processes (acetosolv, formosolv, and acetosolv/formosolv) to extract different lignins. The obtained lignins (acetosolv lignin (AL), formosolv lignin (FL), and acetosolv/formosolv lignin (AFL)) were depolymerized using three different solvents (methanol, ethanol, and acetone) under supercritical cond...

The depolymerisation of lignin directly in the black liquor was studied, comparing two ionic liquids as extracting solvents (butylimidazolium hydrogen sulphate and triethylammonium hydrogen sulphate), under oxidising conditions. H2O2 was chosen as the oxidant agent. It was observed that lignins derived from butylimidazolium hydrogen sulphate were m...

Lignin is the second major component of lignocellulosic biomass and represents the most important source of aromatics in nature. However, traditionally lignin has being considered as a waste or used for energy generation in pulp and paper mills. Lignin can be used in a wider range of fields, among all applications, smallaromatic building blocks fro...

The hydrothermal treatment has been developed as an industrial method to enhance the biological durability and dimensional stability of wood. The resistance against wood- rotting fungi of Pinus radiata and Fraxinus excelsior industrially-heat treated at 210 ºC was evaluated inoculating Trametes versicolor and Gloeophyllum trabeum according to stand...

The development of green techniques for biomass processing and fractionation is crucial from the point of view of sustainability and environmental protection. Lignin is the second most abundant bio-renewable material on Earth. Ionic liquids are considered as green solvents due to their low vapour pressure and their reuse possibility. In this work,...

Lignin is considered the second most abundant organic natural compound in the world. Lignin represents a promising source of new materials based on renewable resources. Currently the lignin is used in low value-added applications and for energy production and chemical recycling for industrial process itself in production of pulp and paper. Only a s...

Organosolv lignin, obtained from olive tree pruning under optimised conditions, was subjected to a hydrothermal depolymerisation process catalysed by sodium hydroxide. The depolymerisation of lignin was carried out at 300 ºC using different reaction times (20, 40, 60, 70, 80, 90 and 100 min) in order to study the influence of this parameter on lign...

Nowadays, most of commercial lignin is obtained as a by-product from lignocellulose treatments performed in the pulp and paper (P&P) processes, as lignosulfonates and kraft lignins. Most of these lignins are used for energetic purposes and only a small part of them are commercially used due to the dispersing, binding and emulsifying properties...

Today, in the chemical industry, solvents are used in large quantities. Therefore, solvents establish a significant part of the environmental performance of a process and also impact on safety and health issues. In order to get greener processes especially in the case of new biorefineries it is essential the use of green solvents. Ionic liquids as...

Olive tree pruning lignin was studied to be considered as a raw material candidate for biorefinery. Different extraction treatments (organosolv treatment: 60% wt ethanol, 180 C, 90 min; alkali treatment: 90 to 1008C, 7.5% wt NaOH, 90 min; and autohydrolysis process: 1808C, 30 min) were applied to extract lignin. The isolated lignins were deeply cha...

In the hydrothermal treatments of wood, the wood is subjecting to temperatures from 170 °C to 210 °C in specific inert atmosphere where chemicals are not added, which improves different physical-mechanical characteristics directly related to wood durability and dimensional stability, at the same time decreasing the pathogens attack as well as the s...

BACKGROUND In new biorefineries the use of new green solvents is essential in order to minimize the employment of volatile organic solvents.Lignin is the most abundant residue in paper industries, however, it is necessary to purify it in order to obtain revalorized products. RESULTSIn this study, soda and organosolv lignins obtained from apple tree...

Lignin is a good candidate for photocatalytic cracking due to the presence of hydroxyl groups. The photocatalytic cracking reaction involves TiO2 as heterogeneous catalyst. In the present work lignin obtained by two different pulping methods is treated under photocatalytic conditions to be depolimerized. Different exposure times to UV radiation wer...

Different organosolv processes (acetosolv, formosolv and acetosolv/formosolv) were applied to extract lignin from olive tree pruning. Obtained lignins were characterized by several methods to determine their composition, structure and functional groups with the aim of evaluating their potential to be used for obtaining added value compounds. All li...

Different sonication times (15, 30, 60 and 120 min) were applied in aqueous media to olive tree pruning residues lignin obtained by alkaline fractionation (7.5% w/w NaOH, solid to liquid ratio 1:10 w/w, 90 min, 85 °C). The observed sample solubilisation ratio due to ultrasonic irradiation was 24–28%. The resulted liquid fractions were analyzed by H...

Nowadays, lignin is gaining importance as a potential source for aromatic chemicals. Commercial lignins are usually contaminated with cellulose, hemicelluloses and other inorganic impurities, which constitute an obstacle in their direct processing for obtaining aromatic precursors. In this work, lignins obtained from Malus domestica by alkaline ext...

In this work, olive tree pruning was used as raw material to delignify it employing organosolv treatment. Obtained liquor was hydrolyzed at a high pressure reactor at 300 degrees C for 40 min to depolymerize lignin it contains. Thus, lignin from the liquor was depolymerize avoiding the precipitation step. Different experiments were carried modifyin...