Roger Moya Roque

• PhD.
• www.tec.ac.cr at Instituto Tecnológico de Costa Rica

Pyrolysis of biomass residues can generate savings in the value chains of forest products due to the potential uses of its products in the forestry sector. The aim of this study was to determine the performance during slow pyrolysis process and the yields of different products of two types of residues, wood chips and solid wood board-ends from Gmel...

Physical properties were studied in commercial plantation of balsa established in Costa Rica. Among other variables studied, physical properties varied mainly for tree age, spacing, stand density, diameter, and height of trees, which we named dasometric conditions. The aim of this study was (i) to determine the variation of specific gravity (SG), a...

There is limited information regarding the adaptation of anatomical features and growth ring formation to ecological site conditions in Costa Rican mangrove trees. We used the methods and principles of ecological anatomy to explore the relationship between wood properties (e.g., ring formation, anatomical characteristics) and ecological factors for...

Surface charring is a wood modification process in which wood is charred by applying heat at high temperatures. Several tropical species from forest plantations have been widely studied for different wood modification processes in Costa Rica. This study aimed to investigate the effect of one-sided surface charring by using a heating plate at three...

One-sided surface charring of wood is a modification process used to lower moisture absorption and improve the resistance to biological degradation for durable surface exterior claddings. Cupressus lusitanica, Gmelina arborea, and Tectona grandis wood samples from fast-growth plantation were charred with a hot plate using three temperatures (300, 3...

Coco Island, located 530 km off the Pacific coast of Costa Rica, experiences rainfall of over 7000 mm/year. This study aims to explore the distinctiveness of the growth ring boundaries and the dendrochronological potential (DP) of nine tree species found on Coco Island. The distinctiveness was classified into type 1: density variation; type 2: marg...

Costa Rica produces a considerable, important quantity of wood residues. This waste can be pyrolyzed to produce charcoals as main products that can be effectively used as an energy source or to immobilize carbon for soil treatment. However, there is a lack of information about the pyrogenic carbonaceous materials (PCMs), such as charcoal or biochar...

Costa Rica produces an extensive amount of forest residues, which can be pyrolyzed slowly to produce by-products like charcoal, wood vinegar, bio-oil, and non-condensable that can be effectively used in agricultural crops, providing a comprehensive approach to leveraging forest resources for finding renewable sources for agriculture production. How...

Short-rotation crop (SRC) systems with woody species have been planted in Costa Rica. However, information about different tree species and spacing is limited. The objective of the present study was to examine biomass production and the physical, energy, and chemical properties of feedstock of four tropical tree species (Cordia alliodora, Dipteryx...

Introducción: Gmelina arborea Roxb. es plantada en los programas de reforestación con clones para mejorar la productividad.Objetivos: Evaluar las propiedades de la madera y determinar la heredabilidad de 14 clones de G. melina para establecer un ranking genético de selección.Materiales y métodos: El ensayo se estableció con un diseño de bloques com...

Forest plantations biomass is an interesting energy source for power generation with downdraft gasifier of less than 1 MW in Costa Rica. Thus, this work aims at evaluating the performance and efficiency of the electrical and thermal energy generation system in a downdraft gasifier with five woody biomass (Acacia mangium, Cupressus lusitanica, Gmeli...

Dipteryx panamensis and Hieronyma alchorneoides are two species of high specific gravity used in reforestation programs in Costa Rica, but they lack products with structural value for commercialization. In order to introduce the wood of these two species in the market, the objective was established to study the behavior of solid timber beams and gl...

Pineapple leaf fibers (PALF) were biopulped using Trametes versicolor, and the resulting biopulp was bleached with xylanase-enzymatic treatments. The biopulping was extensively described using determinations of fiber morphology, color, chemical composition, extractive content, and thermal stability using the structural characteristics determined by...

Nanomaterials have emerged as a promising and exhilarating class of materials that gained prominence in the advancement of technology due to their properties. It is in high demand for several practical applications, and one of them is in wood science, particularly as an adhesive used in wood composites and as an adhesive for wood joints in the prep...

Alnus acuminata, Vochysia ferruginea and Vochysia guatemalensis, low-density species, have been previously studied due to their potential in the thermomechanical densification process. However, their spring back and set recovery values are reported to be high. Therefore, the objective of this work was to investigate and evaluate the effects of stea...

Smallholders who own Tectona grandis plantations receive limited profit from residues. Charcoal production from wood residues allows smallholders to become part of the commercial chain. The purpose of this study was to examine the process of making charcoal from T. grandis wood residues using the earth pit method, as well as the costs and economic...

The treatment of acetylation on tropical woods is influenced by their different levels of permeability and how these affect the weight percentage gain (WPG) in acetylated wood. The objective of this study was to identify the effect of acetylation on physical properties, hygroscopic and dimensional stability, wetting rate, and durability of nine tro...

The present study aimed to analyze the effect of the addition of Ricinus communis and Jatropha curcas seeds in two mass percentages (10 and 30%) in coffee pulp waste feedstocks on the physical, chemical, and energetic properties, compressive strength, and durability. The results showed that the high ash content, low apparent density, and higher hea...

Physical-mechanical properties of three-layer counter-laminated boards (CLT) were determined, made with Tectona grandis and Gmelina arborea wood, from forest plantations. Two types of adhesive were used, isocyanate polymer emulsion (EPI) and pre-catalyzed vinyl acetate modified with 3% nanoclay (PVA-na). They applied two treatments to activate the...

Magnetic wood is a composite material that achieves harmony between both woody and magnetic functions through the active addition of magnetic characteristics to the wood itself. In addition to showing magnetic characteristics, magnetic wood offers low specific gravity, humidity control and acoustic absorption ability. It has potential for broad app...

Dipteryx panamensis is used in reforestation in Costa Rica and a genetic improvement program has been recently started in the country. The objective of the present study was to study the effect of tree trunk height on the variation of bark, sapwood, heartwood, green density (GD), specific gravity (SG) and green moisture content in green condition (...

The relaxation of growth stress in trees growing in fast-growth conditions, as plantation in tropical areas, affects lumber quality during of sawing or drying process. It was evaluated two pretreatments (heating and steaming application) before sawing process and endless screw use to maintain the boards pressed during drying ofDipteryx panamensisan...

The Dipteryx genus has a natural distribution throughout several tropical countries in Latin America. This taxon has several tree species, all recognized for their high-density wood. The objective of this research was to study the variation and genetic control of several wood properties, including bark, sapwood, heartwood, green density (GD), speci...

The relaxation of growth stress in trees from plantation forests of tropical areas is manifested in the quality of wood after the sawing and the relaxation of drying stress is expressed during the drying process, producing low wood quality. The present study aims to evaluate the lumber quality in logs by heating and steaming application before sawi...

The lianas in the family Sapindaceae are known for their unique secondary growth which differs from climbing species in other plant families in terms of their cambial variants. The present study deals with the stem anatomy of self-supporting and lianescent habit, development of phloem wedges, the ontogeny of cambial variants and structure of the se...

The purpose of the work was to assess the combined effect of furfurylation, along with the addition of silver nanoparticles (NPsAg), on the thermal stability, density, water absorption, hardness and biological durability of juvenile tropical woods originating from Costa Rican forest plantations. It was demonstrated that the weight percentage gain (...

Biochar from agroforestry biomass residues is an alternative source of fertilizers for improving the soil fertility. In Costa Rica, Cedrela odorata is planted in pure plantations and agroforestry systems and different types of substrates are used in the nursery to enhance the growth and performance of the young saplings. The main objective of the p...

Paulownia tomentosa is utilized in Costa Rica and other countries for wood production and as feedstock for biomass, though the variation of wood properties for this species is scarcely known. In this work, the specific wood properties of a 5-year-old plantation in Costa Rica were studied. The results showed that bark and pith percentage and wood sp...

Charcoal production from woody species from fast-growth plantations has gained importance in a variety of uses. The objective of the present work is to determine the density, compression resistance, moisture content (MC), gross calorific value (GCV), ash and volatile content, chemical modification by Fourier-transform infrared spectroscopy (FTIR) s...

Teakwood is popular in the international market due to its excellent durability, good aesthetic properties and mechanical resistance. Teak has been the priority species in reforestation programs for many years because of its unique features. Since 1900, this species has been planted in areas where it grew naturally. In the present century, it is es...

Key messageGrowth stresses are usually present in the fast-growing trees of forest plantations and can be evaluated along stem diameter. Growth stresses are relaxed after tree felling and during sawing and drying, and are manifested in the lumber quality. Different methods have been employed to reduce the effect of growth stresses, such as steaming...

There is considerable interest in the development of thermo-hydro-mechanical (THM) treatments to increase the density of low-density woods. However, the development of processes for improving the properties of low-density woods in regions with lower investments in investigations and development, such as tropical areas, is often limited by the equip...

The main objective of this research was to evaluate the use of unmanned aerial vehicles (UAVs) in estimating the aboveground biomass and carbon, and the dasometric characteristics at three different spacings (2.5 m × 1.0 m, 2.5 m × 2.0 m and 2.5 m × 3.0 m) in a silvopastoral system (SPS) for the biomass production of Tectona grandis. A total of 90...

Evaluation of the glue line in CLT panels and in other wood composite products in general is of great interest. Non-destructive methods such as determination of the velocity of ultrasound waves going through the materials are commonly applied to evaluate wood products. The present work is aimed at mapping ultrasound velocity (UV) to identify proble...

Steaming and heating as pretreatments before log sawing reduce the negative effects of growth strain (GS). The object of this work was to study the reduction of GS in logs of Dipteryx panamensis from a fast-growth plantation using steaming and heating treatments and evaluate the effects on the lumber quality. According to the results, the maximum t...

This work focused on the upgrading of non-durable tropical wood species originating from fast-growing plantations of Costa Rica. Modification of such tropical woods with furfuryl alcohol, although has not been broadly studied up to date, offers a potential way to increase their low durability. The purpose of this research was to investigate the mod...

Densification is one method used to modify low-density woods to make them achieve the hardness required for flooring application. The purpose of this study was to investigate the effect of thermo-mechanical densification with pre-heating in wood of Alnus acuminata, Vochysia ferruginea and Vochysia guatemalensis from, seeking to stabilize and reduce...

The present work aims at determining the behaviour relative to load applied and displacement and the design values of Howe trusses 7.2 m long fabricated with timber from Gmelina arborea, Tectona grandis and Cupressus lusitanica, using metal plates. The static flexural strength of the trusses was tested by applying the load to three different points...

Alnus acuminata, Vochysia ferruginea, and Vochysia guatemalensis are three low-density wood species used for reforestation in Costa Rica. The goal of this work was to study a thermo-hydro-mechanical densification process and test the characteristics of densified wood of these species. Twelve densifying treatments based on temperature, compression t...

Micro- and nanofibrillated cellulose (MNFC) was extracted from pineapple stems by acid hydrolysis, then characterized and tested in two concentrations (0.5 and 1.0 wt%) in polyvinyl acetate (PVAc) and urea-formaldehyde (UF) adhesives. The modified adhesives were used to glue three tropical wood species ( Vochysia ferruginea , Cordia alliodora , and...

Acetylation of softwoods has been largely investigated to increase the dimensional stability and biological resistance of wood. However, the knowledge of this technology has not been applied to tropical hardwood species up to date. The objective of this work was to study the effect of acetylation on nine tropical hardwood species, from forest plant...

This work aimed to evaluate the effect of the precipitation of CaCO3 via subsequential in-situ mineral formation based on a solution-exchange process of two solution-exchange cycles via impregnation with CaCl2 in ethanol and NaHCO3 in water. The effects were investigated in terms of the structure of the wood and the thermal, physical, mechanical, a...

The vertical density profile (VDP) of thermo-hydro-mechanically (THM) densified wood is a result of the combined effect of process parameters and properties of unmodified wood. The effect of thermosetting resins on VDP of THM densified wood has not been extensively studied. The aim of this study was to determine the combined effect of methylated me...

The first tested in energy crops plantation with short rotation species (SRC) in the tropical region are based in the establishment of clones used in the production of sawlog. Thus, in this study aims to assess aspects of growth, tree architecture, production and quality of biomass and the effect on wood gasification of Gmelina arborea trees plante...

Highlights Arundo donax, Pennisetum purpureum, and P. purpureum × P. glaucum planted at 10 ³ plants ha ⁻¹ were studied. Biomass production and energy characteristics were evaluated at 12, 18, 24, and 30 months. The production of dry biomass varied between 2.52 and 39.25 Mg ha ⁻¹ . The biomass quality and production of Arundo donax were different fr...

Research and implementation of energy crops using short-rotation woody species (SRWC) are increasing in Latin America, especially for biomass production and use in bioenergy. For this purpose, one of the main factors to consider is species assessment. Therefore, the objective of the present study was to evaluate the growth characteristics, the prod...

The construction sector in Costa Rica produces approximately 100 kg per square meter of residues, of which wood waste comprises 30%. Utilization of these wastes is still limited, but options are being sought and biomass is one of them. The aim of this work was to evaluate the characteristics of biomass produced from wood waste from construction, it...

The first attempts to establish energy crops in the tropical regi­on using short rotation species are premised on the utilization of clones for wood production. Therefore, the present study is aimed at examining the growth aspects (survival, diameter and tree height), leaf architecture (leaf area index [LAI], number and angle of the branches and sy...

The objective of this study was to characterize the performance of composite wood blocks (CWB) by testing internal bonding, nail extraction resistance, and water absorption. The CWB were glued with two wood adhesives, polyvinyl acetate (PVAc), and urea formaldehyde (UF), modified with 1% nanocrystalline cellulose (NCC). Three tropical species were...

Gasification is a thermochemical process in which organic raw materials are converted into gases containing H2 and CO (syngas), which can be used to obtain products such as electricity, fuels and other chemicals. It is influenced by characteristics of the system where the thermal conversion takes place, the operating conditions and the raw material...

Mortality, diameter at 30 cm over ground level, height, biomass production, and carbon capture (CC) for different tree components (trunk, bark, branches, and leaves) in two locations in Costa Rica, during their first three years and with three plantation spacings (1.0 × 0.5 m, 1.0 × 1.0 m, and 1.0 × 2.0 m) were obtained for Gmelina arborea Roxb. tr...

El conocimiento de las propiedades de la biomasa proveniente de clones de Gmelina arborea Roxb en cultivos energéticos en sistemas de corta rotación (SRC en inglés) en Costa Rica es limitado. Los primeros intentos están basados en el uso de clones para la producción de madera, pero plantados en SRC. Así, el presente estudio tuvo como objetivo evalu...

The present work studies the morphological, physical, mechanical and chemical properties, decay resistance, preservation and workability of Cedrela odorata wood from trees growing in agroforestry systems with Theobroma cacao at four ages (4-, 5-, 6- and 7-years-old) in Costa Rica. It was found that the morphological properties (heartwood, pith and...

In countries like Costa Rica, there is an interest in developing wooden trusses in a versatile and light way. However, there is a key aspect in the behavior of truss connections in this product. Therefore, the present study determines the structural behavior of the truss connections and the displacement, the resistance, the stiffness values and the...

Tectona grandis (teak) is an important commercial tree species that is widely used in tropical dendrochronology due to the formation of climate-sensitive annual growth rings. However, young trees growing in plantation conditions exhibit poor ring visibility during the first years of growth, limiting the dendrochronology application. In the present...

Tectona grandis (teak)is an important commercial tree species that is widely used in tropical dendrochronology due to the formation of climate-sensitive annual growth rings. However, young trees growing in plantation conditions exhibit poor ring visibility during the first years of growth, limiting the dendrochronology application. In the present s...

A composite between particles obtained residual pallets of Pinus sp and cement was manufactured. Also, three methods were performance for wood particles: hot water washed, unwashed and unwashed with calcium carbonate (CaCO3). Different concrete-wood particle ratios were tested. Curing time was evaluated with ultrasonic pulse velocity (USV) and dens...

Studies related to biomass production, with a focus on energy uses for short-rotation woody crops (SRWCs), are limited in Latin America. The research that is available relates to a variety of tested SRWC species (50 species), however, the most important species are Populus, Salix, Eucalyptus, Acacia, and Gmelina arborea. In the existing studies, st...

Multilayer carbon nanotubes (MWCNT) have been used in the reinforcement of materials due to their versatility; however, only little is known about their use in tropical wood. In the present study, functionalized MWCNT were introduced a hydroxyl group in water solution at two concentrations, 0.05% and 0.10%; and injected using the vacuum pressure me...

Shade-trees with energy use in coffee plantations are an important alternative to increase profitability in groforestry systems. The aim of this study was to investigate gross calorific value (GCV) of 15 shade-tree species in coffee plantations in Costa Rica. The relationships between specific gravity and extractives content on GCV was evaluated. T...

En construcción de viviendas, las estructuras más eficientes para soportar las cargas provenientes de techumbres corresponden a las cerchas. Cuando se trata de fabricarlas con madera, un punto importante de estas son las uniones. Actualmente se ha introducido la utilización de placas metálicas dentadas para estas uniones, sin embargo, el mercado aú...

To elucidate the development of heartwood, bark, sapwood, pith and specific gravity of wood in fast-growing teak (Tectona grandis) plantations in Costa Rica, we sampled three trees in each of 55 plantations and modelled each variable with age, site and different tree heights. Age and stand density of plantations were significant correlated with ste...

The present study had the objective of determining the behaviour of Pratt-type trusses made from Gmelina arborea and Hieronyma alchorneoides lumbers relative to loads, displacement and design load stiffness using two types of fasteners (nails and screws) for two spans (6 and 9 m). It was found that the maximum load values were greater in H. alchorn...

ProposeTree diameter and height, yield and chemical and energy properties increment throughout two different ages (1- and 2-year-old) were evaluated in Gmelina arborea trees growing in short rotation woody crops at three sites and three spacings (0.5 × 1.0, 1.0 × 1.0 and 2.0 × 1.0 m). ResultsThe results showed great variation in parameters evaluate...

Aim of study: Plantations are threatened by an emerging disease called “Gmelina death disease”. The objective of this study was measured the incidence and severity of this disease and were correlated with the characteristics of the plantations, micro- and macronutrients in the soil and climatic parameters. Area of study: The present study evaluate...

We evaluated the thermogravimetric and devolatilization rates of hemicellulose and cellulose, and the calorimetric behavior of the torrefied biomass, of five tropical woody species (Cupressus lusitanica, Dipteryx panamensis, Gmelina arborea, Tectona grandis and Vochysia ferruginea), at three temperatures (TT) and three torrefaction times (tT) using...

This study evaluated the properties of wood from Cedrela odorata trees of two populations planted in an agroforestry system with Theobroma cacao (cocoa). Morphological, physical and mechanical properties differences were determined between two populations and the variation of the properties (morphological and physical) at different tree heights. Pr...

La présente étude vise à établir les variations du duramen (pourcentage, diamètre, rayon, volume) rapportées à la hauteur des arbres et à l’épaisseur de l’aubier, ainsi que l’âge de début de formation du duramen et sa hauteur maximale pour les arbres de l’essence Tectona grandis. Les résultats de l’échantillonnage de seize plantations réparties dan...

This study evaluated the effect of thermo-treatment (THT) at 4 temperatures on the density, shrinking, mass loss, moisture absorption, color, durability in terms of resistance to decay, flexural strength, tensile adhesion of glue line and the infrared spectrum of the wood of Tectona grandis and Gmelina arborea. Sapwood, heartwood and radial and tan...

Physical and mechanical properties were evaluated on cross-laminated panels (plywood) fabricated with three plantation species (Cordia alliodora, Gmelina arborea and Vochysia ferruginea) from tropical climates in Costa Rica. The panels were glued with urea-formaldehyde resin modified with nanoclay at four concentrations (0,75; 1,00; 1,50 and 2,00 %...

The object of this research is to develop a model for the calibration of prefabricated timber wall frames (PTWFs) with dimension of 244 by 244 cm (width by height) respectively made of Gmelina arborea Roxb. and Hieronyma alchorneoides Allemão wood and two types of fastener (nails and screws). The PTWFs were submitted to a lateral load test and the...

p>Se analizó el sistema de clasificación visual de la madera por defectos admisibles estructurales en Costa Rica. Se propuso incluir en la norma INTECO 06-07-03:2011 de Costa Rica un cuadro de evaluación visual de la madera aserrada por tres grados estructurales, según defectos admisibles. Se muestra su aplicabilidad en madera aserrada de Cupressus...

Hot water and alkali treatments were performed on pineapple leaves at three different temperatures (50ºC, 70ºC and 90ºC) and three different levels of concentrations of NaOH solution (2, 4, and 6%). The effect of pre-treatment was analyzed by comparing the physical qualities of pineapple leaf fiber (PALF). A physical property analysis of the PALF e...

En Strychnos bredemeyeri, pequeñas porciones de cambium dejan temporalmente de producir xilema secundario y produce más floema centrífugamente. Un nuevo segmento del cambium se diferencia en la parte exterior de este floema formado, entonces estos se unen al cilindro regular para formar un anillo. Esta repetida actividad da como resultado la inclus...

Stem flattening in Rhynchosia pyramidalis (Fabaceae) is achieved by the development of crescent-shaped successive cambia on two opposite sides of the stem (referred hereafter as distal side). Other lateral sides of the stem (adjacent to supporting host and its opposite side, referred as proximal sides) usually possess single cambium. In the young s...

Torrefaction can increase the energy yield of biomass for better utilization in bioenergy, but chemical changes occur during the pretreatment process. Wood residues of Cupressus lusitanica, Dipteryx panamensis, Gmelina arborea, Tectona grandis, and Vochysia ferruginea were torrefied for three different time periods (8, 10, and 12 min) and three dif...

The purpose of the biomass torrefaction and pelletizing processes is to increase its energy properties, be environmentally friendly, decrease shipping costs, and make handling easier. The objective of the present work is to evaluate the density, internal density variation by X-ray densitometry, moisture content, water absorption, and compression fo...

Nanotechnology applications have potential for improving decay resistance of wood under tropical conditions. In this work, nine commercial timbers from Costa Rica were treated with silver nanoparticles synthetized with NPsAg-ethylene glycol through pressure. White-rot (Trametes versicolor) and brown-rot (Lenzites acuta) fungi were tested. According...

This study evaluated the durability in terms of decay and mechanical resistance of thermally modified (TM) wood of Tectona grandis and Gmelina arborea treated at 160, 180, 200 and 220 °C. The TM wood of both species treated above 200 °C and 180 °C respectively presents lower weight loss (WL) after 300 days exposure in field and accelerated testing....

Se diseñaron dos cerchas “tipo pratt” con luces entre apoyos de 6 m y 9 m, construidas con madera de Gmelina arborea (melina) e Hieronyma alchorneoides (pilón), utilizando dos tipos de uniones: clavos y tornillos. Las cerchas fueron sometidas a cargas de flexión para establecer los valores de resistencia y luego derivar los cuadros de diseño para s...

Torrefaction is a thermal pretreatment commonly applied to biomasses developed at 200-300 °C in the absence of oxygen. This allows to obtain improved biomasses´ properties for energy purposes. In the present work, a study of five fast-growing species (Cupressus lusitanica, Dipteryx panamensis, Gmelina arborea, Tectona grandis and Vochysia ferrugine...