Research Articles

The proper selection of solvents is important during liquefaction of biomass process to produce fuel additives and valuable chemicals. In this study, novel low-cost liquefying agents such 1,2-propanediol (PG), diethylene glycol (DEG), and 1,4-butanediol (BDO), as well as the traditional liquefying agent, ethylene glycol (EG), were used. It was found that the liquefaction yield of corn stalk in the presence of PG at the optimum temperature of 180 °C was up to 99.2%, which was higher than that of the other three liquefying agents. The main components and functional groups of bio-oil with an acid catalyst were characterized by gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR). The chief constituents of bio-oil were complex, and corn stalk could be effectively degraded with PG liquefaction. Moreover, the thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) data also revealed that the fiber structure of the liquefied corn stalk was destroyed and essentially liquefied during PG liquefaction. Consequently, all the results in the study successfully confirmed that PG can provide an efficient and environmental process for generating bio-oil from lignocellulosic mass at a low cost in liquefaction of corn stalk.

To solve the odor emission problem of lacquer veneer particleboards, as well as to identify the key odor compounds and their sources, alkyd resin enamel-coated particleboards were studied via gas chromatography-mass spectroscopy-olfactometry. A single-factor experiment was established under various environmental conditions. The odor-causing compounds were identified, and the effects of environmental factors on the volatile organic compounds (VOCs) and odor emissions were investigated. The results showed that the main odor substances released from the alkyd resin enamel-coated particleboard were aromatic compounds, aldehydes, and alkanes, which are typically low in toxicity. The total volatile organic compounds concentration and total odor intensity increased as the temperature and relative humidity increased, but decreased as the air exchange rate to loading factor ratio increased. The temperature had a greater impact on the release of VOCs from the alkyd resin enamel-coated particleboard than either the relative humidity or air exchange rate to loading factor ratio. The odor substances concentration increased with an increase in the temperature, while the relative humidity and air exchange rate to loading factor ratio had little effect.

This study investigated the effects of furfurylation on the acoustic vibration performance of Paulownia wood on the basis of improving dimensional stability. Paulownia wood was chemically modified with 25%, 50%, and 75% furfuryl alcohol and different curing times (8 h, 12 h, and 15 h). The dimensional stability of Paulownia wood was significantly improved after furfuryl alcohol modification. As indicators of acoustic vibration efficiency, the acoustic impedance (ω,), attenuation coefficient (δ), and periodic energy loss (tanδ/E) parameters were improved. The vibration sound evaluation indicator E/G was also evaluated. The best treatment conditions were 25% furfuryl alcohol and an 8 h curing time. Under these process conditions, the acoustic impedance ω, attenuation coefficient δ, and periodic energy loss parameter tanδ/E of the Paulownia wood increased by 21.1%, 156%, and 157%, respectively, the E/G indicator increased by 38.8%, and the specific dynamic elastic modulus E/r and acoustic quality constant R decreased by 36% and 45%, respectively. The sound quality was reduced under other process conditions.

This study aimed to identify the performance properties that drive the shelf price of kitchen paper towels and evaluate whether sustainability is an important driver for pricing. Nineteen products were compared according to their performance (softness, absorbency, and strength), technology, and fiber morphology. Metrics to rank the products in different grades (economy, premium, and ultra) according to their performance were provided. A multiple linear regression showed that absorbency and softness are the most significant properties used to predict the price. Market data indicates that there is a segment of consumers willing to pay a premium price for products marketed as “sustainable”, even though their performance is comparatively inferior to the majority of the samples. Sustainable products are up to 85% more expensive than regular products. The metrics obtained in this work can contribute to improvement in market transparency, and aid companies in deciding strategies for product development and new investments.

The depleted state of the northern hardwood forests of Quebec, Canada has forced the hardwood flooring industry to adapt its production. American beech (Fagus grandifolia), a traditionally less desired species, is now increasingly being included in wood supplies to sawmills in western Quebec, where forest managers hope this resource can be valued before the onset of significant mortality and wood degradation from the beech bark disease. This study aimed: 1) to assess the preferences of consumers towards American beech flooring products compared to well known species traditionally used in this market; and 2) to compare results obtained in face-to-face surveys with web-based surveys of consumer preferences. Results from both survey types revealed that the finishing colour was the most important factor affecting the decision of respondents, followed by species and price. American beech ranked third in species preferences, just above birch. Divulgating species names only affected (positively) the perception of respondents towards oak. It was concluded that American beech could be included in the current wood flooring market, probably among cheaper options such as birch. The similarity of results from face-to-face and online surveys suggests that general trends in consumer preferences could be rapidly and cheaply assessed using the latter option.

The waste generated from the palm oil production chain is increasing. The purpose of this work is to enable more effective use of empty fruit bunches (EFB) to produce reducing sugars by a hydrothermal treatment process (hydrothermolysis) at elevated pressures and temperatures. The EFB was dried and milled to obtain three different granulometries: thin (> 60 mesh), medium (28 to 60 mesh), and thick (< 28 mesh). The operating conditions were defined using a complete factorial design of 25, while considering the variables as particle size (thin, medium, and thick), solid/liquid ratio (1/13.33 and 1/20), temperature (130 and 170 ºC), reactor pressure using CO2 (150 bar and 200 bar), and reaction time (10 and 20 min). The reactional system converted the EFB into 17.5% and 57.9% of reducing sugars, for thin and medium samples, respectively, which were performed under the same conditions. The statistical analysis indicated that the main effects for hydrothermal treatment are time and temperature.

The best extraction characteristics and optimal parameters for the steam-distillation extraction of bamboo leaf hydrosols were investigated to provide a data foundation for the subsequent study of bamboo leaf hydrosols and their industrial applications. The colligation score (CS) of the bamboo leaf hydrosols antioxidant activity (based on its DPPH free radical scavenging ability and total antioxidant capacity) was used as an evaluation index. The extraction time, crushing degree, and solid-to-liquid ratio were selected as the extraction parameters and response surface methodology was used to optimize the extraction process. The CS and sensory evaluation were used to determine the best distilled volume of bamboo leaf hydrosols. The results showed that the prepared bamboo leaf hydrosols had a high CS of 0.9967 (the DPPH free radical scavenging capacity was 0.052 mg/mL Vc equivalent, and the total antioxidant capacity was 0.2771 mg/mL Trolox equivalent) when the bamboo leaf crushing degree was 10 mesh, the solid-to-liquid ratio was 1:25, and the extraction time was 6 h. When the distilled volume was one-quarter of the total aqueous extract volume, the bamboo leaf hydrosols were highly active, colorless, and had a pleasantly aromatic odor.

This work highlights the synthesis of high purity silica from rice husks and the effect of rice husk silica (RHS) loading on the mechanical, physical, and thermal properties of natural rubber (NR) compounds. The RHS was synthesised using the solvent-thermal extraction method, which was adopted from TAPPI T204 (2007) and TAPPI T264 (1997) standards with some modifications. The treatment successfully produced high purity RHS particles, with 99.9% SiO2 content between 100 to 300 nm in size. The high purity RHS was then incorporated in NR compounds at 2, 4, 6, 8, and 10 parts per hundred rubber (phr). Even without any surface modification, the high purity RHS-filled NR compounds showed tremendous improvements in strength-related properties at the optimum loading of 4 phr. In addition, the thermal stability of the NR compounds was remarkably improved with the addition of RHS.

The article presents research on the effect of the sharpness angle on the quality of machined surface of native wood species (pine, beech, and black locust) and an exotic species called iroko. Four sharpness angle values were analyzed at 25, 40, 45, and 55°. The experiment was conducted on a bottom-spindle milling machine, with a constant spindle rotational speed (6000 min-1) and four feeding speeds of 3.2, 8.3, 12.5, and 16.7 m/min. The influence of sharpness angle, feeding speed, and wood species on the quality of machined surface of wood was determined. The optimum ranges of the sharpness angle were established with respect to wood surface quality. The surface roughness of the samples decreased with decreasing in the sharpness angle in range of 55° to 40°. The optimal value of the angle was 40°, and the roughness increased with increasing feeding speed. It was found that an increase in wood density decreased surface roughness.

The aim of this paper was to investigate the influence of zinc oxide (ZnO) nanoparticles on the resistance of pine wood to fire and ultraviolet (UV) radiation. The ZnO nanoparticles were prepared from aqueous zinc nitrate via a proteic sol-gel method. Dried samples were impregnated using immersion in an aqueous solution of ZnO nanoparticles in the amount of 1 wt.% wood. Samples were exposed to an open flame to test the fire retardance, and a high-pressure UV lamp was used to test the UV resistance. The results showed an improvement in the fire retardance and UV radiation resistance after the impregnation of ZnO nanoparticles.