Volume 17 Issue 1

Wood-consuming furniture manufacturers (WCFM) are major users of forest products in the United States. Between 2000 and 2009, the real value of domestic WCFM shipments (production) declined by 51%. After 2009, WCFM shipments fluctuated, but by 2019 shipments were 48% below 2000 levels. A major contributor to this decline was furniture imports. In 1997, imports accounted for 6% and 23% of the value of upholstered household furniture (UHF) and wood household furniture (WHF), available to U.S. consumers, respectively. In 2019, imports accounted for 35% and 78% of domestically available UHF and WHF, respectively. The primary source of imported UHF in 2019 was China, while Vietnam was the most important source of WHF. Domestic consumption also influences WCFM shipments. Between 1997 and 2019, consumption of UHF by U.S. end-users increased; since 2002, this increase was primarily supplied through increased imports. Since 2005, domestic consumption of WHF declined by 45%, which contributed to the 75% decline in domestic shipments since that year. Wood office furniture and related products also have experienced a 40% decline in consumption since 2000, which coincided with a 41% decline in shipments. More research is needed to determine the impact of decreased WCFM shipments on U.S. forest product production and prices.

The totally chlorine free (TCF) bleaching was studied for wheat straw soda-anthraquinone (AQ) pulp with a low kappa number of 8.3 using the sequence of OQP_O and OQP_OP_O. It was found that the oxygen delignification on wheat straw pulp was still effective despite its low initial kappa number. A delignification extent of 42% and an ISO brightness increase of 10.9% were achieved. In the OQP_O sequence, an ISO brightness ceiling of 87.2% was achieved as the hydrogen peroxide (H₂O₂) charge was increased from 2% to 6% in the P_O stage. In the OQP_OP_O sequence, 2% H₂O₂ was added in the second P_O stage and the pulp brightness exceeded 88% with a total charge of 4% H₂O₂ in the P_OP_O bleaching. Higher brightness values of 89.5% and 90.1% were obtained under the total charges of 6% and 8% H₂O₂, respectively. Compared to the OQP_O sequence, the higher brightness and equal viscosity of the bleached pulps were obtained under the same total charge of H₂O₂ in the OQP_OP_O sequence. The bleached pulps with high ISO brightness values (greater than 88%) retained acceptable strength properties. A slight decrease of fiber length occurred as the bleaching sequences proceeded, while the fiber width and curl index somewhat increased.

Ancient architectural wood components were evaluated in terms of mechanical properties, material color expression, ultrasonic shape, chemical components, and deformation of shape and position by comparing them with new red pine materials. The results showed that the deterioration of the surface material properties of wood components was very serious, mainly caused by weathering. The attenuation degree of the inner layer of the wood component was relatively low, and the color change of the wood was obvious, which was mainly caused by fungi. Ultrasonic nondestructive testing technology was used to detect the internal damage of ancient wood components. According to the test results, it was speculated that the root defects of pillar components were serious. Three components of wood after long-term weathering changed significantly, and lignin had been seriously damaged. This damage was reflected in the degradation of the number of aromatic groups and the changes in the nature of the group. The main wood beams in the main halls of the three yards were bent at 0 mm offset scale and unit offsets of the pillars of the four courtyards were within the safe range.

Water treatment using nano-materials can have a significant impact due to its surface properties. Coagulation techniques were studied by using 3 mL/L of 0.5% of different coagulants (polyacrylamide, poly aluminum chloride (PAC), ferric chloride, aluminum sulfate, and nanocellulose). Results indicated that the turbidity removal efficiency were 91.6%, 93.04%, 95.2%, 95.4%, and 99.4%, respectively. Treatment of water samples collected from the Ismailia Canal, the Damietta branch of the Nile Delta, and a wastewater treatment plant located in Cairo (Egypt) using nanocellulose fibers was studied. For the Ismailia Canal sample, the removal of turbidity, chemical oxygen demand (COD), biological oxygen demand (BOD), and phosphorous were 96%, 83.3%, 100%, and 100%, respectively. For the Damietta branch sample, the removal of turbidity, COD, BOD, and phosphorous were 87.5%, 81.3%, 88.9%, and 99.1%, respectively. For the wastewater treatment plant sample, the removal of turbidity, COD, BOD, and phosphorous were 86.4%, 91.96%, 92.86%, and 91.74%, respectively. Nanocellulose-nano zero-valent iron composite (NC-nZVI) was investigated for phosphorous removal at different operating conditions. Results showed phosphorous removal efficiencies of 91 and 100% for initial phosphate concentrations of 10 and 1 mg PO43– P/L, respectively. Different isothermal analyses were performed for monolayer and multilayer adsorption processes.

To develop an efficient solution for the storage of renewable electricity and utilization of biomass or waste within the power-to-X concept, the electrical heating gasification (EHG) technology for industrial-scale application was proposed and compared with water electrolysis-assisted gasification (WEG). The two technologies were compared in terms of composition, yield, and exergy efficiency. The results indicate that EHG consumes less electricity and generates syngas with higher chemical exergy. The maximum exergy efficiency of EHG was calculated as 80.76%. Electrical heating gasification is more efficient than WEG based on either the current state or the potential progress in the future. Additionally, the exergy efficiency of water electrolysis ranges between 54.1% and 79.1%, which implies that more efforts are needed in the future to reduce the specific electricity consumption. This work is valuable to guide the development of an electrical heating gasifier and to improve performances of power-to-X technologies.

Corn straw and potato residue are common agricultural biomass. Although they have a wide range of applications, the disadvantages of low bulk density and high storage and transportation cost hinder their utilization. The densification of these biomass into briquettes facilitates their storage, transportation, and reuse. The rheological properties of corn straw and potato residue during co-briquetting were investigated in creep tests. The Four-element Burgers Model accurately and intuitively fit the creep curves of the mixed materials, with fitting coefficients above 0.99. The experiment used the relaxation ratio as an indicator, and the influence of compression speed, dwell time, feeding amount, loading force, mass ratio, and temperature were obtained. The response surface analysis indicated that all factors except compression speed had an effect on the relaxation ratio. The results suggested that compressing corn straw and potato residue in a feeding amount of 28 g with a mass ratio of 1:5 at 101 °C under 35 KN loading force and 918 s dwell time produces cost-effective agricultural biomass briquettes. This study provides a reference for improving the co-briquetting process of corn straw and potato residue.

The viscoelastic behavior and the dynamic mechanical properties were studied for wood-melamine-urea-formaldehyde composites prepared from fast-growing poplars using in situ polymerization. The changes in stress relaxation (SR), storage modulus (E′), and damping parameter (tan δ) were considered. The relationship between the dynamic mechanical properties and the modifier concentration was also studied. The SR value decreased as the modifier content increased in all the samples examined. The urea content had a greater impact than the melamine-urea-formaldehyde mixture content on the SR value of the wood samples. A similar trend was observed for E′. The modified wood samples exhibited a higher tan δ. The results confirmed that a better interfacial interaction between melamine-urea-formaldehyde and wood fiber contributed to the improvement of mechanical properties in the fast-growing poplar wood.

Effects of nanofibrillated cellulose (NFC) and nano-silicon dioxide on dynamic mechanical thermal analysis and physical properties of nanocomposites films made of poly (vinyl alcohol) (PVOH) were investigated. For this purpose, the nanoparticles were mixed with PVOH at 0%, 5%, and 10% weight. Water absorption, dynamic mechanical thermal, transparency, and wettability properties were evaluated according to corresponding standard test methods. The morphology of nanocomposites was explored by using a field emission scanning electron microscope technique. The films became increasingly opaque with increasing nanoparticles contents, although the composites also retained moderate transparency. According to the results of the tests, the dynamic mechanical thermal (DMTA) properties of PVOH composite films were significantly improved with the increase of NFC and silica nanoparticles loading. The samples containing 20 wt% of nano-SiO2 exhibited higher hydrophobicity compared with that of 20 wt% NFC.

New experimental data is presented for the mechano-sorptive coefficient of Eucalyptus nitens wood analyzed in the longitudinal direction through the principle of total deformation superposition. The procedure was based on the determination of the partial strain components: elastic strain, free shrinkage strain, and mechano-sorptive strain. The methodology included the design of cantilever flexion tests of a wooden beam in an air-conditioned environment with variable relative humidity. These conditions made it possible to estimate each of the deformation components separately and then to determine the mechano-sorptive coefficient using the rheological stress-strain model. Deformations and displacements were evaluated with extensometers and displacement sensors, respectively, in conditions of 0 to 30% of the breaking load applied perpendicularly to beams oriented in the longitudinal direction. The cross-section was positioned according to the relation between the action line of the load applied and the growth rings orientation. The variation of moisture content was considered, decreasing from 22 to 12%. The results exposed a direct proportionality between the intensity of the applied load and the mechano-sorptive strains. The values determined for mechano-sorptive coefficients were 0.1224 and 0.1746 GPa-1 for loads applied to radial and tangential directions, respectively.

A novel Ru-modified composite catalyst, Ru-W/Sn-AlOx, was prepared, and the effects of the catalyst on lignin depolymerization were investigated in this study. The catalyst converted approximately 95% lignin into liquid product at 300 °C in 12 h and 2/3 of the liquid product could be soluble in petroleum ether. The petroleum ether (PE) soluble product was mainly composed of monomers, dimers and some trimmers. This indeed indicated that the catalyst could effectively depolymerize lignin into small-molecule products. 7.22% of monomers was obtained at 310 C for 12 h. Meanwhile, the catalyst effectively reduced the char formation to 2%. After the catalytic depolymerization, the higher heating value (HHV) of the liquid product increased from 25.7 to 32.4 MJ/kg. The product could be utilized as fuel additive or converted to biofuels. This catalysis system showed great potential in the conversion of lignin into biofuels.