Volume 12 Issue 1

While only a very small percentage of hardwood logs sawn by conventional sawmills in the U.S. have small-end diameters less than 10 in, portable and scragg mills often saw smaller logs. With the closure of regionally important oriented strand board and pulpwood operations, small-diameter logs are considered to have no value in some markets. This study was conducted to assess the volume and value of lumber produced from small-diameter hardwood logs of three important commercial species: red oak, sugar maple, and black cherry. Value assessments included determining yields for both green and kiln-dried lumber subjected to different dry kiln schedules. Volume and grade recovery from these small-diameter logs were lower than prior studies suggested. The value of recovered lumber per ft3 of log volume was not found to be affected by log small-end diameter class for black cherry and red oak, but the value was significantly affected for sugar maple. The loss in lumber value that was attributed to kiln-dried based grade changes was greatest for red oak and least for sugar maple. For red oak, the modified dry kiln schedule did not affect the lumber value. For black cherry and sugar maple, there were kiln-schedule based differences in the value of the dry lumber recovered.

Ultrasonic-assisted pulping technology integrates pulping and bleaching processes in one reactor with good yields performance of approximately 60% to 70%. The properties of ultrasonic-assisted wheat straw pulp were compared, i.e., composition, strength, and whiteness, with those of other conventionally pulps. The ash content of ultrasonic wheat straw pulp (the content is 27.81%) was much higher than that of traditional wheat straw pulp (the content was approximately 15%). Upon comparison with the ash content of the raw material, X-ray diffraction analysis, and thermogravimetry, the authors believe that some heat-resistant material was produced during the ultrasonic pulping process. The strength and whiteness performance of ultrasonic wheat straw pulp was better than that of traditional wheat straw pulp and was close to that of reed soda-anthraquinone (soda-AQ) pulp. Offset paper was successfully made using ultrasonic wheat straw pulp.

Acidic hot water flowthrough pretreatment (AHWF) is an attractive approach primarily because of its high efficiency for sugar recovery. However, a significant portion of carbon content in the solubilized fractions from lignin depolymerization and monosugar degradation has been studied to a lesser degree. Herein, we investigated the solubilized non-carbohydrate products from a series of flowthrough pretreatments of poplar wood by water-only or very dilute acid (0.05% to 0.1% w/w, H2SO4) at different temperatures (220 to 280 °C) and flow rates (10 to 62.5 mL/min). Results revealed that tailoring reaction parameters (temperature) and operational parameters of reactor (flow rate) without adding expensive catalysts can selectively produce specific non-carbohydrate compounds. Up to 50.9% selectivity of vanillin and 45.0% selectivity of syringaldehyde were obtained at 240 °C for water-only treatment with flow rates of 25 mL/min and 62.5 mL/min, respectively. Lower temperature (e.g., 220 °C) was favorable for the formation of coniferyl alcohol, with the highest selectivity of 36.2%. Higher temperature (e.g., 280 °C) or lower flow rate (e.g., 10 mL/min) led to the formation of varied other aromatic compounds and HMF. Adding very dilute acid (0.05% to 0.1% w/w, H2SO4) into the water-only system considerably enhanced the formation of HMF with up to 66.7% selectivity.

Joints are one of the most important issues in the design of furniture structures. Joints in furniture structures made from wood and wood materials represent a critical area because furniture most often breaks at the joints of structural elements. This article discusses the analysis of the effect of selected factors: type of loading (compressive, tensile), wood species (Fagus sylvatica L., Picea abies L.), thickness of joint (one-third and half the thickness of the tenon), type of glue (polyvinyl acetate and polyurethane), and the annual ring deflection, on the elastic stiffness of joints. These results indicated significant effects for the wood species, thickness of joint, and type of glue used. The annual ring deflection was on the borderline of statistical significance, while its effect was more significant than the effect of the basic material characteristic, i.e., the wood density. The type of loading was not statistically significant.

The risk of possible ignition and burning is one of the greatest disadvantages of using wood as a construction material. An environmentally appropriate method of improving the fire-resistant properties of wood is available via thermal treatment. In this study, spruce wood (Picea abies L.) was thermally modified at 160 °C, 180 °C, and 210 °C. The effect of thermal modification on the fire performance of the wood, including weight loss and burn rate, was evaluated. A new testing method was designed to be sufficiently sensitive to monitor fire performance. The results showed that the thermally modified spruce wood had a lower weight loss than untreated wood. The burn rate of wood that was thermally modified at 160 °C was similar to that of untreated wood. Higher thermal treatment temperatures caused a higher burn rate. After the flame was removed, the burning process was rapidly stopped in thermally treated wood.

This research assessed the geospatial supply of cellulosic feedstocks for potential mill sites in Kansas (KS), with procurement zones extending to Arkansas (AR), Iowa (IA), Missouri (MO), Oklahoma (OK), and Nebraska (NE). A web-based modeling system, the Kansas Biomass Supply Assessment Tool, was developed to identify least-cost sourcing areas for logging residues and upland hardwood roundwood biomass feedstocks. Geospatial boundaries were used according to the 5-digit zip code tabulation area (ZCTA). This higher level of resolution advanced the understanding of the geospatial economics of modeling the supply chain for cellulosic feedstocks. The analyses were conducted for six sub-regions (Chanute, Effingham, El Dorado, Manhattan, Ottawa, and Pratt) within Kansas that were identified by the US Forest Service as suitable for forest habitat. Atchison County of Effingham region had the least marginal costs for upland hardwood roundwood, ranging from $92.59 to $108.68 per dry metric ton, with an available annual supply of approximately 72 thousand dry metric tons. The least favorable was the El Dorado region, where the marginal costs ranged from $97.32 to $108.05 per dry metric ton, with an annual supply of approximately 4.4 thousand dry metric tons.