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Journal articles
Open Access
Could biomass-fueled boilers be operated at higher steam temperatures? Part 1: Laboratory evaluation of candidate superheater alloys, TAPPI JOURNAL August 2014

Could biomass-fueled boilers be operated at higher steam temperatures? Part 1: Laboratory evaluation of candidate superheater alloys, TAPPI JOURNAL August 2014

Journal articles
Open Access
Pressures on webs in wound rolls due to winding and contact, TAPPI JOURNAL February 2014

Pressures on webs in wound rolls due to winding and contact, TAPPI JOURNAL February 2014

Journal articles
Open Access
Effect of silicon on properties of causticized calcium carbonate produced in wheat straw soda pulping, TAPPI JOURNAL July 2014

Effect of silicon on properties of causticized calcium carbonate produced in wheat straw soda pulping, TAPPI JOURNAL July 2014

Journal articles
Open Access
The contribution of pulp brightness and optical brightening agents to paper whiteness, TAPPI JOURNAL March 2014

The contribution of pulp brightness and optical brightening agents to paper whiteness, TAPPI JOURNAL March 2014

Journal articles
Open Access
Composites from a forest biorefinery byproduct and agrofibers: Lignosulfonate-phenolic type matrices reinforced with sisal fibers, TAPPI JOURNAL September 2012

Composites from a forest biorefinery byproduct and agrofibers: Lignosulfonate-phenolic type matrices reinforced with sisal fibers, TAPPI JOURNAL September 2012

Journal articles
Magazine articles
Open Access
Evaluating the effect of recovery boiler operation on green liquor dregs concentration using multivariate analysis, TAPPI Journal June 2023

ABSTRACT: Poor settling and filterability of green liquor dregs has been a persistent problem in many kraft pulp mills. While the concentration and settling/filtering behaviors of dregs are expected to be related to how black liquor is burned in recovery boilers, the effect of boiler operation is not well understood. A systematic study was conducted to examine how recovery boiler operation may affect the dregs concentration in the raw green liquor (RGL) at three kraft pulp mills using SIMCA, a multivariate data analysis (MVDA) program. Daily average boiler operating data from three kraft mills were analyzed over a 3-year period. Results of both principal component analysis (PCA) and partial least squares regression (PLS) suggest that the main boiler operations contributing to high dregs concentrations in RGL are low liquor firing load, low bed temperature, poor char burning, and unstable char bed.

Journal articles
Open Access
The effect of Stachys floridana Shuttlew.ex Benth extract as an additive on the chemical properties of chitosan biodegradable film, TAPPI Journal June 2025

ABSTRACT: The purpose of this study is to explore chitosan with Stachys floridana Shuttlew. ex Benth (SFSB) extract as an additive to prepare an active film. The effects of the SFSB extract on the physical, antioxidant, and bacteriostatic properties of chitosan biodegradable films were studied. The results showed that the addition of SFSB extract significantly improved the antioxidant and antibacterial properties of the film, and its biodegradation rate increased rapidly. Compared to the control film, the water solubility was lower at 19.40%, the expansion degree was higher at 288.90%, the water vapor permeability (WVP) was 0.364 g·mm/(m²·d·kPa), the surface hydrophobicity increased, and the mechanical strength was also improved. The contact angle increased to 89.3°. In addition, as the amount of SFSB increased, the thermal stability of chitosan-Stachys floridana Shuttlew. ex Benth (CS-SFSB) films also increased significantly, and their ultraviolet (UV) blocking ability was gradually enhanced. The results indicate that CS-SFSB has potential as a food packaging material.

Journal articles
Magazine articles
Open Access
Boiler retrofit improves efficiency and increases biomass firing rates, TAPPI Journal March 2021

ABSTRACT: Domtar’s fluff pulp mill in Plymouth, NC, USA, operates two biomass/hog fuel fired boilers (HFBs). For energy consolidation and reliability improvement, Domtar wanted to decommission the No. 1 HFB and refurbish/retrofit the No. 2 HFB. The No. 2 HFB was designed to burn pulverized coal and/or biomass on a traveling grate. The steaming capacity was 500,000 lb/h from coal and 400,000 lb/h from biomass. However, it had never sustained this design biomass steaming rate. As the sole power boiler, the No. 2 HFB would need to sustain 400,000 lb/h of biomass steam during peak loads. An extensive evaluation by a combustion and boiler technologies supplier was undertaken. The evaluation involved field testing, analysis, and computational fluid dynamics (CFD) modeling, and it identified several bottle-necks and deficiencies to achieving the No. 2 HFB’s biomass steam goal. These bottlenecks included an inadequate combustion system; insufficient heat capture; excessive combustion air temperature; inadequate sweetwater con-denser (SWC) capacity; and limited induced draft fan capacity.To address the identified deficiencies, various upgrades were engineered and implemented. These upgrades included modern pneumatic fuel distributors; a modern sidewall, interlaced overfire air (OFA) system; a new, larger economizer; modified feedwater piping to increase SWC capacity; replacement of the scrubber with a dry electrostatic precipitator; and upgraded boiler controls.With the deployment of these upgrades, the No. 2 HFB achieved the targeted biomass steaming rate of 400,000 lb/h, along with lowered stack gas and combustion air temperatures. All mandated emissions limit tests at 500,000 lb/h of steam with 400,000 lb/h of biomass steam were passed, and Domtar reports a 10% reduction in fuel firing rates, which represents significant fuel savings. In addition, the mill was able to decommission the No. 1 HFB, which has substantially lowered operating and maintenance costs.

Journal articles
Magazine articles
Open Access
Peracetate/singlet oxygen chemistry used in post-bleaching of kraft pulp as a practical oxidant for paper machines, TAPPI Journal May 2021

ABSTRACT: The use of a novel sodium peracetate/singlet oxygen chemistry for brightening bleached kraft pulp shows exciting potential for technical performance, supply logistics, safety, and cost reduction. Potential chemical carryover to the paper machine raises questions about whether peracetate will impact paper machine performance, such as metal corrosion, useful press felt life, and interference with existing biocide programs or paper machine chemistry. Sodium peracetate/singlet oxygen chemistry can be used in high-density storage chests for brightening/whitening and to increase color stability. Any oxidant used directly before the paper machine has the possibility of impacting paper machine operations. Traditional oxidants used in bleaching, such as chlorine dioxide and hydrogen peroxide, are known to cause corrosion on machinery metals and press felts. Hydrogen peroxide residuals can interfere with common biocide programs. Traditional oxidants used in biocide treatments themselves significantly degrade press felt life when the rule-of-thumb concentration thresholds are exceeded. Sodium peracetate is evaluated in this paper for its impact on nylon press felt fiber degradation, metal corrosion, and interference with typical biocide programs.Laboratory results indicate that sodium peracetate/singlet oxygen chemistry is less corrosive than chlorine, bromine, and hydrogen peroxide on press felt nylon fiber and can therefore be used at higher levels than those chemistries to increase brightness without increasing negative downstream impact. Sodium peracetate can also be used with current biocide programs without negative impacts such as consumptive degradation. Higher residuals of peracetate going to the paper machine may be useful as a biocide itself and can complement existing programs, allowing those programs to stay within their safe operating levels and thereby extend press felt useful life.

Journal articles
Magazine articles
Open Access
Removal of silicon from green liquor with low-temperature precausticizing, TAPPI JOURNAL January 2017

Removal of silicon from green liquor with low-temperature precausticizing, TAPPI JOURNAL January 2017