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Flow characteristics of drag-reducing natural bamboo fiber suspensions with minimal environmental load, TAPPI Journal September 2019

ABSTRACT: The reduction of pipe friction loss by adding drag-reducing agents has attracted attention as an aid to energy conservation. Drag-reducing agents induce drag reduction (DR) effects and should have a minimal environmental load, with natural resource-saving potential. This study demonstrates bamboo fiber as a drag-reducing agent that saves natural resources and has a low environmental load. Using pressure drop measurements, we report DR with suspensions of bamboo fibers with the average diameter of 13.3 µm and aspect ratio of 98.7. The maximum DR obtained in this experiment is 43% at the concentration of 4000 ppm and pipe diameter of 30 mm; DR is affected by the Reynolds number, suspension concentration, and pipe diameter. In addition, the bamboo fibers can be easily removed from the suspensions by filtration. We found that low-environmental-load bamboo fiber has DR effects like those of other fibers; its effects are greater than those of conventional synthetic fibers and wood pulp. Furthermore, it is resistant to mechanical degradation, recoverable, and recyclable. Therefore, DR effects can be selectively obtained by adding the fibers only when DR is needed; the fibers can then be collected when DR is no longer necessary. This method might greatly expand the application range of DR agents. The results demonstrate the usefulness of bamboo fibers as DR additives.

Visible and Invisible Costs, Paper360º September/October 2019

Visible and Invisible Costs, Paper360º September/October 2019

A financial analysis of north american pulp and paper companies, TAPPI JOURNAL, July 2000, Vol. 83(7)

A financial analysis of north american pulp and paper companies, TAPPI JOURNAL, July 2000, Vol. 83(7)

Global multi-pigment savvy from imerys, TAPPI JOURNAL, June 2000, Vol. 83(6)

Global multi-pigment savvy from imerys, TAPPI JOURNAL, June 2000, Vol. 83(6)

Bay state paper company: a mill that reinvented itself, TAPPI JOURNAL, March 2000, Vol. 83(3)

Bay state paper company: a mill that reinvented itself, TAPPI JOURNAL, March 2000, Vol. 83(3)

Paper companies adopt sophisticated techniques to win customers, TAPPI JOURNAL, October 2000, Vol. 83(10)

Paper companies adopt sophisticated techniques to win customers, TAPPI JOURNAL, October 2000, Vol. 83(10)

The role of science in setting the environmental agenda, TAPPI JOURNAL, September 2000, Vol. 83(9)

The role of science in setting the environmental agenda, TAPPI JOURNAL, September 2000, Vol. 83(9)

Pilot scale black liquor concentration using pressure driven membrane separation, TAPPI Journal April 2023

ABSTRACT: Black liquor concentration using pressure driven membrane separation has long been proposed as a means of achieving energy savings and breaking production bottlenecks. To date, limitations in membrane performance and stability under black liquor process conditions have prevented those promises from being realized out-side of tightly controlled laboratory settings. In this work, we describe the first successful pilot scale field deployments of a membrane system for black liquor concentration. Using a purpose-built system and commercial sized, spiral wound graphene oxide membrane elements, we have logged nearly 6000 h of runtime across deployments to multiple mill sites. We demonstrate concentration of black liquor from 14% to >20% total solids, while generating permeate water comparable in quality to that of evaporator condensate and an 81% reduction in energy consumption relative to evaporation. At a commercial scale, these results translate to $2 M/year in net energy savings for a typical mill, as well as an opportunity to support production increases or mill expansions. These results represent a significant leap forward in the ability of membrane systems to deliver substantial value via black liquor concentration.

Evaluation of soap recovery efficiency from black liquor — analytical tools, TAPPI Journal April 2023

ABSTRACT: Soap skimmings (“soap”) are typically recovered from black liquor in kraft mills that process a high percentage of softwood. In many mills, the recovery of soap is inefficient, negatively impacting performance of evaporators and recovery boilers and resulting in loss of potential revenue. A thorough evaluation of soap recovery performance in a kraft mill requires measurement of soap content in black liquor at various sampling locations, especially around the soap skimmer.The standard laboratory method for evaluating soap content in black liquor is a complex, multi-step process that relies on solvent extraction and titration; most mills send these samples to an outside laboratory for this analysis. In this study, 100 black liquor samples, with a wide range of soap concentrations, were tested by the standard solvent extraction method. After additional dilution, each sample was also tested for surface tension with a bubble pressure tensiometer. The results were found to correlate very closely with the solvent extraction tests results. This alternate method, using surface tension measurements of diluted black liquor samples, produces rapid results and can be easily implemented in most kraft mills, which would facilitate much more frequent in-house evaluations of soap recovery performance.

Maximizing Process Efficiency with Advanced Vacuum Systems, Paper360º September/October 2025