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A case study review of wood ash land application programs in North America, TAPPI Journal February 2021
ABSTRACT: Several regulatory agencies and universities have published guidelines addressing the use of wood ash as liming material for agricultural land and as a soil amendment and fertilizer. This paper summarizes the experiences collected from several forest products facility-sponsored agricultural application programs across North America. These case studies are characterized in terms of the quality of the wood ash involved in the agricultural application, approval requirements, recommended management practices, agricultural benefits of wood ash, and challenges confronted by ash generators and farmers during storage, handling, and land application of wood ash.Reported benefits associated with land-applying wood ash include increasing the pH of acidic soils, improving soil quality, and increasing crop yields. Farmers apply wood ash on their land because in addition to its liming value, it has been shown to effectively fertilize the soil while maintaining soil pH at a level that is optimal for plant growth. Given the content of calcium, potassium, and magnesium that wood ash supplies to the soil, wood ash also improves soil tilth. Wood ash has also proven to be a cost-effective alternative to agricultural lime, especially in rural areas where access to commercial agricultural lime is limited. Some of the challenges identified in the review of case studies include lengthy application approvals in some jurisdictions; weather-related issues associated with delivery, storage, and application of wood ash; maintaining consistent ash quality; inaccurate assessment of required ash testing; potential increased equipment maintenance; and misconceptions on the part of some farmers and government agencies regarding the effect and efficacy of wood ash on soil quality and crop productivity.
Journal articles
Magazine articles
Continuous tannin extraction by use of screw reactor, TAPPI Journal February 2021
ABSTRACT: A pilot-size screw reactor (extraction unit) was used for tannin extraction of spruce. Yield of the same magnitude or better was obtained when comparing a screw reactor with batch reactors. A longer presoaking time in water seemed to be better than a short one for obtaining higher yield. A higher yield is obtained with lower dry-water ratio, which suggests that the internal diffusion in bark does not determine mass transfer as much as is the case without presoaking of bark. The higher dry-water ratio decreased the yield. The prior soaking of the bark also minimized the mechanical reactor feeding problems (clogging). The benefits of a screw reactor likely are that run time changes for different process conditions are flexible; it simplifies design and construction of an industrial unit for tannin production; and it saves space because of the need for fewer and smaller intermediate storage tanks.
Journal articles
Magazine articles
Addressing production bottlenecks and brownstock washer optimization via a membrane concentration system, TAPPI Journal July 2021
ABSTRACT: Advancements in membrane systems indicate that they will soon be robust enough to concentrate weak black liquor. To date, the economic impact of membrane systems on brownstock washing in kraft mills has not been studied and is necessary to understand the viability of these emerging systems and their best utilization.This study investigated the savings that a membrane system can generate related to brownstock washing. We found that evaporation costs are the primary barrier for mills seeking to increase wash water usage. Without these additional evaporation costs, we showed that our hypothetical 1000 tons/day bleached and brown pulp mills can achieve annual savings of over $1.0 MM when operating at higher dilution factors and fixed pulp production rate. We then investigated the impact of increasing pulp production on mills limited by their equipment. In washer-limited mill examples, we calculated that membrane systems can reduce the annual operating cost for a 7% production increase by 91%. Similarly, in evaporator-limited mill examples, membrane systems can reduce the annual operating cost for a 7% production increase by 86%. These results indicated that membrane systems make a production increase significantly more feasible for these equipment-limited mills.
Journal articles
Magazine articles
Editor's Note: Recovery Boiler Insights, TAPPI JOURNAL Febru
Editor's Note: Recovery Boiler Insights, TAPPI JOURNAL February 2010
Journal articles
CFD-Based Modeling of Kraft Char Beds â?¢ Part 1: Char Bed Burning Model, TAPPI JOURNAL February 2010
CFD-Based Modeling of Kraft Char Beds • Part 1: Char Bed Burning Model, TAPPI JOURNAL February 2010
Journal articles
New Possibilities In Bleaching Wood-Containing Dip: Alternative To Alkaline Peroxide Bleaching, February 2010
New Possibilities In Bleaching Wood-Containing Dip: Alternative To Alkaline Peroxide Bleaching, February 2010
Journal articles
Determination of aluminum soaps in pitch deposits by gas chromatography, TAPPI JOURNAL October 2010
Determination of aluminum soaps in pitch deposits by gas chromatography, TAPPI JOURNAL October 2010
Journal articles
Influence of oxidation and cationization on the properties of thermomechanical pulp fibers, TAPPI JOURNAL October 2010
Influence of oxidation and cationization on the properties of thermomechanical pulp fibers, TAPPI JOURNAL October 2010
Journal articles
Characterization of spruce thermomechanical pulps at the fiber cell wall level: a method for quantitatively assessing pulp fiber development using Simonsâ?? stain, TAPPI JOURNAL October 2010
Characterization of spruce thermomechanical pulps at the fiber cell wall level: a method for quantitatively assessing pulp fiber development using Simons’ stain, TAPPI JOURNAL October 2010
Journal articles
Integration of hemicellulose pre-extraction in the bleach-grade pulp production process, TAPPI JOURNAL October 2013
Integration of hemicellulose pre-extraction in the bleach-grade pulp production process, TAPPI JOURNAL October 2013