Inventory audit notice: TAPPI Press orders will not be processed from August 21–28 during our fiscal year-end inventory audit. Orders placed during this time will ship starting August 31, in the order received. Normal payment processing also resumes August 31.

Thanks for your patience — this helps us serve our members better.

Search

Use the search bar or filters below to find any TAPPI product or publication.

Showing 421–430 of 2,031 results (Duration : 0.016 seconds)

Filters

Industry

Topics

Content Type

Publications

Level of Knowledge

Committees

Collections

Journal articles
Magazine articles
Open Access
A feasibility study of using the organic Rankine cycle for power generation from the flue gases of recovery boilers, TAPPI Journal August 2022

ABSTRACT: Almost 415 tons/h of flue gases with a temperature of 160°C are released to the atmosphere from the recovery boiler of a pulp mill with capacity of 1000 air dried (a.d.) metric tons of pulp per day. This is a large waste heat stream that can be used to generate power, to decrease the operating costs of a pulp mill, and to save carbon dioxide (CO2) emissions. In this work, the feasibility of using an organic Rankine cycle (ORC) with ammonia as the working fluid to generate power from the flue gases of recovery boilers is studied. CHEMCAD and Taguchi methods are used for simulation of the process and for optimization of operating conditions, respectively. The temperature of the ammonia and flue gases at the exit of evaporator, exit pressure of the pump and turbine, and the degree of subcooling of ammonia at the exit of the condenser are five operating parameters that are manipulated to optimize the process. Three different scenarios are defined: minimizing the net power cost, maximizing the ORC efficiency, and maximizing the net profit. Different aspects of these scenarios, such as net power generation, cost, efficiency, and CO2 emission savings are discussed, and optimum operating conditions are reported.

Journal articles
Magazine articles
Open Access
Causes of poor dregs settling in a green liquor clarifier, TAPPI Journal August 2022

ABSTRACT: A study was conducted to examine the most likely parameters responsible for poor dregs settling at a kraft mill over a 2.5-year period, using multivariate data analysis (MVDA) and machine learning (ML) techniques. The dregs settling behavior seems to be seasonally influenced, implying that wood quality variation can be a factor. The results from the MVDA/ML analysis show that poor dregs settling is correlated to incomplete combustion and/or low load conditions in the recovery boiler, low sulfidity in the causticizing plant, and high flow in the green liquor•weak wash cycle. Compositions of dregs and black liquor were also examined to identify correlations with impaired dregs settling. The results show that poor dregs settling strongly correlates with high silicon (Si) content in dregs and moderately correlates with high iron (Fe) and high aluminum (Al) contents, and with low bulk density in dregs. For mills that experience dregs settling or green liquor filtering issues, regular compositional analyses of dregs, green liquor, weak wash, and black liquor are recommended in order to monitor the dynamics of silicon and other constituents in the recovery cycle.

Journal articles
Magazine articles
Open Access
Utilization of kraft pulp mill residuals, TAPPI Journal February 2022

ABSTRACT: Kraft pulp mills produce on average about 100 kg of solid residuals per metric ton of pulp produced. The main types of mill waste are sludge from wastewater treatment plants, ash from hog fuel boilers, dregs, grits, and lime mud from causticizing plants and lime dust from lime kilns. Of these, about half is disposed of in landfills, which highlights the need and potential for waste recycling and utilization. Sludge is either incinerated in hog fuel boilers to generate steam and power or used in various forms of land application, including land spreading, composting, or as an additive for landfill or mine waste covers. The majority of hog fuel boiler ash and causticizing plant residues is landfilled. Alkaline residuals can be conditioned for use in land application, manufacture of construction materials, and production of aggregates for road work. This technical review summarizes residuals utilization methods that have been applied in pulp and paper mills at demonstration- or full-scale, and therefore may act as a guide for mill managers and operators whose goal is to diminish the costs and the environmental impact of waste management.

Journal articles
Open Access
Improving energy efficiency of existing recovery boilers 15FEB105

Improving energy efficiency of existing recovery boilers, TAPPI JOURNAL February 2015

Journal articles
Open Access
Design of refractory linings for balanced energy efficiency, uptime, and capacity in lime kilns 15FEB141

Design of refractory linings for balanced energy efficiency, uptime, and capacity in lime kilns. TAPPI JOURNAL February 2015

Journal articles
Open Access
Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill 15-Feb-73

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill, TAPPI JOURNAL February 2015

Journal articles
Open Access
Optimization of a brownstock washing line 15-Feb-83

Optimization of a brownstock washing line, TAPPI JOURNAL February 2015

Journal articles
Open Access
Impact of wood chip leaching pretreatment on wood chemical composition 15-Jan-09

Impact of wood chip leaching pretreatment on wood chemical composition, TAPPI JOURNAL January 2015

Journal articles
Open Access
Recovery boiler sootblowers: History and technological advances 15-Jan-51

Recovery boiler sootblowers: History and technological advances, TAPPI JOURNAL January 2015

Journal articles
Open Access
New challenges regarding nonprocess elements in the liquor and lime cycle, TAPPI JOURNAL July 2015

New challenges regarding nonprocess elements in the liquor and lime cycle, TAPPI JOURNAL July 2015

Inside this Section