scholarly journals Corrosion damage and in-service inspection of retractable sootblower lances in recovery boilers

TAPPI Journal ◽  
2021 ◽  
Vol 20 (10) ◽  
pp. 655-662
Author(s):  
FLAVIO PAOLIELLO
Keyword(s):  
Paper Industry ◽  
Effective Means ◽  
Corrosion Damage ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Near Miss ◽  
Chemical Recovery ◽  
Pulp Mills ◽  
Recovery Boilers ◽  
Component Failures

Several reports of accidents involving serious mechanical failures of sootblower lances in chemical recovery boilers are known in the pulp and paper industry. These accidents mainly consisted of detachment and ejection of the lance tip, or even of the entire lance, to the inside of the furnace, towards the opposite wall. At least one of these cases known to the author resulted in a smelt-water explosion in the boiler. In other events, appreciable damage or near-miss conditions have already been experienced. The risk of catastrophic consequences of the eventual detachment of the lance tip or the complete lance of a recovery boiler soot-blower has caught the attention of manufacturers, who have adjusted their quality procedures, but this risk also needs to be carefully considered by the technical staff at pulp mills and in industry committees. This paper briefly describes the failure mechanisms that prevailed in past accidents, while recommending inspection and quality control policies to be applied in order to prevent further occurrences of these dangerous and costly component failures. Digital radiography, in conjunction with other well known inspection techniques, appears to be an effective means to ensure the integrity of sootblower lances in chemical recovery boilers used in the pulp and paper industry.

scholarly journals Integration of dual fluidized bed steam gasification into the pulp and paper industry

2021 ◽  
Author(s):  
Matthias Kuba ◽  
Florian Benedikt ◽  
Katharina Fürsatz ◽  
Josef Fuchs ◽  
Martin Demuth ◽  
...  
Keyword(s):  
Natural Gas ◽  
Separation Efficiency ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Steam Gasification ◽  
Chemical Recovery ◽  
Recovery Cycle ◽  
Product Gas ◽  
Gas Burner

AbstractThe pulp and paper industry represents an industry sector which is characterised by its already high degree of sustainability. Biomass is a renewable input material, and typically highly developed recovery cycles minimise the loss of chemicals used in the pulping process. However, certain parts of the recovery cycle are still operated on fossil fuels. This study deals with the substitution of the fossil-based gaseous fuel with product gas from biomass gasification.Gasification experiments have shown that bark available at pulp and paper mills is suitable to produce a product gas via dual fluidised bed steam gasification as a promising substitute for natural gas. Based on the comparison of process layouts regarding the separation of non-process elements, separation efficiency is derived for different setups. To ensure operational security of the chemical recovery cycle, comprehensive gas cleaning including heat exchangers, a particle filter, and a liquid scrubber unit is advised. The gas flow of fuel gas into the gas burner is increased as the heating value of the product gas is accordingly lower in comparison to natural gas. Furthermore, adaptions of the gas burner might be necessary to address the earlier ignition of the H2-rich product gas compared to natural gas.

Evaluation of Purification Efficiency of Activated Sludge Treatment Plants for Pulp and Paper Industry Wastewaters in Finland

1990 ◽  
Vol 22 (9) ◽  
pp. 199-206
Author(s):  
J. Junna ◽  
J. Rintala
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Pulp Mills ◽  
Sludge Treatment ◽  
Actual Performance ◽  
Loading Rates ◽  
Removal Efficiencies

Since 1984, when the first activated sludge treatment plant (ASTP) was built to treat pulp and paper industry wastewaters in Finland, twenty more plants have been introduced by 1989. An evaluation was undertaken to find out the actual performance of the ASTPs in BOD7, CODc r and phosphorus removal. The evaluation included all the 12 ASTPs in operation in the pulp and paper industry at the beginning of 1987. The highest average BOD7 removals were about 90 % at pulp mills as well as paper and board mills. CODc r removal was generally higher at paper and board mills (about 40-70 %) than at pulp mills (about 25-55 %). Phosphorus was added to wastewater in most plants. In some ASTPs, phosphorus concentrations were lowered by 20-40 % compared with wastewater from the mill. In some plants phosphorus load on the recipient was higher than the load coming from the mill. In treated wastewater, correlations between suspended solids and BOD7, CODc r, phosphorus and nitrogen were significant in most plants. This indicated that low removal efficiencies resulted from poor suspended solids removal in the secondary clarification. Volumetric and sludge CODc r loading rates could not explain removal efficiencies when all plants were included in the comparison. In plants treating chemical pulping effluents, higher removal efficiencies were normally achieved with lower loading rates. When the plants were studied separately, the influence of loading rate was generally significant.

Co-cooking moso bamboo with hardwoods

TAPPI Journal ◽  
2014 ◽  
Vol 13 (6) ◽  
pp. 9-15 ◽  
Author(s):  
TROY RUNGE ◽  
JACKIE HEINRICHER ◽  
DAN MEIER
Keyword(s):  
Paper Industry ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Pulp Mills ◽  
Fiber Properties ◽  
Kraft Process ◽  
Native Forests ◽  
Hardwood Species ◽  
Gradual Introduction

Bamboo is one of the world’s fastest growing feedstocks and represents a promising nonwood resource that can be utilized in the pulp and paper industry. The timber varieties offer low feedstock costs, can be processed similarly to trees from a logistics standpoint, and have useful fiber properties for papermaking. Plantations have not yet been established due to propagation costs, limiting adoption of bamboo as a pulp feedstock to smaller pulp mills primarily in China, where there are native forests. Recent advances in micropropagation may allow lower establishment costs, but gradual introduction into the supply chain will be required. One concept is to gradually include bamboo feedstock into an established pulp mill as plantations are established, using co-cooking with a wood species. Previous work has shown that bamboo cooks fairly easily using the kraft process with conditions similar to hardwood species.

A hundred years of corrosion in the pulp and paper industry

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 253-258
Author(s):  
Max Moskal
Keyword(s):  
Paper Industry ◽  
Production Capacity ◽  
Corrosion Damage ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Corrosion Control ◽  
Materials Engineering ◽  
The Past ◽  
The Cost ◽  
Control Management

Through the decades, the pulp and paper industry greatly expanded production capacity to meet increasing demands. Correspondingly, the cost of corrosion damage soared. The most serious corrosion control challenges were researched and met by university and governmental researchers, and by task groups within the TAPPI Engineering Division’s Corrosion and Materials Engineering Committee. Today, thanks to material and process advances, mills encounter less corrosion than in the past. This overview takes a historical look back, covering many decades, at how corrosion problems have been managed in the pulp and paper industry. Yet, corrosion keeps on going, and today mills appear less able to manage corrosion problems for which known solutions are available. This paper also addresses the significant yet underrated task of optimizing corrosion control management in the present and into the future. Discussion is provided on best practices needed to mitigate new and ongoing corrosion problems.

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