Pulp Manufacturing Industry Research Articles

Lignin Modification for Enhanced Performance of Polymer Composites.

The biopolymer lignin, which is heterogeneous and abundant, is usually present in plant cell walls and gives them rigidity and strength. As a byproduct of the wood, paper, and pulp manufacturing industry, lignin ranks as the second most prevalent biopolymer worldwide, following cellulose. This review paper explores the extraction, modification, and prospective applications of lignin in various industries, including the enhancement of thermosetting and thermoplastic polymers, biomedical applications such as vanillin production, fuel development, carbon fiber composites, and the creation of nanomaterials for food packaging and drug delivery. The structural characteristics of lignin remain undefined due to its origin, separation, and fragmentation processes. This comprehensive overview encompasses state-of-the-art techniques, potential applications, diverse extraction methods, chemical modifications, carbon fiber utilization, and the extraction of vanillin. Moreover, the review focuses on the utilization of lignin-modified polymer blends across multiple manufacturing sectors, providing insights into the advantages and limitations of this innovative approach for the development of environmentally friendly materials.

Application of Colloidal Chemistry and Polymer Chemistry in Papermaking Industry

Colloidal chemistry is a science to study the physicochemical properties of generalized colloidal dispersion systems. Polymer chemistry is a new comprehensive subject that studies the synthesis, chemical reaction, physical chemistry, physics, processing and application of polymer compounds. The development of polymer chemistry mainly experienced four periods: the utilization and processing of natural polymers, the modification of natural polymers, the production of synthetic polymers and the establishment of polymer science. Since the 1930s, with the development of synthetic polymers, polymer related sub disciplines such as reaction kinetics, chemical thermodynamics, structural chemistry, polymer physics and biopolymers have been gradually established, forming a systematic polymer science. Papermaking industry is an industrial sector that manufactures all kinds of paper and paperboard. It includes the pulp manufacturing industry that uses wood, reed, bagasse, straw, wheat straw, cotton straw, hemp stalk, cotton and other raw materials to manufacture pulp, the paper and paperboard industry, and the processing paper manufacturing industry that produces coated, polished, glued, laminated and other processing paper and font paper plate. Paper industry is an important industry closely related to the development of national economy and the construction of social civilization. This paper focuses on the relationship between colloidal chemistry, polymer chemistry and papermaking industry, especially its application in cooking, washing, bleaching, papermaking and water treatment, and introduces in detail the current situation and development trend of flocculation method for papermaking wastewater according to colloidal chemistry theory.

Paper making in a low carbon economy

Paper and pulp manufacturing industry produces versatile products from renewable feedstock that are easily recycled. It is the fourth largest industrial sector in terms of energy use. Much of the energy used comes from biomass derived fuels or high efficiency combined heat and power plants so the industry is not considered as carbon intensive. But at production paper making emits five times the CO₂/tonne of steel; this is gradually removed from the atmosphere by the growth of replacement trees which can take between 7 and 90 years. This study reviewed existing literature to establish estimates for future energy requirements, and way that these could be met with minimum carbon emissions in a world where there are electricity grids with low carbon intensities, high recycling rates and growing demand for sustainable biomass. It was found that energy consumption could be reduced by 20% using technologies that have been demonstrated at an industrial scale. Most virgin pulp is made using the kraft chemical processing method. It was found that it should be possible to eliminate all fossil fuel use from this process, by combustion of by-product while exporting a small amount of electricity. Recycled paper is becoming the largest source of pulp. In this case the waste streams cannot provide sufficient energy to power the process, but process heat can be produced by burning some of the collected waste paper in steam plants or by using electric heat pumps. The energy needed to produce high quality office paper is nearly twice that required for non-deinked packaging paper. This couples with the lower pulp yields obtained with high quality pulp means that the environmentally preferred option for energy supply to the recycling process is dependent on the grade of pulp being produced.

Reliability analysis comparison on punching tool sets due to different maintenance decisions: a case study from the pulp manufacturing industry

This paper presents a case study describing reliability analysis comparisons due to different maintenance decisions for punching tool sets that are used for perforating in a line-making process. Field maintenance data for punching tools are classified according to different maintenance decisions. The data were analyzed further to identify the best fit distribution models. The related reliability characteristics are then revealed and discussed. The reliability analysis results of four different major maintenance decisions shows that the short-term view indicates no significant differences of mean-time-to-failure (MTTF) for the equipment. However, the range (lower and upper limit values) for MTTF for each replacement decision package can be used by a maintenance engineer for equipment spare parts planning. The results found that the failure rate of the equipment was due to replacement decisions packages that are in a deteriorating state. Thus, the maintenance engineering team noticed that the determination of optimum preventive maintenance time is beneficial and cost effective. This study concludes the importance of reliability analysis to better understand the probability nature of the subject under consideration, i.e., it helps a technical team to utilize proper preventive maintenance and spare parts planning.

Structured maintenance engineering policy development based on a production machine process perspective

PurposeThe purpose of this paper is to present the development of a maintenance engineering policy in the context of a decision support model based on a production machine process perspective.Design/methodology/approachThe structure of the policy is called the maintenance decision support (MDS) model, which consists of three steps: initial setup, deterioration monitoring, and decision making. A detailed presentation of each step of the proposed model together with a real case example from the pulp manufacturing industry proves the applicability of the model.FindingsValidation of the proposed MDS model is as follows. In Task 1 of Step 1, the cutting, sealing, and perforating line processes are classified as critical machining processes. The analysis of Task 2 of Step 1 found that cutting knife, bearing, and motor are classified as the components that most possibly contribute to the cutting appearance quality. In Task 3 of Step 1, it was found that the cutting knife is classified as a maintenance-significant component with non-repairable and single-component type characteristics. The result of Step 2 suggested that at the 29th hour of operating time, the decision of do-something was suggested. In the following step (Step 3), for the case of the cutting knife, which has been classified as a non-repairable type component, the decision to perform preventive replacement of cutting knife is recommended to be carried out at the 29th hour of operating time.Research limitations/implicationsThe uniqueness of this model is that it systematically considers different machinery component(s) characteristics, including single- and multiple-component cases, repairable and non-repairable types, and functional or/and physical failure types, to make maintenance decisions.Practical implicationsThe proposed MDS model provides a systematic guideline for identifying, evaluating, and monitoring, which makes maintenance-related decisions. Three significant maintenance decisions can be determined based on the proposed MDS model, which includes an appropriate time-to-perform maintenance, correct maintenance actions to be performed, and the right component required for maintenance (for multi-component cases).Originality/valueOne of the vital elements in considering the production machine process perspective toward the development of the MDS model is the need to use product output/quality characteristics for machine deterioration-monitoring and decision-making processes.

Application and comparison of three maintenance techniques for replacement decision making - a case study in the pulp manufacturing industry

The current paper presents the application of three maintenance techniques, namely, age replacement-based maintenance (ARBM), wear rate-based maintenance (WRBM), and output-based maintenance (OBM), for replacement decision making. The first two techniques are available in the literature, whereas the third one is a technique proposed in the present paper. The theory and principles underlying each technique are briefly discussed before the applicability of each is validated through a case study in the pulp manufacturing industry. The results of each maintenance technique for replacement decision making are compared and discussed from a practical point of view. The present paper concludes that OBM, the proposed technique, provides a more realistic approach towards replacement decision making compared with the other two techniques for functional failure type component. This conclusion is supported by a review of the entire process of replacement decision making based on four practicability criteria, namely, the basic theory and principle of each technique, data requirements and challenge in data collection, data analysis/modelling, and the decision process. Future research recommendations for the application of OBM are also given.

Thermal processing of paper sludge and characterisation of its pyrolysis products

Paper sludge is a waste product from the paper and pulp manufacturing industry that is generally disposed of in landfills. Pyrolysis of paper sludge can potentially provide an option for managing this waste by thermal conversion to higher calorific value fuels, bio-gas, bio-oils and charcoal. This work investigates the properties of paper sludge during pyrolysis and energy required to perform thermal conversion. The products of paper sludge pyrolysis were also investigated to determine their properties and potential energy value. The dominant volatile species of paper sludge pyrolysis at 10 degrees C/min were found to be CO and CO(2), contributing to almost 25% of the paper sludge dry weight loss at 500 degrees C. The hydrocarbons (CH(4), C(2)H(4), C(2)H(6)) and hydrogen contributed to only 1% of the total weight loss. The bio-oils collected at 500 degrees C were primarily comprised of organic acids with the major contribution being linoleic acid, 2,4-decadienal acid and oleic acid. The high acidic content indicates that in order to convert the paper sludge bio-oil to bio-diesel or petrochemicals, further upgrading would be necessary. The charcoal produced at 500 degrees C had a calorific value of 13.3MJ/kg.

Pulp mill process closure: a review of global technology developments and mill experiences in the 1990s

The impact of effluent discharges continues to be an important issue for the pulp manufacturing industry. Considerable progress has been made in pollution prevention to minimize waste generation, so-called manufacturing "process closure." Since the mid-1980s many important technologies have been developed and implemented, many of these in response to organochlorine concerns. Zero effluent operation is now a reality for a few bleached chemi-thermomechanical pulp (BCTMP) pulp mills. In kraft pulp manufacturing, important developments include widespread adoption of new cooking techniques, oxygen delignification, closed screening, improved process control, new bleaching methods, and systems that minimize pulping liquor losses. Coupled to this is a commitment to reduce water use and maximize reuse of in-mill process streams. Some companies pursued bleach plant closure, and many have been successful in eliminating a portion of their bleaching wastewaters. However, the difficulties inherent in closing bleach plants are considerable. For many mills the optimal solution has been found to be a high degree of closure coupled with external biological treatment of the remaining process effluent. No bleach plants at papergrade bleached kraft mills are known to be operating effluent-free on a continuous basis. This paper reviews the important worldwide technological developments and mill experiences in the 1990s that were focused on minimizing environmental impacts of pulp manufacturing operations.