Determination of the Chemical Composition of Eucalyptus spp. for Cellulosic Pulp Production

The chemical composition of wood is important to assess the quality of this raw material for the industry of cellulosic pulp production. The purpose of this work was to determine the chemical composition of Eucalyptus spp. grown for cellulosic pulp production. Ten Eucalyptus spp. clones with six years of age, located in the municipality of Itamarandiba, Minas Gerais, Brazil, were used. Quantification was obtained for extractives, monosaccharides, uronic acids, acetates, lignin, ash and the phenolic composition of the extracts. In average, clones showed around 2.7% extractives, with a predominance of polar compounds soluble in ethanol and water; 27.7% lignin and 0.3% ash. Glucose was the main sugar detected (64.2%), followed by xylose (19.3%). The main components of the extractives were steroids, fatty acids and aromatic acids, followed by smaller amounts of substituted alkanoic acids, fatty alcohols, glycerol derivatives and triterpenes. The ethanol–water extracts presented total phenol contents ranging from 321.4 to 586.6 mg EAG/g of extract, tannins from 28.1 to 65.1 mg catechin/g of extract and flavonoids from 73.6 to 256.9 mg catechin/g of extract. Clones with a higher holocellulose amount and a lower lignin content showed a higher potential for cellulosic pulp production. These findings are important for the development of high-quality wood based on important traits for the pulp and paper sector.

Determination of Ideal Cooking Conditions for Pulp Production from Avocado Wood (Persea americana Mill.) by Kraft Method

In this study, hand sheets were made from pulp produced by the Kraft method using avocado wood. The raw materials were supplied by a fruit orchard and consisted of avocado (Persea americana Mill.) trees that had completed their useful life and were cut during routine thinning maintenance. In order to determine the ideal cooking conditions in the production of pulp from avocado wood via the Kraft method, 16 cooks were carried out by varying the cooking time (T), active alkali (AA), and sulfidity (S) ratios. The general pulp properties, especially the screened pulp yield, pulp viscosity, and Kappa number, were evaluated. The pulp yield was taken as the primary basis in determining the cooking conditions. The ideal cooking conditions were also determined by considering some physical, mechanical, and optical properties of the paper. According to this study, the conditions found to be ideal in pulp production from avocado (Persea americana Mill.) wood via the Kraft method were: 18 % AA, 22 % S, and 75 min T.

A Novel and Effective Recyclable BiOCl/BiOBr Photocatalysis for Lignin Removal from Pre-Hydrolysis Liquor

The presence of lignin hampers the utilization of hemicelluloses in the pre-hydrolysis liquor (PHL) from the kraft-based dissolving pulp production process. In this paper, a novel process for removing lignin from PHL was proposed by effectively recycling catalysts of BiOCl/BiOBr. During the whole process, BiOCl and BiOBr were not only adsorbents for removing lignin, but also photocatalysts for degrading lignin. The results showed that BiOCl and BiOBr treatments caused 36.3% and 33.9% lignin removal, respectively, at the optimized conditions, and the losses of hemicellulose-derived saccharides (HDS) were both 0.1%. The catalysts could be regenerated by simple photocatalytic treatment and obtain considerable CO and CO2. After 15 h of illumination, 49.9 μmol CO and 553.0 μmol CO2 were produced by BiOCl, and 38.7 μmol CO and 484.3 μmol CO2 were produced by BiOBr. Therefore, both BiOCl and BiOBr exhibit excellent adsorption and photocatalytic properties for lignin removal from pre-hydrolysis.

Technological evaluation of Pinus maximinoi wood for industrial use in kraft pulp production

This study characterized Pinus maximinoi wood and evaluated its performance for pulp production. Samples of Pinus taeda wood were used as reference material. For both species, wood chips from 14-year-old trees were used for the technological characterization, pulping, bleaching process analysis, and pulp properties. A modified kraft pulping process was carried out targeting kappa number 28±5% on brownstock pulp. The bleaching sequence was applied for bleached pulp with final brightness of 87±1 % ISO. Refinability and resistance properties were measured in the bleached pulps. Compared to P. taeda wood, P. maximinoi showed slightly higher basic density (0.399 g/cm³) and higher holocellulose (64.5%), lignin (31.1%), and extractives content (4.5%), along with lower ash content (0.16%). P. maximinoi tracheids showed greater wall thickness (6.4 µm) when compared to P. taeda tracheids. For the same kappa number, P. maximinoi and P. taeda resulted in similar screened yield, with an advantage observed for P. maximinoi, which resulted in lower specific wood consumption (5.281 m³/o.d. metric ton), and lower black liquor solids (1.613 metric tons/o.d. metric ton). After oxygen delignification, P. maximinoi pulp showed higher efficiency on kappa reduction (67.2%) and similar bleaching chemical demand as P. taeda pulp. Compared to P. taeda pulps, the refined P. maximinoi pulps had similar results and the bulk property was 10% higher. Results showed that P. maximinoi is an interesting alternative raw material for softwood pulp production in Brazil.

Addressing production bottlenecks and brownstock washer optimization via a membrane concentration system

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.

Agricultural Residues as an Alternative Source of Fibre for the Production of Paper in Kenya-A Review

The pulp and paper industry is primarily dependent on fibrous wood for pulp and paper production. However, this over-dependence on fibrous wood poses serious environmental challenges such as the diminishing of the fibrous wood stocks, deforestation, emission of greenhouse gases, and global warming. Therefore, to mitigate these environmental challenges associated with its utilization for paper and pulp production, other sustainable raw material sources can also be considered for the production of paper and pulp. There are enormous benefits associated with the utilization of non-wood fibres as an alternative and sustainable raw materials source for the production of paper and pulp. These benefits have in the recent past prompted millers in China, India, Brazil, and the USA to consider the utilization of non-wood fibres in paper and pulp production. In Kenya, the pulp and paper industry is very much dependent on fibrous wood for production and the industry is yet to fully embrace the utilization of nonwood fibres for paper and pulp production. Further, the dependence on fibrous wood has contributed significantly to the decline of paper pulp and paper production, deforestation, and rise in paper importations due to insufficient raw material supplies. The importation of paper and pulp products has further led to the collapse of the paper industry in Kenya. The sector stands a chance of revival and vibrancy through the utilization of the abundant agricultural residues and feedstocks lying in the agricultural fields across the country. Similar experiences elsewhere have proved that the abundance of agricultural waste can be utilized for the production of paper and pulp due to their excellent fibre content for specialty papers, and easy pulpability. The agricultural residues are therefore considered a quintessential alternative and sustainable source of raw materials for the pulp and paper industry. Moreover, their utilization will mitigate environmental impacts such as deforestation, climate change, and pollution .

Characteristics and Analyses of Strategic Factors in Reverse Channels of Açaí Pulp Production Waste in the Municipality of Castanhal/PA/ Caracterização e análise de fatores estratégicos nos canais reversos do resíduo da produção de polpa de açaí no município de Castanhal-PA

When disposed of inappropriately, waste from the production of açaí pulp, originating from the açaí production chain, is the cause of many environmental, economic, and social problems. In an attempt to minimize impact, Reverse Logistics is an instrument of economic, environmental, and social development characterized by actions aimed at the treatment and reuse of waste, which is managed and moved through Reverse Channels. Consulted bibliography defines Strategic Factors capable of promoting the structuring and organization of waste for environmentally appropriate destination by different production sectors. This research analyzed economic, environmental/ecological, technological, logistical, and legislative strategic factors of the reverse channels for açaí production waste in the city of Castanhal/PA, as this municipality’s açaí pulp production is nationally relevant. For this purpose, it was necessary first to characterize local reverse channels, since bibliographic and documentary research did not yield relevant information on the subject. Field research—consisting of in loco observation, structured interviews, and application of online questionnaires to agents directly and indirectly involved—was fundamental to characterize the object of this study. As a result, we achieved the characterization of reverse channels, as well as their logistical resources and the stakeholders involved, starting from the generation of waste through to transportation and final destination, ending our analysis with the main forms of waste revaluation. Our research also allowed the identification and analysis of strategic factors capable of influencing the structuring and maintenance of activities in this reverse chain.

Identification of comparability indicators of the pulp mill discharged treated effluents quality with the technological parameters of the production nature intensity

В соответствии с изменением природоохранного законодательства проблема минимизации природоёмкости сульфат-целлюлозного производства, влияющего на экосистему озера, неразрывно связана с изучением вопроса трансформации и превращения загрязняющих веществ в воде с учетом гидрологических характеристик водоема. Природоёмкость целлюлозного производства определяется следующими показателями: количество и качество используемого сырья – древесина, щепа, химические реагенты, вода; технологический процесс производства целлюлозы, бумаги, картона, побочных продуктов – скипидар, талловое масло; эффективность систем очистки сбросов и выбросов предприятия, а также применяемые природоохранные технологии по их управлению. Решались задачи снижения негативного воздействия сульфат-целлюлозного производства на водную экосистему. Совместно с лабораторией отдела охраны окружающей среды целлюлозного завода в летне-осенний период 2020 г. проведен ряд лабораторных исследований сточных вод разной степени очистки после варки разных марок целлюлозы с целью изменения показателей экологичности состава сточных вод ЦБП по критериям региональной экологической техноёмкости. Реализована модель исследования трансформации загрязняющих веществ очищенных и неочищенных сточных вод сульфат-целлюлозного производства при различных разбавлениях природной водой. Представлены целевые и репрезентативные показатели щелокосодержащих сточных вод с учетом наилучших доступных технологий (НДТ) в области производства целлюлозы. Проведены исследования параметров кинетики биохимического окисления при пяти кратностях разбавления водой, имитирующих зону начального и основного разбавления. Произведено соизмерение определяющих технологических характеристик производственно-территориального комплекса в рамках решения задачи эколого-технологического нормирования. In accordance with the changes in environmental legislation the issue of minimizing the nature intensity of sulfate-pulp production, which affects the ecosystem of the lake, is inextricably linked with the study of the transformation and transformation of pollutants in the water, taking into account the hydrological characteristics of the reservoir. The natural intensity of pulp production is determined by the quantity and quality of the raw materials used – wood, wood chips, chemical reagents, water; the technological process of production of pulp, paper, cardboard, as well as by-products such as turpentine, tallow oil and efficiency and applied environmental technologies for the management of discharges, emissions and waste of production and consumption. The tasks of reducing the negative impact of sulfatecellulose production on the aquatic ecosystem were solved. Together with the laboratory of the environmental protection department of the pulp mill, a number of laboratory studies of treated and untreated waste water after cooking of different grades of pulp were carried out in the summer-autumn period of 2020 in order to implement the procedure for rationing waste water of the pulp and paper mill according to the criteria of regional environmental technology intensity. A model is presented for studying the transformation of pollutants in treated and untreated wastewater from sulfate-pulp production at various dilutions with natural water. Target and representative indicators of alkaline-containing wastewater are presented, taking into account the best available technologies (BAT) in the field of pulp production. The parameters of the biochemical oxidation kinetics were studied at five water dilution multiplicities simulating the initial and main dilution zones. The main characteristics of the production and territorial complex were measured within the framework of the tasks of environmental rationing.