Wood and bark lignin contents of trees from deciduous forests of eastern India

Lignin is a polyphenolic compound found in plant tissues, especially wood and bark. The lignin content determines the quality of wood biochar in agroecological uses, and is used in the production of synthetic resins and adhesives. Despite its importance in plant physiology and its agricultural and industrial utility, there exists a wide gap of knowledge of lignin contents of tropical hardwood trees of South Asia, except for a few species. We present here the first estimation of lignin content in wood and bark of 48 species from tropical deciduous forests of India. We show that some species are characterized by greater wood lignin (WL) compared with bark lignin (BL) content, contrary to the generalization held for hardwood trees, and suggest a plausible correspondence between the WL to BL ratio and timber quality.

Using Synthetic Resins for Removal of Emulsified Oil from Produced Water

In this study, adsorption of emulsified oil in produced water was experimented using synthetic resins. Adsorbent dosage, contact time, initial oil concentration, and PH were the main key parameters evaluated for Optipore L493, Amberlite IRA 958, Amberlite XAD 7 and Lewatit AF 5. Oil removal rates have reached up to 98% using AF 5, XAD 7 and L493, while they are lesser than 25% for IRA 958. Isotherm data were fitted using Langmuir, Freundlich, Toth, Flory Huggins and Dubinin-Radushkevich models. Adsorption isotherms for XAD 7 and L 493 were best fitted using Langmuir model, whereas AF 5 curves were best fitted using Dubinin-Radushkevich. Kinetic data describing the rate of adsorption for each resin were studied and fitted using pseudo-first and second order equations in addition to intraparticle diffusion models. The experimental results were best-fitted using pseudo second order kinetics. The obtained results confirm the applicability of the resins for the removal of oil from produced water.

Environmental Impact of the Reclaimed Sand Addition to Molding Sand with Furan and Phenol-Formaldehyde Resin—A Comparison

Increasingly strict regulations, as well as an increased public awareness, are forcing industry, including the foundry industry, to develop new binders for molding sands, which, while being more environmentally friendly, would simultaneously ensure a high quality of castings. Until recently, binders based on synthetic resins were considered to be such binders. However, more accurate investigations indicated that such molding sands subjected to high temperatures of liquid metal generated several harmful, even dangerous substances (carcinogenic and/or mutagenic) from the benzene, toluene, ethylbenzene and xylenes (BTEX) and polycyclic aromatic hydrocarbons groups (PAHs). An assessment of the most widely used molding sands technologies at present with organic binders (synthetic resins) from the no-bake group (furan no-bake and phenolic-ester no-bake) and their harmfulness to the environment and work conditions is presented in this paper. In the first stage of this research, gases (from the BTEX and PAHs groups) emitted when the tested molds were poured with liquid cast iron at 1350 °C were measured (according to the authors’ own method). The second stage consisted of measuring the emission of gases released by binders subjected to pyrolysis (the so-called flash pyrolysis), which simulated the effects occurring on the boundary: liquid metal/molding sand. The gases emitted from the tested binders indicated that, in both cases, the emission of harmful and dangerous substances (e.g., benzene) occurs, but, of the given binder systems, this emission was lower for the phenolic-ester no-bake binder. The obtained emission factors of BTEX substances show higher values for furan resin compared to formaldehyde resin; for example, the concentration of benzene per 1 kg of binder for furan no-bake (FNB) was 40,158 mg, while, for phenol-formaldehyde no-bake (PFNB), it was much lower, 30,911 mg. Thus, this system was more environmentally friendly.

Pengaruh prosentase larutan NaOH pada proses alkalisasi serat kulit pohon waru (hibiscus tiliaceus) sebagai reinforcement komposit terhadap kekuatan tarik serat tunggal

The utilization of natural fiber, nowadays, has employed as reinforcement of composite materials. Natural fiber can benefit the composite material because of the characters of fibre which is more environmental friendly, economics, lighter and stronger. There are many natural fibers that can be used as reinforcement of composite materials such as the bark fibers of Hibiscus Tiliaceus. Hibiscus Tiliaceus is one species of Hibiscus Tiliaceus that can be found in the mountains in Indonesia. This study aims to determine the tensile strength of a single fiber in Hibiscus Tiliaceus fiber with the additional various percentage of NaOH in the alkalization treatment. The alkalization treatment analyzes the alkali process of NaOH substance by 3%, 6%, 9%, 12%, and without treatment within the bark of Hibiscus Tiliaceus tree. The treatment was undertaken by soaking the NaOH substance in a duration of 120 minutes. After the NaOH solution was immersed, the bark fiber of Hibiscus Tiliaceus was washed with aquades until the solution reaches a pH of 7. The results of this study show the percentage of NaOH solution in the alkaline immersion process affects the tensile strength of a single fiber on Hibiscus Tiliaceus and the process of NaOH solution which has a release of 6% lignin, cellulose, and semilulose content. In addition, the NaOH treatment with a percentage of 6% can be the standard of the process of alkalizing the bark fiber of Hibiscus Tiliaceus which can be used for composite reinforcement. Therefore, 6% of NaOH can affect the bond between the Hibiscus Tiliaceus fibers as reinforcement and synthetic resins as a matrix which can increase the strength of the composite.

Current technological problems in the production of synthetic resins and wood-based panels

Проведен опрос специалистов по выявлению актуальных проблем в технологии изготовления древесных плит и синтетических смол для их производства. Исследование проведено методом группового анкетного опроса. Анкета содержала 3 перечня вероятных проблем по разделам: производство синтетических смол, производство древесностружечных плит и производство древесноволокнистых плит. Перечни технологических проблем взяты как итоговые результаты прошлых социологических исследований, а также на основании предложений специалистов. Оценка актуальности проблемы производилась по 5-балльной шкале. По величине средневзвешенного балла определяли уровень актуальности технологической проблемы: чем он выше, тем значимее анализируемая проблема. На вопросы анкеты ответили 47 человек. Эксперты имеют большой опыт, их средний стаж работы в отрасли 22,7 года. Более 70 участников опроса работники предприятий, остальные научные сотрудники, проектировщики и преподаватели. Исследовали 10 проблем по технологии синтетических смол, 12 по технологии древесностружечных плит, 10 по технологии древесноволокнистых плит. Для сравнения приведены данные аналогичных опросов, проведённых в 2005 и 2011 гг. По мнению экспертов наиболее значимыми являются проблемы, связанные с созданием и применением синтетических смол в производстве плит. Это новые низкотоксичные смолы, обеспечивающие, помимо снижения содержания формальдегида в смоле и плитах, необходимые физико-механические свойства плит, низкий расход связующего, высокую скорость прессования, экологические параметры производства. В производстве синтетических смол 2 проблемы относятся к категории высокоактуальных (балл актуальности проблемы в диапазоне от 4,01 до 5,00), 8 проблем к категории повышенной актуальности (балл актуальности от 3,01 до 4,00). Высокоактуальные проблемы: снижение токсичности смол для плит и реакционная способность смолы. К проблемам повышенной актуальности относятся вопросы синтеза новых смол, улучшение показателей смол, качество сырья и экологические вопросы производства смол. Среди 12 анализируемых проблем производства древесностружечных плит 2 относятся к категории высокоактуальных, 4 к категории повышенной актуальности, 6 к категории средней актуальности (балл актуальности от 2,01 до 3,00). Высокоактуальные проблемы: снижение токсичности плит и снижение расхода смолы в производстве плит. Проблемы повышенной актуальности: снижение разбухания плит, интенсификация процесса горячего прессования, снижение расхода древесного сырья, переработка низкокачественной древесины. В производстве древесноволокнистых плит 6 проблем относятся к категории высоко актуальных, 3 к категории повышенной актуальности, 1 к категории средней актуальности. Высокоактуальные проблемы для производства древесноволокнистых плит сухого способа: новые экологически чистые смолы, снижение токсичности плит, снижение расхода смолы. Высокоактуальные проблемы для производства древесноволокнистых плит мокрого способа: снижение токсичности сточных вод, новые экологически чистые смолы, очистка сточных вод. A survey of specialists to identify current problems in the technology of making of wood-based panels and synthetic resins for their production was conducted. The study was conducted by a group questionnaire. The questionnaire contained three lists of likely problems by sections: the production of synthetic resins, the production of particleboards and the production of fiberboards. Lists of technological problems are taken as the final results of past sociological studies, as well as on the basis of experts proposals. The topicality of the problem was assessed on a 5-point scale. The weighted average score determined the level of relevance of the technological problem the higher it is, the more significant the problem analyzed. Forty-seven people answered the questionnaire. Experts have a lot of experience, their average work experience in the industry is 22.7 years. More than 70 of the survey participants are employees of enterprises, the rest are scientists, designers and teachers. We studied 10 problems on synthetic resin technology, 12 on technology of particle boards and 10 on the technology of fiberboards. For comparison, data from similar surveys conducted in 2005 and 2011 are given. According to experts, the most significant problems are ones associated with the creation and use of synthetic resins in the production of plates. These are new low-toxic resins, providing in addition to reducing formaldehyde content in resin and slabs the necessary physical-mechanical properties of plates, low binder consumption, high pressing speed and environmental parameters of production. In the production of synthetic resins two problems are in the category of highly relevant (the problem relevance score in the range from 4.01 to 5.00), 8 problems to the category of increased relevance (relevance score from 3.01 to 4.00). Highly relevant problems: reducing the toxicity of slabs resins and the reactionary ability of resin. Issues of increased relevance include the synthesis of new resins, improved resin sins, the quality of raw materials and environmental issues of resin production. Among the 12 analyzed problems of particleboards production, 2 are classified as highly relevant, 4 are in the category of increased relevance and 6 in the category of average relevance (relevance score from 2.01 to 3.00). Highly relevant problems: reducing the toxicity of plates and reducing the consumption of resin in plate production. Problems of increased relevance: reducing swell of plates, intensifying the process of hot pressing, reducing the consumption of wood raw materials, processing of low-quality wood. In the production of fiberboards 6 problems belong to the category of high-actual, 3 to the category of increased relevance and 1 to the category of medium relevance. Highly relevant problems for the production of fiberboards of dry method: new environmentally friendly resins, reduced toxicity of plates, reduced resin consumption. Highly relevant problems for the production of fiberboards of wet method: reducing the toxicity of wastewater, new environmentally friendly resins, wastewater treatment.

Study of binders for ecologically safe anhydrous tap-hole clays

Detailed analytical review of the existing tap-hole clays used in the blast furnace production at various metallurgical enterprises is made. It is established that it is necessary to ensure environmental safety when using tap-hole clay. It is clarifi ed that synthetic resins (phenol-formaldehyde and novolac resins) are used instead of harmful coal-tar resin for the production of tap-hole clays. The oxidation of coal-tar resin and pitch occurs up to temperature of 600 °С, which is especially important for large blast furnaces equipped with 2...4 tap-holes.