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1

Briquettes from a Mixture of Cow Menure, Rice Husks and Wood Dust as Alternative Fuel

Athaillah Teuku, Masykur, Husin Hasanuddin, Adib, Aulia Muhammad Reza

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

290--299

EN

There is a lot of promise for the creation of briquettes made of wood dust, rice husks, and cow menure as alternative fuels. The water content (%) and ash content (%) was measured in this study. Carbon ratio (%), value calorific (cal/g), briquettes’ percentage of volatile content and their compressive strength (g/cm2). A financial feasibility analysis of briquettes was also conducted as part of this study. Sample 1 briquettes had a water content of 16%, whereas sample 2 briquettes had a water content of 12%. Because the results of this water content test range between 5% and 20%, they are still considered acceptable. According to the test results, sample 1 had an ash level of 33% and sample 2 had an ash value of 29%. There were 65% and 60% of flying chemicals in sample 1 and sample 2, respectively. The quality of the briquettes increases with decreasing volatile matter content. From the test results, sample 1 of the briquettes has a carbon level of 2%, whereas sample 2 has an 11% carbon content. Because carbon concentration affects the calorific value, it is a measure of fuel quality. Sample 1’s briquette density is 0.539 g/cm3, whereas sample 2’s briquette density is 0.337 g/cm3. Briquettes for sample 1 have a compressive strength of 13.26 g/cm2, whereas sample 2 has a compressive strength of 15.3 g/cm2. Overall, the briquettes’ financial feasibility study is really promising, with a favorable net present value (NPV) of 144.074.566, a high internal rate of return (IRR) of 72.154%, a respectable net B/C of 4.37, and a comparatively short payback period (PBP) of 3.22 years. This indicates the value of continuing this project. It is believed that by using these briquettes, the amount of deforestation would decline and the dependence on firewood will decrease. We may protect biodiversity and ecosystems by protecting forests.

2

Preparing Shrimp Shell-Derived Chitosan with Rice Husk-Derived Biochar for Efficient Safranin O Removal from Aqueous Solution

Phuong Do Thi My, Thao Nguyen Thi Thanh, Loc Nguyen Xuan

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

248--259

EN

In this study, the shrimp shell-derived chitosan was coated onto rice husk-derived biochar to form chitosan/biochar bio-composite beads. The physicochemical properties of biochar (BC) and chitosan/biochar beads (CS@BC) were characterized by BET, SEM-EDX, FTIR, and pHpzc analyses, which were then tested for their capacity to remove Safranin O (SO) from water. In kinetics, the pseudo-second-order model was found to well represent experimental data, indicating the adsorption was mainly a chemical process. The intra-particle diffusion model was not the sole rate-limiting step, because the results did not pass through the origin. In isotherms, both the Langmuir and Freundlich models described well the equilibrium adsorption data. The CS@BC adsorbent showed adsorption capacity at 77.94 mg/g for SO, which is higher than BC adsorbent with 62.25 mg/g (experimental conditions: pH ~ 7.0, dosage = 0.2 g, contact time = 240 min, and temperature = 298 K). The findings revealed that the biochar-loaded chitosan can improve the adsorption capacity of SO. It is predicted that the enhancement in the functional groups (i.e., -NH2 and -OH groups) of CS@BC could contribute to the electrostatic interactions and the complexation between SO and CS@BC, thereby enhancing the Safranin O adsorption from water.

3

Influence of Sieve Size on Calorific Value and Proximate Properties of Bio-Briquette Composites

Aliah Hasniah, Winarti Indri, Iman Ryan Nur, Setiawan Andhy, Safarina Rizky, Sawitri Asti

Journal of Ecological Engineering

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2023

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Vol. 24, nr 7

25--34

EN

This work aimed to observe the influence of calorific value and proximate properties in the fabrication of rice husk (RH) and coffee shell (CS) briquettes composite. Rice and coffee husks contain cellulose, hemicellulose, and lignin. These contents are necessary for the adhesive to bind the briquette (amylose and amylopectin). The raw materials were carbonized at 400 °C for 60 minutes. Variations of sieving size (60, 80, and 100 mesh) and the composition ratio of raw material CS:RH were reviewed to study their effect. Tests of density, moisture content, volatile matter content, ash content, fixed carbon content, shatter index, combustion rate, and calorific value were carried out to determine the optimum composition. The results were obtained with the best quality at a particle size of 60 mesh with the highest calorific value of 17.422 MJ/kg. It showed that the briquettes have good quality and are comparable with the standard briquette.

4

Characteristics of Charcoal Briquettes from Rice Husk Waste with Compaction Pressure Variations as an Alternative Fuel

Yusuf Mega Ayu, Witdarko Yus, Parjono, Pamungkas Wiyan Afriyanto, Suryadi

Journal of Ecological Engineering

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2023

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Vol. 24, nr 4

237--243

EN

The availability of increasingly scarce fossil fuels causes high fuel prices, so alternative fuels are needed to reduce the use of fossil energy. Briquettes are an alternative energy that can be made from biomass, one of which is rice husk. The quality of the briquettes was determined by the material, the type of adhesive, and the strength of the briquette pressure. The briquette pressure will affect the mechanical properties of the briquettes such as density, stability and durability of the briquettes. This study aimed to determine the features of rice husk charcoal briquettes with variations in compacting pressure as an alternative fuel. The compaction pressure used in this study was 3 tons, 5 tons, and 7 tons. In general, the briquettes produced from this study can be used as an alternative energy source in terms of the resulting combustion temperature which ranges from more than 300–500 °C.The combustion rate obtained shows that the briquettes with a compaction pressure of 3 tons have a high combustion rate value of 0.553 g/minute, while the briquettes with a compaction pressure of 5 tons and 7 tons have a low combustion rate value of 4.20 g/min and 0.418 g/minute respectively. Therefore, the best quality briquettes from this study were the briquettes with a compaction pressure of 5 tons and 7 tons, so that they could be considered as alternative energy for wood and fossil fuels for energy needs in the domestic industry.

5

Cadmium Removal from Contaminated Soil by Electro-Kinetic Method

Hawal Laith Hamdan, Al-Sulttani Ali Omran, Hamza Jinan N.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

79--86

EN

For this study, an electro kinetic method used to eliminate cadmium from the polluted soil. This method is useful at low permeability medium. Several experiments were conducted with variable operating circumstances, using different pH purging solutions. Rice husks were used in this work as an adsorbent medium available and free of charge to counteract the reverse osmosis process that occurs and affects the work efficiency. The final results after the end of the practical experiments of this process showed that the percentages of the removal process began to increase after the pH gradually decreases. The pH of the solution for the three experiments conducted was 3, 6 and 9, respectively. The best removal rate was 68% in this process at pH 3 ; when compared with the second and third tests at pH 6 and 9, the removal ratios were 58% and 51.5%, respectively. It was discovered that the cadmium removal rate began to decrease along with voltage. At 30 volts the removal rates were 68%, whereas 20 volts they were 66%. Rice husks have been shown to be an effective adsorbent for counteracting reverse osmosis. Therefore, it can be successfully used as an adsorbent medium.

6

Properties of Ni60/SiO2 Coating Prepared by the Pyrolysis Products of Rice Husk

Wei Chunxue, Li Hongbing

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

37--42

EN

Surface coating technology, as the main technology to improve the fatigue life of mechanical systems, has been well applied in mechanical equipment. The present study aimed to explore low-cost surface coating preparation technology using inexpensive rice husk as the research object, and the pyrolysis process behavior of rice husk was analyzed. The Ni60/SiO2 coating was prepared on the surface of the 45# steel substrate using the pyrolysis product SiO2 fiber as the reinforcing phase and supersonic plasma-spraying equipment. The results showed no defects such as cracks, pores, and inclusions in the prepared coating. The nanohardness of the Ni60/SiO2 coating reached 6506 μN, and the average friction coefficient reached 0.42. In the friction-and-wear experiment, the Ni60/SiO2 coating was manifested as an abrasive wear mechanism.

7

Wpływ przyspieszonego starzenia na mikrostrukturę i wybrane właściwości mechaniczne profili z kompozytów polimerowych zbrojonych łuskami zbóż

Kozikowska Ewelina, Sudoł Ewa

Materiały Budowlane

|

2022

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nr 9

76--79

PL

Analizowano wpływ czynników atmosferycznych na przebieg starzenia kompozytów polimerowych zbrojonych włóknami lignocelulozowymi, które zostały pozyskane z łusek roślin uprawnych. Poddanie profili kompozytowych procesowi starzenia wyraźnie zmienia morfologię powierzchni. Analiza mikrostruktury powierzchni zewnętrznych uwidoczniła przetopienia wierzchniej warstwy osnowy polimerowej prowadzące do odsłonięcia powierzchni cząstek wypełniacza. Przeprowadzone badania wykazały najlepsze właściwości użytkowe profili z dodatkiem łusek owsa w stanie wyjściowym oraz po starzeniu, których właściwości były porównywalne z komercyjnymi profilami zbrojonymi łuskami ryżowymi.

EN

The influence of atmospheric factors on ageing of polymer composites reinforced with lignocellulose fibers has been analysed. Three natural fibers obtained from the husks of cultivated plants: rice, oat, millet husk were used as fillers. The microscopic analysis of the surfaces revealed melting of the top layer of the polymer matrix, leading to the exposure of the filler particles. The carried out mechanical tests showed the best properties for profiles with oat hulls in the initial state and after ageing, whose properties were comparable to those of commercial profiles reinforced with rice hulls.

8

Odporność profili budowlanych z kompozytów polimerowych zbrojonych łuskami zbóż na grzyby domowe

Sudoł Ewa, Kozikowska Ewelina, Goron Maria

Materiały Budowlane

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2022

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nr 9

70--75

PL

Analizowano odporność profili z kompozytów PVC z napełniaczem z pulweryzowanych łusek owsa, prosa i ryżu na działanie na grzybów domowych. Wyroby z łuskami owsa i ryżu wykazały porównywalną podatność na działanie Coniophora puteana, Gloeophyllum trabeum oraz Coriolus versicolor, ale mniejszą niż kompozyt z łuskami prosa. Coniophora puteana wykazał największy stopień rozwoju grzybni i zmienił morfologię powierzchni profili. Ekspozycja na działanie grzybów w środowisku mokrym skutkowała zmniejszeniem wytrzymałości na zginanie i modułu sprężystości, największym w przypadku kompozytu zbrojonego łuskami prosa. Kluczowy był wpływ samego środowiska mokrego. Mikroorganizmy nieznaczenie zmieniły właściwości przy zginaniu.

EN

The resistance to fungi of oat, millet and rice husks reinforced PVC composite profiles was analysed. Products with oat and rice husks showed comparable susceptibility to Coniophora puteana, Gloeophyllum trabeum and Coriolus versicolor, lower than the composite with millet husks. Coniophora puteana showed the highest degree of mycelium growth, changing the morphology of the profile surface. Exposure to fungi in a wet condition caused a decrease in flexural strength and modulus of elasticity, the greatest in the case of millet husks reinforced composite. The influence of the wet conditions itself was crucial. The microorganisms slightly changed the bending properties.

9

Carbonized Sorbents of Shungite and Rice Husk for Purification of Petroleum Contaminated Soils

Ongarbayev Yerdos, Baigulbayeva Moldir, Tileuberdi Yerbol, Ualieva Perizat, Abdieva Gulzhamal

Journal of Ecological Engineering

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2022

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Vol. 23, nr 5

16--25

EN

Contamination of soil and water with petroleum during its extraction, collection, transportation, storage and preparation occurs frequently, and purification of oil spills is one of the pressing environmental problems of oil producing organizations. There are a large number of methods for utilization oil spills. The sorption method in combination with bioremediation is capable of effectively purification of petroleum contaminated soils. The paper shows the possibility of using a carbonized mixture of shungite from the Koksu deposit (Kazakhstan) with rice husk as a sorbent and carrier of microorganism strains. The physicochemical properties and elemental composition, as well as the microstructure of carbonized samples were established. The maximum sorption capacity of carbonized sorbents when purifying the soil samples from oil from the Karazhanbas field was 1.86 g/g after 60 days. The carbonized samples with microorganism strains immobilized on them showed a degree of oil destruction reaching 90%.

10

Comparison between the Tensile, Water Absorption and Flammability Properties of Recycled High-Density Polyethylene/Rice Husk Composite from Twin-Screw Extruder and Heated Two-Roll Mill

Salleh Mohd Nazry, Aziz Roslaili Abdul, Shan Chen Ruey, Musa Luqman, Razak Mohd Fairul Sharin Abdul, Nabiałek Marcin, Jeż Bartłomiej

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

661--668

EN

This study compares the mechanical properties of recycled high-density polyethylene (r-HDPE)/rice husk (RH) composites from a twin-screw extruder and a heated two-roll mill, and the effect of different filler loadings using different melt blending processes on the mechanical properties of r-HDPE/RH composites. Polyethylene-graft-maleic anhydride (MAPE) acts as the coupling agent to enhance interfacial bonding between the fibre and the polymer matrix. The filler loading used was in the range of 10-40 wt. %. In this work, r-HDPE/RH blends were prepared using a twin-screw extruder and a heated two-roll mill. The ratio of 70/30 twin-screw extruder compounded composites significantly showed higher tensile based on improved to about 45.5% at 11 MPa compared to those compounded in the heated two-roll mill. The same ratio showed an increment almost up to 9% of elongation at break. It has also been verified that the higher filler loading used reduced the tensile strength and elongation at break, while the Young’s modulus increased. The result was evidenced by the increase in water absorption and longer burning time as the filler loading increased.

11

Adsorption of Lead Ions from Aqueous Solutions onto Rice Husks, Continuous System

Hawal Laith Hamdan, Al-Sulttani Ali Omran, Kariem Nagam Obaid

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

269--274

EN

The continuous system of lead adsorption on rice husks was investigated in this paper. A fixed bed study was performed in many tests to investigate the influence of pH, the adsorbent height, the initial concentration of lead, the flow rate and processing time on the lead adsorption process. The results demonstrated that the lead removal capacity decreased when the pH value of the solution and the flow rate increased. The lead removal capacity increased due to the decreased initial concentration of lead. The results showed that the removal capacity increases along with the processing time and the adsorbent height in column. The largest removal was (81%) at pH of 4, the adsorbent height (50 cm), the initial concentration of lead (10 mg/l), the processing time (90 min.) and the flow rate (10 ml/min.). As a result, rice husks can be used to remove the lead instead of expensive commercial adsorbents, due to its availability, inexpensive and perfect adsorption property.

12

Production and Characterization of Rice Husk Biochar and Kenaf Biochar for Value-Added Biochar Replacement for Potential Materials Adsorption

Saeed Anwar Ameen Hezam, Harun Noorfidza Yub, Sufian Suriati, Afolabi Haruna Kolawole, Al-Qadami Ebrahim Hamid Hussein, Roslan Farah Amelia Shahirah, Rahim Syahirah Abdul, Ghaleb A. A. S.

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 1

1--8

EN

Two raw biomass materials from different sources were investigated: aluminosilicate obtained from rice husk and agricultural lignocellulosic waste from kenaf fiber. The properties of the optimal mixing ratio of biochar were investigated by using proximate analysis, ultimate analysis, thermogravimetric analysis, surface area and pore volume determination, Fourier Transform Infrared Spectroscopy analysis, X-ray diffraction, and Scanning Electron Microscopy. According to the proximate analysis, the ash content is increasing while the moisture content fixed carbon and volatile matter decrease. On the basis of the BET characterization finding, the surface area is increased proportionally to the increasing mixing ratio RHB: KFB (0.8:0.2, 0.5:0.5, 0.2:0.8). The SEM images showed that both biochars are suitable sources of blending because of the differences and the availability of good adsorbents. This study indicated that RHB and KFB as pure biochar have a great potential to be applied as adsorbents. However, blending is not giving the desired result to be used as an adsorbent.

13

Development of technology for wasteless processing of rice husk

Sukharnikov Yuriy I., Rusowicz Artur, Dikhanbaev Bayandy I., Yefremova Svetlana V., Zharmenov Abdurassul A.

Rynek Energii

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2019

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Nr 4

60--70

EN

The purpose of the work is a technical and technological justification for the creation of an industrial production of a multifunctional silica-carbon material from rice husk. The proposed method involves thermal processing (pyrolysis) of rice husk at a temperature of 600-650 ° C to produce silica-carbon material and pyrolysis gas. The silica-carbon contains 48-53% C, 37-40% SiO2 and 10-15% hydrocarbons, it is non-toxic, non-flammable and non- explosive. Pyrolysis gas contains, % mass: CH4 - 35; СО - 20; H2 - 5, CO2 - 27; H2O - 10; N2 - 3, and has a calorific value of about 12500kJ / m3. The pyrolysis gas is used as an energy fuel. It is burned in a heat generator, and its combustion products with a temperature of more than 900 ° C are used to heat the pyrolysis reactor. The main elements of the thermal processing (pyrolysis) unit of the rice husk are selected. A circuit diagram of the apparatus is shown, the main ones being a rotating pyrolysis reactor, a pyrolysis gas combustion apparatus, and a silica-carbon cooling apparatus. The material and thermal balances of the process of pyrolysis of rice husk are fulfilled. The output of silica-carbon from rice husks is 33.3%, and of pyrolysis gas 66.7%. According to the heat engineering calculation, the amount of heat at the combustion of pyrolysis gas is 1.8 times higher than necessary value for heating the rice husks in the reactor. Excess heat is supposed to be sent to heat water in the heat exchanger and use it for domestic needs. The industrial module for industrial use is designed for processing 5000 tons of rice husks a year to produce 1750 tons of silica-carbon is offered. Silica-carbon is a polyfunctional material and can be used as a filler of elastomers and carbon structural materials, and also as a fodder additive in poultry farming. Considering the great demand for Kazakhstan and the world in this material, the creation of its production is very topical.

PL

Celem pracy jest techniczne i technologiczne uzasadnienie stworzenia przemysłowej produkcji wielofunkcyjnego materiału krzemionkowo-węglowego z łuski ryżowej. Proponowana metoda polega na obróbce termicznej (piroliza) łuski ryżowej w temperaturze 600-650°C w celu wytworzenia materiału krzemionkowo-węglowego i gazu pirolizacyjnego. Krzemionka - węgiel zawiera 48-53% C, 37-40% SiO2 i 10-15% węglowodorów, jest nietoksyczna, niepalna i niewybuchowa. Gaz pirolityczny zawiera (% masowy): CH4 - 35; SO - 20; H2 - 5, CO2 - 27; H2O - 10; N2 - 3 i ma wartość opałową około 12500kJ/m3. Gaz z pirolizy jest wykorzystywany jako paliwo energetyczne. Jest on spalany w generatorze ciepła, a jego produkty spalania o temperaturze powyżej 900°C są wykorzystywane do ogrzewania reaktora do pirolizy. Opisane są główne elementy jednostki przetwarzania termicznego (pirolizy) łuski ryżu. Pokazano schemat aparaturowy, z których głównym elementem jest obracający się reaktor do pirolizy, aparat do spalania gazu do pirolizy oraz urządzenie do chłodzenia materiału krzemionkowo-węglowego. Spełnione jest bilans materiałowy i cieplny procesu pirolizy łuski ryżowej. Wydajność krzemionki węglowej z łusek ryżu wynosi 33,3%, a gazu pirolitycznego 66,7%. Zgodnie z obliczeniami inżynierii cieplnej, ilość ciepła przy spalaniu gazu pirolitycznego jest 1,8 razy większa, niż wartość niezbędna do ogrzania łusek ryżu w reaktorze. Nadmiar ciepła ma być przekazywany do wody grzewczej w wymienniku ciepła i wykorzystywany na potrzeby gospodarstwa domowego. Moduł przemysłowy do użytku przemysłowego przeznaczony jest do przetwarzania 5000 ton łusek ryżu rocznie w celu wyprodukowania 1750 ton krzemionki i węgla. Krzemionka węglowa jest materiałem wielofunkcyjnym i może być stosowana jako wypełniacz elastomerów i węglowych materiałów konstrukcyjnych, a także jako dodatek paszowy w hodowli drobiu. Biorąc pod uwagę duży popyt na ten materiał w Kazachstanie i na świecie, stworzenie jego produkcji jest bardzo aktualne.

14

Carbonaceous Materials from Rice Husk: Production and Application in Industry and Agriculture

Zharmenov A., Yefremova S., Sukharnikov Y., Bunchuk L., Kablanbekov A., Anarbekov K., Murtazayeva D., Yessengarayev Y.

Inżynieria Mineralna

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2018

|

R. 19, nr 1

263--274

EN

A solid carbonaceous material and a liquid product were produced by the rice husk pyrolysis. Chemical analysis and GC-MS were used to investigate the compositions of the prepared materials, respectively. X-ray, SEM, TEM, BET were applied to study the structure and textural properties of the carbonaceous material. It was determined that the solid product is a composite consisting of carbon (52%) and silicon dioxide (31%) nanoparticles. Therefore, it was named a silicon-carbon. The liquid product is a water solution containing various organic compounds (carboxylic acids, phenols, ketones, alcohols and ethers, cyclic aliphatic hydrocarbons, heterocyclic compounds). The possibility to apply the solid carbonaceous material as a reducing agent and a sorbent and the liquid organic product as a flotation reagent was determined in the electro thermal smelting process, sorption and flotation processes. Veterinary and toxicology studies were performed to estimate toxicity of solid carbonaceous material and possibility to apply it as a feed additive. It was shown, that due to its chemical composition the silicon-carbon is a complex raw material for metallurgical silicon, aluminum-free and titanium-free ferrosilicium, and silicon carbide production. The produced sorbent had high rare and heavy metals adsorption capacity. The solid carbonaceous material, that was found to be non-toxic, was an effective feed additive and improved quality of laying hens and broiler chickens. The liquid product had properties of a blowing agent in the flotation of lead-zinc ores. It was concluded that both rice husk derived solid and liquid carbonaceous materials are economically effective alternative materials for various technological processes and agriculture.

PL

Stały materiał węglowy i produkt płynny wytworzono prowadząc pirolizę łusek ryżu. Do zbadania składu otrzymanych materiałów wykorzystano odpowiednio analizę chemiczną i GC-MS. W celu zbadania struktury i budowy materiału węglowego zastosowano badania rentgenowskie, SEM, TEM i BET. Stwierdzono, że produkt stały jest kompozytem złożonym z węgla (52%) i nanocząstek dwutlenku krzemu (31%). Dlatego został nazwany krzemo-węglem. Produktem ciekłym był roztwór wodny zawierający różne związki organiczne (kwasy karboksylowe, fenole, ketony, alkohole i etery, cykliczne węglowodory alifatyczne, związki heterocykliczne). Zbadano możliwość nanoszenia stałego materiału węglowego jako środka redukującego i sorbentu, natomiast zastosowanie dla ciekłego produktu organicznego jako odczynnika flotacyjnego weryfikowano w procesie elektrotermicznego wytapiania oraz w procesach sorpcji i flotacji. Przeprowadzono również badania weterynaryjne i toksykologiczne w celu oceny toksyczności stałego materiału węglowego i możliwości jego zastosowania jako dodatku paszowego. Wykazano, że ze względu na skład chemiczny, krzemo-węgiel stanowi kompleksowy surowiec do produkcji metalurgicznego krzemu, węglika krzemu oraz żelazokrzemu bez dodatku glinu i tytanu. Produkowany sorbent miał dużą zdolność adsorpcji metali rzadkich i ciężkich. Stały materiał węglowy, który okazał się być nietoksyczny, był skutecznym dodatkiem do pasz poprawiając jakość kur niosek i brojlerów. Produkt ciekły wykazywał właściwości środka porotwórczego we flotacji rud ołowiu i cynku. Stwierdzono, że zarówno stały jak i ciekły materiał węglowy pochodzący z łupin ryżowych są ekonomicznie efektywnymi materiałami dla różnych procesów technologicznych i rolnictwa.

15

Qualitative analysis of baked clay bricks available in Larkana region, Pakistan

Khoso S., Wagan F., Khan J., Bhatti N., Ansari A.

Architecture Civil Engineering Environment

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2014

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Vol. 7, no. 2

41--50

EN

Apparently in the beginning non-fired bricks were used for the shelter over the head. As the world progressed fired clay bricks found acceptability for construction. In Pakistan fired clay bricks are used in-plenty for erecting the houses. However, the technology is quite old and the practice is being repeated for several years. More commonly the bricks are porous; water absorbability is quite high and consequently the compressive strength and other properties are much lower than they should have been. In order to get an idea about quality of bricks, a comparative study of the properties of fired clay bricks of Hoofmann kiln versus Sada Bhatta (manually operated kiln) is done. A systematic study was carried out to determine various properties such as water absorption, efflorescence, crushing strength, specific weight, specific gravity of common bricks and specific weight of baked clay. This was particularly deemed imperative because of the fact that the process of burning is not uniform. This is done in two forms; i.e. by burning in the kiln with wooden logs and wooden fuels and in the Sada Bhattas where the fuel is bagasse and rice husks. Obviously it was expected that the compressive strength of bricks in the kiln was somewhat higher than Sada Bhattas. The systematic study consists of compressive strength, modulus of elasticity and Poisson's ratio as major points of investigations.

PL

Najprawdopodobniej początkowo niewypalonych cegieł używano do budowy prostych schronów. Wraz z postępem cywilizacyjnym w budownictwie zastosowanie znalazły wypalane cegły gliniane. W Pakistanie gliniane cegły wypalane są masowo i wykorzystywane do wznoszenia domów. Technologia ta jest bardzo stara, a praktyka powtarzana przez wiele lat. Powszechnie cegły są porowate; ich nasiąkliwość jest dość wysoka, a tym samym wytrzymałość na ściskanie i inne właściwości są znacznie niższe niż powinny być. Aby ocenić jakość cegieł, przeprowadzono badania porównawcze właściwości cegieł wypalanych w glinianych piecach Hoofmana oraz w Sada Bhatta (piecach obsługiwanych ręcznie). Badania przeprowadzono w celu określenia różnorodnych właściwości, takich jak absorpcja wody, wykwity, wytrzymałość na ściskanie, ciężar względny, ciężar właściwy, ciężar właściwy zwykłych cegieł i ciężarze względny wypalanej gliny. Takie badania uznano za konieczne zwłaszcza ze względu na fakt, że proces spalania nie jest jednorodny. Odbywa się on w dwóch formach, tj. przez spalanie w piecu z drewnianych bali i paliw oraz w drewnianych Sada Bhatta, gdzie paliwem są wytłoki i plewy ryżu. Zgodnie z oczekiwaniami, wytrzymałości na ściskanie cegieł wypalanych w piecach jest nieco wyższa niż tych wykonywanych w Sada Bhatta. Badania właściwości mechanicznych obejmowały wytrzymałość na ściskanie, moduł sprężystości i współczynnik Poissona jako głównych kryteriów oceny.