Flax Straw Research Articles

Catalytic production of furfural by pressurized liquid water liquefaction of flax straw

In this study, the throughput and kinetics of furfural production by the liquefaction of wet flax straw was conducted. The reaction was carried out in the temperature range of 200–325 °C, pressure of 0–60 bar, retention time in the range of 0–120 min, catalyst amount of 0.5–1.5 g, and a flax straw mass fraction of 10% using three types of solid acid catalysts: γ–alumina, H-ZSM-5, and silica-alumina. The results show that the highest yield of furfural was obtained using γ-alumina catalyst of weight of 1 g and the highest conversion of 66% at 325 °C. It was found that the acidity of the catalyst is key to enhance the production of furfural with a direct correlation with the number of the Lewis acid sites. The catalysts in order of the number of Lewis acid sites was found to be γ–alumina > H-ZSM-5 > silica-alumina. The kinetic data were also developed using an empirical rate model. The apparent activation energy was found to be 9.46 kJ/mol and the reaction order was 2.0. Also, the model-predicted rate showed a good agreement with the experimental rates with more than 91% accuracy.

Evaluate the influence of starch on earth/hemp or flax straws mixtures properties in presence of superplasticizer

In this paper, we study the influence of two types of starch on earth hemp or flax straw mixtures at fresh and hardened states. The main goal is to propose new non-load bearing earthen for indoor. The mass percentage of starch/binder (S/B) in mixtures was fixed at 1% of mass. The VEBE consistometer test has been used to fix a similar consistency between mixtures. The targeted workability has to allow an easy introduction of materials in the moulds. Adding both of starch has shown a positive effect on mixtures workability at the fresh state and mechanical resistances at the hardened state. At hardened state, mechanical and thermal-acoustic performances have been measured on laboratory samples and blocks at real scale. Results have shown a significant effect of starch on mechanical strengths.

Application of Biologically Active Substances for Storage of Oil Flax Straw

Application of Biologically Active Substances for Storage of Oil Flax Straw

Determination of the Bonding Force Between the Rettery and Flax Swaths in Their Picking Up by Pick-­Up Device Fingers

The quality of flax products depends on the way of flax straw retting. Currently, the best and most widely used method of flax straw retting is way of dew retting. Flax stems are laid in a thin layer on the flax field where they were grown or on a clover or grass field. During the retting process, plants tend to grow through the flax swaths depending on the air temperature (starting from 18°C) and humidity (50­-60%). Therefore, the flax straw picking up process should be done with certain efforts, however, without damaging the stems. (Research purpose) To determine the bonding forces of the flax straw with the rettery (a flax field or a grass field). (Materials and methods) The authors have designed an instrument to measure and register the considered forces as well as a general mechanism of the flax straw picking up process, which operates in conjunction with the IP 264 (BS) measurement information system, and also developed a research methodology. This system is integrated with to a laptop with the pre-­installed «Testing» software. The system is adopted to use the MS Excel software to transfer data in MS Excel format for further plotting. (Results and discussion) It has been shown that the bonding forces of flax stems, their changing pattern, and the maximum value during the picking up process depend on the degree of penetration by grass plants into flax swaths and the grass plant density per square meter. (Conclusions) In process of picking up the grass-­penetrated swaths, they show weak strength characteristics for transportation and an increased tendency to break the continuity of their picking up. The values of the ratio of the translational speed of a pick-­up device and the rotary speed of a picking device fingertip can be greater than the value of the relative elongation at the point of pulling the swath away from the ground. The coefficient of strength to pick up the swaths from a clover rettery is higher than that of flax and grass retteries.

Застосування біологічно активних препаратів для зберігання соломи льону олійного

Застосування біологічно активних препаратів для зберігання соломи льону олійного

Study of Thermal Properties of Lightweight Insulation Made of Flax Straw

Abstract The article presents the results of a study of the properties of flax straw as a raw material and as a lightweight, environmentally-friendly insulation made of a two-component mixture of flax straw and liquid glass. The flax is considered to be renewable and is a 100% natural waste product of the agriculture industry, which may be widely used as sustainable building insulation after light modifications. The ratio mixes of the two-component eco-insulation of flax straw and liquid glass (Na2O(SiO2)) have been developed in terms of sustainability principles such as environmental friendliness and energy efficiency. We used thermal analysis to compare flax straw as a raw material, and a complex insulation made of flax straw demonstrated a slower decomposition of the composite and shorter peaks, which supports the concept of the transformation of flax straw with liquid glass to increase its fire resistance properties. The peaks of the loss of mass with the exothermal process were defined for both flax samples. The thermal conductivity coefficient of the material is around 0.085 W/m K, which permits its use as an effective insulation material for sustainable buildings.

Production of fiberboards from shives collected after continuous fiber mechanical extraction from oleaginous flax

ABSTRACTIn this study, fiberboards were produced from shives collected after continuous fiber mechanical extraction from oleaginous flax straw. Fiberboards were produced through thermo-pressing, and their mechanical and thermomechanical properties were studied, as well as their water resistance. The influence of two pretreatments for shives and lignin addition was investigated on the different properties. Boards obtained were all cohesive hardboards. The optimal board was obtained from fibers extruded from the shives and without addition of any supplementary lignin amount. Looking at its characteristics and standard NF EN 312, the latter perfectly complied with the requirements for type P1 boards, i.e., boards for general uses in dry conditions.

Highly soluble cellulose nitrates from unconventional feedstocks

Celluloses isolated by the nitric-acid process from domestic unconventional feedstocks such as Miscanthus, oat hulls, and intermediate flax straw were used herein to produce cellulose nitrates (CNs) with a high solubility. For the synthesis of CNs, a commercial technique was employed that involves nitration of cellulose with mixed acid containing 14 wt.% water followed by high-temperature treatment of the nitration product in acidic, alkaline, and neutral environments. The obtained CNs are similar in physicochemical attributes: 12.04–12.26% mass fraction of nitrogen, 10–14 mPa·s viscosity, and 98% solubility in alcohol– ester mixture. FTIR spectra of CNs had absorption bands (2559–2557, 1646–1631, 1277–1271, 825–812, 747–744, 683–680 cm-1) typical of nitro group vibrations. 13C NMR spectra showed chemical shifts representative of 6-mononitrocellulose, 2,6-dinitrocellulose, 3,6-dinitrocellulose, and 2,3,6-trinitrocellulose. DSC revealed that the resultant CNs were highly chemically pure with an exothermic peak at 209–212°С. The CNs obtained from the said unconventional feedstocks were compared with a commercial, highviscosity, lacquer-grade Colloxylin derived from cotton cellulose, as well as with other commercial Colloxylins, to show that the experimental CNs meet the requirements for comercial grades. Thus, the CNs obtained from the unconventional feedstocks are promising candidates as the component of composite explosives.

Environmental Assessment of Flax Straw Production for Non-Wood Pulp Mills

Environmental Assessment of Flax Straw Production for Non-Wood Pulp Mills

Influence of Filler Particle Size on Physical Properties and Biodegradation of Biocomposites Based on Low-Density Polyethylene and Lignocellulosic Fillers

This study examined biocomposites based on low-density polyethylene (LDPE) and lignocellulosic fillers [wood flour (WF) and oil flax straw (FS)] selecting four size fractions of each lignocellulosic material as fillers for the composites. The primary aim was to evaluate the influence of fraction size on the composites’ basic properties; to accomplish this, the composites’ mechanical properties, thermal oxidation, thermophysical characteristics, and water absorption capacity were examined. Then microphotographs of the samples were created and length-to-diameter (L/D) ratio of the fillers was calculated, finding that the L/D ratio increased with increasing particle size. The particle size influenced the oxidative degradation and water absorption processes in composites with oil flax but not in those with WF. Biodegradation tests performed on the recovered soil found that the loss of mass in composites based on LDPE and FS was higher than in the same composites with WF. Moreover, at the initial stage of composting, the biodegradation rate correlated with the size of filler particles (i.e., the larger the particles, the higher the degradation rate of the biocomposite).

Ethylene–octene copolymer–wood flour/oil flax straw biocomposites: Effect of filler type and content on mechanical properties

The properties of biocomposites based on ethylene–octene copolymers (EOCs) were studied. The mechanical, rheological, and physical properties of the biocomposites were investigated with attention to the filler type, filler content, and grade of EOC. Three grades of EOC with different viscosities were used as the polymer matrices. Two lignocellulosic raw materials were selected as fillers: birch wood flour (WF) and oil flax straw (FS). The effect of the filler variation range (30%–70%) on the biocomposites was studied. According to microphotographs, the filler particles were quite uniformly distributed in the polymer matrix. The WF particles had ellipsoid shapes, whereas the FS particles were characterized by cylindrical shapes. The addition of fillers decreased the elongations at the copolymer's break and tensile strengths, but increased the elasticity moduli. The fillers’ hard particles increased the stiffness of the polymer chains in the biocomposites, resulting in declines in elongation at break. The biocomposites with WF had higher tensile strengths and elongations at break than those with FS because the latter were characterized by lower density values than the former. Melt viscosity analysis showed that filler content increased with melt viscosity. The FS biocomposites had higher melt viscosities than the WF biocomposites. POLYM. ENG. SCI., 57:756–763, 2017. © 2017 Society of Plastics Engineers

Catalytic pyrolysis of straw biomasses (wheat, flax, oat and barley) and the comparison of their product yields

In this study, the pyrolysis of several Canadian straw biomasses was studied using a thermogravimetric analyzer and a bench-scale horizontal fixed-bed reactor, in order to better understand the devolatilization process and to obtain information about the product yields of these biomasses. The straw biomasses were converted through pyrolysis performed in a fixed-bed reactor at temperatures of 500°C to study the influence of the feedstock on product yields. The effects of various catalysts on product yields are also discussed. When using zeolite catalysts, the bio-oil and bio-char yields of the straw pyrolysis were increased to 46.44% and 38.77%, respectively, while the bio-gas yield was decreased to 13.65%. The use of catalyst zeolite ZY-SS had the most significant effect on overall bio-oil and bio-char yields, increasing the bio-oil yield by about 2% and the bio-char yield by 8%. This catalyst had the most significant effect on the pyrolysis of flax straw, where the bio-oil yield was increased to 46.44%. In the pyrolysis of oat straw, the use of the catalyst consistently decreased the bio-gas yield; however, the bio-oil yield increased the most significantly (43.32%) with the use of catalyst zeolite ZY-NS. The use of zeolite ZY-NS also increased the bio-oil yield during the pyrolysis of barley straw (43.03%).

Incorporating denitrification-decomposition method to estimate field emissions for Life Cycle Assessment

This study focuses on a detailed Life Cycle Assessment (LCA) for flax cultivation in Northern France. Nitrogen related field emissions are derived both from a process-oriented DeNitrification-DeComposition (DNDC) method and the generic Intergovernmental Panel on Climate Change (IPCC) method. Since the IPCC method is synthesised from field measurements at sites with various soil types, climate conditions, and crops, it contains significant uncertainties. In contrast, the outputs from the DNDC method are considered as more site specific as it is built according to complex models of soil science. As it is demonstrated in this paper the emission factors from the DNDC method and the recommended values from the IPCC method exhibit significant variations for the case of flax cultivation. The DNDC based emission factor for direct N2O emission, which is a strong greenhouse gas, is 0.25–0.5%, significantly lower than the recommend 1% level derived from the IPCC method. The DNDC method leads to a reduction of 17% in the impact category of climate change per kg retted flax straw production from the level obtained from the IPCC method. Much higher reductions are recorded for particulate matter formation, terrestrial acidification, and marine eutrophication impact categories. Meanwhile, based on the DNDC and IPCC methods, a comparative LCA per kg flax straw is presented. For both methods sensitivity analysis as well as comparison of uncertainties parameterisation of the N2O estimates via Monte-Carlo analysis are performed. The DNDC method incorporates more relevant field emissions from the agricultural life cycle phase, which can also improve the quality of the Life Cycle Inventory as well as allow more precise uncertainty calibration in the LCA inventory.

Hydrophobization of Lime Composites with Lignocellulosic Raw Materials from Flax

ABSTRACTThe aim of the study was to evaluate the possibility of applying lime binder together with flax fibers and straw to the production of wall materials. Properties of the composites were modified by additives and admixtures. The following laboratory tests were performed: the analysis of the physical characteristics, compressive strength, a water droplet absorption test, water absorption of hydrophobized and standard samples, drying time, and analysis of the structure using scanning electron microscope (SEM). In the paper, there was examined the effectiveness of two formulations differing in the degree of hydrolytic polycondensation, viscosity, and concentration, as these are the factors that determine the final impregnation effect.

Fibre Extraction from Oleaginous Flax for Technical Textile Applications: Influence of Pre-processing parameters on Fibre Extraction Yield, Size Distribution and Mechanical Properties

Cultivated primarily for its seeds, oleaginous flax could also be valued for the different fractions that can be extracted from the straw. However, as the straws are not harvested with the same technique and care than for the textile flax, the classical scutching technique cannot be used. As a consequence, an “all fibre” device was used to perform the separation of the different constituents of the oleaginous flax straws. The different fractions were quantified for two retting levels and for two degrees of rewetting of the stems. The physical and mechanical properties of fibres were then evaluated. It appears that the relative amount of fibres extracted from oleaginous flax straw is comparable to the one from textile flax (i.e. 40% of the stem dry mass), and their tensile properties are situated in the lower part of the textile flax range. This work shows that the individual fibre length of oleaginous flax (between 3 and 6 cm) is comparable to that of the scutched textile flax fibres. This makes them suitable for the production of carded aligned fibre yarns for technical reinforcement textiles (e.g. composites or geotextiles). These results demonstrate the interest and the potential added value of harvesting the stems for technical fibre applications.

Properties of Hemp–Flax Composites for Use in the Building Industry

ABSTRACTThis article presents the results of research concerning lightweight composites produced on the basis of lime, cement, and clay binders, with the addition of perlite, hemp shives, and flax straw. Tests of physical and mechanical properties of composites were performed and their basic characteristics were determined, i.e. absorptivity, density, thermal conductivity coefficient, and compressive and flexural strength. The study was conducted to determine the use of hemp and flax composites to fill the frames of a wooden house. The results prove that the composites have low thermal conductivity, apparent density, and low strength properties compared with conventional building materials.

Cellulose nitrates from intermediate flax straw

The results of studying the synthesis of cellulose nitrates from oilseed production residues (intermediate flax straw) and subsequent autoclaving of the obtained ethers are presented for the first time. Cellulose was isolated by the dilute nitric acid method, and cellulose nitrates were synthesized using an industrial sulfuric—nitric acid mixture. The resultant sample was autoclaved in three different modes. It was found that cellulose nitrates with the following properties can be obtained from the intermediate flax straw: weight fraction of nitrogen 12.23–12.34%, viscosity 2.7–16.0 cP, and solubility in an alcohol—ether mixture 95–96%. A similarity of the obtained cellulose nitrates and linter Colloxylin was shown by IR spectroscopy. The results of thermogravimetric analysis (TG) and 13C NMR spectroscopy for cellulose nitrates obtained from intermediate flax straw are presented.

Plants diagnostics of nitrogen nutrition of flax

Field experiments with fiber-flax varieties Zaryanka, the Alpha and the Lada was carried out on soddy-podzolic soil under Northern part of the Nonchernozem zone. As a result of 5 years of research studied the influence of increasing doses of nitrogen fertilizer on the dynamics of mineral nitrogen in the soil, total nitrogen content of the flax plant. The mathematical model of flax straw yield has been developed. It was revealed that the increase of productive moisture reserves in the soil from 30 to 40 mm in a layer of 0–40 cm in the phase of “herringbone”–the beginning of rapid growth, increased productivity of flax straw varieties Alpha on 2.8 t ha–1. The simultaneous increase in the total nitrogen content of the flax plants in the phase of “herringbone” on the 0.1% increment crop yield increase up to 3.0 t ha–1.

FABRICATION AND EVALUATION OF A MACHINE FOR SEPARATING FIBER FLAX

Flax stalks usually considered a waste product which may be utilized by separation into marketable fiber and shive. The fiber can be used for applications such as composites and paper. Separation of traditional long line fiber from fiber flax stalks is a rigorous and expensive process that requires the stalk to be biologically degraded (retted) befor processing. A local machine for removing flax fiber from chopped seed flax straw has been manufactured at a private workshop in kafr El-sheikh Governorate during summer season of 2015. The manufactured machine consists of three main devices namely: feeding and breaking device, scutching and hackling device and cleaning device. The manufactured machine has been evaluated under three straw moisture contents of 10.2, 13.2and 15 %, three deram schell speeds of 500, 650 and 800 rpm and five feeding roller speeds of 1, 1.5, 2, 2.5and 3 m/s. The Separation efficiency, fiber longth and fineness, machine Productivity, consumed Energy, and quality of fiber were studied. The obtained results can be summarized as follows: The maximum separation efficiency of flax fiber (82.13%) and fiber fineness (191.6 mm/mg) was obtained at straw moisture content 0f10.2%, feeding roller speed of 1m/sec and derma schell speed of 800 r.p.m . The fiber Length (92.8cm) was obtained at straw moisture content of 10.2%, feeding roller speed of 1m/sec and derma schell speed of 500 r.p.m. The lowest value of energy consumption was (1 kw) recorded at straw moisture content of10.2%, feeding roller speed of1m/s and dearm schell speed of 500 r.p.m. It is recommended for the operators of the manufactured separation machine to operate it at straw moisture content of 10.2%, feeding roller speed of 1 m/s and derma schell speed of 800 r.p.m to obtain the optimum performance.

Flavonoid C-glucosides Derived from Flax Straw Extracts Reduce Human Breast Cancer Cell Growth In vitro and Induce Apoptosis.

Flax straw of flax varieties that are grown for oil production is a by product which represents a considerable biomass source. Therefore, its potential application for human use is of high interest. Our research has revealed that flax straw is rich in flavonoid C-glucosides, including vitexin, orientin, and isoorientin. The objective of this study was to evaluate the cytotoxicity and possible proapoptotic effect of flax straw derived C-glucosides of flavonoids in the human breast adenocarcinoma cell line (MCF-7). The effects of flax straw derived flavonoid C-glucosides on cell proliferation of MCF-7 cells were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and sulforhodamine B assays. The expression of apoptosis-related genes was assessed by real-time PCR. Our data revealed that flax C-glucosides as well as pure compounds are cytotoxic toward MCF-7 cells and inhibit their proliferation. Moreover, the induction of apoptosis was correlated with the changes in the mRNA level of pro-apoptotic genes. Increased expression of bax and caspase-7, -8, and -9 and decreased mRNA expression of bcl-2 was observed, whereas the mRNA levels of p53 and mdm2 were not altered. These results clearly demonstrated that flax straw metabolites effectively induced growth inhibition and apoptosis in human breast adenocarcinoma cells.