Papers by Keyword: Wheat Straw

Abstract: The key drivers of the growing interest in the recovery of local materials, particularly land and waste plants, are low-cost building materials, thermal comfort, decreased energy consumption, and decreased carbon dioxide polluting emissions. This work's primary objective is to test a bio-sourced composite material that takes the form of a block of unfinished soil that has been stabilized with cement and blended with wheat straw. This study is being done with the objective of examining the impact of this fiber at different weight percentages (0, 2, 3%, and 4%) on the mechanical behavior, durability, and thermophysical properties of the produced blocks. The results obtained indicated an increase in thermal conductivity, from 2.75 W/mK for the blocks without wheat straw fiber to 0.398 W/mK for those getting 4% of the wheat straw fiber, signifying an improvement in thermal insulation. While retaining the low performance threshold required by the earth construction standard, this improvement was accompanied by an average decrease in mechanical performance.

Abstract: Some industrial crops residuals like wheat straw, buckwheat husks and reeds were used in the study as raw lignocellulosic materials to evaluate their potential as thermal insulation material. Steam explosion (SE) pre-treatment was used to disrupt and convert the raw material smooth shape to foamy fibrous shape. Two level Factorial design was used to evaluate the impact of raw material fraction size (10-20-30 mm), moisture content (10-30-50%), SE temperature (200-215-230 °C) and duration (00-30-60 s) on bulk density and thermal conductivity of the obtained loose-fill materials. The results show that all selected raw materials could be characterized as thermal insulation materials as the determined thermal conductivity was in the range of 0.042–0.058 W (m K)^-1 including neat samples. In spite of effective fibrillation of raw materials SE pre-treatment did not improve their thermal conductivity. The determined bulk density of loose-fill crops varied in range of 23–184 kg m^-3 depending on all variables; the SE pre-treatment showed the most significant effect on its reduction. Based on the study results the most suitable crops residues for bio-based thermal insulation purposes are suggested wheat straw and reeds demonstrating the lowest values of bulk density and thermal conductivity.

Abstract: The aim of this study was to determine the compressive mechanical properties and the energy absorption characteristics of a bio-composite material based on lime, wheat straw, and additives (protein and entraining agent). The selected samples with fiber to binder ratio of 30% were subjected to compression tests at different strain rates (1 mm/min, 10 mm/min, and 100 mm/min), in the perpendicular and parallel directions to fiber orientation. Image analysis supported with Digital Image Correlation (DIC) method is performed to follow longitudinal and lateral deformations, thus making it possible to evaluate elastic properties. The results show that the highest density and compressive strength in the parallel direction are ~349 kg/m³ and ~0.101 MPa, respectively. The perpendicular specimens at 100 mm/min of speed test showed the highest values of densification strain, stress plateau, energy efficiency, and absorbed-energy of 47.27%, 0.32 MPa, 16.98 %, and 13.84 kJ/m², respectively. The values of Young’s modulus identified with DIC are significantly different from those determined by the slope of the linear part of the stress-strain curve. A slight influence of strain rate on mechanical properties is observed.

Abstract: External carbon sources provide additional nutrients that improve the efficiency of nitrate removal in constructed wetlands. Typha angustifolia L. were planted in four vertical subsurface-flow constructed wetlands. Different external carbon sources were fed into the columns, to investigate and compare their treatment of nitrate in synthetic wastewater, with initial influent C/N ratio of 1:1. Wetland A (WA) with 50g wheat straw as external carbon source, wetland B (WB) with 50g woodchips, wetland C (WC) with additional 10mg/L glucose and wetland D (WD) without external carbon source to serve as the control, were used in the lab-scale experimental study. WA, WB, WC and WD within a period of 24 days, cumulatively removed 109.38mg/L, 93.75mg/L, 85.14mg/L, and 64.01mg/L nitrate, respectively, from the influent. The nitrate-nitrogen (NO₃–N) removal efficiency as aided by the external carbon sources was in the order: wheat straw > woodchips > glucose > control. Wheat straw treated 93% NO₃–N, woodchips 78%, glucose 72% and the control 53%. The results indicate that WA, WB and WC outperformed the control system, due to the additional carbon sources. In general, the wheat straw had a better performance than wood chips and glucose. Thus, wheat straw as low cost biological waste product is recommended for the treatment of nitrate in wetlands.

Abstract: In this work, the pyrolysis behavior of bituminous coal (BC) wheat straw (WS) and the blends were investigated by thermogravimetric analysis. It was found that the main thermal degradation stage of BC and WS lies in different temperature range and there is nearly no overlapping. Interaction was observed during the co-pyrolysis process of BC and WS. At high temperatures, the volatile releasing is slightly inhibited by WS addition. Coats-Redfern method was used to analyze the apparent kinetic parameters. The results indicated that both the two reaction stages during pyrolysis process are well correlated by first-order reaction. The variation trend of activation energy value further confirm the synergistic effects between BC and WS. The experimental results may provide useful data for co-thermochemical utilization of biomass with coal.

Abstract: In recent years, research has shown the advisability of seeking new types of biofuel. It has been shown that apart from one-component fuel, it is also advisable to use mixtures composed of basic raw materials. These mixtures may have a favourable effect upon the overall recovery of such fuels. This paper focuses upon options for the energy use of various mixtures of biomass waste. Biomass waste originates from primary agricultural production and countryside maintenance. This mainly consists of plant residues, i.e. straw and hay. Pellets were made using the given biomass. The pellets were prepared by mixing plant residues with spruce shavings as well as from pure materials, i.e. wheat straw, hay and sawdust. Individual types of biomass were mixed in various ratios: 50% wheat straw + 50% hay, 50% wheat straw + 50% sawdust, 50% hay + 50% sawdust, 33% wheat straw + 33% hay + 33% sawdust. The following basic parameters of the prepared samples were monitored: humidity, calorific value and ash content. These parameters influence the environmental as well as economic aspects of options for using these plant residues as fuel. It was discovered during the tests that the highest calorific value was achieved using a sample of biomass prepared by mixing 50% straw and 50% hay. The highest humidity was found in a sample of sawdust and the highest ash content in a sample prepared by mixing 50% straw and 50% hay.

Abstract: A novel denitrification process with wheat straw as both carbon source and biofilm carrier was developed to simultaneously remove nitrate and pentachlorophenol (PCP) from contaminated drinking water. The experimental results indicated that the reactor packed with wheat straw could be started up readily, and the removal efficiencies of nitrate and PCP reached approximately 98% and 40%, respectively, with 8 h of HRT at 25 °C. A significant increase in PCP removal was observed with prolonged HRT. Approximately 85% of PCP removal efficiency was reached, and 1.61mg/L of chloride ion was released from the contaminated water containing 5 mg/L of PCP with 16 h of HRT. Reductive dechlorination reaction was a major degradation mechanism of PCP under the denitrifying conditions with wheat straw as carbon source.

Abstract: From a carbon cycle perspective, the thermochemical conversion of lignocellulosic biomass is inherently carbon neutral. Pyrolysis of biomass for energy supplying, such as bio-oil and bio-char, has been attracted much attention worldwide. Successful understanding the fundamental issues about the pyrolysis, including pyrolytic behavior and kinetic analysis of lignocellulosic biomass model compounds and real biomass, is essential for the further understanding and optimizing the pyrolysis process. In this paper, pyrolytic behavior of a typical lignocellulosic agricultural residue (wheat straw) and model compounds (cellulose) were measured through thermogravimetric analysis with various heating rates (10, 20, 40 °C·min^-1) under nitrogen atmosphere. The results indicated that the interval of the weight loss for both wheat straw and cellulose moved upwards with the increment of heating rates. The maximum decomposition rates of cellulose were higher than those of wheat straw, and the temperature of maximum decomposition rates increased with the heating rates. Values of activation energy were solved through iso-conversional method. And the average values of activation energy for wheat straw and cellulose were 146.89 kJ·mol^-1 and 134.56 kJ·mol^-1 calculated from Flynn-Wall-Ozawa method, 144.05 kJ·mol^-1 and 130.91 kJ·mol^-1 calculated from Kissinger-Akahira-Sunose method, respectively.

Abstract: Utilization of wheat straw for bio-based chemicals production is a research focus. In this work, experiments were conducted to study the preparation conditions of activated carbon from formic acid hydrolysis residue of wheat straw applying response surface methodology. The effects of activation reaction temperature, retention time and activator quantity on the decolorizing capacity of activated carbon were dealt with in this paper. Optimal preparation conditions were abtained by response surface methodology as followed: the content of ZnCl₂ solution was 14.2%, reaction temperature was 798°C and retained time was 30 mins with a decolorizing capacity of 15.8 mL methylene blue. Results indicated that the technology was available.

Abstract: Adsorption of copper ion and methylene blue (MB) ion from aqueous solution was performed by natural wheat straw (NWS) and modified wheat straw (MWS) with citric acid (CA) in fixed-bed column. Adsorption behaviors of single system and binary system were compared at same experimental condition. There was higher adsorption capacity of MWS for binding Cu²⁺ and MB. In the binary system of Cu²⁺ and MB coexisted in solution, there was competitive adsorption. The adsorption quantity of Cu²⁺ or MB decreased with MB or Cu²⁺ existed. NWS and MWS can simultaneously adsorb Cu²⁺ and MB from mixtures.