High Nitric Acid Concentrations Research Articles

Adsorption of terbium (III) on DGA and LN resins: Thermodynamics, isotherms, and kinetics

Two commercially available extraction chromatography (EXC) resins containing N,N,N’,N’-tetra-n-octyldiglycolamide (DGA Resin, Normal, 50 – 100 μm) and Bis(2-ethylhexyl) phosphate (LN Resin, 100 – 150 μm) were used as adsorbents to study fundamental adsorption properties such as thermodynamic values, equilibrium isotherms, and kinetic uptake models for terbium(III) adsorption. Weight distribution ratios (Dw) for terbium on DGA and LN resins were measured using a [160Tb]Tb3+radiometric tracer in nitric acid as a function of acidity, temperature, initial analyte concentration, and equilibrium time. The Dw values showed increasing binding affinity for DGA resin at high nitric acid concentrations and decreasing binding affinity for LN resins. Thermodynamic studies for DGA and LN resins revealed that the Gibbs free energy (ΔG) increased consistently with temperature. To model equilibrium data, increasingly higher parameter equilibrium isotherm models (Henry (1) < Langmuir, Freundlich (2) < Redlich-Peterson (3) < Fritz-Schluender (4)) were compared on their root mean squared errors (RMSE) and adjusted determination coefficients to determine the most applicable model. In all cases, the empirical four-parameter Fritz-Schluender isotherm demonstrated a superior fit. Similar comparisons for reaction-based kinetic models (Pseudo-first-order < Pseudo-second-order < Pseudo-n-order) revealed that the higher-order PNO model yielded a superior fit of kinetic data for both resins. However, in some cases, adsorption isotherms and kinetic models could also be modeled by a lower-order model with minimal change in error parameters. Weber-Morris plots revealed that two linear sections are observed for each resin, where the first linear segment is attributed to fast (film diffusion) adsorption of terbium, followed by slower intraparticle diffusion of terbium through the pores as the rate-limiting step. Based on the Weber-Morris plot, both film and intraparticle diffusion are involved in controlling the kinetic rate of adsorption for DGA and LN resins.

Glass formulation and lab-scale testing of glasses designed for in-can Melter and in-container Vitrification of high-assay low-enriched uranium aqueous polishing Raffinate waste

Glasses were designed for processing a nuclear waste from aqueous polishing of high-assay low-enriched uranium using either In-Can Melter or GeoMelt® In-Container Vitrification™ (ICV) technologies, which operate at temperatures of Tp ≤ 1100 °C and Tp ≤ 1450 °C, respectively. Due to the different operating conditions, the melt and glass properties were optimized differently for each technology. Each glass was designed to optimize for maximum waste loading while simultaneously satisfying processing (e.g., crystallization, viscosity, conductivity) and product quality (e.g., durability, hazard characteristic, crystal content) constraints. The raffinate waste contains high nitric acid (4 M) and low total solids (9 g∙L−1) concentrations. Feed preparation processes were tested to facilitate concentration and nitrate destruction/removal while controlling redox of the melter feed. A successful lab-scale feed process including sugar addition and spray-drying was performed to generate an adequate melter feed for ICV processing.

Catalytic Ozonation of Air toward Direct Nitric Acid Production Using Hierarchical Co3O4 with a Tunable Microstructure.

The nitrogen oxidation reaction (NOR) to form nitric acid by applying natural air and H2O under ambient conditions is a sustainable approach to achieving efficient and selective N2 fixation for industrial applications. In this study, four kinds of Co3O4 catalysts with a controllable microstructure were prepared to catalyze the direct NOR of N2 in the air. At the same time, the reaction mechanism of the conversion of N2 to nitric acid under catalytic ozonation was explored through experimental research and density functional theory (DFT) calculation. The results showed that the prepared porous nanosheets self-assembled into microflower-structured samples. The HCOF showed extraordinary catalytic performance for direct NOR to produce a high concentration of nitric acid. The maximum rate of nitric acid formation could be as high as 6.67 mmol/(h·gcat), which was higher than those of most reported photocatalytic or electrocatalytic N2 fixation processes for direct NOR to produce NO3-. Furthermore, the 15N isotopic-labeling experiment confirmed that the produced NO3- originated from N2 in the air by the direct NOR process. In the direct NOR mechanism, inert N2 molecules were captured at the Co3+ active sites by the acceptance-donation electron conduction mode, and the oxygen vacancies boosted the chemical adsorption of N2 molecules and greatly reduced the activation energy barrier of N2 molecules. The active free radicals •OH and •O2- generated by the decomposition of O3 molecules oxidized N2 to the intermediate *NO, which was the rate-determining step, and it was then absorbed by water to form nitric acid. The air catalytic ozonation method in this study was proposed as a facile pathway for efficient nitrogen fixation. This research provides a new method for environmental protection and efficient production of nitric acid at distributed sources.

Efficient Adsorption of Ammonia by Surface-Modified Activated Carbon Fiber Mesh.

In view of the characteristics and risks of ammonia, its removal is important for industrial production and environmental safety. In this study, viscose-based activated carbon fiber (ACF) was used as a substrate and chemically modified by nitric acid impregnation to enhance the adsorption capacity of the adsorbent for ammonia. A series of modified ACF-based adsorbents were prepared and characterized using BET, FTIR, XPS, and Boehm titration. Isotherm tests (293.15 K, 303.15 K, 313.15 K) and dynamic adsorption experiments were performed. The characterization results showed that impregnation with low concentrations of nitric acid not only increased the surface acidic functional group content but also increased the specific surface area, while impregnation with high concentrations of nitric acid could be able to decrease the specific surface area. ACF-N-6 significantly increased the surface functional group content without destroying the physical structure of the activated carbon fibers. The experimental results showed that the highest adsorption of ammonia by ACFs was 14.08 mmol-L-1 (ACF-N-6) at 293 K, and the adsorption capacity was increased by 165% compared with that of ACF-raw; by fitting the adsorption isotherm and calculating the equivalent heat of adsorption and thermodynamic parameters using the Langmuir-Freundlich model, the adsorption process could be found to exist simultaneously. Regarding physical adsorption and chemical adsorption, the results of the correlation analysis showed that the ammonia adsorption performance was strongly correlated with the carboxyl group content and positively correlated with the relative humidity (RH) of the inlet gas. This study contributes to the development of an efficient ammonia adsorption system with important applications in industrial production and environmental safety.

An Integrated Model Combining Mass Transfer and Chemical Reaction for Co-Decontamination Extraction Step of PUREX Process in a Pulsed Extraction Column

ABSTRACT The accurate prediction of the extraction behaviors of various solutes in PUREX reprocessing process is crucial for the operation and implementation of the actual process. In this paper, an integrated model is developed to predict the extraction behaviors of U, Np, Pu, and HNO3 in the co-decontamination step (1A extraction step) in a pulsed extraction column. The model couples several physical and chemical processes, such as countercurrent flow, mass transfer, and chemical reaction. The mass transfer coefficients and the distribution ratios of U(VI), Pu(IV), Np(IV), Np(V), Np(VI), HNO3 and HNO2 can be obtained using this model. In particular, the redox and disproportion reactions of Np are considered in the model, and the flow direction of Np can be judged under various process conditions and the corresponding influential factors can be analyzed. The judgment is based on the yield calculated from the relative concentration profiles of Np(VI), Np(V), and Np(IV) in the two phases. For neptunium to inter 1AP step, it is necessary to select high nitric acid concentration, low nitrite concentration and especially high flow ratio. For neptunium to inter 1AW step, low nitric acid concentration, high nitrite concentration and low flow ratio are needed. Compared with the experimental data, the relative errors of the distribution ratios of various solutes are less than 30%, and the relative errors of the concentrations of U(VI) and Pu(IV) at the outlet of the organic phase are less than 10%, and our model is indicated to be reliable and applicable for co-decontamination step in the PUREX reprocessing process.

Synthesis and formation mechanism of pitch-based carbon foam for three-dimensional structural applications

Carbon foam is a three-dimensional porous, rigid, and permeable material with applications in many fields owing to its excellent electrical and thermal properties. Pitch is a promising carbon source for carbon foam production, and its modification with nitric and sulfuric acids has been widely investigated. However, the foaming phenomenon resulting from the acid treatment of pitch and the resultant formation of porous structures remain poorly understood. Herein, we clarified the mechanism by which the porous structure of pitch-derived carbon foam is formed by analyzing the components of pitch modified by nitric acid treatment and identifying essential conditions for foam production. Carbon foam was obtained by pitch modification at a high concentration of nitric acid (60 wt%), whereas no carbon foam was formed at low nitric acid concentrations (<60 wt%). Furthermore, at high nitric acid concentrations, carbon foam formation proceeded at a relatively low temperature (280 °C). The formation of carbon foam from modified pitch was attributed to the synergistic effect of the functional groups introduced onto pitch and the low-molecular-weight components resulting from cracking. This work provides new insights into pitch as a precursor and provides a straightforward method for producing carbon foam.

Highly Efficient Pertraction of Tetravalent Neptunium Ions Across a Flat Sheet Supported Liquid Membrane Containing Two Different Aza-Crown Ether-Based Multiple Diglycolamide Ligands

ABSTRACT Pertraction of Np(IV) across a PTFE membrane containing two different aza-crown ether-based multiple diglycolamide (DGA) ligands termed as L I (3 DGA arms) or L II (4 DGA arms) was investigated using nitric acid as feed solution. A few of the studies were also carried out with Pu(IV) for comparison purposes. The kinetics of the extraction of Np(IV) and Pu(IV) was fast at 3 M HNO3 and within 10 min reaches the equilibrium distribution (D) ratio with both ligands. However, the stripping kinetics was slower especially with ligand L II . The extraction and transport studies were carried out using 1.0 × 10−3 M ligand solution in 95% n-dodecane + 5% isodecanol. The transport rates were slower with ligand L II than with L I at higher nitric acid concentrations (>1 M HNO3) and the transport rates decreased with nitric acid concentration with both ligands. The effective diffusion coefficients (D eff) of Np(IV) were estimated using the lag-time method as 6.2 × 10−8 cm2 s−1 (L I ) and 4.6 × 10−8 cm2 s−1 (L II ). The stability data suggest that the L I containing supported liquid membrane (SLM) is comparatively more stable than that of L II and the transport flux remains the same up to nine days of operation in case of ligand L I .

DGA-functionalized super-magnetic acid-stable sorbent for treatment of acidic rich nuclear effluent

An acid-stable magnetic nanoparticle coated with silica bound to diglycolamide (MNCSDGA) has been synthesised and its sorption behavior for UO22+, Th4+ and Eu3+ from mediums containing high concentrations (0.5–6.0 M) of nitric acid (HNO3) was examined.

Kinetic study on the reaction routes in the oxidation of K/A oil by nitric acid with microreactors

A continuous-flow microreactor system was applied to evaluate the detailed kinetics of the reaction routes involved in the oxidation of K/A oil by nitric acid, which is essential to obtain an in-depth comprehension of complex reaction mechanisms, having important guiding significance for the two-stage temperature control strategy. 6-hydroxyimino-6-nitrohexanoic acid (AMNA) was identified as a major intermediate and its presence was confirmed through UPLC-MS and 1H NMR characterizations. A multi-step reaction kinetic model was developed, revealing good prediction with the experimental results. Finally, the model was applied to investigate the effects of operating parameters on the reaction routes distribution and reaction rate. The simulation results showed that high temperature and nitric acid concentration contributed to high selectivity of adipic acid through promoting the AMNA route, and greatly reduced the required reaction time, indicating that the accurate control over the conditions in this rapid and strongly exothermic process was of paramount importance.

Insights into the Third Phase Formation Behaviour of N,N‐Didodecyl‐N’,N’‐Dioctyl Diglycolamide in n‐Dodecane Investigated by Dynamic Light Scattering and FTIR Spectroscopy

AbstractN,N‐didodecyl‐N’,N’‐dioctyl diglycolamide (D3DODGA) was regarded as a promising ligand for the extraction of trivalent lanthanides and actinides from nuclear waste, owing to the absence of undesirable third phase formation during liquid‐liquid extraction. However, the reason for the absence of third phase formation in D3DODGA as compared to other diglycolamides was not known. To unravel the absence of third phase formation, the extraction behaviour of nitric acid and Nd(III) in 0.2 M D3DODGA in n‐dodecane (n‐DD) was studied and the reverse micellar aggregation behaviour of the organic phase was probed by dynamic light scattering (DLS) and FTIR spectroscopy. The results were compared with those obtained in popular ligands abbreviated as TODGA, TEHDGA and TDdDGA in n‐dodecane under similar conditions. The limiting reverse micellar aggregate size for third phase formation was determined to be 11.6 nm at the limiting nitric acid concentration of 0.54 M in organic phase. The investigations revealed that the absence of third phase in D3DODGA and TDdDGA was due to the presence of long chain dodecyl group attached to the molecule, as compared to the octyl moiety present in TODGA and TEHDGA. As a result, it was possible to load higher concentration of nitric acid or Nd(III) in D3DODGA without the problem of third phase formation. In view of this, the D3DODGA in n‐DD can be employed efficiently for the separation of trivalent actinides and lanthanides from nuclear waste.

Experimental based CO2 transport specification ensuring material integrity

Material choice has a large impact on the total cost of the CO2 transport system for carbon capture and storage (CCS). Cost-considerations make carbon steel the preferred candidate for long pipelines. As carbon steel will corrode if aqueous phases are present, it is important to control the CO2 composition and operate the system such that formation of water containing phases is avoided.There are many suggested specifications and recommendations for the type and concentration of impurities to be allowed in the CO2 stream. The impurity limits were often set from a health, safety, and environmental point of view and are due to lack of knowledge not so much based on material integrity issues. This gap of knowledge makes it difficult to define a specification that will ensure safe operation and long-term integrity.The present paper summarises the results of a large research project that systematically tested CO2 with various combinations and concentrations of potentially reactive impurities (H2O, NO2, SO2, H2S, O2). It was clearly shown that many impurity combinations were basically inert, while other resulted in chemical reactions and some combinations even resulted in the formation of a separate aqueous phase that contained high concentrations of sulfuric and nitric acid as well as elemental sulphur. This aqueous phase was corrosive to carbon steel. Corrosion was also observed in certain situations even when a separate aqueous phase was not observed visually.It is important to avoid precipitation of solid products since it may cause problems at the injection point and in the reservoir. The present work demonstrated that the types and combination of impurities that are present are important for the maximum impurity concentration that can be allowed before chemical reactions and corrosion occur. For the investigated conditions, 100 bar and 25 °C, the concentration limit for each impurity should be below 20 ppmv if NO2, SO2, H2S, O2 are present together. The limits may be different at other temperatures and pressures.

High efficient and selective removal of U(VI) from lanthanides by phenanthroline diamide functionalized carbon doped boron nitride

Separating and recovering uranium (U(VI)) efficiently from lanthanides is crucial for mitigating the radioactive hazard generated by hydrometallurgical residual solutions of lanthanide minerals and ensuring the long-term sustainability of uranium resources. The present work exploited phenanthroline diamide functionalized porous carbon doped boron nitride (BCN-DAPhen) as an adsorbent, which displayed outstanding adsorption performance for the separation of U(VI) from lanthanides. The results of batch adsorption tests indicated that BCN-DAPhen exhibited rapid adsorption kinetics and the adsorption process achieved equilibrium within 10 min. BCN-DAPhen also performed ultra-high maximum adsorption capacity that was calculated to be 2050.8 mg g−1 by fitting with the two-site Langmuir model. Theoretical calculation and experimental results of adsorption were combined to illustrate the adsorption mechanism as well, the results showed that two structures of DAPhen groups on BCN performed discrepant adsorption properties for U(VI). BCN-DAPhen retained excellent adsorption ability owing to the strong affinity of DAPhen groups with U(VI) even in the solution with high concentration of salt and acid. The selectivity coefficients of U(VI) toward various lanthanides were beyond 192.5 at a high nitric acid concentration of 5 mol L−1. This study suggested a general technique for the functionalization of porous BCN, which is expected to be useful in the treatment of residual solution in lanthanides hydrometallurgy.

High-yield production of monolayer boron nitride nanosheets by cationic-surfactant-assisted solvothermal exfoliation for the ultrafast and selective separation of U(VI) from lanthanides

The efficient separation and recovery of uranium(VI) (U(VI)) from lanthanides is pivotal to reduce the radioactive threat of hydrometallurgical residue solution of lanthanide minerals and benefits the sustainability of U resources. Here, we develop a cationic-surfactant-assisted solvothermal exfoliation method to prepare monolayer boron nitride nanosheets (BNNSs) for the ultrafast and selective separation of U(VI) from lanthanides. With the assistance of the strong “cation–π” interaction between cationic surfactants and BN, the monolayer BNNSs were prepared. Functionalization with diamide phenanthroline (DAPhen) groups endows the pristine BNNSs, which can hardly adsorb U(VI), with outstanding U(VI) adsorption performance. Batch adsorption experiments demonstrate that the obtained DAPhen modified BNNSs (BNNSs-DAPhen) exhibited high maximum adsorption capacity and ultrafast adsorption kinetics. The adsorption process reached equilibrium less than 1 min and the maximum adsorption capacity was estimated to be 313 mg g−1 by fitting with Langmuir model. Even under high concentrations of salts and acids, BNNSs-DAPhen still maintained excellent adsorption performance owing to the strong complexing ability of DAPhen groups with U(VI). The selectivity coefficients of U(VI) toward various lanthanides including lanthanum(III), cerium(III), europium(III), gadolinium(III), ytterbium(III), and lutetium(III) were beyond 120 at a high nitric acid concentration of 5 mol L−1. This work proposed a universal strategy for the production of monolayer BNNSs and the subsequent functionalization, which might be promising in the treatment of residual solution for lanthanides hydrometallurgy and decontamination of U(VI).

Electrochemical Oscillation during Dissolution of Iron in High Concentration of Nitric Acid

Electrochemical oscillations are attractive phenomena from the viewpoint of dynamic self-organization of molecular systems. In general, an N-shaped negative differential resistance (N-NDR) plays a crucial role in the appearance of oscillations because it gives rise to oscillatory instability [1]. Most of the oscillations can be classified into an N-NDR type or “hidden” N-NDR (HN-NDR) type oscillator. The former shows current oscillations under potential controlled conditions and hysteresis loops under current-controlled conditions, whereas the latter shows not only current oscillations but also potential oscillations.Iron dissolves in aqueous HNO3 solutions, accompanied by hydrogen evolution reaction. This dissolution reaction is written as follows:Fe → Fe2+ + 2e- (1)2H+ + 2e- → H2. (2)On the other hand, the dissolution does not take place in concentrated HNO3 solutions (i.e., 13 M HNO3) because of the formation of a passivation film on the surface. However, when the concentration of HNO3 is approximately 10 M, the dissolution and passivation of iron occur alternatively. In other words, only when an iron wire is immersed in a high concentration of HNO3, the rest potential of the iron wire oscillates spontaneously. This phenomenon is of interest because its appearance does not require any external devices.In this work, to clarify the mechanism of the spontaneous oscillation, we observe the surface of an iron wire during the oscillation using a high-speed camera (Figure 1) and measure electrochemical impedance spectra. From these studies, we can say that the oscillation is an HN-NDR type, which will be discussed in the presentation. Reference M. Orlik, Self-Organization in Electrochemical Systems I, Springer-Verlag Berlin Heidelberg, Berlin (2012). FIGURE CAPTION Figure 1 Time course of rest potential of an iron electrode in 10 M nitric acid and snapshots of the electrode. Figure 1

Carrier mediated transport of actinides using hexa–n-hexylnitrilotriacetamide (HHNTA)

Solutions of N,N,N’,N’,N”,N”-hexa-n-hexylnitrilotriacetamide (HHNTA) in 20 % isodecanol-80 % n-dodecane (v/v) were employed for the supported liquid membrane (SLM) transport of U(VI), Np(IV), and Pu(IV) from nitric acid feed solutions using PTFE (polytetrafluoroethylene) flat sheet membranes. Preliminary transport studies revealed poor transport of U(VI) when compared with that of the tetravalent ions Np(IV) and Pu(IV) which may find application for their separation from acidic radioactive feeds. In view of this, all subsequent studies were carried out using Np(IV) and Pu(IV). The SLM studies performed with 0.08 M HHNTA as the carrier extractant indicated increased transport of the tetravalent actinide ions with increasing nitric acid and carrier extractant concentrations, while using 0.5 M HNO3 + 0.5 M oxalic acid as the strip (or receiver) phase composition. However, while > 80 % transport of Np(IV) and Pu(IV) was obtained for a feed phase of 3 M HNO3, a sharp decrease in the transport rate was seen at a feed acidity of 6 M HNO3 probably due to anionic hexanitrato complex formation of the metal ions and also because of lower availability of the free ligand in the membrane phase at higher nitric acid concentrations. The membrane stability was poor suggesting the need for continuous replenishment for long term use.

Alkynyl-Based sp 2 Carbon-Conjugated Covalent Organic Frameworks with Enhanced Uranium Extraction from Seawater by Photoinduced Multiple Effects

Biofouling is a major obstacle to the efficient extraction of uranium from seawater due to the numerous marine microorganisms in the ocean. Herein, we report a novel amidoxime (AO) crystalline cova...

Experimental based CO2 transport specification ensuring material integrity

Material choice has a large impact on the total cost of the transport system for carbon capture and storage (CCS). Cost-considerations make carbon steel the preferred candidate for the pipelines. As carbon steel will corrode if aqueous phases are present, it is important to control the CO2 composition and operate the system such that formation of water containing phases is avoided. There are many suggested specifications and recommendations for the type and concentration of impurities to be allowed in the CO2 stream. These impurity limits are often set from a health, safety, and environmental point of view and due to lack of knowledge are not so much based on material integrity issues. This gap of knowledge makes it difficult to make a specification that will ensure safe operation and long-term integrity. The present paper summarises the results of a large research project that systematically tested CO2 with various combinations and concentrations of potentially reactive impurities (H2O, NO2, SO2, H2S, O2). It was clearly shown that many impurity combinations were basically inert, while other resulted in chemical reactions and some combinations even resulted in formation of a separate aqueous phase that contained high concentrations of sulfuric and nitric acid as well as elemental sulphur. This aqueous phase was corrosive to carbon steel. Corrosion was also observed in certain situations even if a separate aqueous phase was not observed visually. It is important to avoid precipitation of solid products since it may cause problems at the injection point and in the reservoir. The present work demonstrated that the types and combination of impurities that are present is important for the maximum impurity concentration that can be allowed to prevent chemical reactions and corrosion from occurring. The concentration limit for each impurity should be below 20 ppmv if NO2, SO2, H2S, O2 are present together.

Solid-Solution Effect on Grain Boundary Character Distribution and Corrosion Resistance of 304 Stainless Steel

In this study, we focus on the effect of solid-solution treatment on the susceptibility to intergranular corrosion and electrochemical corrosion of 304 stainless steel. The results show that with the solution temperature rises, the grain size of the steel increases and the intergranular corrosion tendency decreases. After corrosion, it exhibits a step microstructure and grooves at grain boundary on surface of the steel. The corrosion resistance of the steel can be improved by means of properly increasing the solution temperature and choosing a faster cooling way such as water quenching. Besides, with the nitric acid solution temperature rises, the corrosion current (Icorr) increases and the pitting corrosion potential decreases, in which pitting corrosion is more likely to happen. Moreover, in high concentration of nitric acid, a stability passive film can be formed on the surface of 304 stainless steel, which prevents the reaction of the anode, lowers the corrosion, and shows a better anti-corrosive ability.

Isolation and characterization of microcrystalline cellulose extracted from banana fiber in poly(lactic acid) biocomposite produced from solvent casting technique

The purpose of this project is to extract Microcrystalline Cellulose (MCC) from Banana fiber to produce Poly(Lactic Acid)/Microcrystalline Cellulose, (PLA/MCC) biocomposite film using a solvent casting technique. The initial phase is the production of MCC from Banana fiber by involving three steps; alkaline treatment, bleaching and acid hydrolysis. MCC produced from the different concentration of Nitric acid in the acid hydrolysis process, were used to analyze the morphological and crystalline properties using SEM and XRD respectively. MCC produced from the higher concentration of Nitric acid shows good morphological properties and higher % crystallinity. Then, MCC compounded into PLA with different filler loading to produce PLA/MCC biocomposite film using a different solvent which is Chloroform and Dichloromethane. Results show that lower MCC loading, induces good filler matrix interaction and this evidences by the improvement of the Tensile strength and Young’s Modulus, as well as shows improvement in loss factor and storage modulus which studied from DMA. Moreover, the addition of MCC slightly improved the thermal stability of PLA. From using a different solvent to produce PLA/MCC biocomposite film, Dichloromethane solvent improves the tensile strength and Young’s modulus of biocomposite film, while Chloroform reduces the tensile properties of biocomposite film.

Surface treatment of recycled carbon fibre for interfacial enhancement in reinforced polypropylene product

Recycled carbon fibre (rCF) is used in various applications as measures to reduce the carbon fibre waste in landfill. This study focuses on using rCF in powder form in injection moulded polypropylene (PP) products. The rCF was treated with 0.5 mol/L and 1.0 mol/L nitric acid. The tensile and flexural properties were evaluated and morphological surface of the samples was characterised using scanning electron microscopy (SEM). As the result, higher concentration of nitric acid increased the tensile strength but leads to lower flexural strength. Apart from that, the environmental assessment using OpenLCA software shows that the addition of RCF filler loading leads to reduction of climate change and acidification potential.