Optimum Conditions For Esterification Research Articles

Construction of the novel PMA@Bi-MOF catalyst for effective fatty acid esterification

A novel Bi-based metal-organic framework impregnated phosphomolybdic acid (PMA@Bi-MOF) catalyst has been fabricated via a simple hydrothermal procedure, and successfully applied in the preparation of biodiesel using oleic acid (OA) as the raw material. The PMA@Bi-MOF composites were exhaustively characterized with the help of FTIR, XRD, TPD-NH3, SEM-EDX, N2-physisorption, TGA, and XPS analyses. Experimental findings showed that the PMA@Bi-BTC exhibited a higher activity than that of PMA@Bi-BDC and Bi-BTC, attributed to its textural property, the presence of more acid sites with higher strength, and synergistic catalytic effects between PMA and Bi-BTC. The optimum conditions for esterification of OA, with a conversion of up to 92.5%, were found to be a molar ratio of methanol to OA of 20:1 and 0.15g PMA@Bi-BTC catalyst at 160 °C in 3 h. Meanwhile, reused studies indicated that the OA conversion reached more than 80% after seven reaction cycles. Furthermore, the activation energy of esterification catalyzed by PMA@Bi-BTC was also calculated as 54.8 kJ/mol. It is expected that our study provides an efficient route to biofuel production involving polyoxometalates/MOF synergistic catalysts.

Esterification and transesterification of palm fatty acid distillate in chitosan membrane reactor

Biodiesel from palm fatty acid distillate (PFAD) with FFAs of 87.1 ± 1.3 wt% was studied in a 2-litres chitosan membrane reactor. The reactor used in this study comprised of three parts; i.e., upstream side for reaction, membrane cell and downstream side connecting with a vacuum pump. The feed was operated under esterification reaction followed by transesterification reaction without intermediate washing. Flat sheet symmetric dense uncrosslinked chitosan membrane was used preferably in the laboratory 2-litres reactor. Operating the reactor under the pervaporation process, the optimum esterification condition was at 1:15 of PFAD to methanol ratio, 2.0 wt% H2SO4 and 20 ml/min methanol feed rate for 120 min. The FFA and methyl ester contents in the esterification product were 1.09 ± 0.03 and 85.9 ± 0.1 wt%, respectively. On the transesterification condition at 1:6 of PFAD to methanol ratio, 1.0 wt% NaOH and 20 ml/min methanol feed rate for 60 min, the methyl ester was increased to 97.9 ± 0.0 wt%. On performance and potential application, an 8-litres reactor installing a set of membrane modules was studied. Several membrane modules with flat sheet reinforced crosslinked composite chitosan membranes were installed in the pilot 8-litres reactor. Together with operating the reactor under the pervaporation process, the esterification was operated at 1:15 of PFAD to methanol ratio and 1.5 wt% H2SO4 for 180 min followed by the transesterification reaction at 1:6 of PFAD to methanol ratio and 1.0 wt% NaOH for 60 min without intermediate washing. The methyl ester yield of 96.6 ± 0.02 wt% was obtained.

Characterization and Conversion of Sludge Palm Oil (SPO) into Biodiesel

Sludge Palm Oil (SPO) is a potential low-cost feedstock for biodiesel production. The conversion efficiency and the quality of biodiesel produced is governed by the feedstock and the conversion reaction. To our knowledge, the potential of SPO produced by palm oil mills in Sarawak has yet to be explored. Hence, this paper aims to characterize the SPO obtained from Sarawak palm oil mills and to optimize the predominant conversion reaction. The SPO was converted into biodiesel via a sulphuric acid catalyzed esterification reaction, followed by transesterification using potassium hydroxide and methanol.  This SPO contained 1.30 - 10.15% moisture, 2.91 - 7.63% sediment and 47.05 – 87.86% free fatty acids (FFA). The optimum esterification conditions identified were: SPO:methanol ratio (1:10), sulphuric acid concentration (1.84%) and reaction time (3.25 hr). Under these conditions, the biodiesel yield was 74% with an FFA conversion efficiency of 79.87%. The water produced during the esterification process was found to hinder the reaction, reducing both conversion efficiency and biodiesel yield. The findings of this study offer important insights about the challenges and feasibility of biodiesel conversion from SPO, where esterification is inevitable due to its high FFA content. &nbsp

Synthesis and characterization of new bifunctional SnZrSi oxide catalysts for biodiesel production

A set of unprecedented (mesoporous SnO2/ZrSiO4) solids has been synthesized via the ultrasound-assisted co-precipitation path. The impact of silica dopant content (ranged between 0.05 and 0.4 mol%) on the characterization evolution of the sonicated ZrSnO4 interface and their biodiesel production efficiency were examined. Physio-chemical characteristics of the synthesized catalysts were analyzed by XRD, SEM-EDS, TEM, TGA-DTG, N2 adsorption–desorption analysis, NH3-TPD, UV–Visible/ DR, and FT-IR before and after pyridine adsorption. The obtained results revealed the formation of reconstructed rutile-SnO2 and zircon as new active phases by calcination at 500 °C, good morphology with mesoporous structure, and significant increase in the SBET, pore volume, interesting optical behavior, and exhibited different acidic properties. The impacts of reaction temperature, silica dopant content, fatty acid type and calcination temperature on the biodiesel % were examined. The tertiary oxide catalysts were gainful for the biodiesel production. The optimum catalyst (0.2 % SiO2/ZrSnO4) had the biggest number of both strong Brönsted and Lewis acid sites compared to the doped and undoped catalysts, so, its maximum yield at optimum conditions for esterification of palmitic acid reaction was 90.2 % and can be reused until the fifth run with giving excellent yield for biodiesel production. But, for the transesterification of soybean oil reaction with methanol was maxima at 88% for (0.4 % SiO2/ZrSnO4) sample. The kinetic, mechanism studies and thermodynamic parameters were estimated. The important role of the doped silica molecules in the mechanism of the esterification process was emphasized by the computational chemistry study.

Two steps methanolysis and ethanolysis of olive pomace oil using olive-pomace-based heterogeneous acid catalyst

Olive pomace (OP) and olive pomace oil (OPO) are low-cost, non-edible, by-products of olive oil processing. Converting OPO into biodiesel by (trans-)esterification and olive pomace into a heterogeneous acid catalyst by sulfonation with sulfuric acid could promote waste-to-energy actions. OPO has a high fatty acid content of 126.39 mgKOH/goil, which does not allow the use of base catalyst for biodiesel production. Homogeneous acid catalyst such as sulfuric acid could be used, however the wastewater should be neutralized and the catalyst could not be regenerated nor reused.The objective of this paper is to use the OP to produce a heteregeneous acid catalyst, that will be used in the esterification reaction of OPO to produce biodiesel.OP was pyrolyzed, activated with steam and sulfonized. Then OPO esterification was performed as at 60 °C and 65 °C for 5 h under agitation at 400 rpm using methanol and ethanol, respectively. The optimization of reaction was performed using an full factorial design by varying oil-to-methanol/ethanol molar ratio (1:3, 1:6, and 1:9) and catalyst loading (10 wt%, 15 wt%, and 20 wt%). The optimum esterification conditions were obtained at 1:9 oil-to-ethanol molar ratio and 20 wt% catalyst. Final products acidities reached 1.14 mgKOH/goil and 3.89 mgKOH/goil with methanol and ethanol, respectively.Work was then focused on ethanolysis and a second step of homogeneous alkali-catalyzed transesterification was performed. FAEE yield registered 95.7% using the products of optimized first step. The physical and chemical properties of final product were measured and they respect EN14214 requirements except glycerides contents that were slightly higher than the norm. It registered a viscosity of 3.38 mm2/s, a flash point of 168 °C, and a Cold Filter Plugging Point of 14 °C. Its Copper Strip Corrosion class (1a) respects EN14214. Solid catalyst was regenerated and reused up to 6 cycles before being mechanically degraded.

Optimization studies on esterification of waste cooking oil using sulfated montmorillonite clay acidic catalyst

Currently, refined edible oils are used to produce biodiesel with the help of a base catalyst. The most important problem with the base-catalyzed esterification process is that they produce soap when they have higher free fatty acids (FFA). The present study indicates that montmorillonite (k10) can be a significant catalyst prepared by the impregnation method using H2SO4 in the ratio of 1:5. The prepared novel catalyst was characterized using XRD, FTIR and SEM-EDS techniques. The optimum conditions for esterification have been determined by applying RSM with CCD methodology for each significant variable like oil-methanol molar ratio, catalyst amount, reaction time and temperature. The optimum acid conversion of 80.8% was observed at an oil-methanol molar ratio of 1:12, amount of catalyst 6 wt% and 120 min of reaction time at 55 °C.

Production of methyl ester from mahua oil: Characterization and optimization by using RSM

The Production of fatty acid Methyl Esters, to be used as a diesel substitute (Biodiesel) has been studied. In the present work Methyl Ester (Biodiesel) was produced from Mahua Oil through esterification followed by transesterification. The preparation of mahua oil methyl Ester was carried out at different parameters like: Methanol to oil molar Ratio, Concentration of Catalyst, Effect of Temperature and reaction time. The results shows that 6:1 liquor to oil molar proportion with 1% KOH impetus, 60 °C response temperature and time 120 min gives 92% ideal yield are the optimum conditions for esterification. Streamlining of chosen boundaries is finished by Response Surface Methodology system in Design Expert programming by Box-Behnken Method. The various fuel properties of mahua oil methyl ester were compared with ASTM Standards. It was concluded that the mahua oil is a potential raw material for the methyl ester. It is cost effective and can be a viable alternative fuel in near future. GCMS and FTIR Analysis were also carried out to identify and confirm the presence of fatty acid methyl esters.

Catalytic performance and deactivation mechanism of a one-step sulfonated carbon-based solid-acid catalyst in an esterification reaction

In this study, catalytic activity and deactivation mechanism of a carbon-based solid-acid catalyst in the esterification of oleic acid and methanol were investigated. The experimental results showed that the S150-4 catalyst, prepared by sulphonating at 150 °C for 4 h, yielded the highest sulfonic acid density. The conversion yield reached 97.98% under the optimum esterification conditions (i.e. catalyst loading, 10 wt%; methanol/oleic acid molar ratio, 8:1; reaction temperature, 65 °C; reaction time, 8 h) and decreased to 79.19% after four cycles. In the first batch of esterification, the formation of sulfonic esters was the main reason for the deactivation of the catalyst, whereas the leaching of sulphur was the main contributor in the second to fourth batches. Therefore, it is believed that reducing the leaching of sulphur and the formation of sulfonic esters by changing the addition method of methanol is an effective method to extend the service life of the catalyst.

Biodiesel synthesis from oil palm empty fruit bunch biochar derived heterogeneous solid catalyst using 4-benzenediazonium sulfonate

In this research, biomass from oil palm empty fruit bunch was used as the carbon precursor and sulfonated by 4-benzenediazonium sulfonate (4-BDS) to produce solid acid catalyst. The as-synthesized catalysts were characterized and the performances were tested in esterification of palm fatty acid distillate (PFAD) for biodiesel production. Scanning Electron Microscopy (SEM) showed that clear porous and rough carbon surface was successfully developed after calcination which favored the attachment of sulfonic groups. Thermogravimetric Analysis (TGA) result showed that the catalyst was thermally stable up to 600 °C. Fourier Transform Infrared Spectroscopy (FTIR) proved that SO and SO3H sulfonic groups were successfully attached to the carbon catalyst. From the catalytic activity tests, the results showed that the catalyst which was calcined at 200 °C and sulfonated with 15:1 sulfanilic acid to AC ratio was the optimum catalyst as it provided the highest biodiesel yield. Further investigation showed that the reaction time of 7 h and 20 wt.% of catalyst loading were reported as optimum esterification conditions which provided the highest biodiesel yield at 98.1 %.

Esterification of Palm Fatty Acid Distillate for Biodiesel Production Catalyzed by Synthesized Kenaf Seed Cake-Based Sulfonated Catalyst

Sulfonated kenaf seed cake (SO3H-KSC) catalyst, was synthesized to aid biodiesel production from palm fatty acid distillate (PFAD). It was chemically activated with phosphoric acid for an impregnation period of 24 h in order to enhance the porosity and the specific surface area of kenaf seed cake (KSC). After the carbonization and sulfonation, the resultant catalyst was characterized with powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscope (FESEM), NH3-temperature programmed desorption (NH3-TPD) and thermogravimetric analysis (TGA). The SO3H-KSC catalyst was amorphous in nature and had an acid density of 14.32 mmol/g, specific surface area of 365.63 m2/g, pore volume of 0.31 cm3/g and pore diameter of 2.89 nm. At optimum esterification conditions--reaction time 90 mins, temperature of 338 K, methanol:PFAD molar ratio of 10:1 and catalyst concentration of 2 wt.%—a free fatty acid (FFA) conversion of 98.7% and fatty acid methyl esters (FAME) yield of 97.9% was achieved. The synthesized SO3H-KSC catalyst underwent five reaction cycles while maintaining a fatty acid methyl esters (FAME) yield and free fatty acid (FFA) conversion of >90%. Thus, the SO3H-KSC catalyst was shown to be an excellent application of bio-based material as a precursor for catalyst synthesis for esterification of PFAD.

Sol-gel synthesis of barium hexaferrite and their catalytic application in methyl ester synthesis

Fine barium hexaferrite, BaFe12O19 has been synthesized through sol-gel technique using barium chloride dihydrate (BaCl2.2H2O) and iron (III) chloride hexahydrate (FeCl3.6H2O) as starting materials. The BaFe12O19 particles were characterized by X-ray diffraction (XRD), TGA, Fourier-Transform Infrared Spectroscopy (FTIR) and N2 Adsorption-Desorption Isotherm. XRD revealed that high calcination temperature is beneficial for the formation of fine BaFe12O19. The results show that the crystallite size of the produced samples increased with an increase in calcination temperature. It was found that the crystalline BaFe12O19 phase was well formed above 700°C. BaFe12O19 was as employed as a new heterogeneous acid catalyst for the application production of methyl ester. The suitability of BaFe12O19 as catalyst for esterification of palmitic acid was evaluated on the basis of catalyst dosage, reaction time and molar ratio of the reactants to optimize the reaction condition. The catalyst gave excellent methyl ester yield of 91.7% at optimum conditions. The optimum esterification conditions for of 0.5 g palmitic acid are; 2 wt.% of BaFe12O19 with 1:15 molar ratio of palmitic acid to methanol at reaction temperature 120°C for 2 hours.

Esterification of Microwave Induced Pyrolytic Oil from Sago Bark Waste

In this study, microwave induced pyrolytic oil from sago bark (SB) was subjected to esterification to improve its properties. Improvement on properties of the pyrolytic oil was performed via esterification with ethanol and the presence of sulfuric acid as a catalyst. The optimum esterification condition was studied using general factorial design. The esterified oil (EO) showed improved properties with pH (4–6), reduced moisture content (2.95–3.45%), density (0.9–1.1 g cm−3), and acid value (39.3–123.4 mg KOH−1 g−1), and maintained the CV (20.2–21.6 MJ kg−1). GC–MS analysis showed that EO was sulphur free, and low in carboxylic acid and oxygenated compounds. The optimal esterification condition with optimum quality of EO was at 65 °C temperature, 60 min reaction time and 1:1 ethanol to oil volume ratio. Results indicated that the EO can be potentially used in robust combustion engines upon properties refinement.

Producing Fatty Acid Methyl Esters from Free Fatty Acids with Ionic Liquids as Catalyst

AbstractThree Brønsted acidic imidazole dicationic ionic liquids (ILs) with different length of alkyl chains, [Cn(Mim)2][HSO4]2 (n = 3, 6, 12), were prepared and used as catalyst for the esterification reaction of free fatty acids and methanol. Taking oleic acid as model acid, the catalytic performances of the synthesized ILs for the esterification were evaluated. The main physicochemical properties of the ILs, thermal stability, acidity, solubility in common solvents, and causticity on Austenitic stainless steel 316, were examined. [C3(Mim)2][HSO4]2 demonstrated the highest catalytic activity and enabled to assess the preliminary optimum esterification condition of oleic acid and methanol. Under optimized reaction conditions, the yield of oleic acid methyl ester was up to 95 %. The ILs have great potential as catalysts for producing fatty acid methyl esters from long‐chain free fatty acids.

Preparation of carbon-based solid acid with large surface area to catalyze esterification for biodiesel production

A series of carbon-based solid acid catalysts are synthesized from bamboo through the approach of partial carbonization and sulfonation, where predecessor of the catalyst is activated by phosphoric acid in advance. After carbonization at 350°C for 2h and sulfonation at 105°C for 4h, the catalyst gained amorphous carbon structure with large surface area of 1208m2g−1 and strong acid density of 1.28mmolg−1. The biodiesel yield reached 97.3% with the optimum esterification conditions. Due to the leaching of SO3H groups, after fourth reused cycle of the catalyst, the biodiesel yield declines to 83.7%.

A renewable lipid source for biolubricant feedstock oil from housefly (Musca domestica) larva

Biolubricants are gaining increased attention because of their low toxicity, high biodegradability, and miscibility with additives. These features render them ideal for lubrication, especially in total-loss processes. In this study, housefly (Musca domestica) larvae were used as low-cost, non-food biolubricant feedstock. A larval lipid with high acid value (AV) of 63 mg KOH/g was used as feedstock for esterification to produce 2-ethylhexyl fatty acid esters (2-EH esters). We developed a method of producing high-purity 2-EH esters in which housefly larva free fatty acids (HLFFAs) were derived from larvae fed with kitchen waste. HLFFAs were esterified with 2-ethyl-1-hexanol (2-EHOH) catalysed with benzenesulfonic acid (BSA). The optimum esterification conditions were as follows: catalyst loading, 0.5 wt%; 2-EHOH-to-HLFFAs molar ratio, 3:1; temperature, 130 °C; and reaction time, 2 h. These conditions yielded 98.6% esterification rate. Excess 2-EHOH was removed by molecular distillation at 80 Pa and 110 °C. Residual fatty acids were neutralised by alkali refining. The chemical and physical properties, including the tribological properties, of the produced high-purity 2-EH esters (>99.7%) were also tested.

Esterification of Cochineal Carmine Used for Dyeing Cationic Modified Cotton with High Color Fastness

In order to reduce the electronic cloud density for higher color fastness, ester groups were introduced into cochineal carmine matrix structure. The optimum esterification conditions were selected by varying the level of acid-binding agent, the reaction temperature, the reaction time, and the amount of acetylation reagent. The structure and properties of esterified cochineal carmine was characterized by UV-vis spectroscopy, FT-IR spectrometry and metallographic microscopy. The build-up property, dyeability, light fastness, perspiration and rubbing fastness of cochineal carmine before and after esterification on cationic modified cotton were investigated. The results show that the optimum esterification condition is treating 1.0 g cochineal carmine with 50 mL acetic anhydride and 4.0 g anhydrous sodium acetate at 80°C for 2.0 hours. The acid perspiration fastness and wet rubbing fastness of the resulting dyed samples were increased by one grade. The perspiration fastness to alkalis and the light fastness were improved by one-half grade.

Optimization of enzymatic esterification of dihydrocaffeic acid with hexanol in ionic liquid using response surface methodology

BackgroundDeveloping an efficient lipophilization reaction system for phenolic derivatives could enhance their applications in food processing. Low solubility of phenolic acids reduces the efficiency of phenolic derivatives in most benign enzyme solvents. The conversion of phenolic acids through esterification alters their solubility and enhances their use as food antioxidant additives as well as their application in cosmetics.ResultsThis study has shown that lipase-catalyzed esterification of dihydrocaffeic acid with hexanol in ionic liquid (1-butyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide) was the best approach for esterification reaction. In order to achieve the maximum yield, the process was optimized by response surface methodology (RSM) based on a five-level and four independent variables such as: dosage of enzyme; hexanol/dihydrocaffeic acid mole ratio; temperature and reaction time. The optimum esterification condition (Y = 84.4%) was predicted to be obtained at temperature of 39.4 °C, time of 77.5 h dosage of enzyme at 41.6% and hexanol/dihydrocaffeic acid mole ratio of 2.1.ConclusionFinally, this study has produced an efficient enzymatic esterification method for the preparation of hexyl dihydrocaffeate in vitro using a lipase in an ionic liquid system. Concentration of hexanol was the most significant (p < 0.05) independent variable that influenced the yield of hexyl dihydrocaffeate.Graphical abstractSynthesis of different Hexyl dihydrocaffeates in ionic liquid

Optimization of Two-Step Biodiesel Production from Beef Tallow with Microwave Heating

Animal fats are by-products from slaughterhouses that may be utilized as renewable energy source. This study was about biodiesel production from high free fatty acid beef tallow waste using two-step process with microwave heating. Sulfuric acid and NaOH were used as catalysts with methanol for the first esterification and second transesterification step, respectively. Catalyst loadings were between 0.25% and 2.5%, with applied microwave power of 340 W, operation time of 10–50 min, and oil-to-methanol molar ratio between 1:3 and 1:15. These process parameters were optimized using the design of experiments. The yields and properties of the biodiesel were assessed. The results indicated that the two-step process were successful in converting the beef tallow to biodiesel. Statistical analysis of the results showed that significant contributions were from the linear and quadratic terms of these three variables. The optimum conditions for esterification and transesterification were reported. Validity of the predicted models was confirmed by the experimental verification.

Sulfonated mesoporous ZnO catalyst for methyl esters production

The SO3H group-functionalized mesoporous zinc oxide catalyst (SO3HZnO) was synthesized in order to catalyze the esterification of palm fatty acid distillate (PFAD) containing high free fatty acid (FFA∼90%). In this regard, a mesoporous zinc oxide catalyst was hydrothermally fabricated and further functionalized by post-sulfonation treatment to apply SO3H acid group on the mesopore walls. Structural, textural, physicochemical, thermal, and morphological properties of the synthesized catalysts were characterized by X-ray diffraction (XRD), surface area analysis (Brunauer-Emmett-Teller), Fourier transform infrared spectroscopy (FT-IR), ammonia temperature programmed desorption (NH3-TPD), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The synthesized mesoporous SO3HZnO catalyst possessed unique characteristics such as high surface area of 305.62 m2g-1, an average pore diameter of 3.16 nm, pore volume of 0.12 cm3g-1, and high acid density of 1.72 mmolg−1. The optimum esterification conditions were found as 9:1 of methanol to oil molar ratio, 2 wt% of catalyst concentration, 120 °C of temperature, and 90 min of reaction time to obtained 95.60% yield of PFAD methyl esters. Additionally, the recyclability experiments revealed that the spent catalyst was highly potential to be recycled for seven consecutive runs without further treatment. Furthermore, some important fuel properties of generated PFAD methyl ester such as density, kinematic viscosity, water content, acid value, could-, pour-, and flash-point were compared well with those of EN 14214 and ASTM D6751 specifications.

Sulfonated mesoporous zinc aluminate catalyst for biodiesel production from high free fatty acid feedstock using microwave heating system

Abstract Methyl ester was derived from one-step esterification of palm fatty acid distillate (PFAD) in presence of mesoporous SO3H–ZnAl2O4 solid acid catalyst using microwave irradiation heating system. The catalyst characteristics were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), temperature programmed desorption (TPD) and thermogravimetric analysis (TGA). The mesoporous SO3H–ZnAl2O4 catalyst possessed unique properties such as surface area of 376.26 m2 g−1, total pore volume of 0.16 cm3 g−1, an average pore diameter of 3.55 nm and an acid density of 2.10 mmol g−1. A sequence of experiments were carried out in order to assess the influence of reaction parameters as follows: catalyst concentration (0.5–3.0 wt%), methanol to oil molar ratio (3:1–15:1), reaction temperature (50–70 °C), and mixing intensity (200–500 rpm) for methyl ester production. The evaluation of the esterification was conducted by gas chromatographic (GC) analysis of the PFAD methyl ester at various reaction times. The highest FAME yield was achieved (94.59%) at 20 min under optimum esterification condition (catalyst concentration of 1.5 wt%, methanol to PFAD molar ratio of 9:1, reaction temperature of 60 °C, and mixing intensity of 300 rpm using microwave irradiation heating system. The recyclability experiments revealed that the synthesized catalyst was potential to stay stable for eight consecutive reaction runs with only 22.55% drop in ester synthesis. The quality of the produced ester was assessed by determination of some key fuel properties such as density, acid value, kinematic viscosity, water content, pour point, could point, and flash point. The PFAD methyl ester was establish to satisfy those of European (EN 14214) and American Standards for Testing Materials (ASTM) specifications.