High Free Fatty Acid Feedstocks Research Articles

Efficient production of biodiesel from palm fatty acid distillate using a novel hydrochar-based solid acid catalyst derived from palm leaf waste

To combat fuel shortages, pollution, and the exhaustion of natural oil resources, an environmentally friendly alternative to fossil fuels, such as biodiesel, is essential for meeting global transportation demands. A novel heterogeneous acid catalyst for production of biodiesel from low-cost, high free fatty acid feedstocks was synthesized in this study by activating and impregnating hydrochar from palm leaf (PL) waste with H3PO4 and H2SO4. Subsequently, the sulfonated catalyst was utilized for the esterification of palm fatty acid distillate (PFAD). FT-IR, XRD, FESEM, EDX, BET, TGA, and surface acidity methods were employed to characterize the acid catalyst. Using the one-variable-at-a-time (OVAT) technique, the optimized reaction conditions for esterification of PFAD using the hydrochar-based catalyst were 4 wt% catalyst loading, 353.15 K reaction temperature, 4 h reaction time, and 18:1 methanol: PFAD molar ratio. At these conditions, a maximum biodiesel yield of 93.56% was achieved. The catalyst exhibited excellent reusability and stability throughout five reaction cycles, maintaining biodiesel yields above 80% after each cycle. Analysis of the fuel properties revealed that the biodiesel derived from PFAD met the physiochemical criteria outlined in ASTM D6751, the American biodiesel standard. The kinetic study revealed that the esterification reaction followed pseudo-first-order kinetics with an activation energy (Ea) of 23.70 kJ/mol. Furthermore, the thermodynamic enthalpy (∆H*) and Gibbs' free energy (∆G*) of esterification were 20.9 and 33.41 kJ/mol, respectively, indicating that the reaction was an endothermic and non-spontaneous process.

Influence of desilication route of ZSM-5 zeolite in mesoporous zeolite supported calcium oxide catalyst for biodiesel production

The application of calcium oxide (CaO) as transesterification catalyst for biodiesel production is restricted as there is a high tendency for the calcium (Ca2+) active species to be leached out during the reaction. To overcome this problem, CaO was supported with mesoporous zeolite. A series of mesoporous zeolite supports were prepared via 3 different desilication routes, which are conventional desilication, desilication in the presence of pore directing agent and surfactant-assisted desilication method. The catalytic efficiency of the synthesized catalyst, which are CaO/Zeo, CaO/Zeo-NaOH, CaO/Zeo-TPAOH and CaO/Zeo-CTAB catalyst, in the transesterification of waste cooking oil (WCO) was evaluated. Results revealed that the surfactant-assisted desilication route demonstrates the partial incorporation of the dissolved Al species into the zeolite framework and thus led to highly crystalline material. An obtained high mesoporosity of the zeolite support through this route caused the high dispersion of CaO species in the pores of zeolite support. As a results, the CaO/Zeo-CTAB catalyst exhibited the best performance with 89% biodiesel yield, due to strong acidic and basic properties together with high surface area. The catalyst also showed the higher resistance against Ca2+ active sites leaching by restraining the agglomeration, due to the stronger interaction between CaO and zeolite. The optimum reaction conditions were found to be 4 wt% catalyst dosage, 4 h reaction time, 5:1 methanol to oil molar ratio and 65 °C reaction temperature. The CaO/Zeo-CTAB catalyst could be reused for 6 consecutive runs without significant loss in biodiesel yield and displayed an excellent tolerance to high free fatty acid (FFA) feedstock. For the final remark, these results suggest that the surfactant-assisted desilication is an efficient route for the production of mesoporous zeolite for catalyst support.

One-Step conversion of high FFA Crude Karanja oil (Pongamia pinnata) to Bio-diesel Using Portland cement as excellent heterogeneous catalyst

Heterogeneous catalyst was prepared from Portland cement. The prepared heterogeneous catalyst was tested for catalytic activity in the transesterification of non-edible, high free fatty acid feedstock, such as crude karanja oil (CKO), for biodiesel production, at methanol reflux temperature. Gas chromatographic (Gc) analysis technique was used to determine the fatty acid methyl ester yield. The preparation of heterogeneous catalyst from low-cost sources, and the use of non-edible feedstock, only at methanol reflux temperature, were all aimed at reducing the cost of biodiesel production. Insight into the catalytic activities of catalyst was obtained by characterizations for their textural properties, using Brunnear-Emmet-Teller (BET) analysis technique, surface scanning electron microscopy (SEM) and electron dispersive x-ray (EDX) for microstructure, surface morphology and chemical composition; x-ray diffraction (XRD) and Fourier-Transform Infra-Red (FTIR) spectroscopy for structural and functional groups analyses, respectively. Differential thermal and thermogavimetric (DTA/TGA) analyses were performed to determine the proper temperature ranges for the dehydration, decomposition, desorption and oxidation of sample via the TGA curves and their melting points and changes in crystal structures via the DTA curves, for effective determination of calcination temperature. The application of Portland Cement-derived heterogeneous catalyst in the transesterification reaction revealed excellent activity in the transesterification of crude karanja oil, with excellent fatty acid methyl ester yield of over 97.87 %. Operational conditions such as methanol/oil mole ratio (1:3 - 18), catalyst loading (3 - 9 % by wt) and reaction time (0.5 – 7 hours), were investigated to obtain the optimum reaction conditions for the feedstock, while the reaction temperature was kept constant at methanol reflux temperature, to minimise cost of production, in line with the objective of this investigation. Calcined heterogeneous catalysts gave over 80% fatty acid methyl ester yields than the raw counterpart, which were attributed to changes in crystal structures and phases of catalysts, observed in the characterization of catalysts, after calcination. Keywords: Portland cement, heterogeneous catalyst, Crude Karanja oil, transesterification reaction, Feedstock

Multi-Feedstocks Biodiesel Production from Esterification of Calophyllum inophyllum Oil, Castor Oil, Palm Oil and Waste Cooking Oil

Biodiesel can be produced from various vegetable oils and animal fat. Abundant sources of vegetable oil in Indonesia, such as Calophyllum inophyllum, Ricinus communis, palm oil, and waste cooking oil, were used as raw materials. Multi-feedstock biodiesel was used to increase the flexibility operation of biodiesel production. This study was conducted to determine the effect of a combination of vegetable oils on biodiesel characteristics. Degumming and two steps of esterification were applied for high free fatty acid feedstock before trans-esterification in combination with other vegetable oils. Potassium hydroxide was used as a homogenous catalyst and methanol as another raw material. The acid value of C. inophyllum decreased from 54 mg KOH/gr oil to 2.15 mg KOH/gr oil after two steps of esterification. Biodiesel yield from multi-feedstock was 87.926% with a methanol-to-oil molar ratio of 6:1, temperature of 60 ℃, and catalyst of 1%wt. ©2020. CBIORE-IJRED. All rights reserved

Production of biodiesel from high free fatty acid feedstock using heterogeneous acid catalyst derived from palm-fruit-bunch

ABSTRACT A novel solid acid catalyst was prepared from the palm-fruit-bunch by in-situ incomplete sulphonation carbonization method. The prepared catalyst was characterized to determine its physical and chemical properties which are determine its performance in a reaction. The catalyst was then subjected to esterification and transesterification reactions to produce biodiesel from high free fatty acid (FFA) Calophyllum inophyllum (C. inophyllum) oil. An optimum yield of 88.5 wt% methyl ester was achieved at 4 wt% of catalyst, methanol to oil molar ratio of 21:1 and a reaction temperature of 60ºC in 180 min. The fuel properties of the biodiesel were analyzed as per ASTM standard methods, and their properties were found to be in accordance with ASTM D6751.

Biodiesel Production from Recycled Grease Trap Waste: A Case Study in South Australia. Part 1: The Pre‐Treatment of High Free Fatty Acid Feedstock

AbstractGrease trap waste (GTW) often has a very high content of free fatty acids (FFA) which requires a pre‐treatment step before it can be converted to biodiesel via the transesterification reaction. In this study, the esterification reaction was performed to reduce the level of FFA in the GTW, utilizing ethanol as the reagent in the presence of the catalyst H2SO4. Response Surface Methodology (RSM) based on Central Composite Design (CCD) was applied to determine the optimal conditions for the esterification reaction through four process variables, these being: the molar ratio of ethanol to fats, oils, and grease (FOG), reaction time, reaction temperature, and catalyst loading. A set of 30 experiments were conducted in triplicate to study the interactive effects of the above variables on the reduction of the level of FFAs. An FFA% of 0.84% was obtained at the optimum conditions, which were 6:1 ethanol to FOG molar ratio, 3 hr reaction time, 750C reaction temperature, and 3 wt% H2SO4 loading per FOG weight.

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.

Screening of Novel Materials for Biodiesel Production Through the Esterification of Oleic Acid

The present contribution screens the specific activity of various inorganic and enzymatic based materials in the esterification of oleic acid that is typically used as a test reaction for the production of biodiesel from high free fatty acid feedstocks. The inorganic materials investigated in this contribution are bulk fosfotungstic heteropoly acid of the Wells Dawson structure H6P2W18O62.nH2O (HPA), as well as dispersed on titanium dioxide 18 % w/w H6P2W18O62/TiO2 and the insoluble cesium salt of the Wells Dawson heteropoly anion Cs2H4P2W18O62. Additionally, the commercial biocatalyst Novozym® 435 (immobilized lipase B of Candida antarctica) and a self-supported lipase of vegetable origin obtained from the latex Araujia sericifera (ASL) were studied among the materials of enzymatic nature. The density and accessibility of Bronsted acid sites have a key role in the specific activity of the fosfotungstic based heteropoly compounds. The HPA dispersed over an oxide support catalyzed the esterification of the fatty acid in a heterogeneous fashion with the highest activity (6.4 µmol mg−1 h−1 at 85 °C) among the inorganic materials. In contrast, the enzymatic materials are more active at lower temperature than the inorganic ones. Particularly, ASL catalyzed the homogenous methanolysis with the highest specific activity (30.7 µmol mg−1 h−1 at 40 °C) at the lowest temperature among the materials assayed.

Oxidation stability of biodiesel derived from high free fatty acid feedstock

ABSTRACTAt present, with fluctuating feedstock prices, the biodiesel manufacturing industries are facing some downfall. High free fatty acid (FFA) non-edible oil, which is a byproduct of vegetable oil refineries, is available at low price and in considerable quantities at vegetable oil refinery sites. This high FFA oil can be utilized as a potential low cost feedstock for biodiesel production. In the present work, high FFA (51.6%) oil was synthesized into biodiesel by a two-step process. Except oxidation stability, other fuel properties of the produced biodiesel were found to be comparable with that of biodiesel specifications. Oxidation stability was found to be only 2.1 h at 110°C as determined by the Rancimat apparatus.In order to study and further improve the oxidation stability, the biodiesel (B100) was dosed with a suitable antioxidant (pyrogallol) and stored for 6 months. The acid value, peroxide value, and kinematic viscosity which are closely associated with oxidation behavior were studied. It was found that biodiesel dosed with an antioxidant showed the least increase in the acid value, peroxide value, and kinematic viscosity. Also, induction period was improved and found to be within the American Society for Testing and Materials limit . Thus, the high FFA oil-based biodiesel with a suitable antioxidant can be used as a potential feedstock to resolve the issue of the high cost of biodiesel production.

Rapid high conversion of high free fatty acid feedstock into biodiesel using continuous flow vortex fluidics

Rapid reduction of free fatty acids in biodiesel feedstock: the rapid conversion of problematic free fatty acids in bio-oils has been achieved using room temperature, environmentally benign vortex fluidic flow chemistry.

Kinetic analysis for the esterification of high free fatty acid feedstocks with a structural identifiability approach

Esterification is the first step in the biodiesel production process from low cost feedstock, which is typically characterized by its high content (>5%) of free fatty acids (FFAs). Although multiple attempts have been made to describe the kinetics of the esterification process for this feedstock, there is no consensus regarding which model is the most suitable. In this paper, two models were evaluated as candidates to describe the esterification of grease trap wastes, a synthetic mixture of tallow fat and canola oil, and oleic acid, which all have a high degree of acidity. The first model considers a pseudo‐first order reaction, whereas the second model considers the reversibility of the reaction. All parameters involved in these models are structurally identifiable and are estimated with the Levenberg–Marquardt method. A statistical analysis based on Akaike's weights show that the reversible model provides the best fit for all experimental runs compared to the first order model. This result was obtained from variations in catalyst loading and moisture content.Practical applications: The design and implementation of monitoring algorithms or robust control laws for a process carried out in a continuous stirred tank reactor (CSTR) require the knowledge of its dynamical mathematical model that contains a kinetic term. In the particular case of the esterification reactions for feedstock with high content of FFAs developed in the presence of homogeneous acid catalyst, there exists a discrepancy on the mathematical structure of such kinetic term. In this study we perform some batch experiments, considering industrial reagent grade alcohols, to deduce which model (among the two simplest kinetic models) better describes the esterification of oleic acid, grease trap wastes and a mixture of tallow fat and canola oil. Then, the results obtained from this basic research could be applied if monitoring‐regulation tasks are required for the esterification of the feedstock considered herein when such esterification be carried out in a CSTR under industrial conditions.Low cost feedstock has been esterified under variations in catalyst loading and initial moisture content. Two kinetic models were used to fit experimental data and a structural identifiability analysis has been conducted for each parameter contained in these models. According with Akaike's weights, the kinetic model that considers the reversibility of the esterification reaction provides the best fit for all experimental runs.

Biomass-Based Sulfonic-Functionalized Carbon Solid Acid for Esterification of Acetic Acid

Sulfonic-functionalized carbon material derived from the incomplete carbonization of mungbean vermicelli was reported here as a catalyst for esterification of acetic acid. The catalyst with the highest activity (SBET= 18.1 m2/g and acid site density of 1.53 mmol H+/gcat) was obtained by carbonization at 573 K and sulfonation at 373 K due to a feasible attachment of more SO3H groups to flexible carbon sheets compared to the other synthesized solids. Approximate 64% yield of methyl acetate was achieved over (2:1) molar ratio of methanol to acetic acid with 3 wt% of catalyst. From the economic outlook, this environmentally benign C-SO3H catalyst could be a promising candidate for the esterification of high free fatty acid feedstocks reducing the production cost of biodiesel.

Enzymatic large‐scale production of biodiesel

AbstractEnzymatic production of biodiesel has been the subject of intensive research over the last 5‐10 years. When comparing the economy of enzymatic and chemical produced biodiesel important factors include yield, flexibility in feedstock, value of by‐products, recovery costs for alcohol as well as the cost of enzyme, enzyme lifetime, reaction time are important factors. By 2009 large‐scale enzymatic biodiesel was considered to be cost effective [1]. Since then development work has further improved the technology which is now ready for the market. We have developed a full enzymatic two‐step process for converting oils to biodiesel, and a pretreatment unit which can be installed in an existing chemical biodiesel plant to enable it to process high free fatty acid feedstocks.

Production of aromatic green gasoline additives via catalytic pyrolysis of acidulated peanut oil soap stock

Catalytic pyrolysis was used to generate gasoline-compatible fuel from peanut oil soap stock (PSS), a high free fatty acid feedstock, using a fixed-bed reactor at temperatures between 450 and 550°C with a zeolite catalyst (HZSM-5). PSS fed at 81gh−1 along with 100mLmin−1 inert gas was passed across a 15g catalyst bed (WHSV=5.4h−1, gas phase residence time=34s). Results indicate that fuel properties of PSS including viscosity, heating value, and O:C ratio were improved significantly. For PSS processed at 500°C, viscosity was reduced from 59.6 to 0.9mm2s−1, heating value was increased from 35.8 to 39.3MJL−1, and the O:C ratio was reduced from 0.07 to 0.02. Aromatic gasoline components (e.g., BTEX), were formed in concentrations as high as 94% (v/v) in catalytically-cracked PSS with yields ranging from 22% to 35% (v/v of PSS feed).

Biochar based solid acid catalyst for biodiesel production

A promising catalyst based on a biomass pyrolysis by-product, biochar, has been developed for the production of biodiesel. Two carbon-based solid acid catalysts were prepared by sulfonating pyrolysis char with concentrated or fuming sulfuric acids. Prepared catalysts were studied for their ability to catalyze transesterification of vegetable oils and esterification of free fatty acids. The catalyst sulfonated with the concentrated sulfuric acid demonstrated considerable conversion in free fatty acid esterification, while indicating limited transesterification activity. Using the stronger sulfonating reagent, fuming sulfuric acid, resulted in much higher transesterification activity. Further investigation of the latter catalyst was conducted to determine the effect of sulfonation time (5 and 15 h) and surface area on the transesterification reaction. The surface area of the biochar was increased by chemical treatment using 10 M potassium hydroxide through porosity development. The resulting four catalysts were compared for their catalytic activity. Results showed the catalyst with the highest surface area and acid density to have the highest catalytic activity for the production of biodiesel from canola oil in the presence of methanol as the reagent. Furthermore, the catalyst with the higher surface area indicated higher transesterification activity among the catalyst with similar acid densities. The effects of alcohol to oil (A:O) molar ratio, reaction time and catalyst loading on the esterification reaction catalyzed by the sulfonated biochar were also investigated. Free fatty acid (FFA) conversion increased with increasing A:O molar ratio, reaction time and catalyst loading. The catalyst has a tremendous potential to be used in a process converting a high FFA feedstock to biodiesel.

A Single-Step Solid Acid-Catalyzed Process for the Production of Biodiesel from High Free Fatty Acid Feedstocks

Biodiesel is a nontoxic, renewable, and biodegradable alternative green fuel for petroleum-based diesel. However, the major obstacle for the commercial production of biodiesel is the high cost of raw material, i.e., refined vegetable oils. This problem can be addressed using low-cost feedstocks, such as waste oils and fats. However, these feedstocks contain a high amount of free fatty acids (FFAs), which cannot be used for the production of biodiesel using a traditional homogeneous alkali-catalyzed transesterification process. A solid acid catalyst based on a supported heteropolyacid catalyst (PSA) was evaluated for the production of biodiesel from soybean oil (SBO) containing up to 25 wt % palmitic acid (PA). It was demonstrated that this solid acid catalyst catalyzed simultaneously esterification and transesterification. The total glycerin, ester content, and acid numbers were determined according to ASTM D 6584, EN 14103, and ASTM D 974, respectively. It was found that at 200 °C, 1:27 oil/alcohol molar ratio, and 3 wt % catalyst, a high-quality biodiesel with an ester content of 93.95 mass % was produced from a feedstock (SBO containing 10% PA) in 10 h. The PA and chemically bound glycerin (CBG), which includes triglyceride (TG), diglyceride (DG), and monoglyceride (MG), conversions of 92.44 and 99.38% were obtained, respectively. The effect of process parameters, such as catalyst amount, oil/alcohol molar ratio, and FFA content in the feedstock, has been investigated. This single-step solid acid-catalyzed process has potential for industrial-scale production of biodiesel from high FFA feedstocks.

Biodiesel processing and production

Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats. It consists of the monoalkyl esters formed by a catalyzed reaction of the triglycerides in the oil or fat with a simple monohydric alcohol. The reaction conditions generally involve a trade-off between reaction time and temperature as reaction completeness is the most critical fuel quality parameter. Much of the process complexity originates from contaminants in the feedstock, such as water and free fatty acids, or impurities in the final product, such as methanol, free glycerol, and soap. Processes have been developed to produce biodiesel from high free fatty acid feedstocks, such as recycled restaurant grease, animal fats, and soapstock.

A PILOT PLANT TO PRODUCE BIODIESEL FROM HIGH FREE FATTY ACID FEEDSTOCKS

Biodiesel is an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animalfats. Currently, most biodiesel is made from soybean oil, methanol, and an alkaline catalyst. However, there are large amountsof fats and oils that are unsuitable for human consumption that could be converted to biodiesel at lower cost. The problemwith processing these waste oils is that they often contain large amounts of free fatty acids that cannot be converted to biodieselusing an alkaline catalyst. These free fatty acids react with the alkaline catalyst to produce soaps that inhibit the separationof the biodiesel, glycerin, and wash water. Previous research has developed a process for pretreating these high free fatty acidfeedstocks using acid catalysts, which do not form soaps. The objective of this study was to construct a pilot plant to producebiodiesel from a wide variety of feedstocks including those with high free fatty acids. A 190 L batch pilot plant has been builtthat can process high free fatty acid feedstocks using an acidcatalyzed pretreatment followed by an alkalinecatalyzedtransesterification. Case studies of pilot plantscale production of biodiesel from soybean oil, yellow grease with 9% free fattyacids, and brown grease with 40% free fatty acids are presented. The effect of varying the reaction parameters is discussed,and the separation and washing processes are described. Estimates of the fuel cost using different feedstocks are alsoprovided.

COMPARISON OF ENGINE PERFORMANCE AND EMISSIONS FOR PETROLEUM DIESEL FUEL, YELLOW GREASE BIODIESEL, AND SOYBEAN OIL BIODIESEL

Biodiesel is a nontoxic, biodegradable and renewable alternative fuel that can be used with little or no enginemodifications. Biodiesel is currently expensive but would be more cost effective if it could be produced from lowcost oils(restaurant waste, frying oils, animal fats). These lowcost feedstocks are more challenging to process because they containhigh levels of free fatty acids. A process for converting these feedstocks to fuelgrade biodiesel has been developed anddescribed previously. The objective of this study was to investigate the effect of the biodiesel produced from high free fattyacid feedstocks on engine performance and emissions. Two different biodiesels were prepared from animal fatbased yellowgrease with 9% free fatty acids and from soybean oil. The neat fuels and their 20% blends with No. 2 diesel fuel were studiedat steadystate engine operating conditions in a fourcylinder turbocharged diesel engine. Although both biodiesel fuelsprovided significant reductions in particulates, carbon monoxide, and unburned hydrocarbons, the oxides of nitrogenincreased by 11% and 13% for the yellow grease methyl ester and soybean oil methyl ester, respectively. The conversion ofthe biodiesel fuels energy to work was equal to that from diesel fuel.