Low-cost Feedstock For Biodiesel Production Research Articles

Kinetics, thermodynamics, and optimization analyses of lipid extraction from discarded beef tallow for bioenergy production

ABSTRACT The wide expansion of the meat industry generated tremendous amounts of animal-based waste. Discarded beef tallow (DBT) is one of those prevalent lipid-rich wastes disposed of by slaughterhouses, meat processing units, and tanneries. The current study utilized the advanced technology of supercritical CO2 (SC-CO2) to extract lipid content from DBT for biodiesel production through transesterification. The effects of SC-CO2 parameters on the extraction rate were investigated over ranges of (32–80°C) for temperature, (10–50 MPa) for pressure, and (15–150 min) for treatment time. Using response surface methodology (RSM), both processes of SC-CO2 and transesterification were optimized. The highest extraction rate was 86.10%, obtained at the experimental conditions of 60°C for temperature, 30 MPa for pressure, and 120 min for treatment time. For the transesterification, the maximum yield of biodiesel was 95.15%, obtained at the reaction conditions of 1:7.5, 1.16 wt%, 58°C, and 72 min for lipid to methanol molar ratio, catalyst ratio, temperature, and time, respectively. The outcomes of the kinetic and thermodynamic analyses showed that the SC-CO2 extraction was an endothermal, unspontaneous, and temperature-dependent process. The characteristics of the synthesized biodiesel largely comply with the ASTM D6751 and EN 14,214 standards. The findings of the current study confirm the viability of SC-CO2 to extract lipids from DBT as a low-cost feedstock for biodiesel production.

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

Kinetics and Transesterification of the Oil Obtained from Cussonia bateri (Jansa Seed) as a Step in Biodiesel Production Using Natural Heterogeneous Catalyst

The ongoing search for a more sustainable, renewable, and affordable fuel source has necessitated the quest and search for a better diesel. Biodiesel, an environmentally friendly diesel, has been able to solve many of the issues that have arisen as a result of the use of fossil fuels. They are mostly synthesized by transesterification of a FFA with an alcohol employing an appropriate catalyst. This study examines the use of jansa seed oil as a low-cost feedstock for biodiesel production. Transesterification of free fatty acids (FFA) with methanol and ethanol catalyzed by snail shell was used to process the biodiesel. In the biodiesel production, the alcohol to oil molar ratio was 12:1, the catalyst amount was 0.75 g, and the reaction temperature was 65°C. The reversible second-order reaction rate was used to characterize the kinetics of FFA transesterification. Kinetic modeling of the biodiesel production process was also carried out in order to determine the sequence of the reaction and estimate the reaction rate constant. The activation energy of the ethyl ester was higher than that of the methyl ester, implying that the ethyl ester would require more energy (slower reaction rate) to activate a molecule for chemical transformation. The reusability of the catalyst for continuous transesterfication runs was investigated under the same operating conditions, and the conversion of the catalyst declined from 99.6 percent to 86.4 percent after the fifth regeneration cycle. Jansa seed oil has the potential to be a valuable raw source for generating fatty oil for the use as an alternate feedstock in the production of biodiesel.

Kinetics and Transesterification of the Oil Obtained from <i>Cussonia bateri</i> (Jansa Seed) as a Step in Biodiesel Production Using Natural Heterogeneous Catalyst

The ongoing search for a more sustainable, renewable, and affordable fuel source has necessitated the quest and search for a better diesel. Biodiesel, an environmentally friendly diesel, has been able to solve many of the issues that have arisen as a result of the use of fossil fuels. They are mostly synthesized by transesterification of a FFA with an alcohol employing an appropriate catalyst. This study examines the use of jansa seed oil as a low-cost feedstock for biodiesel production. Transesterification of free fatty acids (FFA) with methanol and ethanol catalyzed by snail shell was used to process the biodiesel. In the biodiesel production, the alcohol to oil molar ratio was 12:1, the catalyst amount was 0.75 g, and the reaction temperature was 65°C. The reversible second-order reaction rate was used to characterize the kinetics of FFA transesterification. Kinetic modeling of the biodiesel production process was also carried out in order to determine the sequence of the reaction and estimate the reaction rate constant. The activation energy of the ethyl ester was higher than that of the methyl ester, implying that the ethyl ester would require more energy (slower reaction rate) to activate a molecule for chemical transformation. The reusability of the catalyst for continuous transesterfication runs was investigated under the same operating conditions, and the conversion of the catalyst declined from 99.6 percent to 86.4 percent after the fifth regeneration cycle. Jansa seed oil has the potential to be a valuable raw source for generating fatty oil for the use as an alternate feedstock in the production of biodiesel.

Co-production of biodiesel and alginate from Laminaria japonica

A process to produce both biodiesel and alginate in an integrated manner from a brown seaweed, Laminaria japonica, was established. Mannitol, a major carbon constituent in L. japonica, served to produce neutral lipids via the heterotrophic cultivation of an oleaginous yeast, Cryptococcus sp.; and simultaneously alginate, a high value product, was extracted to enhance the economic feasibility of the entire process. Only autoclave pretreatment, without need of any chemical agents, was enough to recover all the essential nutrients for the yeast cultivation. Specifically, it could recover 6.4 g L−1 of mannitol to a degree comparable to 6.6 g L−1 obtained by acid-aided pretreatment using 1.5% (v/v) of H2SO4. Maximum fatty acids methyl esters (FAME) content was 30.37% with FAME productivity of 0.56 g L−1 d−1, and the produced FAME could meet the biodiesel quality standards. Na2CO3-based method showed the best efficiency of alginate recovery, yielding 21.06% (w/w). This study supports that L. japonica can indeed be a promising low-cost feedstock for biodiesel production, and it is more so when a high-value product alginate is co-produced.

Study on Lipid Accumulation in Novel Oleaginous Yeast Naganishia liquefaciens NITTS2 Utilizing Pre-digested Municipal Waste Activated Sludge: a Low-cost Feedstock for Biodiesel Production.

The economical production of lipids is considered as an appropriate renewable alternative feedstock for biodiesel production because of the contemporary concerns on fuel crisis, climate change and food security. In this study, lipid accumulation potential of a novel oleaginous yeast isolate Naganishia liquefaciens NITTS2 by utilizing pre-digested municipal waste activated sludge (PWAS) was explored. Optimization of culture conditions was performed using response surface methodology coupled with genetic algorithm and maximum lipid content of 55.7% was obtained. The presence of lipid was visually confirmed by fluorescence microscopy and its characteristic profile was determined by GC-MS. The yeast lipid was recovered and converted into biodiesel by garbage lipase with the efficiency of 88.34 ± 1.2%, which was further analyzed by proton nuclear magnetic resonance spectroscopy. Hence, the results of this study strongly suggest the possibility of using PWAS as an efficient and low-cost resource for the production of biodiesel from the oleaginous yeast.

Production of biodiesel by enzymatic transesterification of waste sardine oil and evaluation of its engine performance

Waste sardine oil, a byproduct of fish industry, was employed as a low cost feedstock for biodiesel production. It has relatively high free fatty acid (FFA) content (32 mg KOH/g of oil). Lipase enzyme immobilized on activated carbon was used as the catalyst for the transesterification reaction. Process variables viz. reaction temperature, water content and oil to methanol molar ratio were optimized. Optimum methanol to oil molar ratio, water content and temperature were found to be 9:1, 10 v/v% and 30 °C respectively. Reusability of immobilized lipase was studied and it was found after 5 cycles of reuse there was about 13% drop in FAME yield. Engine performance of the produced biodiesel was studied in a Variable Compression Engine and the results confirm that waste sardine oil is a potential alternate and low-cost feedstock for biodiesel production.

Optimization and characterization of biodiesel production from rohu (Labeo rohita) processing waste

Optimization and characterization of biodiesel production from fish oil extracted from rohu (Labeo rohita) processing waste were investigated in the present study. Wet reduction method showed highest oil yield (95.2%, v/v), compared to other methods (P < 0.05). Physicochemical properties of the oils were investigated before preparing biodiesel through transesterification reaction. Various alcohols, catalysts, reaction temperature and reaction time were evaluated for optimal biodiesel conversion of oil. The maximum yield of biodiesel (95.9%) was obtained with 0.75% KOH as catalyst, 1:0.5 (v/v) oil to methanol ratio and a reaction temperature of 55 °C for 60 min. TLC, FTIR and GC analysis suggested the triglycerides in the RPW oil have completely converted into biodiesel, which contained palmitic acid methyl ester and α-linolenic acid methyl ester as the dominant esters. Physicochemical characteristics of biodiesel were evaluated and the results suggested that quality of biodiesel were feasible. DSC study demonstrated the melting temperature of biodiesel were ranged from −52.56–4.11 °C, indicated the better cold flow property. Moreover, the oxidative stability of biodiesel was improved by adding BHT at 300 mg/kg. Therefore, extracted oil from rohu processing waste could well be used as an alternative source of low-cost feedstock for biodiesel production.

Bioconversion of volatile fatty acids derived from waste activated sludge into lipids by Cryptococcus curvatus

Pure volatile fatty acid (VFA) solution derived from waste activated sludge (WAS) was used to produce microbial lipids as culture medium in this study, which aimed to realize the resource recovery of WAS and provide low-cost feedstock for biodiesel production simultaneously. Cryptococcus curvatus was selected among three oleaginous yeast to produce lipids with VFAs derived from WAS. In batch cultivation, lipid contents increased from 10.2% to 16.8% when carbon to nitrogen ratio increased from about 3.5 to 165 after removal of ammonia nitrogen by struvite precipitation. The lipid content further increased to 39.6% and the biomass increased from 1.56g/L to 4.53g/L after cultivation for five cycles using sequencing batch culture (SBC) strategy. The lipids produced from WAS-derived VFA solution contained nearly 50% of monounsaturated fatty acids, including palmitic acid, heptadecanoic acid, ginkgolic acid, stearic acid, oleic acid, and linoleic acid, which showed the adequacy of biodiesel production.

Optimization and kinetic modeling of esterification of the oil obtained from waste plum stones as a pretreatment step in biodiesel production

This study reports on the use of oil obtained from waste plum stones as a low-cost feedstock for biodiesel production. Because of high free fatty acid (FFA) level (15.8%), the oil was processed through the two-step process including esterification of FFA and methanolysis of the esterified oil catalyzed by H2SO4 and CaO, respectively. Esterification was optimized by response surface methodology combined with a central composite design. The second-order polynomial equation predicted the lowest acid value of 0.53mgKOH/g under the following optimal reaction conditions: the methanol:oil molar ratio of 8.5:1, the catalyst amount of 2% and the reaction temperature of 45°C. The predicted acid value agreed with the experimental acid value (0.47mgKOH/g). The kinetics of FFA esterification was described by the irreversible pseudo first-order reaction rate law. The apparent kinetic constant was correlated with the initial methanol and catalyst concentrations and reaction temperature. The activation energy of the esterification reaction slightly decreased from 13.23 to 11.55kJ/mol with increasing the catalyst concentration from 0.049 to 0.172mol/dm3. In the second step, the esterified oil reacted with methanol (methanol:oil molar ratio of 9:1) in the presence of CaO (5% to the oil mass) at 60°C. The properties of the obtained biodiesel were within the EN 14214 standard limits. Hence, waste plum stones might be valuable raw material for obtaining fatty oil for the use as alternative feedstock in biodiesel production.

Conversion of lipid from food waste to biodiesel

Depletion of fossil fuels and environmental problems are encouraging research on alternative fuels of renewable sources. Biodiesel is a promising alternative fuel to be used as a substitute to the petroleum based diesel fuels. However, the cost of biodiesel production is high and is attributed mainly to the feedstock used which leads to the investigation of low cost feedstocks that are economically feasible. In this paper, we report on the utilization of lipid obtained from food waste as a low-cost feedstock for biodiesel production. Lipid from food waste was transesterified with methanol using base and lipase as catalysts. The maximum biodiesel yield was 100% for the base (KOH) catalyzed transesterification at 1:10M ratio of lipid to methanol in 2h at 60°C. Novozyme-435 yielded a 90% FAME conversion at 40°C and 1:5 lipid to methanol molar ratio in 24h. Lipid obtained from fungal hydrolysis of food waste is found to be a suitable feedstock for biodiesel production.

Biodiesel from waste cooking oils via direct sonication

This study investigates the effect of direct sonication in conversion of waste cooking oil into biodiesel. Waste cooking oils may cause environmental hazards if not disposed properly. However, waste cooking oils can serve as low-cost feedstock for biodiesel production. Ultrasonics, a non-conventional process technique, was applied to directly convert waste cooking oil into biodiesel in a single step. Ultrasonics transesterify waste cooking oils very efficiently due to increased mass/heat transfer phenomena and specific thermal/athermal effects at molecular levels. Thus, energy and chemical consumption in the overall process is greatly reduced compared to conventional biodiesel processes. Specific to this research, thermal effects of ultrasonics in transesterification reaction without external conventional heating along with effects of different ultrasonic, energy intensities and energy density are reported. Optimization of process parameters such as methanol to oil ratio, catalyst concentration and reaction time are also presented. It was observed that small reactor design such as plug-flow or contact-type reactor design may improve overall ultrasonic utilization in the transesterification reaction due to increased energy density and ultrasonic intensity.

Optimization of biodiesel production from camelina oil using orthogonal experiment

Camelina oil is a low-cost feedstock for biodiesel production that has received a great deal of attention in recent years. This paper describes an optimization study on the production of biodiesel from camelina seed oil using alkaline transesterification. The optimization was based on sixteen well-planned orthogonal experiments (OA 16 matrix). Four main process conditions in the transesterification reaction for obtaining the maximum biodiesel production yield (i.e. methanol quantity, reaction time, reaction temperature and catalyst concentration) were investigated. It was found that the order of significant factors for biodiesel production is catalyst concentration > reaction time > reaction temperature > methanol to oil ratio. Based on the results of the range analysis and analysis of variance (ANOVA), the maximum biodiesel yield was found at a molar ratio of methanol to oil of 8:1, a reaction time of 70 min, a reaction temperature of 50 °C, and a catalyst concentration of 1 wt.%. The product and FAME yields of biodiesel under optimal conditions reached 95.8% and 98.4%, respectively. The properties of the optimized biodiesel, including density, kinematic viscosity, acid value, etc., were determined and compared with those produced from other oil feedstocks. The optimized biodiesel from camelina oil meets the relevant ASTM D6571 and EN 14214 biodiesel standards and can be used as a qualified fuel for diesel engines.