Low-quality Feedstocks Research Articles

A stable mesoporous super-acid nanocatalyst for eco-friendly synthesis of biodiesel

Sulfated zirconia is used as solid acid catalyst in simultaneous (trans)esterification of low quality feedstock with free fatty acids for biodiesel production. However, its widespread application in catalytic reaction is limited by its framework and catalytic instability. Therefore, we prepared a stable sulfated zirconia catalyst with mesoporous structure and tetragonal phase nanocrystalline by using dioctyl dimethyl ammonium chloride as a template. The mesoporous sulfated zirconia shows more than 85% conversion of soybean oil after five recycle runs at 140 °C in both the transesterification and the simultaneous (trans)esterification. A comparison of physicochemical properties of the fresh and the reused catalysts shows that covalent sulfates combined with the sufficient of surface defective sites are the basis of the structural stability. With higher sulfate concentration, the ionic sulfate species absorbed on the low-index plane induce the production of abundant Brönsted acid sites, which are responsible for the activity in the transesterification or esterification, while the loss of these active sulfate species during the reaction is the intrinsic reason for the catalyst deactivation. Furthermore, simulation calculations confirm that position of two H+ affects the configurations of SO42− and the most stable 3-fold coordinated configuration sulfates play a dominant role in the formation of stronger Brönsted acid sites.

Estimation of properties of mixed waste cooking oil for production of biodiesel

The major drawback of production of biodiesel in large scale is the cost of raw materials. Raw material source of biodiesel is mostly plant oil (Jatropha, Pongamia, Mahua, Neem, Cotton seed oil etc.) which requires large land area to grow. One of the best methods to reduce the production cost of biodiesel is to employ low quality feedstock, for instance waste cooking oil (WCO). This also solves the disposal problem of WCO. This is socioeconomic and environment friendly, it does not compete with edible oil resources. This study represents the biodiesel production from mixed waste cooking oil. Waste cooking oil collected from different hotels around Manipal, Udupi district of Karnataka State, and India. Collected WCO from various sources (from palm oil and sunflower oil users) have different physical and chemical properties. These WCO has mixed in different ratios ie. 50:50, 75:25 and 25:75 to reduce free fatty acid content of WCO without any chemical pre-treatment. Physio-chemical properties of mixed WCO has been carried out.

Simultaneous application of predictive model and least cost formulation can substantially benefit biorefineries outside Corn Belt in United States: A case study in Florida

Previously, a predictive model was developed to identify optimal blends of expensive high-quality and cheaper low-quality feedstocks for a given geographical location that can deliver high sugar yields. In this study, the optimal process conditions were tested for application at commercially-relevant higher biomass loadings. We observed lower sugar yields but 100% conversion to ethanol from a blend that contained only 20% high-quality feedstock. The impact of applying this predictive model simultaneously with least cost formulation model for a biorefinery location outside of the US Corn Belt in Lee County, Florida was investigated. A blend ratio of 0.30 EC, 0.45 SG, and 0.25 CS in Lee County was necessary to produce sugars at high yields and ethanol at a capacity of 50 MMGY. This work demonstrates utility in applying predictive model and LCF to reduce feedstock costs and supply chain risks while optimizing for product yields.

Comparative techno-economic analysis of single-step and two-step biodiesel production with supercritical methanol based on process simulation

Two alternative processes for biodiesel production from used/waste cooking oil, the single-step supercritical transesterification and the two-step process consisting of oil hydrolysis and subsequent supercritical methyl esterification, were designed and simulated using the Aspen Plus 8.8 software and assessed from a techno-economic point of view. Detailed operating conditions, material and energy flows, and equipment designs were provided for biodiesel plants with 15,000t and 30,000t annual inlet capacities. Results revealed that both technologies offer a techno-economically viable solution for biodiesel production from low quality feedstocks such as used cooking oil. The two-step process requires milder operating conditions, lower investment and overall production costs per unit of biodiesel produced, however, it has higher process energy requirements. Total capital investments for a 15,000t capacity plant which applies the single- or the two-step process were estimated as 6.1 million EUR or 5.8 million EUR, respectively, whereas the production cost of biodiesel are estimated as 0.824EUR/kg and 0.786EUR/kg for the single- and two-step processes, respectively (at used cooking oil price of 0.500EUR/kg). Higher plant capacities have lower production and capital costs per unit of biodiesel output. Supercritical transesterification should lead to a clean, flexible and modular method to process used cooking oil for the production of a more valuable product.

Biodiesel from low-quality feed stocks

Biodiesel from low-quality feed stocks

Biodiesel from low-quality feed stocks

Biodiesel from low-quality feed stocks

Biodiesel Production Potential from Littered Edible Oil Fraction Using Directly Synthesized S-TiO2/MCM-41 Catalyst in Esterification Process via Non-Catalytic Subcritical Hydrolysis

Due to uncontrolled consumption of fossil fuel it is necessary to use alternative resources as renewable energy. Among all the available liquid fuels biodiesel has drawn attention for producing less emissions and having less aromatic contents than diesel and because it can also be obtained from inferior grade feedstocks. Since the various uses of fats and oils have increased, a significant amount of waste animal fat and used edible oil is generated every year. In this work, we produced biodiesel from littered edible oil fraction (LEOF) via hydrolysis followed by catalytic esterification. Nearly 90% free fatty acids (FFA) content was achieved at 275 °C, after 45 min during hydrolysis and linoleic acid (C18:2) was observed to be the highest component. Compared to refined soybean oil (SBO) the reaction rate was accelerated by the auto-catalytic behavior of free fatty acids (FFA) in littered edible oil fraction (LEOF). For catalytic esterification, S-TiO2/MCM-41 catalyst was directly synthesized and characterized by using XRD, SEM, NH3-TPD and Brunauer Emmett Teller (B.E.T). The parameters such as; SO4−2 content, TiO2 loading and calcination temperature were varied to get optimum free fatty acids (FFA) conversion. Fatty acid methyl ester (FAME) conversion was 99.29% using 1% S-TiO2/MCM-41 catalyst at 240 °C whereas 86.18% was observed with 3.5% catalyst at 180 °C with 20 min. Thus, using S-TiO2/MCM-41 catalyst in esterification via hydrolysis would be a better option for treating low quality feedstocks.

Monitoring of a biodiesel production process via reset observer

This paper is concerned with the monitoring of a biodiesel production process, more specifically with the monitoring of the esterification of grease trap wastes, a low quality feedstock for biodiesel production typically characterized by its high content of Free Fatty Acids (FFAs). The esterification takes place in a jacketed Continuous Stirred Tank Reactor (CSTR). A reset observer is designed and applied in order to provide on-line estimation of the concentration of FFAs from temperature measurements within the CSTR. In addition, the proposed reset observer is compared to two other observers (classical fuzzy observer and extended Kalman filter). According to a multiple range test conducted for analyzing the estimation error, the monitoring task for the process under study has been better fulfilled by the reset observer which is able to update the estimation results every instant when the measurements were available.

OPTIMASI PROSES PEMBUATAN BIODIESEL DARI ASAM LEMAK SAWIT DISTILAT (ALSD) DAN DIMETHYL CARBONATE (DMC) MENGGUNAKAN KATALIS NOVOZYM®435

Biodiesel production has rapidly grown over the last decades, and it has attracted much attention in the market as fuel that promising substitute for petroleum diesel, because its physical and chemical properties and energy content are similar to those of petroleum diesel. The main problem in producing biodiesel is its high cost which could be reduced by use of less expensive feedstock. Therefore, in this work biodiesel is synthesized by enzymatic esterification from low quality feedstock which is unrefined and much cheaper than the refined oil, such as palm fatty acid distillate (PFAD) with dialkyl carbonate using immobilized lipase (Novozym®435). Enzymatic process has certain advantages over the chemical process, as it is less energy intensive, allowing the esterification of glycerides with high free fatty acid contents (PFAD, 85-95% FFA) and no enzymatic activity loss. Methanol replaced by dialkyl carbonate, especially DMC due to esterification (methanolysis) is close to equilibrium reaction whereas using DMC the intermediate compound immediately decomposes to carbon dioxide and an alcohol, which have been investigated. Moreover, DMC are cheap, eco-friendly chemical, non-toxic properties and widely available. Factors affecting the reaction such as DMC to PFAD molar ratio, reaction temperature, reaction time and catalyst concentration were systematically analyzed by response surface methodology (RSM) with central composite design (CCD). The optimal condition is using 6:1 molar ratio of DMC to PFAD at 60 oC, for a reaction time 3h in the presence 10wt% of catalyst (based on oil weight). The results showed that synthesis of biodiesel through enzymatic esterification using PFAD suitable for biodiesel production.

Solid-acid catalyzed biodiesel production, part I: biodiesel synthesis from low quality feedstock

A series of catalysts containing phosphotungstic acid (PTA) supported on periodic mesoporous silica were prepared and evaluated for the production of biodiesel from used cooking oil. The catalytic and physical properties of the prepared catalysts were investigated. Mesoporous catalyst, KIT-5 (Korea Institute of Technology 5) loaded with 26% PTA showed high activity for single step esterification, resulting in the successful elimination of a second transesterification step. The yield of fatty acid methyl esters was 93% from used (waste) cooking oil and ∼100% from pure palmitic acid. In addition, the solid acid catalyst retained a proportion of its original catalytic activity after repeated recycling steps. Thus, the prepared solid acid catalyst has the potential to be used for the production of biodiesel from feedstock that contain high amounts of free fatty acids.

Quality of Feedstock Produced from Sorted Forest Residues

Emerging biomass conversion technologies, such as small scale mobile biochar or pyrolysis/torrefaction machines, aim to use forest residues left after extracting merchantable timber from timber harvest or fuel reduction thinning operations. The residues generated from these operations typically produce low quality feedstock which may not be suitable for new biomass conversion technologies. In an effort to increase feedstock quality, our study separated sub-merchantable trees and tops from piled limbs during the timber harvest. A portion of the separated material was further processed to remove limbs to create five material types: processed and unprocessed, conifer and hardwood stem wood, and slash (stems, limbs and chunks). These materials were comminuted with a disc-chipper or a grinder. The quality of the feedstock produced was characterized by moisture content, particle-size distribution, bulk density, and ash content. Moisture content of sample collected ranged from 19 to 29%. The mean geometric lengths for unprocessed hardwood, unprocessed conifer, processed hardwood, processed conifer, and slash were 20.60, 18.27, 18.16, 17.41, and 47.47 mm, respectively. The bulk density of the five material types ranged from 137.20 – 322 kg/m 3 . The least amount of ash were observed in processed conifer samples (0.27%) and greatest in ground slash (1.5%). The results showed that a high quality feedstock can be produced by separating stem wood from other residues during a harvest.

Renewable fuels and lubricants from Lunaria annua L.

A non-edible fatty oil coming from Lunaria annua plant (honesty plant) was investigated as a starting material for the sequential production of biodiesel (fatty acid methyl esters—FAME) and biolubricants (trimethylolpropane esters). Lunaria oil constitutes an attractive feedstock because of its unusual fatty acid profile comprising mainly of erucic (22:1) and nervonic (24:1) acid. For the production of the desired biobased products, the following transesterification methodology was applied. At first, Lunaria oil was converted to the corresponding methyl esters via methanolysis reaction and the produced FAME was assessed as automotive fuel according to the specified requirements and test methods included in the European Standard EN14214. In order to synthesize the environmentally adapted lubricants, part of the previously prepared methylesters was converted to trimethylolpropane (TMP) esters via alkaline transesterification reaction. Lunaria TMP esters were evaluated as potential lubricant basestock regarding their physicochemical properties and their lubricating performance. Concerning fuel properties, Lunaria methyl esters appear to satisfy the majority of the EN14214 requirements with the exception of kinematic viscosity due to the high content of long chain fatty acids. However, the later could be counterbalanced though blending with other types of low quality feedstock. On the other hand, the high monounsaturated content is beneficial to other properties such as oxidation stability. The synthesized TMP esters demonstrate very good lubricating properties as well as oxidation stability, and thus, they could be utilized as lubricant basestock in the formulation of high added value biolubricants for special and environmentally sensitive applications. As a whole, Lunaria oil appears to be an interesting feedstock for the production of biodiesel and especially biobased lubricant basestock.

Highly efficient enzymatic biodiesel production promoted by particle-induced emulsification.

BackgroundAt present, the conversion of oils to biodiesel is predominantly carried out using chemical catalysts. However, the corresponding lipase-catalysed process has important advantages, which include mild reaction conditions and the possibility of using cheap, low quality feedstocks with a high free fatty acid content. Further increases in the efficiency of the enzymatic process are desired to make it even more attractive and suitable for large-scale applications.ResultsHerein, we present a simple and efficient two-phase lipase-catalysed system for the preparation of biodiesel in which different parameters (biocatalyst composition, ethanol concentration and the presence of additives) were optimised in order to obtain the maximum productivity starting from triolein with a high free oleic acid content. In the two-phase system, the enzyme tolerated high-ethanol concentrations, which made it possible to reach high conversions. The addition of silica particles increased the reaction rate substantially. It was suggested that such particles can catalyse acyl migration as a step to the full conversion to glycerol and biodiesel. However, in the system studied here, the effect of the particles was shown to be due to the formation of smaller and more uniform emulsion droplets leading to better mass transfer between the two phases. Particles of widely different size had positive effects, and the highest rate was obtained with silica particles derivatised with phenyl groups. The optimal conditions were applied to the solvent-free ethanolysis of rapeseed oil, and a yield of 96% was reached in 5 h. Under the mild conditions used, chemical catalysts were inefficient.ConclusionsTriacylglycerol oils with a high free fatty acid content can be efficiently converted to ethyl esters using Thermomyces lanuginosus lipase as the catalyst in an aqueous/organic two-phase system. Fast mass transfer can be achieved using silica particles, which helped to decrease the size of the emulsion droplets and thus led to a more efficient process. The high-ethanol concentration tolerated by the lipase in this system made it possible to reach almost quantitative yields.

ChemInform Abstract: Carbohydrate‐Derived Solid Acid Catalysts for Biodiesel Production from Low‐Cost Feedstocks: A Review

AbstractReview: 91 refs.

Catalyst free esterification of fatty acids with methanol under subcritical condition

This study provides an alternative way to produce biodiesel from low quality feedstock oil. Feedstock oil with high water and free fatty acid contents can be hydrolyzed into fatty acids using conventional methods or subcritical water processes. Fatty acids produced can be reacted with methanol to produce fatty acid methyl esters under conditions developed in this work, which is much milder than the supercritical methanol condition and without the use of catalyst. Using palmitic acid and oleic acid as the model free fatty acid, at 175–205 °C, 2.0–2.8 MPa and with a fatty acid:methanol:water ratio of 1:2:0.05 (w/w/w), a conversion of 96.5% can be achieved in 3–4 h. The method can be applied to feedstock with water content up to 15%.

Carbohydrate-derived Solid Acid Catalysts for Biodiesel Production from Low-Cost Feedstocks: A Review

Currently, most biodiesels are produced from virgin vegetable oils using a transesterification reaction. However, there are a number of other potential cheap sources for biodiesels, such as deep-frying oils/fats and palm fatty acid distillate (PFAD). PFAD is a lower-value by-product of the palm oil industry and is an economical source for biodiesel production. Due to the high cost of biodiesel production, the formulation of a new method to produce a cheaper biodiesel is imperative. Low-quality feedstocks (especially PFAD) using green and highly reusable catalysts have gained popularity due to their low production cost. High free fatty acids (HFFA) in the feedstock causes problems during the biodiesel production process, especially with the use of basic heterogeneous and homogenous catalysts. Recently, the effectiveness of a solid acid catalyst to catalyze biodiesel production from HFFA feedstock has caught the attention of researchers.This comprehensive article explores the use of low-quality feedstocks and carbon-based catalysts for the conversion of a waste refinery crude palm oil product which contains a high percentage of FFA. The production and characterization of carbohydrate-derived solid acid catalysts are discussed, including their physico-chemical property measurements. Techniques used for the synthesis of biodiesels are also included. In addition, transesterification process variables such as the oil/methanol molar ratio, catalyst concentration, reaction time, and temperature are investigated. The final part of the article contains the combustion, emissions, and performance of produced biodiesels. Finally, conclusions, including perspectives and future developments, are also presented. The aim of this article is to demonstrate the current state of the use of low-quality feedstocks and green heterogeneous solid acid catalysts for the use in biodiesel production.

Heterogeneous Solid Acid Catalysts for Esterification of Free Fatty Acids

Use of low-quality (and inexpensive) feedstock such as waste oils and animal fats for biodiesel synthesis has been continuously researched as a prospective means of improving the economic efficiency of the process. Pretreatment of free fatty acids by catalytic esterification is necessary for achieving this purpose. This paper reviews some relevant studies on heterogeneous acid catalysts that have been shown to be effective for this reaction.

Biodiesel production from soybean soapstock acid oil by hydrolysis in subcritical water followed by lipase-catalyzed esterification using a fermented solid in a packed-bed reactor

We investigated a new hydroesterification strategy for the production of biodiesel from low-value oil feedstocks: complete hydrolysis of the feedstock to fatty acids in subcritical water, followed by the use of a packed-bed reactor, containing a fermented solid with lipase activity, to convert the fatty acids to their ethyl esters. The fermented solids were produced by cultivating Burkholderia cepacia LTEB11 for 72h on a 1:1 mixture, by mass, of sugarcane bagasse and sunflower seed meal. The esterification of fatty acids obtained from soybean soapstock acid oil was studied in the packed-bed bioreactor, in a solvent-free system, with the best results being a 92% conversion in 31h, obtained at 50°C. When the packed-bed reactor was reused in successive 48-h esterification reactions, conversions of over 84% of the fatty acids to esters were maintained for five cycles at 50°C and for six cycles at 45°C. Unlike previous hydroesterification processes that have used lipase-catalyzed hydrolysis followed by chemically-catalyzed esterification, our process does not expose the lipases to contaminants present in low quality feedstocks such as soapstocks. This advantage opens the possibility of operating the packed-bed esterification reactor in continuous mode.

Liquid Hydrocarbon Fuels from Catalytic Cracking of Waste Cooking Oils Using Basic Mesoporous Molecular Sieves K2O/Ba-MCM-41 as Catalysts

Mesoporous molecular sieves K2O/Ba-MCM-41, which feature base sites, were prepared under hydrothermal conditions. The structure, base properties, and catalytic activity of the mesoporous molecular sieves as heterogeneous catalysts for the cracking of waste cooking oil (WCO) were then studied in detail. K2O/Ba-MCM-41 exhibited higher catalytic performance for the cracking of WCO than traditional base catalysts such as Na2CO3 and K2CO3. Moreover, the cracking of WCO generates fuels (main composition is C12∼C17 alkane or olefin) that have similar chemical compositions to diesel-based fuels, and K2O/Ba-MCM-41 is of excellent stability. The catalyst could be recycled and reused with negligible loss in activity for four cycles. K2O/Ba-MCM-41 is an environmentally benign heterogeneous basic catalyst for the production of liquid hydrocarbon fuels from low quality feed stocks.

Alternative Fuels Based on Biomass: An Investigation of Combustion Properties of Product Gases

Fuels from low quality feedstock such as biomass and biomass residues are currently discussed with respect to their potential to contribute to a more sustainable electrical power supply. In the present work, we report on the study of generic representative gas mixtures stemming from the gasification of different feedstock, from wood and algae. Two major combustion properties—burning velocities and ignition delay times—were measured for different parameters: (i) for two pressures—1 bar and 3 bar—at a constant preheat temperature T0 = 373 K, to determine burning velocities by applying the cone angle method; and (ii) for elevated pressures—up to 16 bar—in the temperature range between about 1000 and 2000 K, at fuel-equivalence ratios φ of 0.5 and 1.0, to obtain ignition delay times by applying the shock tube method. Additional studies performed in our group on gas mixtures of natural gas, methane, and hydrogen were also taken into account as major components of biogenic gas mixtures. It was found that the reaction behavior of the wood gasification product (N2, CO, H2, CO2, CH4) is mainly determined by its H2 content, besides CH4; methane determines the kinetic behavior of the algae fermentation product (CH4, CO2, N2) due to its relatively high amount. Detailed chemical kinetic reaction models were used to predict the measured data. The trends and main features were captured by predictions applying different reaction models. The agreement of the experiments and the predictions is dependent on the pressure range.