Effect of agglomeration of triacylglycerols on the stabilization of a model cream

This study has been carried out on solidification of a model cream using palm oil as a sole fat source. It was found that the addition of 1‐palmitoylglycerol to palm oil promoted the solidification of the model cream while the addition of 1‐oleoylglycerol had no such effect. Solid fat content of palm oil in the cream with 1‐palmitoylglycerol was found to be lower than those of palm oil and palm oil with 1‐oleoylglycerol after cooling from 60 to 5 °C. Crystallization behaviors of bulk palm oil and mixture of 1, 3‐dipalmitoyl‐ 2‐oleoyl‐glycerol (POP) and 1‐palmitoyl‐2, 3‐dioleoyl‐glycerol (POO) were then studied in the presence of monoacylglycerols. Formation of granular crystals was observed for palm oil and POP/POO mixture in the presence of 1‐palmitoylglycerol. HPLC of the granular crystals revealed that agglomeration of higher melting point triacylglycerols (TAGs) around 1‐palmitolyglycerol took place, which promoted the formation of granular crystals. It was suggested that the agglomeration of higher melting point TAGs around 1‐palmitoylglycerol which was preferentially adsorbed at the oil‐water interface of oil droplets in the model cream led to destabilization of oil‐in‐water emulsion and the solidification of the model cream. At the same time, it was suggested that the fatty acid moiety of emulsifiers played an important role in the agglomeration of TAGs and stabilization of o/w emulsions.     

Crystallization Behavior of Molecular Compound in Binary Mixture System of 1,3‐Dioleoyl‐2‐Palmitoyl‐sn‐Glycerol and 1,3‐Dipalmitoyl‐2‐Oleoyl‐sn‐Glycerol

Previous studies showed that the stable β‐form of molecular compound (MC) crystals having a double‐chain‐length structure is formed in a binary mixture system of 1,3‐dioleoyl‐2‐palmitoyl‐sn‐glycerol (OPO) and 1,3‐dipalmitoyl‐2‐oleoyl‐sn‐glycerol (POP) with a 1:1 concentration ratio of OPO and POP. The use of MC crystals made of POP and OPO for edible applications, such as margarine, is advantageous due to no‐trans, low‐saturated, and high‐oleic fats. Industrial manufacturing technology involves rapid cooling processes, and the kinetic properties of crystallization of MC of OPO and POP are required. In this study, we clarified the crystallization of MC of OPO and POP under rapid cooling at rates of 1–150 °C min^?1, using synchrotron radiation time‐resolved X‐ray diffraction and differential scanning calorimetry methods. The main results are as follows: (1) POP and OPO crystallized in separate manners without the formation of MC crystals under rapid cooling (>40 °C min^?1), while MC crystals started to form with decreasing rates of cooling in addition to the POP and OPO crystals (<30 °C min^?1); (2) metastable and stable forms sub‐α, α, β′, and β of POP and OPO were formed, whereas the MC crystals of β were formed during the cooling processes; and (3) the heating processes after crystallization by rapid cooling caused separate melting of the metastable and stable forms of POP and OPO crystals and the formation of MC crystals of β made of POP and OPO, as well as melting of the MC crystals alone.     

Effect of Triacylglycerol Compositions and Physical Properties on the Granular Crystal Formation of Fat Blends

The effect of triacylglycerol (TAG) compositions and physical properties related to solid fat content (SFC) on the behavior of granular crystal formation was investigated. Four fat blends involving different 1,3-dipalmitoyl-2-oleoyl-sn-glycerol (POP) and 1-palmitoyl-2,3-dioleoyl-sn-glycerol (POO) compositions or SFC were prepared, and crystallization was investigated using polarizing microscopy, X-ray diffraction, SFC, whereas hardness was determined using a texture analyzer. Samples containing a higher saturated fatty-acid content from palm and higher SFC showed higher β-type crystals in the initial period, yielding a number of small-sized crystals, with no growth occurring afterward. Growth of the granular crystals as a function of time was observed in the samples, transforming from the β’- to β-type polymorph gradually. Large granular crystals at the initial stage were observed in the sample with a higher POO content and lowest SFC. These results suggested that POO promotes the rate of the crystals’ polymorphic transformation, resulting in the growth of granular crystals. In contrast, excess high-melting-point TAG content, such as tripalmitin and POP, retarded granular crystal growth regardless of the increased β’ to β transition rate. We concluded that the behavior of the growth of granular crystals is influenced by the combined effect of TAG composition and SFC.     

Influence of α′‐/α‐crystal polymorphism on properties of poly(l‐lactic acid)

Poly(l ‐lactic acid) (PLLA) is a biodegradable and biocompatible thermoplastic polyester produced from renewable sources, widely used for biomedical devices, in food packaging and in agriculture. It is a semicrystalline polymer, and as such its properties are strongly affected by the developed semicrystalline morphology. As a function of the crystallization temperature, PLLA can form different crystal modifications, namely α′‐crystals below about 120 °C and α‐crystals at higher temperatures. The α′ modification is therefore of special importance as it may be the preferred polymorph developing at processing‐relevant conditions. It is a metastable modification which typically transforms into the more stable α‐crystals on annealing at elevated temperature. The structure, kinetics of formation and thermodynamics of α′‐ and α‐crystals of PLLA are reviewed in this contribution, together with the effect of α′‐/α‐crystal polymorphism on the properties of PLLA. © 2018 Society of Chemical Industry     

On the formation of granular crystals in fat blends containing palm oil

The use of palm oil for plastic fats has encountered serious difficulty due to its crystallization properties, one of which is the formation of granular crystals. The granular crystals cause sandy teste and inhomogeneity of fat crystal morphology of end products. In the present study, we analyzed the formation process of these granular crystals. Chemical and physical analyses for triacylglycerol (TAG) compositions, polymorphism and melting points of the granular crystals led to the conclusion that the granular crystals are of the most stable polymorph, β₁, of POP (1,3-dipalmitoyl 2-oleoyl glycerol) with triple chainlength fat blend consisting of POP and reapeseed oil. The following characteristics of β₁ polymorph of POP contribute to the formation of granular crystals in fat blends containing palm oil: (i) β₁ reveals well-defined plate-like crystal morphology, which grows easily into the bulky granular from; (ii) the triple chainlength structure of POP has a tendency to segregate and does not from a solid solution together with other TAGs.     

Polymorphism and Mixing Phase Behavior in Ternary Mixture Systems of SOS–SSO–OSO: Formation of Molecular Compound Crystals

This paper reports the phase behavior of ternary mixtures of saturated and cis‐monounsaturated mixed‐acid triacylglycerols (TAG) of SOS (1,3‐distearoyl‐2‐oleoyl‐glycerol), SSO (1,2‐distearoyl‐3‐oleoyl‐rac‐glycerol), and OSO (1,3‐dioleoyl‐2‐stearoyl‐glycerol) examined with X‐ray diffractometry and a differential scanning calorimeter. The ternary mixtures were crystallized by cooling from melt (60 °C) to 5 °C, and the crystals were then stabilized by storing the mixture samples at 28 °C for 10 days. The following results were obtained. (1) Molecular compound (MC) crystals of stable β polymorph having a double‐chain‐length structure (β‐2) were formed in mixtures of SOS/SSO/OSO in which the concentration of SOS was 50% with varying concentrations of SSO/OSO. This is in contrast to the fact that the stable polymorphic forms of the component TAG are β‐3 for SOS and OSO and β′‐3 for SSO. (2) When the concentration of SOS deviated from 50%, immiscible mixtures of β‐2 MC made of SOS/SSO/OSO and the component TAG (β‐3 of SOS and OSO and β′‐3 of SSO) were formed. Therefore, ternary mixtures of SOS/(SSO + OSO) = 50/50 with different concentrations of SSO and OSO are miscible mixtures of β‐2 of SOS/SSO and SOS/OSO.     

Over‐expression of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in Klebsiella pneumoniae and their effects on conversion of glycerol into 1,3‐propanediol in resting cell system

BACKGROUND: Glycerol dehydrogenase [EC.1.1.1.6] and 1,3‐propanediol oxidoreductase [EC.1.1.1.202] were proved to be two of the key enzymes for glycerol conversion to 1,3‐propanediol in Klebsiella pneumoniae under anaerobic conditions. For insight into their significance on 1,3‐propanediol production under micro‐aerobic conditions, these two enzymes were over‐expressed in K. pneumoniae individually, and their effects on conversion of glycerol into 1,3‐propanediol in a resting cell system under micro‐aerobic conditions were investigated. RESULTS: In the resting cell system, over‐expression of 1,3‐propanediol oxidoreductase led to faster glycerol conversion and 1,3‐propanediol production. After a 12 h conversion process, it improved the yield of 1,3‐propanediol by 20.4% (222.1 mmol L⁻¹ versus 184.4 mmol L⁻¹) and enhanced the conversion ratio of glycerol into 1,3‐propanediol from 50.8% to 59.8% (mol mol⁻¹). Over‐expression of glycerol dehydrogenase in K. pneumoniae had no significant influence both on 1,3‐propanediol yield and on the conversion ratio of glycerol into 1,3‐propanediol in the resting cell system. CONCLUSION: The results were important for an understanding of the significance of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in 1,3‐proanediol production under micro‐aerobic conditions, and for developing better strategies to improve 1,3‐propanediol yield. Copyright © 2008 Society of Chemical Industry     

Solvent‐free synthesis of glycerol carbonate and glycidol from 3‐chloro‐1,2‐propanediol and potassium (hydrogen) carbonate

BACKGROUND: An indirect solvent‐free synthetic approach for obtaining glycerol carbonate and glycidol from glycerol and CO₂ through their more reactive and easily synthesizable derivatives 3‐chloro‐1,2‐propanediol (HAL) and potassium (hydrogen) carbonate has been studied. RESULTS: The reaction is fast with source of carbonation and temperature having a strong influence on the results. A yield of 80% glycerol carbonate together with a simultaneous substantial production of glycidol (0.56 mol mol^?1 glycerol carbonate) are obtained using K₂CO₃ as the carbonation source at 80 °C, a reaction time of 30 min and a 3:1 HAL/K₂CO₃ molar ratio. A lower yield of glycerol carbonate (60%) is obtained from KHCO₃ after 50 min with the other experimental conditions remaining unchanged. In this case, glycidol formation is zero or insignificant. Glycerol is also obtained in high yields, although in much lower amounts from KHCO₃ (～0.59 mol mol^?1 glycerol carbonate independent of operating conditions) than from K₂CO₃ (0.84–1.1 mol mol^?1 glycerol carbonate, depending on experimental conditions). CONCLUSIONS: The proposed synthetic strategy overcomes the currently difficult direct reaction between glycerol and CO₂, leading to the simultaneous synthesis of two valuable chemicals: glycerol carbonate and glycidol. However, glycerol is also obtained in substantial amounts thus decreasing the overall yield of the process. Thus, methods for preventing its formation must be developed for industrial feasibility. Copyright © 2010 Society of Chemical Industry     

An experimental and theoretical study of glycerol oxidation to 1,3‐dihydroxyacetone over bimetallic Pt‐Bi catalysts

It is important to utilize glycerol, the main by‐product of biodiesel, to manufacture value‐added chemicals such as 1,3‐dihydroxyacetone (DHA). In the present work, the performance of five different catalysts (Pt‐Bi/AC, Pt‐Bi/ZSM‐5, Pt/MCM‐41, Pt‐Bi/MCM‐41, and Pt/Bi‐doped‐MCM‐41) was investigated experimentally, where Pt‐Bi/MCM‐41 was found to exhibit the highest DHA yield. To better understand the experimental results and to obtain insight into the reaction mechanism, density functional theory (DFT) computations were conducted to provide energy barriers of elementary steps. Both experimental and calculated results show that for high DHA selectivity, Bi should be located in an adatom‐like configuration Pt, rather than inside Pt. A favorable pathway and catalytic cycle of DHA formation were proposed based on the DFT results. A cooperative effect, between Pt as the primary component and Bi as a promoter, was identified for DHA formation. Both experimental and theoretical considerations demonstrate that Pt‐Bi is efficient to convert glycerol to DHA selectively. © 2016 American Institute of Chemical Engineers AIChE J, 63: 705–715, 2017     

Continuous production of 1,2‐propanediol by the selective hydrogenolysis of solvent‐free glycerol under mild conditions

BACKGROUND: The conversion of glycerol to value‐added derivatives is now critical, owing to the large surplus of glycerol from biodiesel production. The main objective of this work is to develop a novel process for converting solvent‐free glycerol to 1,2‐propanediol. RESULTS: Several catalysts were screened for aqueous‐phase hydrogenolysis of glycerol in an autoclave. The most effective catalysts (Ni/Al₂O₃, Cu/ZnO/Al₂O₃) were further tested for vapor phase hydrogenolysis in a fixed‐bed. Ni/Al₂O₃ did not prove as effective for the production of 1,2‐propanediol because of the high selectivity to CH₄ and CO. Over Cu/ZnO/Al₂O₃, glycerol was mainly converted to the desired 1,2‐propanediol and the reaction intermediate acetol. The production of 1,2‐propanediol was favoured at higher hydrogen pressure. At 190 °C and 0.64 MPa, near complete conversion of glycerol was achieved with 1,2‐propanediol selectivity up to 92%. In addition, a higher concentration (between 43.4% and 0.8%) of acetol was detected and an approximately stoichiometric relationship was found between acetol and 1,2‐propanediol. CONCLUSION: 1,2‐propanediol can be produced with high yields via the vapor phase hydrogenolysis of glycerol over Cu/ZnO/Al₂O₃. Furthermore, the mechanism of 1,2‐propanediol formation is suggested to proceed mainly through an acetol route over Cu/ZnO/Al₂O₃. Copyright © 2008 Society of Chemical Industry     

Effect of crystallization temperature of palm oil on its crystallization. IV. The influence of tripalmitoylglycerol (PPP) on the crystallization of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-glycerol (POO)

Triacylglycerin in Palm Oil contains POP (1,3-dipalmitoyl-2-oleoyl-glycerol) at 30%, POO (1,2-dioleoyl-3-palmitoyl-glycerol) at 20% and PPP (tripalmitoylglycerol) at 5%. The crystallization temperature of PPP is high and the rates of crystal nuclear formation and growth are fast. It is thus considered that PPP may have some effect on the manner or mode of Palm Oil. Examination was thus made to clarify how PPP may affect the crystallization of POP and POO by differential scanning calorimetry (DSC) and X ray diffractometry (XRD) conducted on PPP/POP and PPP/POO mixtures. High and low temperature peaks were noted to appear on the DSC crystallization curve for either of these mixtures. The high temperature peak was considered possibly due to PPP, and the low temperature peak, to POP or POO. DSC isothermal analysis indicated the rate of crystal growth of either mixture to exceed that of pure of POP or POO. Crystal mixture structure was also seen to be complicated than either compound in pure form. The present findings thus clearly indicate that clarification should be made of the effects of high melting point triacylglycerin, such as PPP, on the crystallization of Palm Oil.     

The effect of raw glycerol concentration on the production of 1,3‐propanediol by Clostridium butyricum

Raw glycerol, the main by‐product of the bio‐diesel production process, was converted to 1,3‐propanediol by Clostridium butyricum F2b. In batch cultures, 47.1 g dm^?3 of 1,3‐propanediol were produced. Continuous cultures were conducted at a constant dilution rate (= 0.04 h^?1) and various inlet glycerol concentrations with 1,3‐propanediol produced at levels up to 44.0 g dm^?3. At increasing glycerol concentrations in the inlet medium, biomass yield decreased. This decrease was attributed to the microbial metabolism being directed towards the biosynthesis of organic acids (and hence carbon losses as CO₂) instead of biochemical anabolic reactions. An autonomous analytical model was developed, and quantified the effect of inlet glycerol concentration on the production of biomass and metabolites. Indeed, high inlet substrate concentrations positively affected the biosynthesis, principally of butyric acid and to a lesser extent that of acetic acid. In contrast, at increased glycerol concentrations, the relative increase of 1,3‐propanediol production per unit of substrate consumed was lower as compared with that of acetic and, mainly, butyric acid. This could be explained by the fact that the butyric acid pathway represents an alternative and competitive one to that of 1,3‐propanediol for re‐generation of NADH₂ equivalents in the microbial cell. Copyright © 2004 Society of Chemical Industry     

Application of a two‐stage temperature control strategy to enhance 1,3‐propanediol productivity by Clostridium butyricum

BACKGROUND: The purpose of the present work was to enhance 1,3‐propanediol productivity during the batch cultivation on a type of raw glycerol by application of a two‐stage temperature control strategy. RESULTS: First, the effect of the raw glycerol on microbial growth and 1,3‐propanediol production was investigated. The highest 1,3‐propanediol productivity, 1.93 g L^?1 h^?1, was achieved when the initial raw glycerol concentration was 6% (v/v). Second, the effect of temperature on microbial growth and 1,3‐propanediol production was investigated and kinetic analysis was carried out. The results indicated that 37 °C favored microbial growth while 35 °C was best for 1,3‐propanediol production. Finally, a two‐stage temperature control strategy was applied in 1,3‐propanediol production. The incubation temperature was kept at 37 °C from inoculation to 2 h and then switched to 35 °C. Compared with batch cultivations at 35 and 37 °C, the fermentation time was shortened from 10 to 9.2 h, resulting in an increase in 1,3‐propanediol productivity of around 11%. CONCLUSION: 1,3‐propanediol productivity was enhanced effectively by application of a two‐stage temperature control strategy. © 2012 Society of Chemical Industry     

Pre‐treatment and utilization of raw glycerol from sunflower oil biodiesel for growth and 1,3‐propanediol production by Clostridium butyricum

BACKGROUND: The objective of the present work is to report an efficient pre‐treatment process for sunflower oil biodiesel raw glycerol (SOB‐RG) and its fermentation to 1,3‐propanediol. RESULTS: The growth inhibition percentages of Clostridium butyricum DSM 5431 on grade A (pH 4.0) and grade B (pH 5.0) phosphoric acid‐treated SOB‐RG were similar to those of pure glycerol at 20 g glycerol L^?1; i.e., 18.5 ± 0.707% to 20.5 ± 0.7% inhibition. In grade A, growth inhibition was reduced from 85.25 ± 0.35% to 32 ± 1.4% (a 53.25% reduction) at 40 g glycerol L^?1 by washing grade A raw glycerol twice with n‐hexanol (grade A‐2). The kinetic parameters for product formation and substrate consumption in anaerobic batch cultures gave almost similar values at 20 g glycerol L^?1, while at 50 g glycerol L^?1 volumetric productivity (Q_p) and specific rate of 1,3‐propanediol formation (q_p) were improved from 1.13 to 1.85 g L^?1 h^?1 and 1.60 to 2.65 g g^?1 h^?1, respectively, by employing grade A‐2 raw glycerol, while the yields were similar (0.5–0.52 g g^?1). CONCLUSION: The results are important as the pre‐treatment of SOB‐RG is necessary to develop bioprocess technologies for conversion of SOB‐RG to 1,3‐propanediol. Copyright © 2008 Society of Chemical Industry     

Effects of glycerol and PE‐g‐MA on morphology,thermal and tensile properties of LDPE and rice starch blends

The effects of glycerol and polyethylene‐grafted maleic anhydride (PE‐g‐MA) on the morphology, thermal properties, and tensile properties of low‐density polyethylene (LDPE) and rice starch blends were studied by scanning electron microscopy (SEM), differential scanning calorimetry, and the Instron Universal Testing Machine, respectively. Blends of LDPE/rice starch, LDPE/rice starch/glycerol, and LDPE/rice starch/glycerol/PE‐g‐MA with different starch contents were prepared by using a laboratory scale twin‐screw extruder. The distribution of rice starch in LDPE matrix became homogenous after the addition of glycerol. The interfacial adhesion between rice starch and LDPE was improved by the addition of PE‐g‐MA as demonstrated by SEM. The crystallization temperatures of LDPE/rice starch/glycerol blends and LDPE/rice starch/glycerol/PE‐g‐MA blends were similar to that of pure LDPE but higher than that of LDPE/rice starch blends. Both the tensile strength and the elongation at break followed the order of rice starch/LDPE/glycerol/PE‐g‐MA blends > rice starch/LDPE/glycerol > LDPE/rice starch blends. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 344–350, 2004     

Friction‐induced electroactive β polymorph of poly(vinylidene fluoride)

Poly(vinylidene fluoride) (PVDF) has been widely used in electric devices due to electroactive β polymorph. In this article, we probe the formation of β phase under friction by spectroscopy and thermal analysis. During continuous friction, entire sliding of PVDF is identified with two regimes, i.e., running‐in and steady‐state. At initial running‐in period, friction surfaces are dominated by plastic strain, which leads to striking formation of β phase from α polymorph (α→β). Subsequently, melting‐flow domains almost cover friction surfaces at steady‐state. Thus, formation of β crystal is correspondingly induced by shear crystallization. Nevertheless, β‐crystal content at steady‐state is lower than that at running‐in. With sliding proceeding, moreover, β‐crystal content exhibits a gradually decreasing tendency, attributed to rising surface temperature. Besides, the friction‐induced β phase is further confirmed by evaluation of wear debris. Overall, friction plays a crucial role as to the formation of β phase. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46395.     

Biotransformation of glycerol into 1,3‐propanediol

Today, glycerol is mainly a by‐product of fat splitting and biodiesel production. Further growth of the biodiesel market would result in a fall in the price of glycerol. Particularly glycerol‐water from rapeseed oil methyl ester production, for example, would be an interesting raw material if it could be utilised in fermentation without further pretreatment. Under anaerobic conditions, bacteria can transform glycerol into 1,3‐propanediol (PDO), which can be used as a monomer in the chemical industry. PDO can be produced biotechnologically from glycerol with the aid of bacteria. Another way would be the utilization of glucose instead of glycerol, which would provide independence from the fluctuating glycerol market. However, under certain conditions, the classic technique based on glycerol can be quite interesting with regard to technical and economic aspects: A concerted, extensive search for new microorganisms (screening) and improved process design (fed‐batch with pH‐controlled substrate dosage) allowed the product concentrations, which were relatively low at a maximum of 70–80 g/L as a result of product inhibition, to be raised to more than 100 g/L. An additional advantage of the new technique and the newly isolated strains is the utilisation of low‐priced crude glycerol or glycerol‐water. This is a factor which should not be underestimated and has a direct effect on the product costs. Further on, the use of immobilised cells compared to freely suspended cells enables an increase of productivity from about 2 up to 30 g /Lh.     

负载型KI催化甘油与CO2合成甘油碳酸酯

添加不同组分对氧化铝载体进行调变改性,再以改性氧化铝为载体,负载KI制备了一系列负载型催化剂KI/Al₂O₃-MgO、KI/Al₂O₃-ZnO、KI/Al₂O₃-TiO₂和KI/Al₂O₃-ZrO₂,并通过CO₂、环氧丙烷和甘油合成甘油碳酸酯反应评价其催化活性,发现KI/Al₂O₃-MgO具有最高的活性。由不同载体的CO₂-TPD分析可以发现,载体表面少量碱性位的存在有利于反应进行。实验研究了不同负载量KI/Al₂O₃-MgO的活性及稳定性,发现KI负载量为1.5mmol/g较为适宜。同时,实验又通过N₂吸附/脱附(BET)、X射线衍射(XRD)等手段对不同负载量的KI/Al₂O₃-MgO进行了表征,进一步说明了负载量过多会导致KI晶粒团聚,并阻塞载体孔道。优化了反应条件,在最佳条件下(环氧丙烷0.3mol,甘油0.1mol,反应温度130℃,反应时间2h,反应压力6.0MPa),甘油的转化率为65.5%,甘油碳酸酯的产率为60.8%。     

CL‐20 Evaporative Crystallization under Reduced Pressure

The effect of parameters of the CL‐20 crystallization process carried out by solvent removal by evaporation in vacuo on shape, polymorph type, crystal size, and on their shock sensitivity was studied. The CL‐20 crystallization process by this technique was shown to allow a precise control of the crystallization process parameters and of the process run. The o‐xylene/ ethyl acetate system proved to be highly effective. Selecting suitable values of the parameters such as: pressure, process time, temperature, stirring rate, CL‐20 crystals were obtained in the ε form (even with no need for inoculation of the crystallization system with polymorph ε seeds) and of the shape close to a spherical one. The crystal growth modifiers added allowed to additionally control the shape and size of the CL‐20 crystals formed and to produce crystals of reduced impact and friction sensitivity.     

Kinetics of glycerol conversion to hydrocarbon fuels over Pd/H‐ZSM‐5 catalyst

The utilization of glycerol, primary byproduct of biodiesel production, is important to enhance process economics. In our recent prior work, it was shown that glycerol can be converted to hydrocarbon fuels over bifunctional catalysts, containing a noble metal supported on H‐ZSM‐5. Over Pd/H‐ZSM‐5 catalyst, an optimal ～60% yield of hydrocarbon fuels was obtained. In the present work, based on experimental data over Pd/H‐ZSM‐5 catalyst, a lumped reaction network and kinetic model are developed. Using differential kinetic experiments over the temperature range 300–450°C, the rate constants, reaction orders, and activation energies are obtained for each reaction step. The predicted values match well with experimental data for glycerol conversion up to ～90%. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5445–5451, 2017