Acrolein synthesis from glycerol in hot-compressed water (original) (raw)
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Reaction Yield of Acrolein Production Process Using Concentrated Glycerol and Supercritical Water
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 2013
Process feasibility experiments were carried out to form 1,3-propanediol precursor, acrolein, at 400°C and 35 MPa using supercritical water with sulfuric acid and a large concentration of glycerol. In the experiments, optimization methods for reaction time and sulfuric acid concentration deduced from a reaction model were examined as functions of initial glycerol concentration. The optimum reaction time at which the yield peaked was inversely proportional to the initial glycerol concentration. Optimum sulfuric acid concentration was estimated by maintaining a constant ratio of the squared proton concentration to the initial glycerol concentration when the acid concentration was optimized at a certain initial glycerol concentration. A yield larger than 70% was obtained at 15 wt% of the initial glycerol concentration by using the conditions predicted by the optimization methods.
Glycerol for renewable acrolein production by catalytic dehydration
The significant surge in biodiesel production by transesterification of edible or non-edible oils have caused surplus of glycerol in the market. With its characteristics, unique structure, renewability, and bioavailability, glycerol has tremendous potential to be transformed to higher value-added chemicals. This article provides a comprehensive and critical review of glycerol dehydration to acrolein in both petroleum-and bio-based processes. Acrolein has enormous industrial applications as a significant chemical intermediate for acrylic acid, DL-Methionine and superabsorbent polymer production. The current development of several precursors on suitable support such as heteropoly acids, zeolites, mixed metal oxides, and pyrophosphates in creating superior catalytic properties for both liquid-and gas-phase processes has been discussed. The acidity and textural properties of various catalysts, as significant variables affecting acrolein yield and selectivity, are evaluated separately. Techno-economical evaluation on dehydration of petroleum-and bio-based glycerol to acrolein proved that the bio-based processes are more feasible compared to the conventional petroleum-based process. In addition, various proposed mechanisms for catalytic dehydration of glycerol to acrolein have been examined. Particularly, catalyst coking and few crude glycerol applications have been identified as the main drawbacks for immediate industrialization and commercialization of glycerol dehydration to acrolein.
Production of acrolein from glycerol in liquid phase on heterogeneous catalysts
Chemical Engineering Journal, 2015
Glycerol, an abundant by-product of biodiesel production, is urgently considered to increase its usage. Triacetin produced from glycerol is an important material, used in polyester, cryogenics, cosmetics and as a biodiesel additive. Using homogeneous catalysts in triacetin production involves high product separation costs. The purpose of this study is to synthesize heterogeneous catalysts based on alumina and silica from peat clay for use in the production of triacetin from glycerol. The conversion of glycerol for triacetin production using such alumina and silica catalysts yielded levels of 82.7% and 87.4%, respectively. These values were greater than the conversion value of 71.2% using a sulfuric acid homogeneous catalyst. An optimum conversion of 91% was obtained at the mole ratio of glycerol to acetic acid of 8.9. The potential heterogeneous catalysts were confirmed by the results of SEM, XRD and BET characterization. Therefore, the production of triacetin using heterogeneous silica catalyst could be an alternative approach in commercial processes which currently using homogeneous catalysts.
Design and performance evaluation of a plant for glycerol conversion to acrolein
he development of biodiesel industry in th e recent past brought into discussion the va lorization of glycerol as the byproduct of this technology. Dehydration of glycerol leads to acrolein, mainly used as a raw material in the production of acrylic acid and its esters. Several research efforts dealing with the synthesis of acrolein from glycerol are reported in the literature. However, they are limited to catal yst testing on laboratory scale, no a ttention being paid to the process feasibility at an industrial scale. The goal of this paper is to fill this gap by presenting an integrated design study of the glycerol dehydration process. A simplified ki netic model was developed based on publis hed data, this one being able to predict with sufficient accuracy the rate of the main react ion and the formation of relevant by-produc ts (carbonyl compounds, hydrocarbons, carbon monoxide and coke). A reaction system was designed, similar to the reactor-regenerator unit usuall y used in hy...
2010
Sustainable development represents a global approach to the mentioned problems. "Sustainable development meets the needs of the present generations without compromising the ability of future generations to meet their own needs" [3] The sake of sustainability and the skyrocketing prices as well as anticipated scarcity of fossil resources have put pressure on many chemical companies to switch from fossil-derived feed stocks to (still often much cheaper) renewable ones. 100 kg of bio-diesel, 10 kg of glycerol is given out. [5] The oversupply of glycerol by means of oleo-chemistry did not only make the classical production of glycerol unnecessary, but also loaded extra costs on the bio-diesel producers in terms of storage. [6] The so produced glycerol is polluted with oils, salts and additionally it is diluted with water. But only pure glycerol is demanded by the food, pharma or tobacco industry, where it is used as starting materials or as additives. New processes are searched eagerly, where the usage of crude bio-diesel glycerol is possible. [6] Acrolein, on the other hand, is an important intermediate in the organic industrial chemistry. More than 80 % of refined acrolein is used for the production of methionin. Much larger quantities of crude acrolein are produced as an intermediate during the production of acrylic acid. 85 % of the acrylic acid is produced by the captive oxidation of acrolein. Acrylic acid is polymerized further to poly acrylic acid, which is the main component of superabsorbers. These materials are widely used in diapers, hygienic pads and paints. Acrolein is currently produced by the oxidation of
Catalytic Dehydration of Glycerine to Acrolein
Glycerine Production and Transformation - An Innovative Platform for Sustainable Biorefinery and Energy [Working Title]
The biodiesel production yields glycerine as a by-product in quantities around 10 vol% of produced biodiesel. Acrolein can be obtained from glycerine by a dehydration reaction. Catalytic processes in gas phase have been developed to obtain acrolein from a renewable feedstock using heterogeneous catalysts. The main process variables are the reaction temperature, the concentration of glycerol in water, and the space velocity in fixed-bed reactors. A thermodynamic study of the equilibrium has been made to estimate the conversion to equilibrium as a function of temperature. The reactors have been heated usually between 523 and 603 K. Generally, an aqueous glycerol solution is preheated in a preheating zone at a temperature enough to vaporize the feedstock, between 473 and 533 K, depending on the concentration of reactant required in the feed. Some of the most active catalysts in the gas-phase reaction (yield >70%) were NH 4-La-β zeolite, Pd/LaY zeolite, hierarchical ZSM
2 3 Vapour Phase Conversion of Glycerol to Acrolein over Supported Copper
This paper describes the investigations carried out on the vapor-phase conversion(dehydration) of glycerol to acrolein over copper catalysts in a packed bed flow reactor. The catalysts were prepared by deposition precipitation method using metal oxide and mixed metal oxide supports taking ceria as main constituent in all supports. Acrolein was produced unexpectedly as major product. Undesired by-product formation was reduced by, operating the reactor in vapor-phase mode at a specific temperature and thereby increased the overall yield of acrolein.
Vapour Phase Conversion of Glycerol to Acrolein over Supported Copper
Arabian Journal for …, 2013
This paper describes the investigations carried out on the vapor-phase conversion(dehydration) of glycerol to acrolein over copper catalysts in a packed bed flow reactor. The catalysts were prepared by deposition precipitation method using metal oxide and mixed metal oxide supports taking ceria as main constituent in all supports. Acrolein was produced unexpectedly as major product. Undesired by-product formation was reduced by, operating the reactor in vapor-phase mode at a specific temperature and thereby increased the overall yield of acrolein.
Industrial & Engineering Chemistry Research, 2013
22 23 Valorization of bioglycerol to industrially relevant products has been targeted worldwide 24 to make biodiesel production cost competitive. Among several bulk chemicals derived 25 from glycerol, synthesis of acrolein/acrylic acid is one route which is favoured for which 26 several catalysts and processes have been proposed in literature. The present work reports 27 gas phase dehydration of glycerol to acrolein by using several catalysts and supports. 28 Dodecatungstophosphoric acid supported (DTP) on hexagonal mesoporous silica (HMS) 29 showed promise. It was observed that HMS acted as better support for acrolein 30 selectivity as compared to K-10 clay, and octahedral molecular sieves (OMS). 20% w/w 31 DTP/HMS catalyst resulted in 94% of glycerol conversion and 80% of acrolein 32 selectivity at 225 0 C. However, it suffered with severe deactivation due to coke 33 deposition. Various techniques such as NH 3-TPD, BET-surface area, SEM image and 34 EDX analysis were used for catalyst deactivation study. Then a new robust catalyst, 35 MUICaT-5, was then synthesized by using deactivation data of 20% w/w DTP/HMS 36 catalyst. MUICaT-5 catalyst gave 86% of glycerol conversion and 60% of acrolein 37 selectivity. The stability and activity of the MUICaT-5 catalyst were evaluated by time on 38 stream (TOS) studies up to 100 h at 275 o C. After regeneration, reusability of MUICaT-5 39 catalyst was carried out up to six times, without affecting acrolein selectivity and glycerol 40 conversion. Catalyst reusability was also supported by characterization using NH 3-TPD, 41 BET-surface area measurements, SEM and EDX techniques. 42