APPLICATION OF SUSTAINABLE TECHNOLOGIES TO TRANSFORM GLYCEROL DERIVED FROM BIODIESEL INDUSTRY INTO ADDED-VALUE AND/OR ENERGETIC COMPOUNDS

COMELLI, RAÚL A.

Barcelona

Congreso; 10th World Congress of Chemical Engineering; 2017

World Chemical Engineering Council (WCEC), the European Federation of Chemical Engineering (EFCE) and the European Society of Biochemical Engineering Sciences (ESBES)

Biodiesel production generates glycerol as by-product, interesting its transformation into added-values compounds and/or energetic ones to improve the sustainability of the overall process and also to obtain sustainable products. In Argentina, in the influencing area of Rosario, a capacity of 2.5 million tons annual of biodiesel is installed, generating consequently 250,000 tons/year of glycerol. Since 2007, different catalytic routes were studied to valorize glycerol, also applying and integrating the concept of biorefinery, functional unit that converts biomass into added-value products and other ones capable to supply energy. In this context, catalytic processes were developed to transform glycerol into compounds with industrial applications, such as propyleneglycol (PG), 1,3-propanediol, dihydroxyacetone (DHA), lactic acid, and methanol, as well as compounds with energetic use such as hydrogen, synthesis gas, and ethers of glycerol. Possible integration of processes such as selective oxidation and reduction, steam reforming, and hydrogenolysis of glycerol allows show an environment of biorefinery. Selective oxidation to DHA occurred on Pt/K-FER, improving with Pt-Bi/K-FER, reaching 75.9% conversion and 93.9% selectivity to DHA. Selective reduction to PG in gas phase took place on Cu-containing catalysts, reaching the best performance Cu-Ce/Alumina, with 99.8% conversion and 83.2% selectivity to PG, being acetol (14.3%) which is the reaction intermediate. Steam reforming produced mainly hydrogen, carbon oxides, and methane, favoring the catalyst design and operating conditions either the production of hydrogen, an energy vector considered the future fuel, or synthesis gas, a mixture of hydrogen and carbon monoxide, which can be used for methanol and Fisher-Tropsch synthesis or as a fuel mixture in motors; catalysts of nickel supported on alumina, modified with Zr, Mg, Ce, and Co, were employed. Oxidation to lactic acid which demand is increasing, occurred on Cu/Alumina with Cu loadings between 6 and 40%w/w, at 240ºC and 1.4 MPa, improving performance by increasing Cu loading. Finally, hydrogenolysis of glycerol in gas phase to methanol, which is raw material for biodiesel production, allowing its fully sustainability showed promising results. Consequently, only feeding glycerol and integrating processes is possible to obtain DHA, PG, acetol, lactic acid, hydrogen, synthesis gas, carbon dioxide, methane, and methanol. Two catalysts, for selective oxidation to DHA and selective reduction to PG, were developed and patented. Actually, a pilot plant to scaling up to produce 100 tn of PG per year and another one to produce hydrogen by steam reforming are in construction, being glycerol the raw material for both plants.