Production of liquid biofuels from renewable resources

Progress and recent trends in biodiesel fuels

Mechanical and chemical recycling of solid plastic waste.

The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review

A zinc-based metal-organic framework (MOF) can be transformed reversibly from an open (a) to a dense (b) configuration. The microporous solid is the first example of a MOF that is highly selective in the gas-chromatographic separation of alkanes.

A Microporous Metal–Organic Framework for Gas-Chromatographic Separation of Alkanes†

Abstract A heterogeneous magnesium oxide catalyst is a good alternative for homogeneous catalysts for the transesterification of alkyl esters for the production of fine-chemicals as well as for the production of biodiesel. The transesterification of ethyl acetate with methanol was used as a model reaction to simulate fine-chemical production in a batch slurry reactor at industrial conditions. The transesterification of triolein with methanol to methyl oleate was chosen to simulate continuous production of biodiesel from rapeseed oil. A kinetic model based on a three-step ‘Eley–Rideal’ type of mechanism in the liquid phase was used in both process simulations. The transesterification reaction occurs between methanol adsorbed on a magnesium oxide free basic site and ethyl acetate or the glyceride from the liquid phase. Methanol adsorption is assumed to be rate-determining in both processes. Activity coefficients were required to account for the significant non-ideality of the reaction mixture in the simulations of both processes. The simulations indicate that a production of 500 tonnes methyl acetate per year can be reached at ambient temperature in a batch reactor of 10 m 3 containing 5 kg of MgO catalyst, and that a continuous production of 100,000 tonnes of biodiesel per year can be achieved at 323 K in a continuous stirred reactor of 25 m 3 containing 5700 kg of MgO catalyst. Although various assumptions and simplifications were made in these explorative simulations the assumptions concerning the reaction kinetics used, the results indicate that for both processes a heterogeneous magnesium oxide catalyst shows promising potential as a viable industrial scale alternative.

Heterogeneously MgO-catalyzed transesterification for fine-chemical and biodiesel industrial production

The adsorption equilibria of a series of n-alkanes and 2-methyl- and 3-methyl-branched alkanes in the C5−C9 range on ZSM-22 zeolite samples were determined using the tracer chromatographic technique at temperatures between 343 and 623 K. Adsorption experiments were performed with a calcined ZSM-22 sample referred to as “open” ZSM-22 and an as-synthesized ZSM-22 zeolite sample in which the 1,6-diaminohexane template was left inside the pores, denoted as “closed” ZSM-22. In the “open” ZSM-22, the zeolite micropores are available for adsorption. In the “closed” ZSM-22, adsorption can occur in the pore mouths and on the external surface. The closing of the channels of ZSM-22 results in a significant decrease in the Henry constant and adsorption enthalpy and entropy of linear alkane molecules. Contrarily, the adsorption enthalpy and entropy of branched alkanes on “open” and “closed” ZSM-22 are nearly identical, indicating that the preferred adsorption sites for monobranched alkanes are not located inside the p...

Tracer Chromatographic Study of Pore and Pore Mouth Adsorption of Linear and Monobranched Alkanes on ZSM-22 Zeolite

Low-coverage adsorption properties (Henry constants, adsorption enthalpy, and entropy) of linear and branched alkanes (C3−C8) on zeolite MCM-22 were determined using the chromatographic technique at temperatures between 420 and 540 K. It was found that adsorption enthalpy and entropy of linear alkanes vary in a nonmonotonic way with carbon number. The adsorption behavior of alkanes was rationalized on the basis of the pore geometry. Short molecules prefer to reside in the pockets of the MCM-22 supercage, where they maximize energetic interaction with the zeolite. Longer molecules reside in the larger central part of the supercage. For carbon numbers up to six, singly branched alkanes are selectively adsorbed over their linear counterparts. This preference originates from the entropic advantage of singly branched molecules inside MCM-22 supercages, where these species have high rotational freedom because of their small length.

n- and isoalkane adsorption mechanisms on zeolite MCM-22.

Experimental investigation of gas-solid rotating bed reactor in static geometry

A single-event microkinetic model for the catalytic hydroconversion of hydrocarbons on Pt/H−US-Y bifunctional zeolite catalysts developed for low-pressure vapor phase conditions was extended to cov...

Guy Marin

Papers

Heterogeneously MgO-catalyzed transesterification for fine-chemical and biodiesel industrial production

Tracer Chromatographic Study of Pore and Pore Mouth Adsorption of Linear and Monobranched Alkanes on ZSM-22 Zeolite

n- and isoalkane adsorption mechanisms on zeolite MCM-22.

Experimental investigation of gas-solid rotating bed reactor in static geometry

A unified single-event microkinetic model for alkane hydroconversion in different aggregation states on Pt/H-USY-zeolites.