Author
Kleber C. Mundim
Other affiliations: University of Perugia, Federal University of Bahia, Northwestern University
Bio: Kleber C. Mundim is an academic researcher from University of Brasília. The author has contributed to research in topics: Grain boundary & Ab initio. The author has an hindex of 23, co-authored 77 publications receiving 1940 citations. Previous affiliations of Kleber C. Mundim include University of Perugia & Federal University of Bahia.
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TL;DR: In this paper, the pyrolysis reactions of soybean, palm tree, and castor oils were studied, showing the formation of olefins, paraffins, carboxylic acids, and aldehydes.
333 citations
TL;DR: The tensor character of the first-order density matrix leads to the definition of an MO multicenter bond index for closed-shell systems as mentioned in this paper, which is applied to three-center bonds.
Abstract: The tensor character of the first-order density matrix leads to the definition of an MO multicenter bond index for closed-shell systems. It is here applied to three-center bonds. Satisfactory results are obtained for compounds involving “secondary” bonds, strong and normal hydrogen bonds; the index for the peptide bond is found to be similar to that of strong hydrogen bonds.
193 citations
TL;DR: In this paper, a deformation of the exponential function of an arrhenius plot is used to represent the effects of temperature on the rates of chemical and biophysical processes and on various transport phenomena.
137 citations
TL;DR: In this article, a generalized simulated annealing (GSA) algorithm was proposed for quantum chemistry and its utility in quantum chemistry was shown through the use of a semi-empirical quantum method.
Abstract: On statistical-mechanical grounds, a stochastic optimization technique (generalized simulated annealing) has been recently proposed which contains both classical simulated annealing (Kirkpatrick et al., 1983) and fast simulated annealing (Szu, 1986) as particular cases. This technique can be faster than both in detecting global (and also local) minima. Its utility in quantum chemistry is here illustrated, through the use of a semiempirical quantum method, on molecules of the series CH3-R (C2H6, CH3COH, CH3OH), H2X2 (H2O2, H2S2), X2Y4 (N2H4, P2H4, N2F4), for double bonds (C2H4 and CH2NH), and finally for H2O3. © 1996 John Wiley & Sons, Inc.
98 citations
87 citations
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TL;DR: Hydrogen Production by Water−Gas Shift Reaction 4056 4.1.
Abstract: 1.0. Introduction 4044 2.0. Biomass Chemistry and Growth Rates 4047 2.1. Lignocellulose and Starch-Based Plants 4047 2.2. Triglyceride-Producing Plants 4049 2.3. Algae 4050 2.4. Terpenes and Rubber-Producing Plants 4052 3.0. Biomass Gasification 4052 3.1. Gasification Chemistry 4052 3.2. Gasification Reactors 4054 3.3. Supercritical Gasification 4054 3.4. Solar Gasification 4055 3.5. Gas Conditioning 4055 4.0. Syn-Gas Utilization 4056 4.1. Hydrogen Production by Water−Gas Shift Reaction 4056
7,067 citations
TL;DR: Results show that the performance of the ABC is better than or similar to those of other population-based algorithms with the advantage of employing fewer control parameters.
2,835 citations
TL;DR: The most important variables affecting methyl ester yield during the transesterification reaction are the molar ratio of alcohol to vegetable oil and the reaction temperature as discussed by the authors, which is the commonly used alcohol in this process, due to its low cost.
1,798 citations
TL;DR: The chemistry, catalysts, and challenges involved in the production of biofuels are discussed, allowing us to rapidly transition to a more sustainable economy without large capital investments for new reaction equipment.
Abstract: As petroleum prices continue to increase, it is likely that biofuels will play an ever-increasing role in our energy future. The processing of biomass-derived feedstocks (including cellulosic, starch- and sugar-derived biomass, and vegetable fats) by catalytic cracking and hydrotreating is a promising alternative for the future to produce biofuels, and the existing infrastructure of petroleum refineries is well-suited for the production of biofuels, allowing us to rapidly transition to a more sustainable economy without large capital investments for new reaction equipment. This Review discusses the chemistry, catalysts, and challenges involved in the production of biofuels.
1,266 citations
TL;DR: In this paper, the authors reviewed 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.
Abstract: 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.
1,250 citations