Conversion of vegetable oils and animal fats composed predominantly of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to collect and review literature on the thermo-chemical conversion of triglyceride based materials. The literature was divided and discussed as (1) direct thermal cra...

Brønsted acid sites in zeolites catalyze alkene hydrogenation with H2 via the same kinetically-relevant (C-H-H) + carboniumion-like transition states as those involved in monomolecular alkane dehydrogenation. Reactions between C3H6 and H2 selectively form C3H8 (>80% carbon basis) at high H2/C3H6 ratios (>2500) and temperatures (>700 K). Ratios of C3H8 dehydrogenation to C3H6 hydrogenation rate ...

Three Dimensional Simulation of Catalytic Cracking Reactions in an Industrial Scale Riser Using a 11-lump Kinetic Model Ariane C. Barbosa, Gabriela C. Lopes, Leonardo M. Rosa, Milton Mori* Waldir P. Martignoni School of Chemical Engineering, University of Campinas, 500 Albert Einstein Avenue,13083-970 Campinas-SP, Brazil Department of Chemical Engineering, University Federal of São Carlos, Wash...

In this paper we present recent and ongoing results of research on crystallization pressure and the reaction-driven cracking process that can result when hydration, carbonation, and/or oxidation reactions produce large changes in volume, viscosity is high (low temperature) and reaction rates are fast (large chemical potential, catalysts present, etc). Our focus is on natural processes involving...

Cashew nuts are very nutritious but so well defended by caustic chemicals that very few species eat them. We investigated how wild bearded capuchin monkeys (Sapajus libidinosus) living at Fazenda Boa Vista (FBV; Piauí, Brazil) process cashew nuts (Anacardium spp.) to avoid the caustic chemicals contained in the seed mesocarp. We recorded the behavior of 23 individuals toward fresh (N = 1282) an...

A new method to generate chemical reaction network is proposed. The particularity of the method is that network generation and mechanism reduction are performed simultaneously using sampling techniques. Our method is tested for hydrocarbon thermal cracking. Results and theoretical arguments demonstrate that our method scales in polynomial time while other deterministic network generators scale ...

Introduction Polysulfides play a critical role in the optimization of many chemical processes. Dimethyl disulfide (DMDS), for example, is used as coke inhibiting additive in steam cracking furnaces and can also be used as photolytic initiator during free radical polymerization.[1, 2] Also tetrasulfides are frequently used in chemistry, mostly as inhibitors during polymerization reactions. Despi...

This research thesis validates the potential of tall oil as a renewable feedstock for the production of base-chemicals, especially olefins, as conceived in the thermo-chemical bio-refinery concept. The focus was on the use of hydrotreating and steam cracking technologies with different tall oil feedstocks. Particular advances were accomplished in terms of technology development for high yield o...

Valuable chemical by-products can increase the economic viability of renewable transportation fuel facilities while increasing the sustainability of the chemical and associated industries. A study was performed to demonstrate that commercial quality chemical products could be produced using the non-catalytic cracking of crop oils. Using this decomposition technique generates a significant conce...

For many concretes and mortars, self-desiccation results in the creation of empty capillary porosity within the cement paste microstructure, accompanied by a decrease in achieved hydration, an increase in internal stresses, and an increased propensity for early age cracking. One solution to this problem for low water-to-cement ratio concretes where external curing is ineffective has been the de...