Catalyst emissions from fluidising catalytic cracking units have the potential to impact significantly on the environmental compliance of oil refineries. Traditionally it has been assumed that gas velocity and fine particles significantly impact on emission levels. Through the use of a simple fluidised bed model, sensitivity analysis was conducted to identify the key operating parameters that i...

In this paper, a coordinated-distributed model predictive control (MPC) scheme is presented for large-scale discrete-time linear process systems. Coordinated-distributed MPC control aims at enhancing the performance of fully decentralized MPC controllers by achieving the plant-wide optimal operations. The ‘price-driven’ decomposition-coordination method is used to adjust the operations of the i...

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 r...

With its exceptional strength characteristics, diamond has some mechanical drawbacks, significant brittleness being among them. In particular, HPHT-grown diamonds crack when the extreme parameters inherent to growth process gradually decrease. The cracking is caused by excessive stress due poor plastic properties of catalytic medium at certain stages reducing pressure and temperature. An insula...

improvements in the properties of ordinary sidewall compound (nr/br) with the addition of epdm by reactive processing method were evaluated. the results show that ozone resistance of these sidewalls was improved with increased addition of epdm. also the tensile strength and elongation-at-break were increased in comparison with nrbrepdm compounds that were made by non-reactive processing. sem ph...

The aim of this study is to obtain a model that can simulate the performance of an industrial Fluidised Catalytic Cracking (FCC) unit in steady and dynamic state, and which will subsequently be used in studies of control and real time optimisation. In this paper, a dynamic model for a R2R type FCC unit is presented. The model includes the riser, the stripper/disengager, the regeneration system ...

This paper focuses on the synthesis of well-conditioned rnultivariable robust controllers for a broad class of multi-input multi-output two-time-scale nonlinear systems with time-varying uncertain variables, modeled within the framework of singular perturbations. The proposed controller stabilizes the fast dynamics, guarantees boundedness of trajectories, and ensures that the ultimate discrepan...

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...

Database cracking has been an area of active research in recent years. The core idea of database cracking is to create indexes adaptively and incrementally as a side-product of query processing. Several works have proposed different cracking techniques for different aspects including updates, tuple-reconstruction, convergence, concurrency-control, and robustness. However, there is a lack of any...

Understanding Fe deposition in fluid catalytic cracking (FCC) catalysis is critical for the mitigation of catalyst degradation. Here we employ soft X-ray ptychography to determine at the nanoscale the distribution and chemical state of Fe in an aged FCC catalyst particle. We show that both particle swelling due to colloidal Fe deposition and Fe penetration into the matrix as a result of precrac...