Lanthanum Oxide Obtention from Different Spent Fluid Catalytic Cracking Catalysts

An laboratory procedure has been developed to obtain lanthanum oxide from spent fluid catalytic cracking catalyst, commonly used in the cracking the heavy crude oil process. Two different spent fluid catalytic cracking catalysts, which are mainly formed by silica and alumina, and a certain amount of rare earths were leached under several conditions to recover the rare earth from the solids waste. Subsequently, liquid phases were subjected to a liquid-liquid extraction process, and lanthanum was quantitatively stripped using oxalic acid to obtain the corresponding lanthanum oxalates. After the corresponding thermal treatment, these solids were transformed into lanthanum oxide. Both, lanthanum oxalates and oxides solids have been characterized by wide techniques in order to investigate the purity of the phases.

A “Wastes-Treat-Wastes” Technology: Role and Potential of Spent Fluid Catalytic Cracking Catalysts Assisted Pyrolysis of Discarded Car Tires

Spent fluid catalytic cracking catalysts (FCC catalysts) produced by the petrochemical industry are considered to be environmentally hazardous waste, and precious metals and heavy metals deposited on the surface make them difficult to treat. Even so, these catalysts retain some of their activity. The pyrolysis of waste tires is considered to be one of the most effective ways to solve the fossil fuel resource crisis, and this study attempts to catalyze the pyrolysis of waste tires using spent catalysts to increase the value of both types of waste. FCC catalysts reduced the activation energy (E) of waste tire pyrolysis. When the catalyst dosage was 30 wt.%, the E of tread rubber decreased from 238.87 kJ/mol to 181.24 kJ/mol, which was a 19.94% reduction. The E of the inner liner decreased from 288.03 kJ/mol to 209.12 kJ/mol, a 27.4% reduction. The spent catalyst was more effective in reducing the E and solid yield of the inner liner made of synthetic rubber. It should be emphasized that an appropriate increase in the heating rate can fully exert the selectivity of the catalyst. The catalyst could also be effectively used twice, and the optimum ratio of catalyst/waste tires was about 1/4.5. Compared with specially prepared catalysts, it is more cost-effective to use such wastes as a catalyst for waste tire pyrolysis.

Effects of feed properties in spray drying formulation of prototype industrial cracking catalysts

This paper studied the effects of feed properties in spray drying formulation of prototype industrial cracking catalysts at the laboratory scale. The results showed that the pH of the drying feed mainly affected the active phase HY zeolite. At a high pH value, a strongly alkaline medium (pH 14), the HY zeolite structure was completely destroyed, resulting in the cracking catalyst with a low surface area. Hence, the pH of the drying feed should be adjusted to a low value, preferably a slightly acidic medium (pH 3). The solid content mainly affected the particle size of the cracking catalyst. As increasing the solid content in the drying feed, the particle size of the cracking catalysts increased and reached the maximum average value at about 40 μm which corresponded to the solid content of 15 wt.%. At a higher solid content (20 wt.%), the catalyst particle size and surface area tended to decrease. Thus, the solid content of 15 wt.% was considered to be optimal.

Comparative evaluation of various testing methods for FCC catalysts

The article discusses modern methods of stabilization and testing of the activity of cracking catalysts (FCC). Laboratory methods for evaluating cracking catalysts using fixed and fluidized bed reactors are compared, and their advantages and disadvantages are discussed. The correspondence of material balances of cracking was experimentally determined using various laboratory methods and a pilot plant with a riser reactor in comparison with data of industrial unit. Based on the analysis of the results obtained, recommendations are given for the most relevant testing of cracking catalysts.