Technical application of refinery catalysts

At present, the world refining catalyst market is mainly monopolized by companies such as CraceDavison, Albemarle and Engelhard. China has its own unique advanced technology and mature production system for the development and use of refining catalysts, and various types of refining catalysts have been formed in series, and the technology has gradually caught up with various foreign catalysts, and has independent and independent process-specific advantages. 

However, the gap with major foreign catalyst manufacturers is also reflected in the production scale and benefit price, such as China's catalytic cracking catalyst production is far behind foreign countries, the total annual output is less than the production capacity of 1 set of foreign devices, the price is nearly 10% higher than similar foreign products after import taxes, hydrogenation and reforming catalyst prices are nearly 30% higher.

Refining catalysts mainly include catalytic cracking catalysts, catalytic reforming catalysts, diesel and gasoline hydrotreating catalysts, residue hydrotreating catalysts, isomerization, alkylation and hydrocracking catalysts. The performance of the catalysts used must be adapted to the requirements of different processes and meet the requirements of feedstock quality, product distribution and environmental regulations. 

For example, among all methods to improve diesel yield, the key factor is the proper design and selection of catalyst systems used in hydroprocessing units, and catalyst innovation will greatly improve the middle distillate yield of hydroprocessing and hydrocracking units. Refinery catalyst development remains focused on processing light dense oils, improving light oil yields and residue conversions, and producing more chemicals. The global refining catalyst market demand is expected to reach USD 4.7 billion by 2020, growing at an annual rate of 3.6%. The renewal of refining catalysts has become the main direction of refining technology development

The catalytic process is an interdisciplinary science involving multiple fields, and researchers are exploring the use of new phenomena and effects of physical chemistry for the study and characterization of catalytic processes, striving to pinpoint their active structures and quantities and to develop them to the atomic-molecular level, so that catalysis can become a core science for regulating the rate and direction of chemical reactions. 

At the same time, during the production and use of catalysts, the uniform quality of different batches of catalyst products should be ensured, not only at the finished product stage, but also at the semi-finished products or intermediate steps should be exhaustively analyzed for their chemical components, and the impurity content of both the semi-finished products or the final stage should be kept within the limits required by the process and the product.

The raw materials for solid catalyst production are mainly various inorganic acids, bases, metal salts and carrier materials, mostly inorganic compounds. The analysis of raw materials, working solutions, semi-finished products and finished products is mainly inorganic analysis. 

According to the amount of the measured component content to choose the analysis method, according to the measured component content, usually can be divided into the analysis of constant components (greater than 1%), trace components (0.01% ~ 1%) and trace components (less than 0.01%). Weight analysis and titration analysis are commonly used in the determination of the macronutrient components, for the determination of trace components should choose a more sensitive method, such as photoelectric colorimetric method, spectrophotometric method, and plasma spectrometry.

In catalyst preparation, the phase composition of the carrier plays an important role in the structural properties and mechanical strength of the catalyst. For example, the active component is Ni(NO3)2, the co-catalyst is MgO, the carriers are Al2O3, CaAl2O, etc., and the preparation methods are precipitation, impregnation or mixed methods, etc. 

The phase composition analysis revealed that the Ni microcrystals in the Ni-Al2O3 system increased under the same treatment conditions, while those in the Ni-Al2O3-CaO system remained unchanged, indicating that the carrier phase composition had a large influence on the dispersion of the active component Ni and its stability. The determination of the catalyst or carrier phase composition is mainly performed by X-ray diffraction technique, and each crystalline substance has its own characteristic powder diffraction spectrum, which is compared with the standard diffraction spectrum to determine it.