Important PVC Auxiliary – Fischer-Tropsch Wax

Fischer Tropsch wax is a methylene polymer, which is an alkane synthesized from syngas or natural gas. Fischer-Tropsch waxes with high melting points (generally higher than 85°) are mainly composed of linear, saturated high-carbon alkanes with relative molecular masses of 500-1000, which endow the chemical with a fine crystal structure, high melting point, narrow Melting point range, low oil content, low penetration, low mobility, low melt viscosity, hardness, abrasion resistance and high stability.

⑴ molecular weight. The molecular weight of Fischer-Tropsch wax is much lower than that of PE wax, with less branch chains and high crystallinity.

(2) Fischer-Tropsch wax is a saturated straight-linked alkane, without double bonds, with strong anti-oxidation ability and good weather resistance.

(3) The viscosity of Fischer-Tropsch wax is much lower than that of PE wax. Only about 10. The same lubrication effect can be achieved with less dosage. The usage amount is only 70-80% of PE wax. Fischer-Tropsch wax has good compatibility with PVC, and can be used as internal and external lubricants. It can be used as a good internal lubricant to effectively control shear conditions, promote flow, control friction and melting properties, thereby improving thermal stability. At the same time, Fischer-Tropsch wax enables PVC products to obtain the best physical and processing properties due to its high crystallinity and high linearity structure. According to needs, the Fischer-Tropsch process can synthesize alkanes with different chain lengths to change the molecular weight of the final product to form serialized products.

The main application of Fischer-Tropsch wax in the plastics industry: Fischer-Tropsch wax can be used in plastic (pvc) processing, such as injection molding, extrusion and pelletizing industries. Fischer-Tropsch wax helps in the dispersion of fillers and excellent slip during compounding in the production of masterbatches and modified plastics. It can be used as an external lubricant for PVC. The low viscosity can improve the production speed of the product. It is helpful for the dispersion of pigments and fillers during mixing, especially in the extrusion of high-viscosity systems. 40-50% less, and can significantly improve the surface gloss of the product (the gloss can replace the carnauba wax). The melted Fischer-Tropsch wax can effectively wet the dye and reduce extrusion viscosity when using strong colors.

At present, there are more than 30 coal-to-liquid projects in China, the representative ones are China Shenhua Coal-to-Liquid Chemical Co., Ltd. million-ton direct coal liquefaction project, Shenhua Ning Coal’s first domestic coal indirect liquefaction demonstration project, and Inner Mongolia Yitai Co., Ltd. Coal-to-Liquid Co., Ltd. Coal Indirect Liquefaction Project. Others include Shenhua Ning Coal 4 million ton indirect liquefaction project, Yitai Yili 5.4 million ton coal-to-liquid project, Lu’an 1.8 million ton coal-to-liquid project, Yankuang Yulin 1 million ton coal-to-liquid project, Yufu Energy Guizhou 6 million tons of coal-to-liquid project, Jingneng Xilin Gol League 5 million tons of coal-to-liquid project, Inner Mongolia Yuanji Chemical Industry with an annual output of 100,000 tons of Fischer-Tropsch wax refining and 20,000 tons of slag wax refining projects.

At present, there are two foreign companies with relatively good industrialized Fischer-Tropsch wax synthesis devices, namely Sasol Company of South Africa and Royal Dutch Shell Group (Shell). The two companies have built different types of synthesis devices using their own chemical synthesis processes. By the end of 2015, Sasol’s supply of high-melting Fischer-Tropsch synthetic wax was about 70,000 tons per year, and Shell’s supply of high-melting Fischer-Tropsch synthetic wax was about 50,000 tons per year. Evonik is one of the world’s major Fischer-Tropsch wax suppliers. It does not have a Fischer-Tropsch wax synthesis device. It mainly modifies imported high-melting Fischer-Tropsch synthetic crude wax. It has developed VESTOWAX products. Including series of hard alkanes, oxidized and partially saponified waxes.

Domestic production status: my country’s coal-based indirect and direct liquefaction synthetic coal-based Fischer-Tropsch wax technology with independent intellectual property rights was successfully developed by Zhongke Synthetic Oil Technology Company, and three sets of demonstration plants were built, namely Yitai, Lu’an and Shenhua Group Synthesis Oil demonstration device. The construction of the three sets of plants started in 2006, and all of them have been put into commercial operation at present, but these three sets of plants are mainly used to produce diesel oil and naphtha. Among them, Shanxi Lu’an Coal-Based Synthetic Oil Co., Ltd. produced high-melting Fischer-Tropsch wax that meets the South African Sasol standard through process improvement in May 2014, filling the technical gap in this field in China; at the same time, Inner Mongolia Yitai built a new 1.2 million tons of wax. The new unit is already in trial operation. However, the few high-end high-melting Fischer-Tropsch waxes used in China mainly rely on imports. Imported grades mainly include Shell’s SX-100, SX-105, Sasol Wax’s A-series, H-series and EnHance series, and VESTOWAX’s EH – and S-series, C-series and J-series.