Radiation cracking

The minus sign of A /m reflects the way water expands on freezing. This expansion explains why a car radiator cracks in cold weather (if it contains no de-icer ) the water freezes and, in expanding, exerts a huge a pressure on the metal. 

Low-Temperature Radiation Cracking of Hydrocarbons (PetroBeam Process).367... 

The problem of paraffin oil radiation processing was resolved by application of low-temperature radiation cracking in PetroBeam technology where the optimal processing conditions take into account the structural state of the paraffin feedstock (Zaikin and Zaikina... 

LOW-TEMPERATURE RADIATION CRACKING OF HYDROCARBONS (PETROBEAM PROCESS)... 

The dose dependence of the light product yields in the PetroBeam process is similar to that observed for RTC. The maximal yield of stable light products is limited by the critical dose of electron irradiation when the rates of the competing reactions of radiation cracking and radiation-enhanced polymerization of hydrocarbons become comparable. The limiting dose becomes lower as the dose rate increases. However, increase in the dose rate allows greater production of light fractions at lower doses. 

FIGURE 15.16 Fractional contents of heavy crude oil after low-temperature radiation cracking at 120°C. fraction yield from RTC product Yp fraction yield from feedstock. 

Another type of highly viscous oil feedstock used in the experiments on low-temperature radiation cracking in flow conditions was low-grade high-paraflinic fuel oil with the pour point at room temperature. Together with a high concentration of heavy paraffins, this type of oil contained a considerable amount of pitches and asphaltenes. 

Figures 15.18 and 15.19 show that the rate of bitumen cracking in these processing conditions does not obey the law W (Py. They indicate to the maximum rate of radiation-induced bitumen decomposition at the dose rate of about 40 kGy/s. The observed dose rate dependence can be explained in frames of the model of heavy oil radiation cracking developed in the paper by Zaikin and Zaikina (2012).

To describe the specific features of reactions in the processes of radiation-thermal and cold radiation cracking in anomalously heavy oils and bitumen, it is necessary to take into account the following experimental facts (Zaikin and Zaikina 2008a) ... 

Figure 15.23 demonstrates considerable improvement in bitumen fractional contents after PetroBeam processing. The aforementioned examples show that PetroBeam process of low-temperature radiation cracking provides efficient upgrading of any type of high-viscous oil feedstock. 

Zaikin, Y.A. and Zaikina, R.F. 2010. Polymerization as a limiting factor for light product yields in radiation cracking of heavy oil and Bitumen. Radiat. Phys. Chem. In press. 

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