1.2.1 Refinery Processes
It is impertinent to overlook at the refinery chemistry before describing the refinery processes. The chemistry is part of the refinery’s conversion section, which gets affected when the upgrading is considered. The conversion section purpose is to enhance the liquid fuels. There are two types of techniques under the section:
a. Hydrogen addition technologies:
Processes using this technology react hydrogen with the oil heavy products to enhance the H/C such that the yield of the lighter products improved. It is a catalyst base process. It expected to yield more products, but it requires a large investment since it needs hydrogen. Also, it is a sensitive process since the feed’s impurities disturb the catalyst. Due …show more content…
In the atmospheric distillation, the separation bases at the boiling points for liquid components while the separation bases in vacuum distillation at very low pressure flashing points. The two units can accommodate different types of feedstocks (light and heavy oil) with operation adjusting, therefore, it’s the most flexible unit in a refinery. Due to its flexibility, both units can be considered as part of the future refinery. Moreover, a new path can be used, in the future, to handle the heavy oil by applying catalytic distillation or reactive distillation. The reactive distillation is a distillation column consisting of two sections: first section use distillation to separate the light components from crude and second section use chemical reactors to break the heavy components, this leads to energy saving from not heating more the second section (Fahim, Alsahhaf , & Elkilani , 2010). Also, another path is to use membranes for separation since it has low energy usage and low capital cost, but it is required to invent a new membrane with a high selectivity. For the upcoming 20 years the ADU/VDU will remind as the first fractionation stage for the crude utilization, and the expected improved will be in the heat recovery and distillation units (Speight, …show more content…
Most time, the feed is the bottom product of the vacuum column (Fahim, Alsahhaf , & Elkilani , 2010). There are three widely thermal cracking processes used in modern refinery:
• Mild cracking (visbreaking): the unit partially heat the vacuum residues. The main purpose of it is to reduce vacuum residues’s viscosity, and this step produced some light products.
• Delayed coking: the unit totally crack the vacuum residues to produce maximum lighter products.
• Flexi Coking: the unit crack the vacuum residues same as the Delayed coking, but it used steam to gasify most of the coke.
The main characteristics of the thermal cracking and different between three processes are in Figure 3. These processes are part of the future refinery since they take care of heavy product from ADU/VDU, and they are relative simple, cracking through heat. Also, the main use of it in refinery thermal cracking is to prepare the feed to the catalytic cracking. In the future, they will become more efficient where most of the changes will be done in the heater internals and introduce a catalysts in the heater (Speight, 2011). Figure 3: The main characteristics of the thermal cracking types (Speight,
It is impertinent to overlook at the refinery chemistry before describing the refinery processes. The chemistry is part of the refinery’s conversion section, which gets affected when the upgrading is considered. The conversion section purpose is to enhance the liquid fuels. There are two types of techniques under the section:
a. Hydrogen addition technologies:
Processes using this technology react hydrogen with the oil heavy products to enhance the H/C such that the yield of the lighter products improved. It is a catalyst base process. It expected to yield more products, but it requires a large investment since it needs hydrogen. Also, it is a sensitive process since the feed’s impurities disturb the catalyst. Due …show more content…
In the atmospheric distillation, the separation bases at the boiling points for liquid components while the separation bases in vacuum distillation at very low pressure flashing points. The two units can accommodate different types of feedstocks (light and heavy oil) with operation adjusting, therefore, it’s the most flexible unit in a refinery. Due to its flexibility, both units can be considered as part of the future refinery. Moreover, a new path can be used, in the future, to handle the heavy oil by applying catalytic distillation or reactive distillation. The reactive distillation is a distillation column consisting of two sections: first section use distillation to separate the light components from crude and second section use chemical reactors to break the heavy components, this leads to energy saving from not heating more the second section (Fahim, Alsahhaf , & Elkilani , 2010). Also, another path is to use membranes for separation since it has low energy usage and low capital cost, but it is required to invent a new membrane with a high selectivity. For the upcoming 20 years the ADU/VDU will remind as the first fractionation stage for the crude utilization, and the expected improved will be in the heat recovery and distillation units (Speight, …show more content…
Most time, the feed is the bottom product of the vacuum column (Fahim, Alsahhaf , & Elkilani , 2010). There are three widely thermal cracking processes used in modern refinery:
• Mild cracking (visbreaking): the unit partially heat the vacuum residues. The main purpose of it is to reduce vacuum residues’s viscosity, and this step produced some light products.
• Delayed coking: the unit totally crack the vacuum residues to produce maximum lighter products.
• Flexi Coking: the unit crack the vacuum residues same as the Delayed coking, but it used steam to gasify most of the coke.
The main characteristics of the thermal cracking and different between three processes are in Figure 3. These processes are part of the future refinery since they take care of heavy product from ADU/VDU, and they are relative simple, cracking through heat. Also, the main use of it in refinery thermal cracking is to prepare the feed to the catalytic cracking. In the future, they will become more efficient where most of the changes will be done in the heater internals and introduce a catalysts in the heater (Speight, 2011). Figure 3: The main characteristics of the thermal cracking types (Speight,