The delayed coking anti-coke income increasing agent
The delayed coking anti-coke income increasing agent LT （ JZY） - Ⅲ
Delayed coking is the process that the residual oil is transformed into gas in the depth of the thermal cracking,light distillates and coke.It is the primary means of improving light oil yield and production of petroleum coke at the refinery.that this product is added into raw materials residuum can reduce the formation of coke and dry gas,increase the yield of liquid products,is the best solution to improve the delayed coking unit economic benefits.
1, LT (JZY) - Ⅲ,Quality indicators
Enterprise Standard Q/LTJ02-2006
2,LT (JZY) - Ⅲ,Features
a) Oil-soluble, can be miscible quickly with the raw oil;
b) Filling convenience, not affecting the normal production of the device;
c) Can reduce the generation of dry gas and coke, and increase the yield of light oil, prevent coke fouling;
d) High thermal stability, non-volatile and not decompose at a high temperature;
e) Non-flammable, explosive, non-corrosive, no side effects on subsequent steps.
3, LT (JZY) - Ⅲ,Scope of use
Suitable for delayed coking unit which has paraffin base group, the intermediate group, cycloalkyl RESIDUE as raw material. This product can reduce dry gas generation with inhibiting free radical chain reaction .And this product can prevent aromatics condensation, reduce coke formation, improve the thermal cracking reaction activity, improved selectivity of Delayed coking,which improve the yield of gasoline and diesel.
4, LT (JZY) - Ⅲ,Usage
a)This product is injected into the raw residual oil with the gear metering pumps.
b) Add an amount of 100-300ppm. Can increase liquid yield of 1-3%.
c) The adding location is that after Residuum leaving the fractionator bottom and before Residuum entering the furnace radiant section.
d) The process operating conditions of delayed coking unit should be appropriate adjusted with different nature of raw materials Residuum .
5,LT (JZY) - Ⅲ,Mechanism of action
(A) increase income mechanism
a) When the residuum conducted delayed coking, a series of Following complex parallel reaction networks will occur
When the product was added, the lively atom unpaired electron interact with free radical, which inhibit free radicalsβ-key breaking and Promote free radical homolytic reaction.So it can reduce the pyrolysis gas generation.
b)Destruction supramolecular structure of residuum
The residuum is a complex system of thousands of compounds. Especially for the higher boiling residuum,it is not generally simple solution system. It was said that the residuum is composed by the complex unit, and complex structural unit includes a supramolecule structural core and a solvent layer,so that they can not be vaporized during atmospheric and vacuum distillation. By adding the product ,the complex structural unit radius and the degree of association of residual values can be smallest. So that the lighter distillate gasification of the residuum can be released in the delay tar tower, to achieve the purpose of the increase in liquid yield.
c) Inhibit coke formation
Coke formation is the consolidation of thermal decomposition reaction and condensation reaction. The mechanism:
The product also works with peroxides (ROOH) reaction,So that the chain reaction was quenched,and reducing coke formation.
d) Hydrocarbon elements balance in delayed coking process
In residue pyrolysis conversion, there is the the overall material balance and the hydrocarbon elements balance on the yield and composition between raw materials and final products. Under normal circumstances, the residue pyrolysis material balance and hydrocarbon element balance, as Table 1.
Above table shows that, in the residue pyrolysis process in the product C/H ratio polarized. While C/H ratio is raising, the excess hydrogen is left to the low-C/H ratio constituent like the liquid or gas products. Considering the perspective of hydrocarbon elements balance,it is possible to increase liquid products (gasoline, diesel, gas oil) yield by reducing the high-C/H ratio coke and the low-C/H ratio gas generation .
(B)The mechanism of anti-fouling
a) the role of anti-fouling
The delayed coking Residue is easily formed fouling at high temperature, which makes furnace pipe, pipeline clogging. Filthes composed mainly by organic matter.In the organic Filthes, the toluene insolubles that reflect the content of coke precursors is very high .That means the organic Filthes are polymers or condensates. Triggered by trace oxygen dissolved in hydrocarbons in the residual oil, Polymer occurs to generate the polymers or condensates with oxidation chain reaction. Trace metal ions dissolved in residue can accelerate chain reaction. The resulting polymer may be adhered together,which deposited on the metal surface to form fouling. The other hand, in the transition metal catalysis, The resulting polymer occurs to dehydrogenative condensation reaction and generate coke,which viscous form on the device fouling. Chain reaction triggered by the radical chain reaction triggered by the dissolution of trace oxygen and transition metal ions, this
Products containing antioxidants and metal deactivators were able to inhibit the chain reaction caused by trace oxygen-induced chain reaction of free radicals and transition metal ions. Thereby Filthes generation is inhibited.
b), the high-temperature dispersion effect
This product has a high temperature dispersion effect。In the high temperature operating conditions,it is able to disperse or dissolve polymer in the liquid oil. So that it can not form a fouling on the surfaces of equipment. This product can wash down film and coke which is attracted to the device, and disperse them in oil, keep the metal surface clean .
