Hydrodeoxygenation of Guaiacol over Pd–Co and Pd–Fe Catalysts: Deactivation and Regeneration

In bio-oil upgrading, the activity and stability of the catalyst are of great importance for the catalytic hydrodeoxygenation (HDO) process. The vapor-phase HDO of guaiacol was investigated to clarify the activity, stability, and regeneration ability of Al-MCM-41 supported Pd, Co, and Fe catalysts in a fixed-bed reactor. The HDO experiment was conducted at 400 °C and 1 atm, while the regeneration of the catalyst was performed with an air flow at 500 °C for 240 min. TGA and XPS techniques were applied to study the coke deposit and metal oxide bond energy of the catalysts before and after HDO reaction. The Co and Pd–Co simultaneously catalyzed the CArO–CH3, CAr–OH, and multiple C–C hydrogenolyses, while the Fe and Pd–Fe principally catalyzed the CAr–OCH3 hydrogenolysis. The bimetallic Pd–Co and Pd–Fe showed a higher HDO yield and stability than monometallic Co and Fe, since the coke formation was reduced. The Pd–Fe catalyst presented a higher stability and regeneration ability than the Pd–Co catalyst, with consistent activity during three HDO cycles.

A comparative synthesis of ZSM-5 with ethanol or TPABr template: distinction of Brønsted/Lewis acidity ratio and its impact on n-hexane cracking

ZSM-5 by EtOH, possessing an ultra-high Brønsted/Lewis acidity ratio, has a long lifetime and suppresses coke deposit during n-hexane cracking.

Trace elements balance in a refinery

The trace elements balance is performed whenever the refinery processes a new type of oil. The goal of the balance is to find the distribution of the trace elements in the products and residues for the market. Also, the balance can warn about the accumulation of metals in the catalysts, this affecting their activity in time. This work presents the case study of a refinery processing a light and sulphurous oil with a medium concentration of trace elements. The study highlighted the following: the highest levels of concentration in feed and products are for Na and Si; in general, trace elements concentrate in heavier factions and residues and especially in the coke as a product or as deposited on calaysts; following the balance, heavy metals concentrate in the coke deposit on FCC catalyst in range of 53% for V to 83% for As; heavy metals concentrate in the gasoline hydrotreating catalyst in range of 7% for Ni to 87% for V.

In-Situ Continuous Coke Deposit Removal by Catalytic Steam Gasification for Fuel-Cooled Thermal Management

Fuel-cooled thermal management, including endothermic cracking and reforming of hydrocarbon fuels, is an enabling technology for advanced aero engines and offers potential for cycle improvements and pollutant emissions control. The principal engine operability issue that will affect this enabling hydrocarbon fuel cooling technology is coke formation and deposition. Furthermore, the extent to which the benefits of high heat sink cooling technology can be realized is directly related to our ability to suppress coke formation and deposition. The successful implementation of this enabling technology is, therefore, predicated on coke suppression. In situ continuous coke deposit removal by catalytic steam gasification is being developed and successfully demonstrated as a means for suppressing pyrolytic coke deposit in fuel-cooled thermal management systems for advanced aero engines. The objective of this research is to investigate the in situ continuous coke deposit removal by catalytic steam gasification for suppressing pyrolytic coke deposition using a single-tube reactor simulator under representative hypersonic operating conditions. A coke removal system removes coke deposit from the walls of a high temperature passage in which hydrocarbon fuel is present. The system includes a carbon-steam gasification catalyst and a water source. The carbon-steam gasification catalyst is applied to the walls of the high temperature passage. The water reacts with the coke deposit on the walls of the fuel passage side to remove the coke deposit from the walls by carbon-steam gasification in the presence of the carbon-steam gasification catalyst. Experimental data shows the in situ continuous coke deposit removal by catalytic steam gasification is able to reduce coke deposit rate by more than ten times.

In-Situ Continuous Coke Deposit Removal by Catalytic Steam Gasification for Fuel-Cooled Thermal Management

Fuel-cooled thermal management, including endothermic cracking and reforming of hydrocarbon fuels, is an enabling technology for advanced aero engines and offers potential for cycle improvements and pollutant emissions control. The principal engine operability issue that will affect this enabling hydrocarbon fuel cooling technology is coke formation. Furthermore, the extent to which the benefits of high heat sink cooling technology can be realized is directly related to our ability to suppress coke formation. The successful implementation of this enabling technology is, therefore, predicated on coke suppression. In-situ continuous coke deposit removal by catalytic steam gasification is being developed and successfully demonstrated as a means for suppressing pyrolytic coke deposit in fuel-cooled thermal management systems for advanced aero engines. The objective of this research is to investigate the in-situ continuous coke deposit removal by catalytic steam gasification for suppressing pyrolytic coke deposition using a single-tube reactor simulator under representative hypersonic operating conditions. A coke removal system removes coke deposit from the walls of a high temperature passage in which hydrocarbon fuel is present. The system includes a carbon-steam gasification catalyst and a water source. The carbon-steam gasification catalyst is applied to the walls of the high temperature passage. The water reacts with the coke deposit on the walls of the fuel passage side to remove the coke deposit from the walls by carbon-steam gasification in the presence of the carbon-steam gasification catalyst. Experimental data shows the in-situ continuous coke deposit removal by catalytic steam gasification is able to reduce coke deposit rate by more than 10 times.