The overall goal of this laboratory method is to produce biofuels and biochemicals from co-processing of canola oil with fossil-based feeds. This method can help answer key questions in chemical engineering, really, into catalytic cracking of heavy oils, fuel chemistry, catalysis, and reaction mechanisms. The main advantage of this technique is that the method is fast and cost effective, enabling full control over the test parameters and the reduction of human error.
The implications of this technique extend towards catalyst development, as the equipment used is simple, reliable, and productive for testing new formulas. Although this study focus on product distribution and the quality, the main study can also be applied to other fields such as predictive modelling and simulations. I'm pleased to introduce my teammates.
Research Scientist, Nicole Heshka, Yi Zhang, and R&D program advisor Edward Little. They will demonstrate the procedure and/or discuss the method. To begin this procedure, disconnect the oil feed line below the purge valve of a laboratory test unit, or LTU, and attach a short temporary tube to the bottom of the valve.
Following this, preheat a previously prepared feedstock to 85 degrees celsius to enable the heavy gas oil, or HGO, blend to flow easily. Place a tared beaker at the discharge of the short temporary tube connected to the oil feed pump. Then start the preset pump cal user program in the reaction unit software.
After the pump cal program is complete, remove and weigh the beaker containing the feed. Divide the mass of the feed delivered into the beaker by the injection time. Next, adjust the pump speed using the three digit dial on the pump, and repeat the previous steps until the desired feed rate of 1.2 grams per minute is attained.
Then remove the short temporary tube and reconnect the feed line. Through the reaction unit software, switch the valve to the position that enables the zero gas to flow to the IR analyzer. Turn the knob in association with the flow control valve to get about 250 standard cubic centimeters per minute on the flow indicator.
Following this, zero the analyzer using the zero adjustment screw on the front panel with a flat-bladed screw driver. Switch the hand valve to supply the carbon dioxide standard gas to the analyzer. Then adjust the manual valve to obtain a flow of approximately 250 standard cubic centimeters per minute.
Adjust the analyzer reading to match the concentration of the standard span gas using the span screw on the front panel. Place a small plug of glass wool inside the top of each receiver outlet arm. Following this, place the receiver in a flask of suitable size to keep it upright.
Then weigh the receiver in an analytical balance covered by a cubic plastic shield to ensure a draft-free environment. Now install and connect the weighed receiver to the product line. Install an oil feed line in the reactor with a length that allows for 1.125 inch injector height.
Place a filter at the exit of the reactor to prevent any catalyst dust from entering the product line, changing the filter after 50 to 100 runs. It is critical to maintain consistency between runs. For example, always use an on size and coke-free equilibrium catalyst, oil feed line in the reactor with the same injector height, and constant molecular weight for the C5 plus unresolved gas lump.
After feed pump calibration and receiver installation, perform a pressure test on the reactor system by running the program PTEST1. Close the gas vent and pressurize the reactor system with 150 millimeters mercury of nitrogen followed by isolation of the system. Observe the pressure reading for a few minutes to ensure the pressure drop is no more than 0.4 millimeters of mercury per minute, indicating that no leaks are present.
On the LTU setup screen, input the relevant information for the experiment. Then place the system into run mode by clicking the Run button on the process flow screen. Observe as fresh catalyst from the specified hopper is discharged into the reactor.
At this point, monitor the reaction system to ensure it reaches the correct conditions previously specified in the software. When the reaction conditions are met, watch to see that the syringe pump delivers the oil feed into the reactor. Following feed injection, observe vapor products flowing through the liquid receivers into the water displacement system for gas collection.
Check to see that the high boiling products are condensing in the liquid receivers. At the end of the catalyst's stripping cycle, watch to ensure that the air flow begins and the reactor temperature is raised to approximately 715 degrees celsius. Monitor the IR analyzer which should show a sharp increase in carbon dioxide concentration followed by a decrease to below 0.3%At the end of the catalyst regeneration, ensure that the computer software records the mass of displaced water along with the pressure and temperature of the gas in the collection vessel.
After mixing and warming to approximately 30 degrees celsius, observe delivery of the gas to the GC for analysis. Observe the reactor cooling down to skin temperatures, 50 degrees celsius below the reaction set points. Save all the data for the run.
If it is the last run, discharge the spent catalyst to the waste vessel. Using the computer, attach to a gas chromatograph, or GC, integrate the peaks, and process the data using the calibration established. Input the final GC data into the LTU program through the LTU computer.
For good material balance, it is critical to accurately determine the mass of liquid product, including water if present. The following steps include the methodology to recover the liquid product, in a way the long liquid product receiver, in a draft-free environment. After removing the clamp from the liquid product receiver, tilt the receiver and collect any liquid product droplets on the beveled metal tip below the product valve.
Immediately seal the receiver with labeled rubber stoppers and carefully remove it from the ethylene glycol bath. Rinse off the ethylene glycol with cold water, and dry the receiver with a paper towel. Following this, place the liquid product receiver on a rack at room temperature for 20 minutes, allowing any frozen product to thaw and run down into a GC vial placed at the bottom of the receiver.
Collect the liquid holdup around the metal joint of the receiver with a teared cotton wool swab. Determine the mass of the liquid holdup. Open the liquid product receiver to atmosphere in a vented fume hood for pressure equalization by momentarily removing the stopper from the top outlet.
After replacing the stopper, obtain the receiver mass. Next, remove the GC vial with the sample from the condenser. Close and store the vial in a refrigerator at four degrees celsius for later analysis.
If a water droplet is observed in the bottom of the GC vial, use a clean syringe to transfer as much water-free oil product as possible to another vial and close it immediately. Rinse the inner walls of the receiver condenser thoroughly with a small quantity of methanol, and collect all of the methanol wash into the original GC vial containing the water droplet. Finally, close the vial and obtain the mass of the liquid for water analysis.
The yield and conversion data show qualitatively that upon cracking, canola oil in the HGO blend contributes substantially to the yields of biofuels and biochemicals. The presence of water and carbon monoxide plus carbon dioxide as cracked products from the blend but not from HGO alone, indicates that canola oil participates in reactions. The hydrogen and carbon monoxide yields are not very sensitive to catalyst to oil ratio changes for a feed at a given temperature.
However, for a feed at a given catalyst to oil ratio, both hydrogen and carbon monoxide yields increase with increasing temperature, which is the driving force for cracking. Comparing the two feeds, the blend gives higher carbon monoxide yields but lower hydrogen yields than the base oil. After injection of an oil, the reactor temperature drops, reaching a minimum and then rising towards the initial temperature of 530 degrees celsius.
As the catalyst to oil ratio increases, the temperature drop decreases since less oil is injected. Comparing the two feeds, the blend consistently exhibits a smaller drop of temperature due to heat release from the exothermic reaction. While attempting this procedure, it is important to carefully follow the instructions accompanying the laboratory test unit, and to maintain consistent operation between tests.
Demonstration of this procedure is useful because the steps for recovery of liquid product are critical to test quality but are difficult to describe in writing. Following this procedure, other feeds like light tight oil can be co-processed with heavy crudes in order to answer questions about their suitability for refinery operations. Don't forget that crude oil can be hazardous and should only be handled while wearing proper protective equipment.
Additionally, toxic hydrogen sulfide may be present in products and exhaust gas. They should only be handled under good ventilation. After watching this video, you should have a good understanding of how to operate a laboratory test unit for quality results and how to properly collect products for further analysis.
