However, there are concerns that a high percentage of petcoke creates combustion problems such as fouling or clogging of the boiler convection passage due to its low volatility (Narula, 2002). This study also aimed at investigating the suitability of the said petcoke to be used as a water-dispersible solid fuel. Among the interesting parameters in the chemical analysis are the energy content of the samples, CHONS content, calorific value, moisture, volatile substances, solid carbon and ash content.
All findings will be recorded in the form of tables, charts and graphs to discuss the potential of PETRONAS Coke for use as a water dispersible fuel. Some of the work on this topic is available after studies are currently being conducted. Petroleum coke is a by-product of the coke drum in the refining process, upgrading fuel oil by heating and cracking it into higher quality gasoline, aircraft and diesel components.
Crude oil is the term for "unprocessed" oil, the stuff that comes out of the ground. Calcined coke is produced by heating green coke to temperatures up to 1200°C. The burnt petroleum coke is used to make anodes for the aluminium, steel and titanium smelting industries. Nitration occurs when one (or more) of the hydrogen atoms on the benzene ring is replaced by a nitro group, NO2. The experimental results reveal that introduction of the nitro group significantly improved the solubilization of hydrocarbons in aqueous organic solvents.
The role of the NO2 group is of utmost importance with regard to hydrocarbon solubility in aqueous organic solvents.
Test Parameters
- Moisture Content
- Volatile Matter
- Ash Content
- Elemental Composition
- Calorific Values of Petroleum Cokes
The measured weight loss of the sample, corrected for moisture, determines the amount of material (volatile matter) evolved from the kerosene under the test conditions. It can always be confused with mineral matter, which consists of unchanged inorganic minerals in petrolcoke (Given and Yarzab, 1978). Several formulas have been proposed to calculate the amount of mineral matter, originally in petroleum coke, using data from ashing techniques as a basis for the calculations.
Trace elements occurring in petcoke are often included as part of the ultimate analysis. Almost all of the carbon and hydrogen in petcoke occurs in combined form in the complex organic compounds that make up petcoke. Calorific value is a direct indication of the heat content (energy value) of petcoke and represents the combined heats of combustion of carbon, hydrogen, nitrogen and sulfur in the organic matter and of sulfur in pyrite and is gross calorific value with a correction applied if the calorific value is of interest.
For example, the gross calorific value may be used to calculate the total calorific value of the amount of coal or coke represented by the sample for payment purposes. It is also possible to accurately estimate the caloric value (CV) using the formulas (Selvig, 1945):
METHODOLOGY
METHODOLOGY
Analysis Considerations
- Sample History
The moisture value is used for the base conversion of the determined data to the dry base. Data on a dry, ash-free basis is calculated assuming the absence of moisture and mineral material in the sample. The data is determined on the basis of moisture and ash determination and is used for the conversion and determination of the moisture capacity, also known as equilibrium moisture.
Conversion factors for components other than hydrogen and oxygen are given in the table below. Petroleum cokes were collected in bulk and allowed to dry under the sun for a period of 3 days to provide a dry sample.
Nitration of PETRONAS Cokes at 50, 75 and 95 o C and Spectrophotometry
The mixture was cooled using a water bath with constant stirring until evolution of reddish-brown nitric acid gas ceased. The mixture is then cooled to room temperature while insisting under stirring and nitrogen flow (optional) overnight. The filtrate was also checked to see if the product was in solution by treating it with a concentrated HCl solution.
- Proximate Analysis
- Ultimate Analysis
- Calorific Test
- Bulk De
- RESULTS AND DISCUSSION
- Proximate Analysis
- Ultimate Analysis
- Calorific Values Test Using Bomb Calorimeter
All the characteristics of the dissolved or dispersed coke in the buffer solution are observed and analyzed. In order to differentiate and verify the solidification rate of petcoke to settle in pH 4 and pH 7 buffer solution, 3 nitrated cokes were reanalyzed. A rough analysis should be done to determine the percentage of moisture, volatile matter, fixed carbon and ash in the petrocoke.
Mass changes indicate moisture loss and phase changes that occur at set temperature indicate compound. Fuel with a moisture content above about 30% makes ignition more difficult and reduces the CV of the product gas due to the need to evaporate the additional moisture before combustion/gasification can occur (Mckendry, 2001). A high moisture content reduces the temperature reached in the oxidation zone, resulting in incomplete cracking of the hydrocarbons released from the pyrolysis zone.
The purpose of preparing fine dry flour is to analyze the chemical composition of petrocoke. This analysis will report the content (carbon, hydrogen, nitrogen and sulfur) of the coke samples. A set of 5 experiments would be conducted to obtain an average value for the composition of each carbon, hydrogen, nitrogen and sulfur in palm cokes.
High carbon content will highlight the possibility of petcoke becoming a fuel source for the gasification process. Low sulfur content will show palm coke's potential as an environmentally friendly renewable energy source, as sulfur would react with water, oxygen and oxidants to form acidic compound, which is found in acid rain. To determine the amount of energy stored in the petcoke samples, a calorific value test is performed using a LECO AC-350 bomb calorimeter.
Enclose the reaction in a strong chamber to control the high pressure of the rapidly burning sample. The test would be an evaluation parameter for the suitability or potential of the nitrated coke by comparing the value of the data obtained with the predetermined existing data of untreated coke. However, the detailed calculations are done only for the value of the first row of data and the rest (average calculations) are added in the appendices.
The HHV can be defined as the total energy content released when the fuel is burned in air, including the latent heat contained in the water vapor. This is due to the amount of carbon increase after the nitration increases the heat of combustion of the coke.
Run 2 Run 3 Run 4
High density fuels are advantageous because they represent a high energy-for-volume value.
Run 2 Run 3 Run 4
The bulk density of nitrated coke is higher compared to other existing biomass fuels such as wood chips (0.230 g/cm³) and straw (0.560 g/cm³). A high bulk density value for PETRONAS nitrated coke also indicates that the fuel will take up less space in a given refueling time.
CONCLUSION
Mohd Farhan Mat Hassan, Study of Water Dispersibility of PETRONAS Coke Nitreated at Various Temperature, UTP (2010).
APPENDICES
EMERGENCY BLOWING FROM COKE DRUM BLOWING DRUMS FROM COKING DRUMS EXTRA HEATING FROM COKING DRUMS EXTINGUISHING WATER TO COKE DRUM BLOWING WATER HEATER STEAM.
