Please enable JavaScript.
Coggle requires JavaScript to display documents.
How can we optimize the testing and production of the best biodiesel?,…
How can we optimize the testing and production of the best biodiesel?
What is biodiesel?
Biodiesel is a fuel that can be used in place of or as a blend with conventional petroleum-based diesel. It is produced by chemically altering vegetable oils or animal fats. Biodiesel can be made from a variety of feedstocks, such as leftover cooking oils, oilseeds like canola and oil palm, and several other plants that produce oils. (Science.direct)
Transesterification is the process that is most frequently used to produce biodiesel. The long-chain fatty acids in triglycerides (vegetable oils and animal fats) are transformed into molecules with improved characteristics for use as fuels for transportation throughout this process. Three fatty acids are bound together by carbon-to-carbon bonds to form triglycerides, commonly known as fatty acids. These carbon-to-carbon bonds are broken during transesterification, which converts each molecule of triglyceride into three molecules of fatty ester that can be used to make biodiesel. (Science.direct)
Energy content values (measured in megajoules per kilogram, MJ/kg) for different biodiesels:
Palm Oil Biodiesel: ~37.27 MJ/kg
Animal Fat Biodiesel: ~37.10 MJ/kg
Rapeseed Oil Biodiesel: ~37.00 MJ/kg
Low emissions:
Soybean Oil Biodiesel: Known for lower particulate matter (PM), carbon monoxide (CO), and unburned hydrocarbons (HC). NOx emissions may be slightly higher than petroleum diesel.
Rapeseed (Canola) Oil Biodiesel: Lower NOx emissions compared to other vegetable oils, with good reductions in PM, CO, and HC.
Palm Oil Biodiesel: Can have higher NOx emissions, though it performs well in reducing PM, CO, and HC.
High cetane number:
Coconut Oil Biodiesel: Cetane number around 60-65 Palm
Oil Biodiesel: Cetane number around 60
Animal Fat Biodiesel (e.g., tallow or lard): Cetane number around 55-60
Cost effectivity:
Biogas from Agricultural Waste: Utilizes low-cost, readily available feedstocks. Often produced on-site, reducing transportation and processing costs.
Biodiesel from Waste Vegetable Oils: Uses waste materials, making feedstock costs very low. Benefits from being a sustainable recycling option.
Ethanol from Sugarcane: High yield per hectare and relatively low production costs, especially in regions like Brazil.
Availability of raw materials:
Corn Ethanol: Corn is one of the most widely grown crops globally, particularly in the United States.
Ethanol from Sugarcane: Sugarcane is abundantly available in tropical regions, especially in Brazil and parts of Asia.
Biodiesel from Soybean Oil: Soybeans are extensively cultivated, especially in the United States, Brazil, and Argentina.
Low Carbon footprint:
Biodiesel from Waste Vegetable Oils: Utilizes waste cooking oils, reducing the need for virgin feedstock production. Has a significantly lower carbon footprint compared to fossil diesel due to the recycling of waste products.
Biodiesel from Algae: Algae can be grown on non-arable land and does not compete with food crops. Absorbs CO2 during growth, which helps offset emissions from production and use.
Biodiesel from Animal Fats (e.g., tallow or lard): Uses waste by-products from the meat industry, minimizing additional environmental impact. Has a lower carbon footprint compared to plant-based biodiesels because it repurposes existing waste.
Renewable and Sustainable sources:
Biodiesel from Algae: Algae can be grown in a variety of environments, including non-arable land and wastewater. It does not compete with food crops and has a high yield per acre. Algae can also help in capturing CO2, making it a highly sustainable option.
Biodiesel from Waste Vegetable Oils: Utilizes waste cooking oils, reducing waste and recycling a by-product. Does not require additional land or resources for feedstock production. Helps in waste management and has a low environmental impact.
Biodiesel from Animal Fats: Uses by-products from the meat industry, repurposing waste materials. Reduces the need for disposal of animal fats and supports a circular economy. Has a relatively low environmental footprint due to the use of existing waste.
type of alcohol: denatured ethanol, ethanol, pure methanol
typed of oil used: palm oil, sunflower, soybean, rapeseed and castor oil using different types of catalysts1,4,5,9,10,11
Amount of KOH: standard amount (0.75g), or an increased amount
Reaction time: standard time (10 minutes), an extended amount of time
Dependent Variables
Viscosity Measurement: the measure of a substance's resistance to motion under an applied force.
Using a viscometer: an instrument that measure the fluid flow and viscosity of liquids.
Cetane Number Determination: (cetane rating) (CN) is an indicator of the combustion speed of diesel fuel and compression needed for ignition.
Fuels with lower cetane number have longer ignition delays, requiring more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels.
Energy content: Biodiesel has a lower energy content (124,000 BTU/gallon) compared to petrodiesel (136,000 BTU/gallon). Biodiesel has a slightly higher cetane number than petrodiesel, resulting in improved ignition properties
Calorific value measurement: is the amount of energy released in the form of heat during the combustion of a unit mass of fuel. It is also called heat of combustion.
Pour point and Cloud point: Oil pour point and cloud point reflect the properties of oil substances at different temperatures. Oil pour point mainly evaluates the low-temperature performance of oil products, while cloud point mainly evaluates the high-temperature stability of oil products.
Reasons and Justifications
Oil type: Impact on Combustion Properties
Viscosity: Different oils have varying viscosities, which can affect how the biodiesel atomizes during combustion. Lower viscosity biodiesel typically atomizes better, leading to more efficient combustion.
Energy Content: The type of oil used as a feedstock directly impacts the energy content of the resulting biodiesel. Oils with higher energy content, such as palm oil, produce biodiesel with better fuel efficiency.
Emissions Profile: The type of oil can influence the levels of emissions produced during combustion. For instance, biodiesel made from animal fats may result in lower particulate matter (PM) emissions but potentially higher nitrogen oxides (NOx) compared to vegetable oils.
Catalyst Amount: Completeness of Reaction
Cost Efficiency: Optimizing the catalyst amount is also important for cost efficiency. Using the minimum effective amount of catalyst can reduce production costs without compromising the quality of the biodiesel.
Environmental Considerations: The catalyst needs to be neutralized and removed from the biodiesel after production, so using the right amount minimizes waste and reduces the environmental impact of the production process.
Reaction Time: Effect on Yield and Quality
Yield Optimization: Sufficient reaction time is necessary to ensure that the transesterification process is complete and that the maximum possible yield of biodiesel is obtained. Insufficient reaction time can lead to unreacted triglycerides, reducing the overall yield.
Quality Control: Longer reaction times can sometimes improve the quality of the biodiesel by ensuring more complete conversion and reducing the presence of impurities. However, excessively long reaction times can lead to degradation of the product or increased side reactions, such as polymerization, which can negatively affect fuel quality.
Energy and Cost Efficiency: Reducing reaction time while still achieving a complete reaction can save energy and reduce production costs. This is especially important in large-scale biodiesel production, where energy costs can be significant.
Amount of KOH (0.75 g): The precise measurement of potassium hydroxide (KOH) ensures consistent catalysis during the transesterification process, directly influencing the yield and quality of the biodiesel.
Amount of alcohol (10 g): Maintaining a fixed quantity of alcohol (methanol or ethanol) is crucial for achieving a balanced reaction, ensuring that all triglycerides are fully converted into biodiesel.
Amount of oil (50 g): A consistent amount of oil is used to standardize the reaction, which is essential for comparing results across different trials and for ensuring reproducibility of the experiment.
Shaking duration (10 minutes): The duration of vigorous shaking is controlled to ensure thorough mixing of the reactants, which is necessary for a complete and efficient transesterification reaction.
Ambient temperature during the reaction: The temperature of the surrounding environment can fluctuate and is not easily controlled, potentially affecting the rate of reaction and the overall yield and quality of the biodiesel produced.
Purity of reactants: Variations in the purity of the reactants (e.g., impurities in the oil, alcohol, or catalyst) are difficult to control and can influence the efficiency of the reaction and the properties of the final biodiesel product.
What makes a good biodiesel?
Independant Variables
Controlled Variables
Uncontrolled variables