Gas Properties and Renewable Fuels Quiz

Relative Density

• Relative density is the ratio of the density of a gas to the density of air.
• Gases with a relative density less than 0.8 are considered light, such as natural gas.
• Gases with a relative density between 0.8 and 1.2 are considered medium.
• Gases with a relative density greater than 1.2 are considered heavy, such as liquefied petroleum gas (LPG).

Wobbe Index

• The Wobbe index is a measure of the interchangeability of gases.

Flammability Limits

• Flammability limits define the range of concentrations of a combustible gas in a mixture that will allow for combustion.
• The lower flammable limit (LFL) is the leanest mixture that will still burn.
• The upper flammable limit (UFL) is the richest mixture that will still burn.

Renewable Fuels

• Renewable fuels are derived from biomass and are replenished on a yearly or shorter timescale.
• Synthetic fuels can be made from fossil or renewable sources.
• Renewable fuels come in various forms, including gaseous, liquid, and solid.
• Examples of renewable fuels include biogas, gasogen gas, alcohols, ethers, esters, wood, charcoal, and fuel pellets.

Comparison of Fossil Fuels and Renewable Fuels

• Renewable fuels are more widely distributed than fossil fuels.
• Renewable fuels have lower energy content than fossil fuels.
• Renewable fuels have a higher moisture and ash content.
• Renewable fuels require more extensive handling.
• Renewable fuels are more environmentally friendly than fossil fuels.

Biofuels

• Biofuels, biomass fuels, and renewable fuels are sometimes used interchangeably.
• Biofuels specifically refer to biomass derivatives that can replace fossil fuels.
• Biomass refers to unprocessed organic matter, like forest waste, crops, animal waste, and domestic waste.
• Renewable fuels include fuels like hydrogen obtained through electrolysis, even if not from biomass.

Disadvantages of Biofuels

• Most biomass fuels are solid.
• Pre-processing is often needed to convert biomass fuels into liquid fuels, which are more suitable for engines and stationary combustors.
• Biomass fuels have lower energy content than fossil fuels due to their high water and oxygen content.
• Biomass fuels contain non-fuel components that must be removed, such as soil and metals.
• Biomass fuels can contain contaminants.
• While biomass fuels do not contribute to global warming, they can produce more particulates and new chemical emissions if not properly treated.

Biofuels in The Philippines

• The Philippines was the first Southeast Asian country to implement biofuel legislation, embodied by the Biofuels Act of 2007.
• Sugarcane and molasses are used in Philippine ethanol production.
• Coconut oil (CNO) is the preferred biodiesel feedstock, from which coconut methyl ester (CME) is derived.
• The current blend mandates for biofuels in the Philippines are 10% for ethanol and 2% for biodiesel.

Definitions of Biofuel Types

• Bioethanol is ethanol produced from biomass, such as sugars, starch, or cellulose.
• Biodiesel refers to Fatty Acid Methyl Ester (FAME) derived from vegetable oils or animal fats.
• Bioethanol Fuel is bioethanol that is either hydrous or anhydrous and suitable for use as motor fuel.
• Biofuel encompasses bioethanol, biodiesel, and other fuels made from biomass.
• Biofuel blends are gasoline or diesel fuels mixed with biofuels.
• Biomass includes any organic matter, particularly cellulosic or lignocellulosic matter, with a recurring availability. Examples include trees, crops, plant fiber, animal waste, and biodegradable components of solid waste.

Biofuel Production Methods

• Ethanol is produced by fermenting sugars, starch, or cellulose using yeast or bacteria.
• Methane, often part of a biogas mixture, is produced through anaerobic digestion of biomass waste.
• Oils (biodiesel) are produced by reforming oleaginous plant seeds like colza, sunflower, or soya.

Test your knowledge on the properties of gases, including relative density, Wobbe index, and flammability limits. This quiz also covers renewable fuels and their characteristics. Challenge yourself to see how much you know about these critical concepts in gas science.