Tag: substances, objects and energy

Petroleum-derived diesel is composed of about 75% saturated hydrocarbons (primarily paraffin including n, iso, and cycloparaffins), and 25% aromatic hydrocarbons (including naphthalenes and alkylbenzenes). The average chemical formula for common diesel fuel is $C _{12}H _{24}$, ranging approximately from $C _{10}H _{20} ....... C _{15}H _{28}$.

Typically, emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle of the engine and testing methods used. Increases in NOx can be effectively eliminated with the use of normal mechanical remediation techniques (e.g. catalysts or timing changes). Research also documents the fact that the ozone forming potential of the hydrocarbon emissions of pure biodiesel is nearly 50% less than that of petroleum fuel. Pure biodiesel does not contain sulphur and therefore reduces sulphur dioxide exhaust from diesel engines to virtually zero.

Usually derived from vegetable oils - soy is very popular these days, but animal fats can also be used - biodiesel is made through a chemical process called transesterification which essentially splits the oil into two parts: alkyl esters and glycerine; the esters are the fuel, while the leftover glycerine is often the byproduct.

Biomass feedstocks are the plant and algal materials used to derive fuels like ethanol, butanol, biodiesel, and other hydrocarbon fuels. Examples of biomass feedstocks include corn starch, sugarcane juice, soyabean, crop residues such as corn stover and sugarcane bagasse, purpose-grown grass crops, and woody plants.

Biodiesel blend is a mixer of methyl or ethyl esters derived from a broad variety of renewable sources such as vegetable oil, animal fat and recycled cooking oil. These esters are oxygenated organic compounds that can be used in compression ignition engines. Blend of 20% to 80 % with petroleum diesel significantly reduces carcinogenic emissions and gases that contribute to global warming. It can be used as a 20% blend in most diesel equipment with no or only minor modifications. B20 is the most commonly used biodiesel blend in the United States because it provides a good balance between material compatibility, cold weather operability, performance, emission benefits and costs. 

Biodiesel is a renewable alternative fuel created from vegetable oils, animal fats and greases through a chemical process. The chemical process involves reaction of natural oils with an alcohol in the presence of a catalyst (usually sodium hydroxide [$NaOH$] or potassium hydroxide [$KOH$] and then refining the mixture to create molecules which can be easily burned in a diesel engine.

The following is/are true for hydrogen as the future fuel.
Efforts are being taken to reduce the cost of production of hydrogen.
Better and safer methods of transportation and storage of hydrogen are being worked out.
If these problems are solved, hydrogen will prove to be an ideal fuel not only for rockets but also for vehicles and domestic use.

Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.
Sewer gas is a generic name for the collection of gases and airborne agents
that often accompany sewage and the natural processes and reactions associated with sewage processing and the decomposition of organic materials.

Sewer gas is a complex mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.

The following are the advantages of using hydrogen as an automobile fuel.
The amount of energy released per unit weight of the fuel is very high.
The combustion hydrogen does not produce polluting emissions of CO, $CO _2$, oxides of nitrogen, and sulphur, aldehydes etc. Here, combustion product of hydrogen is water with few traces of nitrogen oxides. So no pollution is caused.
The technology required for use of hydrogen fuel is simple and cost effective.
The fuel cells using catalytic combustion of hydrogen have efficiency of 70-80 percent.