All Questions
Tagged with fuel combustion
56 questions
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Testing Combustion Kinetic Mechanisms
The chemical modeling of combustion depends on kinetic mechanisms, that is, intricate networks of chemical reactions that describe the transformation of reactants into products. For a mechanism of $...
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2
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552
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How do I calculate the fuel consumption inside a cylinder-piston stoichiometrically?
Consider I have car 4-cylinders with total cylinder capacity is 1,496cc. Per piston, the cylinder is 374cc. The piston diameter is 72.5mm, height=90.6mm, and compression ratio is 11.5:1. Hence we may ...
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2
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Why is coal and charcoal a good fuel, but not graphite?
Correct me if I'm wrong, but coal(after coking) and charcoal are essentially hard dry lumps of pure carbon.
But of course so is graphite. I understand of course the structure is different lending them ...
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2
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999
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Flash point of naptha and propanol
I filled a Zippo lighter with 2-propanol and it lit up easily when the ambient temperature was around 6-7 degrees Celsius.
It was impossible to light it up when the temperature was around 3-4 degrees ...
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1
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Are solid fuels with calorific values >= 10,000 kcal/kg (42 MJ/kg) physically possible?
I have seen laboratory documentation from a reputable lab in southeast Asia that a company has achieved a solid fuel product made from landfill material with a high heating calorific value ($CV$) of ...
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1
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366
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What chemicals can remove or greatly reduce the smell of burning diesel fuel?
I am not a chemist myself but I am trying to solve a practical problem I am experiencing.
I have a nicely working diesel stove but it produces some smell.
I've read that adding urea to the exhaust may ...
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2
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1k
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Is a hydrocarbon necessary for combustion? [closed]
Oxygen, heat and fuel are essential for combustion. What counts as a fuel? Is a hydrocarbon essential for combustion? Is combustion, say, of magnesium really combustion? And what's the difference ...
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1
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Which is more efficient way to generate energy using hydrogen: direct hydrogen combustion or through fuel cell? [closed]
Which is more efficient way to generate energy using hydrogen: direct hydrogen combustion or through fuel cell? Please explain so that even a primary school student can understand.
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215
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Can oxidizing agents be used to increase the combustion efficiency of waste oil?
Waste oil is atomized and combined with air to produce a very high temperature flame capable of melting iron. I was wondering if it's possible to further increase its combustion efficiency by mixing ...
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1
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880
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Does all fire only emit light on its outermost shell?
This question is about light emission, which may overlap with physics, but I am most interested in combustion and types of flame (incandescence, petrochemical fuel flames, nuclear reactions).
Consider ...
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What is the explanation of negative temperature coefficient in ignition delay of a fuel?
When studying the ignition delay of a fuel, some fuel have a negative temperature coefficient area (NTC) where an increase of initial temperature of the mixture air/fuel produces an increase of the ...
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Is incineration of a solid fuel complete or incomplete?
If I have some solid material like biomass and incinerate it at 1000 Celsius degrees for 15 minutes in an oxidized atmosphere within an incineration oven. As an output it gives me ash. Is the ...
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Why doesn't NASA or SpaceX use ozone as an oxidizer for rocket fuels?
Presumably, it would be expensive to use ozone ($\ce{O3}$) as an oxidizer instead of $\ce{O2}$, but would the extra oomph be worth it? Does $\ce{O2}$ provide as much thrust/energy/heat as can be ...
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Combustion of methane and ethane
I'm having trouble with the following problem:
A gas fuel of Methane ($\ce{CH4}$) and Ethane ($\ce{C2H6}$) is burned
with atmospheric air, and the volumetric analysis of the products of
combustion ...
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1
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How or Why does diesel/kerosene have a much higher 'flash point' but lower auto/self-ignition point than gasoline/petrol?
This is a very common question, but I have yet to find a good theoretical answer to both questions (diesel has higher flash point BUT lower spontaneous ignition temp.)
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How to get the right formulas for combustion (rocket chamber) or where to find them? [closed]
I am a space enthusiast and am intrigued mostly by rockets.
I recently found a book HOW to DESIGN, BUILD and TEST SMALL LIQUID-FUEL ROCKET ENGINES and have been fiddling around with rocket engine ...
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How is octane rating defined for negative values and those over 100?
Based on my reading, the octane rating for a given fuel is calculated by finding the compression ratio at which it knocks and finding a mixture of $X\%$ isooctane and $(100 - X)\%$ n-heptane which ...
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2
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Why does Sodium Bicarb. Reduce Combustion Rate? [closed]
In many common solid-propellant model rocket engines, Sodium Bicarbonate, $\ce{NaHCO3}$, is used to predictably regulate/limit the rate of combustion of the fuel. My questions are as follows:
What is ...
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1
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5k
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Rocket Candy Fuel - Common Alternatives to KNO3?
I'm sort of a model rocket enthusiast, but the most common fuel for model rockets, Rocket Candy, requires Potassium Nitrate as an oxidizer to oxidize Powdered Sugar. Potassium Nitrate is not ...
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Is it possible to have a negative overall activation energy for a whole reaction mechanism?
I am trying to find out correlation for ignition delay for alkane fuels. The activation energy part of the correlation gives me a negative value.
For the ignition delay formulation, is it possible to ...
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Equation of combustion of heavy fuel oil (HFO)
We are researching the use of heavy fuel oil (HFO) on ship vessels, but are having trouble finding the equation of the chemical combustion process of HFO. I understand that it contains long chains of ...
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345
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Using an oxidizing agent to improve combustion of a fuel [closed]
If I were to add an oxidizing agent like dilute Potassium permanganate (aq) to a potential fuel such as plastics (polystyrene etc), would the combustion of this fuel be more complete ie: less sooty ...
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What Is The Heat Of Combustion Of Diesel And How Do I Find It? [closed]
I need help in finding the heat of combustion of diesel, no where online can i find it, and my chemistry teacher does not know how to find it....
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How do you find the heat capacity ratio of combustion products?
For example, if gaseous oxygen $(O_2)$ and paraffin wax $(C_{32}H_{66})$ were to stoichiometrically combust at STP, how would one go about finding the heat capacity ratio ($\gamma={c_p \over c_v}$) of ...
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About Smoke Grenades and Sugar Rockets
The most common formula for smoke grenades and sugar rocket fuel is $60\%\ \ce{KNO3}$ (potassium nitrate) and $40\%\ \ce{C12H22O11}$ (sugar). This is a 3:2 ratio, but I've also seen 2:1 and 5:3 with ...
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1
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703
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Based on their respective number of degrees of freedom, what's the most efficient fuel; hydrogen or gasoline?
The reaction of octane's combustion is:
$$\ce{2 C8H18 + 25 O2 -> 18 H2O + 16 CO2}$$
I am asked for computing the number of degrees of freedom of the octane given that its specific heat is $\pu{...
- 351
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1
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6k
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Why is the auto ignition temperature of petrol higher than that of diesel? [closed]
I can't find any reasonable explanation please help.
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1
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4k
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Why do highly branched alkanes have higher octane numbers than their corresponding linear isomer?
The octane number of fuels are based on a set of primary reference fuels, which are mixtures of iso-octane and n-heptane. Now iso-octane being branched alkane has very less tendency to react and given ...
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Polluting agents generated by road traffic in a city [closed]
I want to measure the air quality according to road traffic in a city.
What are the polluting agents (generated by fuel combustion) strictly related and generated by road vehicles that is worth ...
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How can we separate carbon monoxide from wood gas?
I am thinking about using open source wiki designs from allpowerlabs to construct a wood gas generator. The motivation came from experiencing a 10 day power outage after super storm Sandy. The ...
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Can I approximate the CO concentration of a combustion product, if I know the CO2 and O2 concentration?
Assume I have the product (exhaust gas) from a combusted air/petrol mix. The mixing ratio was richer than stoichiometric (i.e., air:fuel < 14.67 in this case), so there was no excess of oxygen.
I ...
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Is the flame temperature of a burning fuel affected by pre-heating the fuel?
This page on Adiabatic temperatures helpfully lists the theoretical maximum temperatures that flames will reach under certain conditions for a number of fuels. They assume initial atmospheric ...
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188
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Can hydrogen alone be used as a fuel? [duplicate]
I have always thought that fuel such as petrol, diesel, etc.. are getting burnt to move the pistons in the car (I am not bringing physics). Why not hydrogen be used as a fuel but I know the incident ...
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1
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4k
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Why does diesel have a higher energy density than gasoline?
One of the primary reasons why hydrocarbons produce energy is the production of water during the combustion process.
I've been trying to find out why diesel is considered to have a higher energy ...
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Is liquid hydrogen rocket propeller pollution free?
If one searches for the different fuel types used in rockets, one can find that over the years, NASA and other space agencies have used both solid fuels and liquid fuels. I can see that more and more ...
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What single, pure compound would best replace petrol?
Petrol for use as automotive fuel is produced by blending of different product streams of oil refining. It consists of hundreds of different compounds, and the exact composition can vary widely. ...
user7951
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1
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Usage of ammonia as odorant in fuel gases
Usually, thiols such as ethanethiol are added to fuel gases to warn the user of a leak. Why is a few percent of ammonia not used instead?
Ammonia is flammable so it will burn to nitrogen and water in ...
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Which one is the healthiest to operate a lantern with: kerosene, diesel or sunflower oil?
Given a lantern (originally made for kerosene) however, I'm looking for the fuel which is the safest for indoor use.
I've already tried different kinds, and found three of them that burn just as ...
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146
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Making solid fuel out of sugar
I recently tried to make a cheap solid fuel out of sugar. First I attempted burning the sugar cube directly, which did not work well even using a blowtorch. This was expected. Then I attempted to use ...
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2
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1
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Release of sulfur dioxide from odored fuel gases
Often, fuel gases such as butane and natural gas (methane) are mixed with some foul-smelling impurities such as thiols (mercaptans) and hydrogen sulfide. Presumably, anything containing sulfur would ...
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Can ethanol alone be used as Fuel?
Ethanol is a clean fuel and added as an additive to petrol.
Why can't ethanol itself be used as fuel?
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Why do branched hydrocarbons burn more efficiently (complete & clean combustion)?
Branched and cycled hydrocarbons usually a higher octane number than their straight chain counterparts. This is due to a more complete and clean (no residue) combustion. In addition, there is no ...
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Could the net equations for burning hexene be used as a means of energy source?
$6\ce{CO_2} + 6\ce{H_2O}\xrightarrow{some\;catalyst}9\ce O_2 + \ce{C_6H_{12}}$
$\ce{C_6H_{12}} + 6\ce O_2\to 6\ce{CO_2} + 6\ce H_2$
$6\ce H_2 + 3\ce O_2\to 6\ce{H_2O}$
At one point, I had made a ...
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What is the oxidation mechanism of gunpowder?
I've been recently looking into fireworks and the chemistry of explosives, and I found out that, amongst others, one of the most important reactions in gunpowder ignition is the oxidation of charcoal ...
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Is white phosphorus really a cool burning fuel?
About 11 months ago, I posted a question on this SE site on cool flames.
One of the answers mentioned white phosphorus. However, a few weeks earlier, I played a game called Spec Ops: The Lines, in ...
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Determining the Equivalence Ratio
Determine the equivalence ratio of the following mixture: 4g of Butane, $\ce{C4H10}$, and 75 grams of air.
Answer is 0.82
Ok so I try converting everything into mols
$4~\mathrm{g}~(\ce{C4H10}) \...
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1
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Why is the maximum adiabatic temperature found for an equivalence ratio a bit higher than 1?
Why does the peak adiabatic temperature usually happen for an equivalence ratio a bit higher than 1? I think it had something to do with the probability of each fuel molecule finding a corresponding ...
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2
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112k
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What are the differences between diesel and unleaded gasoline?
I am curious about the flammability of diesel fuel and its properties, as I don't deal with it on a regular basis (at all).
In particular, I want to know how the fuel works when powering a diesel ...
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1
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37k
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What is the temperature of heat generated from LPG gas?
I'm working on a project and I require around 300-400 degree Celsius of temperature. As of now I'm taking the normal LPG gas that is available in our house for cooking purposes for my project, but I'm ...
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464
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Why is CO a major species only in fuel-rich combustion?
In fuel-rich combustion, my understanding is that enough fuel reacts and consumes all of the oxygen present. The combustion products $\ce{CO2}$ and $\ce{H2O}$ undergo dissociation until equilibrium is ...
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