PETROLEUM ENGINEERING - QUESTION 25.1 : Fact 1 : Dry air contains 20.95 % oxygen, 78.09 % nitrogen, 0.93 % argon, 0.039 % carbon dioxide, and small amounts of other gases by volume. Fact 2 : Volume occupied is directly proportional to the number of moles for ideal gases at constant temperature and pressure. Fact 3 : 12.5 moles of pure oxygen is required to completely burn 1 mole of pure octane. Fact 4 : Air-fuel ratio (AFR) is the mass ratio of dry air to fuel present in a combustion process such as in an internal combustion engine or industrial furnace. Fact 5 : Molecular weight of oxygen gas is 31.998 g / mole and molecular weight of nitrogen gas is 28.014 g / mole. (a) Find the molar ratio of nitrogen and oxygen, or (moles of nitrogen) / (moles of oxygen) in dry air, by assuming ideal features of nitrogen and oxygen gases. (b) How many moles of nitrogen are available if dry air is used to completely burn the 1 mole pure octane? (c) Find the mass of fuel of 1 mole of octane with molecular weight of 114.232 g / mole. (d) Find the mass of dry air with 12.5 moles of pure oxygen by assuming only oxygen and nitrogen gases exist in the air. (e) Find the air-fuel ratio (AFR) when octane is used as fuel. (f) Find the fuel-air ratio (FAR) when octane is used as fuel.

Answer Posted / kangchuentat

PETROLEUM ENGINEERING - ANSWER 25.1 : (a) Ideally (moles of nitrogen) / (moles of oxygen) = (volume of nitrogen) / (volume of oxygen) = 78.09 % V / 20.95 % V = 3.7274 where V is the volume of dry air. (Fact 1, Fact 2). (b) Moles of nitrogen = (moles of oxygen) x (volume of nitrogen) / (volume of oxygen) = 12.5 x 3.7274 = 46.5925 moles. (c) Mass of 1 mole of octane fuel = 1 mole x 114.232 g / mole = 114.232 g. (d) Mass of dry air = mass of oxygen + mass of nitrogen = 12.5 mole x 31.998 g / mole + 46.5925 mole x 28.014 g / mole = 1705.217295 g. (Fact 5) (e) Air-fuel ratio (AFR) = [ Answer in (d) ] / [ Answer in (c) ] = 1705.217295 g / 114.232 g = 14.928. (Fact 3, Fact 4) (f) Fuel-air ratio (FAR) = 1 / [ Answer in (e) ] = 1 / 14.928 = 0.067. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.

Is This Answer Correct ?    0 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Hi.. Me going to tke test for management trainee(technical) Post I am an chemical engineering student . Can u guide how to prepare for this test.Can u send me test paper pattern..?

2187


Hi. I have completed my masters in chemical engineering from M S University in year 2008 and now going to do MS Chemical engineering in Lamar University. I am planning to appear for interview in two weeks from now. What are the expected questions from VO regarding masters after masters ? and wat should i expect to give reply ? kindly give your suggestions. Thanks

1697


What are the problems that are associated with the expansion joints?

784


Please describe tar, asphalt and bitumine

1298


What is a common source of error in determining the percent spent caustic in refinery applications?

715






Explain what are the criteria involved in choosing mass balances for components?

660


What is a good relation to use for calculating tube bundle diameter?

638


How can hexavalent chromium be removed from aqueous waste streams?

715


What types of pneumatic conveying systems are typically used?

689


What is a good method of minimizing shell side pressure drop in a shell and tube exchanger?

776


Explain what is a good way to get started in doing a plant-wide steam consumption analysis?

639


What is maximum recommended velocity for steam in a plant pipe network?

719


Explain some good strategies for curing tube vibration in shell and tube exchangers?

710


i am a prefinal year student of polymer engineering .could you please send the latest question papers regarding entrace exam.

1737


solution =2oolitre ,solute =Polyelectrolyte,Solution=water ,we have to prepare 1% solution.how much solute And Solvent?

1883