Chapter 7: Renewable or Alternate Energy

Renewable energy means that the energy production and use generate very low _____ emissions and whose production can be sustained _____.

greenhouse, indefinitely

Renewable energy means

a) less sustainable

b) low-cost

c) produce less greenhouse gases

d) efficient

c

Which one is not the incentives behind the production and use of such biofuels rather than fossil fuels

a) carbon-neutral characteristic

b) they are renewable

c) low price and efficient

d) results in smaller amounts of air pollutants

c

E10 means

a) 90% ethanol

b) 10% efficient

c) 90% efficient

d) 10% ethanol

d

Ethanol is produced ___ in industries

a) sugarcane

b) catalytically

c) corn

d) fermentation

b

What are the sources of ethanol

a) sugarcane

b) sugar beets

c) corn

d) cassava

f) All of them

f

Which are the disadvantages of ethanol

a) produce less energy

b) require a large amount

c) lower cost

d) low vapor pressure

e) all of them

e

Bioethanol, second generation of biofuel, mainly produced

a) sugarcane

b) sugar beets

c) corn

d) woody plant

c

The cellulose contains woody plants

a) 35-50%

b) 15-50%

c) 20-30%

d) 50-70%

a

The hemicellulose contains in the woody plants

a) 35-50%

b) 15-50%

c) 20-30%

d) 50-70%

c

The lignin contains in the woody plants

a) 25-50%

b) 10-30%

c) 20-30%

d) 50-70%

6

What are not the advantages of the second generation to biofuel over first generation biofuels

a) much smaller need for fertilizers and irrigation

b) easy to be converted into an alcohol

c) the lower product cost

d) the lesser competition with food crops

b

what is the main depolymerized product lignin

a) D-glucose

b) phenol derivatives

c) ethanol

d) monosaccharides

b

what is the main depolymerized product of cellulose

a) D-glucose

b) phenol derivatives

c) ethanol

d) Monosaccharides

a

what is the main depolymerized product of hemicellulose

a) D-glucose

b) Phenol derivatives

c) ethanol

d) monosaccharides

d

T/F : biofuels are renewable

True

T/F: biofuels produce less air pollutants

true

biofuels produce only a small quantity of _____.

oxygen

biofuels can replace ____

petroleum

the use of ___, ___ residues and dung was the world’s first energy source

wood,crop

biomass was second to ____ power in the production of renewable energy even in the US in the late twentieth century

hydroelectric

ethanol can be used in ____ form or as a component in a solution that includes gasoline

pure

E100 is used mainly in ____

brazil

in cold climates, with pure ethanol there is very little _____ fuel available to start a ____ automobile engine

vaporized, cold

a blend of ___% gasoline and ___ % ethanol has a high enough vapor pressure to overcome the cold start problem of a car (where a car is too cold to start)>

85%, 15%

____ ethanol is currently the most important example of second-generation biofuel.

cellulosic

are second generation biofuels produced from edible food crops?

no

second-generation biofuels are produced from ____ materials from crops such as ____, ____, and ____, from crops not used for food purposes, and from industrial waste ___.

waste, stems, husks, leaves, biomass

in general, second-generation biofuels are more ____.

sustainable

what are some advantages of second-over first-generation biofuels?

• Smaller need for ____ and ____ water

• greater savings in _____ gas emissions required for their processing.

• the lesser competition with ____, or land devoted to ____.

• the lower ____ cost

• fertilizer, irrigation

• greenhouse

• food crops, food crops

• production

in order to be converted into an alcohol, the biomass must first?

first be ground up and pretreated to break the seal of lignin.

___-based cooking oils (whether corn oil, olive oil, or sunflower oil) are candidates for fuels in ____ engines

plant, deisel

the first diesel could be powered using ____ oil.

peanut

Modern diesel engines are designed to use fuel that is not as ____. what does viscous mean?

viscous, not as resistant to flow

natural oils are highly ___ and their component molecules are very ___, each containing about __ to __ carbon atoms- about three times as many as those in petrodiesel.

viscous, large, 50 to 60

unrefined vegetable oils contain unwanted impurities such as ____ acids, ___ and ____ substances

free fatty, water, odorous

the polymerization of unsaturated ____ components produces gum, which results in ____ deposits and thickening of ____ oil in the engine.

hydrocarbons, carbon, lubricating

to overcome the difficulties in using SVOs, the virgin vegetable oils commonly are
transformed into a less viscous, less corrosive fuel called _____.

biodiesel

Because there are technical problems in using the acids themselves as fuel, the ___ acids are reacted with _____, which converts them into ____; thus, the hydrogen atom (green) of the acid group is replaced by a methyl group.

fatty, methanol, methyl esters,

fatty acid methyl esters are the ____ of biodiesel.

constituents

what us this fatty acid called

palmitate

what is the name of this fatty acid

oleate

• Fatty acid carbon atoms are usually numbered beginning with the ____ terminal carbon atom

• carbon atoms 2 and 3 are also referred to as ___ and ___

• fatty acids can also be numbered from the ___ carbon atom, which is called the omega carbon.

• carboxyl

• alpha, beta

• methyl

number this fatty acid

vegetable oils consist largely of _____.

triglycerides

this is a ?

triglyceride

the total number of carbon atoms in a typical glyceride is about ___. This large size accounts for its high ____.

60, viscosity

Petrol fuel is

• A liquid fuel that mainly consists of light hydrocarbons raging from C_ to C_

• more ___ than diesel

• more ____ than diesel because it contains light hydrocarbons.

• C5, C12

• flammable

• volatile

Disel is

• a liquid fuel that consists of heavy hydrocarbons, greater than C_

• less ____ than petrol

• less ____ than petrol because it contains heavy hydrocarbons

flammable, volatile

Diesel contains about ___% saturated hydrocarbons and __% aromatic hydrocarbons. Diesel contains hydrocarbons with ____ chains than petrol and is thus less volatile.

75, 25, longer

Advantages of biodiesel:

• produces significantly fewer ____, other than NOx

• significantly higher ___ point so it is safer to handle

• ____ faster in freshwater and soil and is much less ____

• The growth of plants for biofuel absorbs much of the ____ emitted during its combustion and thus reduces about ___ the greenhouse gas emissions from diesel fuel combustion

• air pollutants

• flash

• biodegrades, toxic

• CO2, half

disadvantages of biodiesel

• biodiesel has a slightly lower ___ content.

• is more ____

• undergoes _____

• may attract __ from atmospheric moisture

• the water causes ____ of the engines fuel system

• the ____ reduction is more than offset for decades if the new land must be cleared to grow plants

• energy

• viscous

• degradation

• corrosion

• CO2

Methanol can be blended with gasoline to produce a fuel that burns more ___than gasoline.

cleany

Blends of methanol are designated by an M rating; thus, M5 corresponds to?

5% methanol and 95% gasoline

disadvantage of methanol blends

• the pure alcohol is only soluble to the extent of about __% gasoline.

15

some concern has been expressed about the safety of methanol for use as a ____ fuel, given the toxicity of the compound.

vehicular

methanol can be used to produce ____, which has been tested as a replacement for diesel fuel trucks and buses

dimethyl ether

dimethyl ether is nontoxic and degrades easily in the ____

atmosphere

since dimethyl ether contains no C-C bonds, ___ particulate matter is produced in its combustion but only in very small quantities compared to diesel fuel.

soot-based

the ___ emissions from dimethyl ether combustion are also lower than usually found for diesel engines.

NOx

methanol is also used to produce methyltertiary-____

methyltertiary-butylether

MTBE is used in north American and European unleaded gasoline blends up to __%.

15

hydrogen is not an ____ source, since it does not occur as the free element on earth’s crust

energy

hydrogen gas is an energy ____ only.

vector

Natural gas or petroleum or coal is reacted with steam to form ____ and ____.

H, CO2

this is a ___ gas reaction

Natural

this is a ____ reaction.

petroleum

this is a ____ reaction

coal

hydrogen is superior to ____ in some ways since its transmission by pipelines over long distances consumes less energy.

electricity

the _______ problems in the production, storage, transportation and usage of hydrogen plus the need to _______ for it means that a hydrogen economy is probably still many decades away.

substantial technical, create a new infrastructure for it.

hydrogen is not an _____ since it doesn’t occur as the free element on the Earth’s crust.

energy

hydrogen fuel must be produced from water and/or _____, by the consumption of large amounts of energy and/ or other ____.

methanol, fuels

virtually all (__%) the hydrogen gas that is currently produced in the world is obtained by reactions of ____, i.e., non-sustainably.

95%, fossil fuels

the most commercial way to produce hydrogen is by _____ of water, using DC electricity generated by an energy source. The water is made by alkaline and conducting by the addition of ____ hydroxide

electrolysis, potassium

one catalyst that has been found to convert sunlight into hydrogen by electrolyzing water is ____ dioxide. Unfortunately, a quarter to one half of the electrical energy is unavoidably converted to ___ and therefore wasted in the process.

titanium, heat

in principle, thermal conversions of sunlight into heat can produce temperature hot enough to decompose water into ___ and ____.

hydrogen,oxygen

hydrogen and oxygen can be combined in ____cells in order to produce electricity.

fuel

fuel cells are similar in operation to ____ except that the reactants are supplied continuously.

batteries

fuel cells have the advantage over combustion in that a more useful form of energy is produced, and the process creates no ______ as by-products.

polluting gases

real fuel cells overall are now about ___-___% efficient, ____% efficiency may be obtained eventually. By contrast, internal combustion engines using gasoline are ___-___% efficient, while diesels are ___-___% efficient.

55-55%, 70%, 15-25%

generating electricity by powering fuel cells with hydrogen:

• in the hydrogen-oxygen fuel cell, the two gases are each passed by an _____ electrical connect through which electrons travel, by an _____ through which ions travel.

• at the catalytic surface of the first electrode, the H2 gas produces H ____ and ____, which travel around the external circuit to the second electrode, across which O2 gas is bubbled.

• Meanwhile, the H ions travel through the electrolyte and ____ with the electrons and O2 to produce ___ at the second electrode.

• external, electrolyte

• ions, electrons

• recombine, water