GREEN CHEMISTRY

Alvin C. EdulsaDISCUSSANT

15.13 Biomass: Photosynthesis for Fuel15.14 Hydrogen: Light and

Powerful15.15 Other Renewable Energy Sources15.16 Energy: How Much is Too Much?

OBJECTIVES:

• To

15.13BIOMASS: PHOTOSYNTH

ESIS FOR FUEL

WHAT ISBIOMASS?

BIO- Any plant and animal material, especially agricultural waste products, used as a source of fuel.

- the fuel energy that can be derived directly or indirectly from biological sources.

refersMASSto…

“dry plant

material”

Why use BIOMASS as an alternative to

FUEL?It burns cleanly; the emissions are just water vapor and carbon dioxide.

It is a renewable resource whose production is powered by the sun.

It can be replenished by nature relatively quickly.

howCANBIOmassBEUSEDas FU

ELA?

• Starches and sugars from plants can be fermented to form ethanol. Wood can be distilled in the absence of air to produce methanol.• Bacterial breakdown

of plant material produces methane.

• Vegetable oils or animal fats can be converted to a fuel called BIODIESEL.

dis× There is a shortage of land.× The production is pricy.× The land is far from where the

energy is needed.× The overall efficiency of biomass

use is only about 3% at best; less than that of solar cells.

ADVANTAGES

ALTERNATIVE WAYS• We can supplement our other

sources by burning agricultural wastes, fermenting some to ethanol, producing methanol from wood where wood is plentiful, and fermenting human and animal wastes to produce methane.

BIOFUELS

WHAT ISBIOFUEL?

BIO • fuel made from

biological materials: a renewable fuel that is derived from biological matter, e.g. biodiesel, biogas, and methane.

refersfuel to…

Biodiesel from Rapeseed Oil

TYPES OF BIOFUELS• The most used and produced biofuels are

ethanol and biodiesel.

“fuel of the future”

Substitute for fuel

ETHANOLBIODIESEL

ETHANOL and BIODIESEL

• To produce ethanol, carbohydrates in biomass are turned into sugars, which are then fermented.

• The alcohol produced can be burned as a fuel directly or added to gasoline to make gasohol.

• Biodiesel is typically made from plant oils combined with alcohol to form esters.

• The esters can be burned as a fuel. In addition to vegetable oils from soybeans, rapeseed, or palm oil, biodiesel can also be made from used cooking oil, animal fats, or oils produced by certain types of microalgae.

HYDROGEN:LIGHT

& POWERFULL

15.14

When Water

and Oxygen Collide…

HYDROGEN

“most abundant element in

the universe”