ME22

E01 SW-8
Decena, Zteifany Anne B.
Research and discuss the following:

1. How is the energy of solar radiation stored?

In the solar panel, solar radiation captured is changed to thermal energy which is deposited in
the brine and increases its temperature. Through extraction of heat through the hot brine of the
storing region, direct use of heat or greater conversion into electrical energy, the use of heat is
feasible.
2. What approximately is the heat of combustion of plant biomass?
Depending on the organism, climate, and other influences, the amount of heat emitted vary, but
it is usually around 20 megajoules of energy per kilogram of dry biomass. The materials should
be well combined at the right temperatures for the correct period of time in order for
combustion to be safe and efficient.
3. Why is biomass heat of combustion less than that of, say, natural gas (methane)?
Because biomass fuels are mainly consists of ash, hydrogen and oxygen , carbon dioxide and
water are the major components of biomass combustion. Suppose it depends mostly on heating
rate and moisture content of the fuel, the volume of air required to fully burn the fuel and the
furnace development, the flame temperatures will reach 2000 ° C.
4. What is the minimum number of absorbed solar photons needed to produce one molecule of
oxygen?
They discovered that in order to obtain one molecule of oxygen, about 2500 molecules of
chlorophyll were necessary and that an average of eight light photons had to be consumed in
the cycle.
5. How is absorbed solar energy channeled for chemical reactions in plants?
Plants, which contains chlorophyll, undertake the photosynthesis process. In this cycle, plants, in
the mere existence of sunlight, absorb carbon dioxide and water and transform them to glucose
and oxygen. Plants thus transform the sun's light energy to the chemical energy of glucose.
6. What are ‘photosystems’ and what do they do?
Photosystems are operational and structural components of photosynthesis-involved protein
frameworks which together bring out the main photochemistry of photosynthesis: light
absorption and energy and electron exchange.
7. What is the efficiency of plant photosynthesis and what are the implications of plant
photosynthesis being ten times greater?
Photosynthesis enables the atmosphere to extract carbon dioxide gas and to generate oxygen in
its place. When oxygen is emitted through photosynthesis, the ultraviolet radiation is absorbed
and the valuable ozone layer arise.
8. Define ‘energy farming’.
Solar energy farms are large-scale commercial power plants that use photovoltaic solar panels
to turn sunlight into clean energy, offering, for several years after completion, a supply of
healthy, locally generated green energy.
9. How many products can you identify from a sugar cane ‘mill/factory’?
sugarcane bagasse, dry leaves, sugarcane press mud and sugarcane molasses.
10. Describe the impact of human food and energy consumption on the Earth’s land ecosystem
 Human beings have such a huge impact on the natural world , and consequently on each other.
The way humans have chosen to build, clothe, shelter and fulfill the needs for essential
resources such as food, electricity and water not only affects the long - term supply of these
commodities, but also the well-functioning Earth systems along with climate systems,
hydrological cycles, atmospheric nutrient cycles, hydrosphere and lithosphere, and the
preservation of a complex biosphere.
11. How is a carbon atom in biomass different in effect from a carbon atom in fossil fuel?
Since it is emerging, biomass takes carbon out of the atmosphere and returns it when it is burnt.
If it is treated on a sustainable environment, as part of a continuously replenished crop, biomass
is harvested. Fossil fuels, on the other hand, emit carbon dioxide into the atmosphere. Hydrogen
is converted to hydrogen as coal is burnt, and carbon is converted to carbon dioxide. Energy is
derived from both hydrogen and carbon, and carbon dioxide ( CO2) is released into the
atmosphere.
12. Give a chemical explanation of the term ‘biomass’.
Biomass is a plant or animal resource used as a raw material for a variety of goods in the
manufacture of oil or in different manufacturing processes. Energy crops, wood or timber
wastes, waste from food crops, horticulture, food manufacturing, animal production, or rotting
food from wastewater treatment plants can be deliberately cultivated.
13. Explain two differences between carbon in CO2 from burning coal and from burning biomass
Coal combustion is liable for 46% of the world's carbon dioxide emissions and accounted for
72% of the power sector 's overall greenhouse gas ( GHG ) emissions. Projections of carbon
emissions from biomass burning relative to carbon emissions from fossil fuels are important.
Gas emissions from fires are expected to range from 20 to 40 percent of fossil fuel carbon
emissions.
14. Compare the heat of combustion (MJ/kg) of dry wood and of petroleum oil.
Recoverable Heat Value per kg (Dry Wood): = 14.8 (MJ/kg) Combustion or heating values for
some common fuels oil grades: 1 Btu/US gal = 278.7 J/liter
15. For a given sample of biomass, which is the larger: its dry-basis or its wet-basis moisture
content?
A moisture level of 50 percent wet basis would be like a moisture level of 100 percent dry
ground. Usually, air-dried biomass have about 15-20 percent moisture, while the moisture
content is about 0 percent for oven-dried biomass. The moisture content of coals, ranging from
2-30 percent, is also an significant trait.
16. What is a ‘wood pellet’ and how big is it likely to be?
Wood pellets are tiny 10-20 cm wide cylindrical parts made from fine-ground wood bark with
diameters ranging from 5 to 10 mm. Typically, due to their short and defined shape, they can be
used as fuel by feeding into the burner automatically.
17. Which biofuel is safest for a policeman to drink and why?
Biodiesel emerges from oils that have been drained of glycerin molecules from plants or poultry.
It makes them less viscous. Biodiesel cars and diesel cars are about the same thing.
18. For cooking, what are the advantages and disadvantages of using a cooking stove as compared
to an open fire?
Benefits: Fewer appliances to carry, anything from roasting to grilling to steaming to baking can
be accomplished, making you feel more fantastic for getting cooked over a fire. Downsides: can
 darken pans, longer to set, difficult to monitor and manage heat, more likely to burn food /
hands.
19. How might you obtain hydrogen from wood?
Currently, 95 percent of hydrogen, including natural gas and oil, is derived either from wood or
from fossil fuels. There are presently three forms of manufacturing process in operation. Natural
gas reform, also called steam methane reforming, is the most efficient hydrogen processing
mechanism since it utilizes high-temperature steam.
20. What is ‘second generation’ bioethanol?
The word' second generation bioethanol 'has appeared as a boost to solve the' food versus fuel'
feud posed by bioethanol of the first generation. Innovative processes mainly use lignocellulosic
feedstock and agricultural forest residues to produce second generation bioethanol, also
referred to as 'advanced biofuels'.
21. What is the main benefit of a Brazilian ‘flexi-car’?
The Flexi-car has an engine that can operate on either traditional fuel or ethanol-mixed gasoline.
The value of petrol is affordable, not a huge change, because it is much affordable to opt to
consume alcohol. Buying a flexi-car is a must.
22. What is ‘national fossil fuel energy ratio’ and why is it important?
Fossil fuels are of considerable value since they can be burnt, generating large quantities of
energy per unit mass (oxidized to carbon dioxide and water). the utilization of coal as a fuel
precedes documented history. Coal has been used to operate metal ore smelting furnaces.
23. Which biomass energy crops and products are (a) most likely, and (b).least likely to affect food
supplies?
Wood waste, industrial waste , urban solid waste, construction waste, and landfill gas are the
major waste energy feedstocks. Another origin of biomass is waste gunk. Research is underway
concerning biomass originating from algae or algae. Enzymes or bacteria from different plants,
produced in cell cultures or hydroponics, are other biomass feedstocks.
24. What benefits may occur if an anaerobic digester is installed at a cattle farm?
For several purposes, anaerobic digesters can be installed, including handling waste, eliminating
odors, providing a source of income and improving the public profile. While basic in principle,
there are several digester types, styles and implementations. To be effective, projects require
thorough technological and financial preparation.
25. Name and quantify anaerobic digestion temperature ranges.
In a wide range of temperatures, anaerobic bacteria thrive, although there are two major types
of methanogens. Medium-temperature (mesophilic) bacteria grow between 68 and 113 ° F (20
and 45 ° C), and anaerobic digestion takes place between 86 and 100 ° F (30 and 38 ° C) using
mesophilic bacteria.
26. What can happen to landfill gas?
Landfills can emit odors that are unpleasant, and landfill gas can pass through the soil and
accumulate in nearby buildings. Ammonia, sulfides, methane, and carbon dioxide are among the
gases contained in landfills of most importance. For the most of the smells of landfills, ammonia
and hydrogen sulfide are liable.
27. What is biodiesel and in what ways does it differ from bioethanol?
In the development of biodiesel by the transesterification cycle, we could utilize methanol as a
non-renewable substitute fuel, if we're using bio-ethnol as a renewable substitute fuel to
 replace petrol, where biodiesel is already a renewable energy option, Gasoline is replaced by
diesel.
28. Identify two social advantages and two disadvantages of utilizing biofuels.
Biofuels are much more eco-friendly. They generate lesser greenhouse gasses than fossil fuels.
But at the other side, immense quantities of land are required to create first-generation
biofuels. The crops tend to be smaller than the initial plants, such as maize, which makes them
unfit for human consumption.