Shared Flashcard Set


Sustainability EML4450
Undergraduate 4

Additional Engineering Flashcards





Clean Coal Technologies - Gasification


o   Gasification - process that converts organic or fossil based carbonaceous materials into carbon monoxide, hydrogen, carbon dioxide and methane. This is achieved by reacting the material at high temperatures (>700°C), without combustion, with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas


Clean Coal Technologies - Coal washing


o   Washing coal to remove impurities before burning

§  Coal is pulverized and washed in water to allow coal to float and impurities to think. Reduces ash content by over 50% and reduces sulfur content by 25%. This improves the heating value of coal, which reduces carbon dioxide emissions.


Clean Coal Technologies - Wet scrubbers


o   Polluted brought into contact with scrubbing liquid through spray or forcing it through a pool of liquid. Dissolves or absorbs gases in liquid

o   90% efficient,  0.5-100µm


Clean Coal Technologies - Sequestration


o   Carbon dioxide is captured after going through a scrub process and is then stored

§  Gaseous storage in deep geological formations, (saline and exhausted gas fields), liquid storage in ocean and solid storage by reactions with carbon dioxide with metal to produce carbonates


Top Three Countries that emit the highest amount of CO2


·         China, USA, Russia 




·         Ocean Thermal Energy Conversion

·         Uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity.

·         Locations:

o   On land, shelf, free-floating

§  On land

·         Longer cold-water intake

§  On shore

·         Reduces cold water intake

§  Shelf mounted

·         Fixed to seafloor

o   Out of turbulent surf zones

o   Closer to cold water resources (more challenging delivery?)

·         Open Cycle:

o   Utilizes warm (surface) water to make electricity

o   It is put into a low pressure container where it boils

o   Expanding water vapor is used to drive a low-pressure turbine

o   Salt of the water remains in the low pressure container

o   Turbine is attached to an electrical generator

o   Cold sea water is then used to condense the steam back into a liquid

o   The air that is released from the water (incondensable) are then compressed to a pressure necessary to remove it from the system

·         Closed Cycle

o   Can be modeled as a saturated Rankine Cycle

o   Unlike open-cycle systems, which use warm water to make electricity, closed-cycle systems utilize ammonia

§  Ammonia is attractive for its low boiling point

§  Other fluids with similarly low boiling points can be used as well

o   Warm (surface) water is pumped through a heat exchanger

§  Here, the ammonia is vaporized

§  Expanding vapor is then used to turn a turbo-generator

o   Cold (deep) water is then pumped into the system

§  This water is used to condense the vapor back into a liquid to be recycled

·         Cons:

o   Expensive

o   Low Efficiency – 2-2.5% Electrical efficiency

o   Biofouling- the undesirable accumulation of microorganisms, plants, algae, or animals on wetted structures.


Fossil Fuel Air Pollutants


o   Carbon dioxide

o   Nitrogen oxide

o   Carbon monoxide

o   Sulfur oxide

o   hydrocarbons


Hurdles for CO2 sequestration


·         Worker Safety

·         Groundwater quality degradation

·         Resource damage

·         Ecosystem, degradation

·         Public safety

·         Structural damage

·         Release to atmosphere

o   Lake Nyos in Cameroon

·         Potential Release pathways

o   Well Leakage (injection and abandoned wells)

o   Poor site characterization (undetected faults)

o   Excessive pressure buildup damages seal




·         International Thermonuclear Experimental Reactor

·         World's largest and most advanced experimental tokamak nuclear fusion reactor at Cadarache in the south of France

·         Collaborating Countries

o   China, India, Japan, Russia, South Korea, USA and European Union

·         First to break even point – Q=1

o   Power in = Power out

o   Promises Q=50

o   Hydrogen + Heavy Hydrogen (extra neutron) forms helium plus neutron

o   Q is power from fusion/power from external heating sources

·         Only one component from entire scheme

·         DEMO

o   A DEMOnstration Power Plant which will incorporate ALL of the knowledge gathered from the creation of ITER

·         PROTO

o   Any last tech advancements after DEMO that would allow PROTO plants to spring up all over the world





·         Corporate Average Fuel Economy (1975)


·         Passenger cars and light trucks


·         Now based on carbon footprint instead of gross weight


·         SUV’s and pick-ups now included

Larger the footprint, lower the required mpg


Supporting users have an ad free experience!