Title: Unit 9 Quiz
Course: ENGY 111 Introduction to Biofuels > Section: ENGY 111 Introduction to Biofuels

Q: "Suspension" burners are solid fuel combustors that burn pulverized coal.
- True
- False
A: True

Q: A "grate-fired system" is a type of a solid-fuel combustor where fuel is fed onto a moving grate where it burns.
- True
- False
A: True

Q: Hydrolysis and fermentation separates organic matter into which of the following?
- Polysaccharides to oligosaccarides and monosaccharides
- Proteins to peptides and amino acids
- Triglycerides to fatty acids and glycerol
- Nucleic acids to heterocyclic nitrogen compounds, ribose, and inorganic phosphate
- The production of hydrogen
- The production of carbon dioxide
- All of the above
A: All of the above

Q: What are the three stages of anaerobic digestion?
- Hydrolysis & fermentation; acidification; methanogenesis.
- Hydrolysis; methanogenesis; char combustion.
- Saccharification; fermentation; distillation.
- Hydrolysis; saccharification; distillation.
A: Hydrolysis & fermentation; acidification; methanogenesis.

Q: Anaerobic digestors produces biogas that is between 55–75% CO_2 by volume.
- True
- False
A: False

Q: Subsequent to pyrolysis, a "char" remains.
- True
- False
A: True

Q: Gasification is exothermic requiring heat from an external source as fuel.
- True
- False
A: False

Q: Which of the following are sources of converting biorenewable resources to heat and power? (Check all correct responses)
- Direct combustion
- Thermal gasification
- Nuclear reaction
- Anaerobic digestion
A: Direct combustion; Thermal gasification; Anaerobic digestion

Q: Which type of gasifier is best used in biomass gasification?
- Updraft gasifier
- Downdraft gasifier
- Fluidized bed gasifiers
- Entrained flow reactor
A: Fluidized bed gasifiers

Q: Fluidized bed combustors inject air into the boiler bottom where suspended sand and air allows combustion temperatures as low as 850°C and lowers nitrogen compound emissions.
- True
- False
A: True

Q: Anaerobic digestion is the decomposition of organic waste that includes polysaccharides, proteins, and lipids and converts them to gaseous fuels.
- True
- False
A: True

Q: Direct combustion can be used with some biomass such as wood chips, forestry residue, municipal solid waste, straws, and grasses.
- True
- False
A: True

Q: Anaerobic digester performance can be controlled via waste pretreatment, heating, mixing, nutrient addition, bacteria addition, and pH.
- True
- False
A: True

Q: In anaerobic digestion, methanogenesis converts nitrogen to CH_4 and CO_2.
- True
- False
A: False

Q: Flaming combustion is the oxidation of volatile gases into the air with only CO_2 as an end product.
- True
- False
A: False

Q: The single most important factor in determining gasifier performance is the "fuel-to-air" ratio.
- True
- False
A: True

Q: Fly ash from biomass meets ASTM requirements for use in concrete mixing and eliminates it as a byproduct for that industry.
- True
- False
A: False

Q: Char is responsible for the "orange color" of wood fires?
- True
- False
A: False

Q: What are the four steps of solid fuel combustion?
- Heating and drying; pyrolysis; flaming combustion; and char combustion.
- Heating and drying; pyrolysis; flaming combustion; and chemical reactions.
- Heating and drying, gasification; cooling; and char combustion.
- Harvesting biomass; reducing biomass to sugars; heating and drying; cooling.
A: Heating and drying; pyrolysis; flaming combustion; and char combustion.

Q: What are three disadvantages of the direct combustion of biomass?
- High moisture fuel lowers the efficiency of the process.
- Alkali causes ash fouling and slagging in the boiler.
- Biomass results in hotter firing processes.
- Steam power plants have lower thermodynamic efficiencies.
A: High moisture fuel lowers the efficiency of the process.; Alkali causes ash fouling and slagging in the boiler.; Steam power plants have lower thermodynamic efficiencies.

Q: Hemicellulosic Pyrolysis can only be used at temperatures higher than 500 degrees C.
- True
- False
A: False

Q: If H_2S is removed, biogas can be used in place of natural gas in situations like stationary power generation.
- True
- False
A: True

Q: Acidification is achieved through acid-forming bacteria.
- True
- False
A: True

Q: In gasification, steam injection and catalysts are used to shift hydrocarbons from toward higher molecular weight compounds.
- True
- False
A: False

Q: All anaerobic digestors produce two effluent streams: biogas and sludge.
- True
- False
A: True

Q: Combustion is the rapid oxidation of fuel to provide heat energy.
- True
- False
A: True

Q: Some advantages of anaerobic digestion of biomass are:
- The ability to use non-sterile vessels.
- Separation through outgassing
- Simple operations and equipment needs.
- None of the above.
A: The ability to use non-sterile vessels.; Separation through outgassing; Simple operations and equipment needs.

Q: When gasifier temperatures and times are reduced, light hydrocarbons and up to 10%-wt heavy hydrocarbons form a black viscous "tar."
- True
- False
A: True

Q: Pulverized coal boilers are well-suited to burning biomass efficiently.
- True
- False
A: False

Q: Co-firing is the mixing of biomass and coal and can result in lower sulfur emissions.
- True
- False
A: True

Q: Biomass is an ideal gasification fuel because it has 70–90% volatile mass compared to coal's 30–40% and is highly reactive with char.
- True
- False
A: True

Q: A "grate-fired" solid fuel combustor is rarely more than 90% efficient.
- True
- False
A: True

Q: A combustor converts fuel's chemical energy into high temperature exhaust gas.
- True
- False
A: True

Q: In fluidized bed gasifiers, the turbulent mix of gas and solids results in gasification taking place in simultaneously at all locations in the bed.
- True
- False
A: True

Q: The heat from high temperature gas cannot be used to in power generation.
- True
- False
A: False