Renewable Chemicals From Biomass

Question 1

What does biomass consist of?

Answer 1

1. Agricultural residues
2. Food processing wastes
3. Livestock production wastes
4. Wood waste
5. Algae

Question 2

What does biomass consist of?

Answer 2

1. Cellulose (sugars / starches)
2. Hemicellulose
3. Lignin

Question 3

What is the reaction of the energy released on burning biomass?

Answer 3

(CH2O)n + nO2 -> nCO2 + nH2O

Question 4

What is the amount of energy released during burning biomass, oil & gas?

Answer 4

biomass: 15 kJ/g
Oil: 48 kJ/g
Natural Gas: 55 kJ/g

Question 5

Is burning biomass carbon neutral? Give an example.

Answer 5

Biomass accounts for 12% of UK’s electricity.
An example: Saw Mills
1. Saw dust generated -> pressed into wood pellets => use in heating applications.
2. Used in energy generating plants => generating electricity.
3. Companies that generate it receive subsidies (from ukgov), supposed to be “carbon neutral”.
4. Wood pellets harvested from forests, replaced at a slower rate than their growth.
Answer: No, it increases CO2 emissions, and air pollution.

Question 6

What are alternative ways to generate energy from biomass?

Answer 6

1. Thermal Transformation (thermal treatment of biomass)
2. Transformation using microorganisms

Question 7

What processes are involved in Thermal transformation?

Answer 7

1. Thermolysis (450 - 800 dC) => charcoal, fuel, gases
2. Pyrolysis (1500 dC) => C2H2, charcoal
3. Gasification (650 - 1200 dC) => CO, H2, CH4, CO2
4. Hydrothermolysis (250 - 600 dC) => charcoal, fuel, CO2

Question 8

What processes are involved in transformation using micrroorganisms?

Answer 8

1. Fermentation => ethanol, CO2
2. Anaerobic digestion => CH4, H2O

Question 9

What are biodiesels and what is their reaction?

Answer 9

• They are mainly obtained from trans-esterification of vegetable oils (triglycerides) with MeOH.
  [O2CR]x3 + 3MeOH <=> [OH]x3 + 3RCO2Me
  In equilibrium: using catalyst.

Question 10

What do palm oil based triglycerides contain? Mention 3 alternative oils.

Answer 10

1. Palmitic acid - 42.8%
2. Oleic acid - 40.5%
3. Linoleic acid - 10.1%
4. Stearic acid - 4.5%
5. Linoleic acid - 0.2%

Alternative oils include:
a) soybean
b) rapeseed
c) sunflower seed

Question 11

State an alternative to produce biodiesel, as well as the chain of its production.

Answer 11

1. Algal biomass is an alternative to producing biomass.
2. Microalgae is a more efficient way of removing CO2.
3. Photosynthetic microorganisms better efficiency for biomass conversion.
   (All that compared to plants)

Sun, CO2, Waste Water (C, N, P, Mn, Mg, K)
|
Algal Cell => O, H exit
|
1. Biomass => food & feed, bioremedation, biogas
2. Carbohydrate => biofuels, bioplastics
3. Pigments => Therapeutics
4. Lipid => Biodiesel, Nutraceuticals
5. Bioactive compound & protein => nutraceuticals & therapeutics

Question 12

What is biodiesel generated from and how is it used?

Answer 12

1. Through engineering algae - augmented neutral lipid contents ~ 60-70%
2. Lipids trans-esterified to biodiesel and residual biomass
   Also, generated from:
   - waste oils and fats
   - waste oil through recycling

Used as animal nutrient or fermented.

Question 13

What is bioethanol produced from?

Answer 13

The fermentation of corn or sugarcane.
- 60% corn
- 25% sugarcane
- 3% wheat
- 2% molasses
The rest: grains, cassava & sugar beets.

Question 14

State two other ways of producing bioethanol.

Answer 14

1. Lignocellulosic feedstocks (forest and wood residues)
2. Cellulose and hemicellulose (agricultural residues)

Question 15

What is the pre-treatment process done prior to fermentation?

Answer 15

Rigid structure of biomass requires opening up, creating amorphous regions, therefore:
=> cellulose and hemicellulose are pre-treated
=> hydrolysis to sugars enabled prior the fermentation step.

Pre-treatment could be done:
1. Upon hydrolysis by enzymes.
2. By treatment with acids or bases.

Question 16

Explain the design process of algae and which components it involves.

Answer 16

Designed with:
- minimal lipid content
- high carbohydrate concentrations (40-50%)
Uses fermentation-based conversion processes.

Question 17

Describe the cycle of production of bioethanol and biobutanol followed.

Answer 17

1. Open pond
2. Harvesting
3. Drying
   (Wet biomass)
4. Pre-treatment
   Acid, alkali, sonication, agitation, grinding, enzyme fractionation, microwaves, high pressure homogenization
5. Processed biomass => sugar hydrolysis
6. Fermentation (with processed/hydrolyzed algal biomass & bacteria/veast cells)
7. Solvent extraction, distillation, in situ gas stripping
8. Bioalcohols (bioethanol, biobutanol)

Question 18

What is the process of syn-gas production, and its uses?

Answer 18

Syn-gas could be used as fuel or feedstock.
Process in order: page 13
1. Biomass (at high T)
2. CO + H2 (syn-gas)
3.
a) (Fischer Tropsch) Gasoline.
b) (N2) NH3
- (CO2) urea
- urea-formaldehyde (Bakelite) resins
c) MeOH
- HCHO => urea-formaldehyde (Bakelite) resins
- (CO, H2) ROH
- acrylic acid => polymers
- (HCl) MeCl
- (zeolite H-ZSM-5) alkanes => (Al2O3 / Pt) Aromatics
- (CO + Ir/Rh cat.) CH3CO2H acetic acid

Question 19

What can be produced from biomass (triglycerides)?

Answer 19

Process in order: page 14
1. Triglyceride
2. Fatty acid
a) (ROH) Wax esters (lipids)
b) (Na, Al, Zn, Mg hydroxides) Metal carboxylates
c) (NR3) Fattty amides
- (-H2O) Nitriles
- (H2) Amine
- (RX) R4N+ salts
d) (H2) fatty alcohol
- (-H2O) 1-alkenes
- (ethylene oxide) Alcohol ethoxylate [pesticides] => (Na2SO3 maleic anhydride) Sulfosuccinates / surfactants

Question 20

Raw chemicals, and Levulinic acid

Answer 20

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