Biofuel

Question 1

What do biofuels refer to?

Answer 1

Typically refers to a liquid or gaseous fuel for transport produced from biomass, which is renewable organic material that comes from plants or animals

Question 2

How many years of fossil fuels are left?

Answer 2

Coal- 139 years
Oil- 57 years
Gas- 49 years

Question 3

What are EU countries obliged to ensure in regards to renewable energy?

Answer 3

Obliged to ensure that the share of energy in final consumption of energy in transport is at least 14% by 2030, including a minimum share of 3.5% of advanced biofuels

Question 4

What are the generations of biofuels?

Answer 4

First generation- Food-related sources
Second generation- Non-food sources
Third generation- Algae
Fourth generation- Other sources

Question 5

What are the generations of Biofuels derived from?

Answer 5

First generation biofuels- produced from oils, sugars and starches originating in food crops (Biodiesel and Bioethanol)

Second generation biofuels- produced from nonfood crops such as perennial grasses and woody materials and nonfood portions of food crops

Third generation biofuels- produced from algae that might produce multifold times higher yields (Oligae)

Fourth generation biofuels- the newest sector of biofuel technology, engineered an gene edited algae

Question 6

What is the most common biofuel worldwide?

Answer 6

Bioethanol is the most common biofuel worldwide
Feedstocks include wheat, corn, sugar cane and sugar beet which need to be converted to glucose

Question 7

What are the most common sugars in plants?

Answer 7

Glucose
Galactose
Fructose
Sucrose
Maltose

Question 8

What do starch based feedstocks require?

Answer 8

Starch based feedstocks require strach hydrolysis (liquefaction and saccharification) to produce fermentable sugars after the feedstocks are milled and mashed

Question 9

For first generation biofuels (bioethanols) what is amylase converted to?

Answer 9

Amylase converts starch to Maltose
Yeast uses invertase to convert sucrose to glucose and fructose

A small part of most plants is sugar or starch that can be digested by animals or fermented by yeast into bioethanol. But the majority of the plant is cellulose

Question 10

What are the common biodiesel feedstocks?

Answer 10

Vegetable oils from soybeans, canola, sunflower, cottonseed
Used cooking oil
Animal fats including beef tallow, pork lard, poultry fat

Question 11

What are the types of biodiesel?

Answer 11

B5= 5% biodiesel blended with 95% petroleum diesel
B20= 20% biodiesel blended with 80% petroleum diesel

Question 12

How is biodiesel made?

Answer 12

Biodiesel is made through a chemical process called transestertification where glycerin is separated from the fat or vegetable oil
The process leaves behind two products- methyl esters and glycerin

Question 13

What is cellulosic bioethanol?

Answer 13

Cellulosic bioethanol is a biofuel produced from wood, grasses, or the non edible parts of the plant:
Woods, grasses, leaves

Question 14

What are the 4 groups of enzymes needed for saccharification and fermentation to produce cellulosic bioethanol?

Answer 14

Saccharification:
- Cellulose to glucose
- Hemicellulose to hexoses pentoses

Fermentation:
- Hexoses to bioethanol
- Pentoses to bioethanol

Question 15

What is the difficulty with producing cellulosic bioethanol?

Answer 15

Need to have genes for saccharification (e.g cellulose and hemicellulose) and fermentation of pentose sugars together. Rare to have both

Question 16

What is the commercial production of biofuels based on generation?

Answer 16

First generation- 4%
Second generation- 96%

Question 17

What is used in third generation biofuels?

Answer 17

Microalgae can contain up to 77% oil, making it an attractive candidate for biodiesel
Algae are auxotrophic organisms = photosynthetic
Single cells or multicellular
Oil can be converted to biodiesel and carbohydrates to bioethanol

Question 18

What is the process of producing biodiesel from algae?

Answer 18

• Fats (oils) grow inside algae
• Algae oik is extracted
• Algae oil is converted to bio-diesel
• Algae bio-diesel placed in the market

Question 19

How is bio-diesel made?

Answer 19

Made through a chemical process called transesterfication where glycerin is separated from the fat or vegetable oil
The process leaves behind two products- methyl esters and glycerin

Question 20

Does algae produce higher yields of oil?

Answer 20

Algae can produce 15 x more oil
Algae harvesting cycle of 10 days
They grow 20-30x faster than conventional food crops
Can be grown on marginal and desert lands

Question 21

How are third generation biofuels cultivated?

Answer 21

Open ponds- These are the simplest systems in which algae is grown in a pond in the open air. They are simple and have low capital costs but are less efficient than other systems
Other organisms can contaminate the pond and potentially damage or kill the algae

Question 22

What are closed loop systems?

Answer 22

Cultivation of third generation biofuels
Photobioreactors are closed systems not exposed to the atmosphere and use a sterile source of Co2

Question 23

What makes the closed loop systems more effective than the open ponds?

Answer 23

The low rate of water loss induced by evaporation, low risk of contamination, increased photosynthetic efficiency, increased cells density per unit area are considered the most important advantages of closed system bioreactors

Question 24

What are the disadvantages of algal biomass of biofuels production?

Answer 24

Higher cultivation cost compared to conventional crops
High energy input, (about 20-30% of production). Centrifugation, flocculation, floatation, sedimentation and filtrationused for harvesting and concentrating algal biomass
Algae, even when grown in waste water, require large amounts of water, nitrogen and phosphorous fertiliser to grow

Question 25

What happens in the fourth generation biofuels?

Answer 25

Genetic engineering/gene editing strategies to modify microalgae and cyanobacteria for increased fatty acid and lipid production. For example, overexpression of genes involved in lipid biosynthesis