C5 Hydrothermal Processing

Question 1

principle hyrothermal processing

Answer 1

ultilise subcritical and supercritical water medium at elevated temp(200-800) and pressure(5-30MPa)

Question 2

advantage hyrothermal

4 advantages

Answer 2

1. acceptance of wet biomas & mixed feedstock
2. selectivity of products
3. product seperation
4. energy efficiency

Question 3

4 categories

Answer 3

1. torwash (extract water,remove salt)
2. hydrothermal carbonisation (produce hydrochar)
3. hydrothermal liquefaction (produce bio-oil)
4. hydrothermal gasification (produce gas)

Question 4

factors affecting hydrothermal liquefaction

Answer 4

1. biomass type&composition
2. biomass particle size&heating rate
3. residence time associate with type of reactor
4. temperature
5. pressure
6. catalyst

Question 5

type of reactor

Answer 5

1. batch reactor
2. continous batch reactor

Question 6

type catalyst

Answer 6

1. alkaline catalyst - enhance bio-oil,supress char formation
2. acid catalyst- increase formation water soluble compound such as carboxylic acid

Question 7

engineering obstacle&challenges

Answer 7

1. reactor design
2. biomass loading in the feed (↓output but ↑ cost)
3. salt precipitate (cause clogging. solution: introduce strring within reactor- prevent salt accumulate on reactor wall)
4. catalyst problems

Question 8

catalyst problems

type catalyst

Answer 8

1. heterogenous
   * advantage: easy seperation (liq & solid)
   * disadvantage: deactivation process
2. homogenous
   * advantage: free deactivation
   * disadvantage: seperate& recovery catalyst