Introduction

Question 1

What is the current energy problem?

Answer 1

Dependence on fossil fuels, which are distributed unevenly.
Oil prices cause economic disruption.
Health and environmental hazards.

Question 2

Definition of sustainability

Answer 2

Fulfil the needs of the present without compromising the ability of future generations to meet their own needs.

Question 3

What factors are considered in a LCA?

Answer 3

Social, economic and environmental.

Question 4

What is the MARKAL model?

Answer 4

Scenarios of how the future will develop based on certain assumptions about key driving forces.
Qualitative and quantitative factors from stakeholders

Question 5

What is the renewable energy share for electricity in UK>
Total energy consumption?

Answer 5

43%
14% (missed target by 15%)

Question 6

Why is biomass considered as a fuel?

Answer 6

Predictable, controllable and can address elecricity, heat and transport.
Global resource is huge.
Source of organic chemicals and natural fibres

Question 7

What are some current challenges with biomass

Answer 7

Energy/food land competition
Supply chain issues for chemicals.

Question 8

How are wood crops harvested? Grasses? example of a grass

Answer 8

Planted as rods, cut back for multiple shoots and harvested after 3 years.
Establisted in 2 years with 15 year lifetime. Miscanthus

Question 9

What are oil crops used for? Examples

Answer 9

Biodiesel, sunflower, rape seed

Question 10

What are sugar and starch crops used for?
Examples

Answer 10

bioethanol
sugarcane, maize, wheat

Question 11

What is the cell structure of woody biomass?

Answer 11

mostly aligned with the stem and responsible for carrying water and minerals (xylem) and food to the plant (phloem)

Cellulose most abundant and provides a skeleton fibril surrounded hemi and lignin+

Question 12

What is lignin

Answer 12

cross linked polymer of phenylpropane
Lost off cross linking, which is harder to break down

Question 13

What are some other components of biomass

Answer 13

Extractives: Chemicals that can be extracted using solvent
Major essential: N, K, Ca, Mg
Minor: Fe, Cu, Zn
Metals as chlorides and sulphates.

Question 14

What is elemental analysis?
How is it measured?

Answer 14

C, H, O, N, S
A few mg is combusted, the gases are separated and detected as H2O and CO2. From the mass of gas produced, CHN is calculated.
O is calculated by difference when moisture and ash are subtracted

Question 15

How is H content calculated in elemental analysis

Answer 15

H = wt% H - (moisture x 2/18)

Question 16

How to calculate daf from ar

Answer 16

daf = a.r / 100 - moisture - ash

Question 17

What does proximate analysis measure?

Answer 17

Moisture, ash, VM, FC

Question 18

What is fixed carbon

Answer 18

Amount of combustible matter present in the char residue after moisture and Vm loss

Question 19

How to measure ProxA
Consideration with VM?

Answer 19

Drying oven: moisture
Ash Oven: Ash
Volatile oven: VM

some of the VM is moisture so it is done after each other or Tot - M = VM

Question 20

What basis are biomass presented on

Answer 20

dry of daf due to moisture content.

Question 21

What is GCV?
Hows it measured

Answer 21

heat released per unit mass, assuming all latent heat is recovered.
bomb calorimeter