Transcript Valorization of spent biomass (digestate) from biogas plants

Waste recycling on BLSS
Higher plants
cultivation on Earth
Waste biomass
Waste biomass and the
biorefinery concept
Plants on BLSS
Use biomass to obtain the
most valuable product
Food production
We can take food
out of waste
Type of tissue
Plant species
Biomass
composition
Growth
conditions, i.e.
light intensity
non structural carbohydrates
proteins
ash
lipids
?
lignin
organic acids
structural carbohydrates
Waste biomass that can be
recovered as food
cellulose and hemicellulose
simple sugars
(digestible)
chemical and enzymatic
methods
Chemical methods:
• use of acid;
• Recycling is difficult.
Enzymatic methods:
• More controllable;
• Slower and less complete.
AIMS
•
characterize 2 different plant tissues (waste biomass:
strawberry and sweet potato leaves) collected at 2
different light intensity ranges;
•
verify to what extent the digestible fraction of waste
biomass could be potentially increased.
Lunar Greenhouse at the Controlled
Environment Agriculture Center
(CEAC, Tucson, University of Arizona)
Leaf disks sampling and light intensity
measurement inside the Lunar
Greenhouse.
Light intensity: 800-1000 (high light) and
20-40 (low light) μmol quanta m-2 s-1
Extraction of plant
tissue components
Acid hydrolysis: structural
polysaccharides degradation and
lignin determination
Spectrophotometric
measurement of
chlorophyll
anion exchange chromatograph and HPLC for the
analysis of carbohydrates and organic acids
Proteins, chlorophyll, non-structural carbohydrates and organic acids in
sweet potato and strawberry leaves under high and low light intensity
(two way ANOVA)
Main effect:
Biomass diversity
Parameter
Main effect:
Light intensity
Interaction
Biomass diversity-Light intensity
Unit
Sweet potato
leaves
Strawberry
leaves
low
high
Potato
low light
Potato
high light
Strawberry
low light
Strawberry
high light
mg cm-2
-
-
0.10a
0.17b
-
-
-
-
mg cm-2
-
-
-
-
0.07a
0.13ab
0.16b
0.17b
µg cm-2
28.67a
51.89b
-
-
-
-
-
-
µg cm-2
-
-
-
-
1.81a
1.92b
2.18c
2.37d
Glucose
µg cm-2
Fructose
µg cm-2
Sucrose
µg cm-2
8.08a
9.37a
39.62a
43.93b
37.84b
210.34b
97.50a 152.54b
-
-
-
-
Tot. soluble
sugars
µg cm-2
57.15a
292.13b
140.33a 208.94b
-
-
-
-
Starch
µg cm-2
15.79a
36.84a
123.27b
219.38c
-
-
-
-
-
-
-
-
Tot. proteins
Soluble
proteins
Tot.
chlorophyll
a/b
chlorophyll
Tot.
µg cm-2
carbohydrates
Malic acid
µg cm-2
Phosphate
µg cm-2
185.26a
361.66b
7.59a
22.92b
166.65a 380.27b
3.47a
-
15.40b
-
Sweet potato leaves
before acid hydrolysis
Structural
polysaccharides
80
80
70
70
60
60
50
starch
40
Ethanol
extractives
30
20
10
soluble lignin
hemicellulose
Cellulose
Water
extractives
Insoluble
lignin
% of dry matter
% of dry matter
Sweet potato leaves
after acid hydrolysis
…become
monomeric
sugars!
Mannose
Xylose
glucose
50
starch
40
Ethanol
extractives
30
Water
extractives
20
10
soluble lignin
Insoluble
lignin
0
0
non digestible digestible
non digestible
digestible
The digestible fraction was increased from about 50% to about
70% of the dry matter…to be tested in BLSS conditions…
galactose
Arabinose