Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
Value Recovery From Solid
Confectionery Waste
Susan T.L. Harrison, Madelyn Johnstone-Robertson, Sharon
Rademeyer, Leslie Murhonyi Mapatana, Carol Ngwenya,
Caryn Horn, Shilpa Rumjeet, Nodumo Zulu and Mariette Smart
____________________________________
March 2019
Prof Susan T. L. Harrison
Director, Project Leader
Dr Madelyn Johnstone-Robertson
(former) Research Officer
Dr Nodumo Zulu
Research OfficerDr Mariette Smart
Research Officer
The Centre for Bioprocess Engineering Research
meet the confectionery waste team: senior researchers
Carol Zethu NgwenyaPhD candidate
Bioenergy
Sharon Rademeyer Researcher, M.Eng. graduate
PGA production
Shilpa RumjeetResearcher
PHA technoeconomics
Leslie Murhonyi MapatanaM.S(Eng) candidate
PHA production
Caryn HornPhD candidate
Pigment production
Literature review on scope and scale of the confectionery industry in South Africa
and its associated waste. Emphasis on the sugar, chocolate and starch
confectioneries.
Review typical treatment approaches to confectionery globally to ascertain
approaches to value creation from similar wastes elsewhere.
RESEARCH
APPROACH
“Start where you are.
Use what you have.
Do what you can.”
- Arthur Ashe -
Explore the waste biorefinery concept to draw together generic approaches from
other wastes for application to the confectionery waste.
Identify appropriate products with potential for market demand.
Propose microbial production systems suited to the bioconversion of confectionery
waste to these products.
Collect productivity and yield data for the production of the selected products.
Develop flowsheets for one product for the integrated utilisation of waste
components while maximising value creation. Compile material and energy
inventories for process assessment. Conduct techno-economic feasibility of the
process of using solid waste confectionery as feedstock to the biorefinery.
Confectionery Manufacture
produces Confectionery
Waste
South Africa’s
confectionery
industry
generates
substantial
organic waste
Confectionery Waste to Landfill:
contaminates water contaminates air
uses space
Currently
South Africa’s
confectionery
waste is
largely sent
to landfill – wasting resources,
polluting ground
water, forming
GHGs, and using
space
Confectionery Waste to Waste Biorefinery:
bioenergynatural soil amelioranteco-friendly “plastics”
natural pigmentclean water
Confectionery
Waste to
Waste
Biorefinery:
bioenergy
natural soil
ameliorant
eco-friendly
“plastics”
natural
pigment
Feedstock ProductsConversion
Processes
Municipal solid waste
Animal waste
Pulp and paper waste
Food waste
Agricultural residues
Timber
Crops
Algal biomass
Bioconversionsfermentation
enzymatic hydrolysis
Chemical Conversions
Thermochemical
Conversionsgasification
pyrolysis
hydrothermal conversion
Physicochemical
Conversions
Bioenergy
biogas
biofuels
Power products
electrical
thermal
Chemical products
polymers
platform chemicals
pigments
surfactants
fertiliser
fatty acids
Biomass products
compost
fibre
Th
e W
ast
e B
iore
fin
ery
Th
e W
aste
Bio
refin
ery
Sele
cti
on
of
bio
pro
cess
op
tio
ns
Complexity & Concentration
Chemically
defined, dilute
Chemically
complex,
concentrated
Chemically
defined, dilute
Physicochemical may be more suitable
Biorefinery units may be more suitable
High C
composition
High solids
content
High N,P
composition
Bacterial bioreactor
may be more suitable
Solids bioreactor
may be more suitable
Concentrated,
and/or high flows
Dilute, low flows,
or sporadic
Algal bioreactor
may be more suitable
Macrophyte bioreactor
may be more suitable
Chemically
defined,
concentrated
Sele
ctio
n o
f bio
pro
cess o
ptio
ns
Fine
Chemicals
Biopolymers
Platform and
Commodity Chemicals
Biomaterials
Bioenergy Products
Biomass Products
Power and Heat
incre
asin
g vo
lum
ein
creasi
ng
valu
e
Product selection criteriaTRL 1 Basic idea
TRL 2 Concept developed
TRL 3Experimental proof
of concept
TRL 4 Lab demonstration
TRL 5 Lab scale validation
TRL 6Prototype
demonstration
TRL 7 Pilot scale
TRL 8 Commercial design
TRL 9Ready for full
deployment
Technology Readiness Levels
ProductProduct
categoryTRL Use Primary feedstock
Poly-γ-glutamic acid (PGA) Biopolymer TRL 6 Soil conditioner
Water retention
C6 sugars
NH4+
Poly--hydroxyalkanoates
(PHA)
Biopolymer TRL 9 Biodegradable plastic for
healthcare products, packaging
and one-use plastic products
C6 sugars
Organic acids
CO2 & H2
Citric acid Organic
acid
TRL 9 Acidulant C6 sugars
Purple Monascus pigment Biopigment TRL 4 Colorant C6 sugars
Bioethanol Alcohol TRL 9 Biofuel, platform chemical,
precursor to polymer
C6 sugars
Biogas Biomethane TRL 9 Bioenergy C6 & C5 sugars,
organic acids etc
Products selected for study
Four products
Four student projects
Purple
pigment
PGA
Bioenergy
PHA
Renewable energy production
Confectionery waste carbohydrate
content = ideal bioprocess feedstock
for renewable energy production.
Here, confectionery waste was used
as a substrate to convert to
bioenergy as:
• Bioethanol by microbial
fermentation using Zymomonasmobilis
• Biogas using anaerobic digestion
(AD).
Valorisation of waste streams results
in increased resource efficiency
producing commodity products and
reducing their environmental
footprint.
Bio
en
erg
y
Bioethanol
0.0
0.2
0.4
0.6
0.8
1.0
Synthetic Mix Candy Mashmallows Chocolate
Yie
ld (
g/g
)
Yx/s Yp/s Max. EtOH ( x10 g/L)
Biogas
0
200
400
600
800
1000
1200
0 10 20 30 40
Cum
ula
tive
bio
gas
pro
duce
d (
mL)
Days
Flour confectionery Mixed confectionery waste
Bio
en
erg
y
Polyhydroxyalkanoate (PHA) production
confectionery
wastePHA
What is it?
Landfill
Why PHA?• Biodegradability
• Biocompatibility
• Renewable feedstock
• Physical and mechanical properties
• Application versatility (packaging,
agriculture, pharmaceuticals etc.)
Intracellular carbon
storage compound
produced by some
microorganisms under
controlled condition
microorganisms
PH
A
Waste characterisation
carbon source
composition
Microorganism selection
Alcaligenes latusCupriavidus necator
Growth of the species
on confectionary waste
0.00E+00
1.00E+08
2.00E+08
3.00E+08
4.00E+08
5.00E+08
6.00E+08
7.00E+08
0 2 4 6 8 10 12 14
Cells
/ml
Time (hours)
candy chocolat
0
5
10
15
20
25
0 5 10 15
To
tal c
arb
ohyd
rate
(g
/l)
Time (hours)
candy chocolate
Experimental growth
and sugar utilisation of
Alcaligenes latus
Optimisation and PHB
production continuing
for A.latus (oils) and
C. necator (sugars)
PH
A
RESOURCE RATHER
THAN WASTE
Bacillus sp
Bioflocculant
Fertiliser/soil
enhancer
Poly(γ-glutamic) acid
(PGA) production
Attractive as a soil conditioner or bioflocculant
• Biodegradable
• Non-toxic
• Hygroscopic
• Can be used as a nitrogen source
• Has many flocculation applications
PGA is produced by Bacillus species that are able
to use confectionery waste as a carbon source
PG
A
1. Identify a Bacillus species that is able to produce PGA
2. Characterise the confectionery waste from an identified factory in SA
3. Identify key nutrients needed to supplement the waste to produce PGA
4. Determine the sugar concentration range needed to produce PGA
5. Commission and operate a bioreactor set-up that will produce PGA
1. Bacillus licheniformis JCM 2505 selected as it can use inorganic nitrogen
2. Waste characterisation showed that hard candy waste consists mostly of sucrose
3. Hard candy waste with “basal medium” can be utilised by B. licheniformis 4. Growth kinetics on candy and sucrose are comparable
5. PGA formation in a fed-batch culture favours a specific C:N ratio
PG
A
Fungal pigment production
Filamentous fungus, produces deep red pigmentation
• Monascus-like polyketide pigments
• Confectionery waste as a potential source of sugars,
but requires a nitrogen source
Penicillium purpurogenum
Shown to be suitable substrate for growth and pigment production
• Culture pH maintained using citrate buffer
• Supplemented with soya peptone
Marshmallow confectionery waste
Shift from chemical to natural colourants
• Health and environmental benefits
Microbial sources gaining interest over plant and insect sources
• Fast growth and consistent, controllable production
Overview
Agar plate
Multiwell plate
Shake flask
7 L Bioreactor
Natu
ral p
urp
le p
igm
en
t
Anaerobic
Digestion
tech-ready
not complex
on site use as CHP
ORpolishing step in
the WBR
Technoeconomics
PGA
production
Technoeconomics
inoculum
preparation
bioprocessing
for PGA
PGA
recovery
Tech
no
eco
no
mic
s: PG
A
cell
culture
@ 26 h
4 g/L cells
40 g/L PGA
Upstream: Inoculum Preparation
Capital cost 2018 (3 chains):
US$ 440 000 * 4.74 = US$ 2 085 600
Main process: PGA Production
Capital cost 2018 (3 chains):
US$ 1 200 000 * 4.74 = US$ 5 688
000
Downstream:
Capital cost 2018:
US$ 168 600 * 4.74 = US$ 799 000
US$ 14 600
US$ 73 000
US$ 50 000
US$ 31 000
PG
A p
rod
uctio
n c
ap
ital c
osts
PG
A p
rod
uctio
n o
pera
ting
co
sts
Inoculum preparation and main process
Operating costs 2018 (3 chains):
US$ 1 285 000 per year
Downstream:
Operating costs
2018:
US$ 133 700
PGA
production
details of
process
economics
TechnoeconomicsUSD (2018)
Revenue: 83810 kg/year PGA
sold at $100/kg$ 8 381 000 / year
Total Operating Cost $ 1 418 700 / year
Fixed Capital Cost $24 702 700
Working Capital (15% of fixed) $3 705 400
Total Capital Cost $28 408 100
Taxation (%) 28,0
Escalation (%) 6,2
Years of depreciation 10
Scrap value (%) 5,0
WACC (discount rate, %) 15,0
ROI (%) 33,8
Payback Period (Years) 4,6
NPV ($ 2018 after 15 years) $12 022 000
IRR (%) 23,0
PGA
production
profitable for
food-grade PGA
less profitable for
agricultural PGA
but opportunity to
improve using low
cost reactors and
offsetting disposal
costs
Technoeconomics
optimise
bioreactors
define
purification
PGA grade
vs
costs
Conclusions waste bio-
refinery
green-
house
gases
load on
landfill
produce
bioenergy
lost bio-
resource
toxic
ground-
water
CONCLUSIONS
Conclusions
Bioenergy
Demonstrated
Biogas – CHP
implemented industrially
Polyglutamic Acid
Demonstrated
Low cost reactors under
evaluation
Scale-up studies and
evaluation planned
Polyhydroxyalkanoates
Demonstrated
Currently being
assessed for industry
Purple MonascusPigment
DemonstratedScale-up studies
planned
CONCLUSIONS
Conclusions waste
bio-
refinery
sugar
chocolate
starch
confe
ctio
nery
ind
ust
ry
CONCLUSIONS
reimagining
confectionery
waste as a
resource
Confectionery waste can be valorised
selecting possible
bioproducts and
bioprocesses for
valorisation
proof of concept
for four selected
products in four
student projects
assessing
economic &
environmental
potential
Contact us
www.CeBER.uct.ac.za
Chemical Engineering Building, UCT
Acknowledgements
Linda Godfrey and team for
project advice and management
DST – CSIR Waste RDI for funding
DST NRF for SARChI chair funding