Advantages and disadvantages of biofuels and other clean alternative fuels…
Fitting is round peg in a square hole?
Prof Sanette Marx
DST/NRF Research Chair in Biofuels
NSTF National Science and Technology Forum
16-17 April, Kempton Park, Gauteng
Sustainable Energy for All in South Africa
Considering biofuels
Bio-based fuels, energy , electricity
and materials
What are the available
resources?
Which conversion processes are
available?
Advantages and issues associated
wth bio-based fuels
• Socio-economic• Environmental• Technological
CONCLUSIONSActions?
Should SA be investing in biofuels ?
USAUnited Emirates
South Africa
Brazil
© 2015 Global Footprint Network.
Overview of bio-based fuel options
Petroleum Alternatives
BIO-ETHANOL
BIO-BUTANOL
Diesel Alternatives
BIODIESEL
RENEWABLE DIESEL
Other Alternative Fuels
BIO-JET FUELBIOGAS
BIO-COAL
Bio-basedFertilisers
Bio-based materials
Bio-electricity
Biogas leachate
Fermentation effluent
Bio-textiles, Bio-polymers
Bio-resins, Bio-chemicals
Bio-coal
Bio-hydrogren
• 1st Generation
• Edible plants and oils
• Starch and sugar for ethanol
• Edible virgin oil
• Advantages• Readily available
• Simple technology
• Proven technology
• Issues• Expensive
• Food vs Energy
• Water footprint
• Carbon footprint
• Biodiversity
• 3rd Generation
• Micro algae
• Macro algae
• Advantages• High growth rate (?)
• Can capture CO2
• More products
• Issues• Water content
• Over estimation of potential
• Micro toxins
• Water footprint
• Biodiversity
• 2nd Generation
• Agricultural residues
• Municipal waste
• Used cooking oil
• Advantages• Readily available (?)
• Less expensive feedstock
• More products
• Issues• Expensive technology
• Water footprint
• Carbon footprint
• Biodiversity
Feedstock options
Petrol
E85 Bioethanol blend
DieselB20 Biodiesel
blend
Biodiesel
Alternative fuel price report, April 2015
The link to crude oil
Conclusions? SOCIAL
ENVIRONMENTAL ECONOMICAL
Tolerable Equitable
Viable
Sustainable
Possible solutions?WaterLand
Standard of living
Water impactCarbon impact
Biodiversity
DevelopmentTechnology
Our reality
We have coal> 200 years ??
Is it economical?
Is it socially acceptable?
Is it environmentally
acceptable?
YES
NOCan we make it environmentally
acceptable ?
YESHOW ?
Clean Coal Technologies
Co-gasification
Co-combustion
Co-refining
Biomass or Biochar?Upstream or downstream?Feedstock?
Our solution
We have sewage
We have municipal solid waste
We have agriculturalwaste
Fermentation
Biodiesel
Pyrolysis
Gasification
Anaerobic digestion
Hydrothermal liquefaction
Why?▪ High water content feed▪ No drying required▪ High value char and oil▪ Bio-chemicals in water
phase▪ Process gas (high P)
Issues▪ Technically difficult▪ Experimental phase
Easy, but• No enough oil• Economics?
Economics
Economics
SlaggingLow density
Drying requiredTechnical issuesLow value oil
How does it work ?
Food wasteLignocellulose
Municipal waste
Nitrogen atmosphere
Water
Pressure100 bar
Temperature280 – 320 °C Biochar (25-32 MJ/kg)
Bio-adsorbentGreenCoalSoil amendment
Bio-oil (29-40 MJ/kg)Renewable fuelPlatform chemicalsBoiler fuel
Bio-gasLight gasesCO, CO2, H2
Water phaseMonomeric sugarsPhenol derivatives
Hydrothermal liquefaction (HTL) Research @ NWU
Yokoyama et al., 1987
20081987
First paperspublished Our 1st batch reactor
2010
1st output
2011/2012
2 more batch reactors
2014
First paper
2016/2017
First patentPilot plant
2022
Commercial plant
SOCIAL
ENVIRONMENTAL ECONOMICAL
Improved living conditionsImproved economic participation
Cleaner energy
Reduced GHG emissionsReduced ecological impact
Improved sewage management
Positive techno-economic simulation
Business case beingcompiled
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What is the significance of this for SA?• ESCOM uses approximately 118 million ton coal/annum
• 42% ash content
• Conversion process is 45% efficient
• Average CV value is approximately 15.5 MJ/kg
• Can theoretically generate 26.3 GW
• If we can replace the coal with biochar from our plant• 1.2% ash content, assume 45% conversion efficiency
• Average CV value is approximately 30.8 MJ/kg
• Can generate 52.2 GW OR
• Need only 60 million tons biochar/annum
• If we co-feed from bio-oil from our plant with crude oil• Reduce S emissions by almost 50%
• Increase kerosene fraction of fuel by 100%
• No need for blending
• Local communities• Struggle to make ends meet;
• Municipal infrastructures are old an inadequate;
• Landfill sites fill up too fast;
• Service delivery to fast developing informal settlements;
• Increasing fuel prices (food and commodity prices)
• Coupling biogas production (sewage) to HTL (landfill waste)• Access to local clean energy products;
• Increased local job creation;
• Municipal revenue by selling products to electricity producers;
• Improved service delivery;
• Reduced local GHG emissions;
• Better environmental living conditions.
How does this relate to Energy for All?
Thank you for your attention
Prof Sanette MarxDST/NRF Research Chair in Biofuels
Centre for Excellence in Carbon-based FuelsNorth-West University
References• Gerbens-Leenes. 2017. Bioenergy water footprints, comparing first, second and third
generation feedstocks for bioenergy supply in 2040. European Water 59, 373-380.
• HLPE, 2013. Biofuels and food security. A report by the High Level Panel of Experts on Food Security and Nutrition of the Committee on World Food Security, Rome 2013
• "Human welfare and ecological footprint" by Travelplannerbased on data from UN Development Programme and Global Footprint Network - Own work. Licensed under CC BY-SA 3.0 via Commons -https://commons.wikimedia.org/wiki/File:Human_welfare_and_ecological_footprint.jpg#/media/File:Human_welfare_and_ecological_footprint.jpg
• Hammond GP. Seth SM. 2013. Carbon and environmental footprinting of global biofuels production. Applied Energy, 112:547-559
• Börjesson P, Tufvesson LM. 2011. Agricultural crop-based fuels: Resource efficiency and environmental performance including direct land use change. Journal of Cleaner Production, 19:108-120
• Liu J, Mooney H, Hull V, Davis SJ, Gaskell J, Hertel T, Lubchenco J, Seto KC, Gleick P, KremenC, Li S. 2015. Systems integration for global sustainability. Research, 347(6225):1258832(1-9)
• Lange M. 2011. GHG balance of biofuels taking into account land use change. Energy Policy, 39:2373-2385
Technology options – 1st generation
Starch
Sugar
Edible oil seeds
Milling
Wet or dry
Pretreatment
Cooking/Enzymatic liquefaction
Hydrolysis
Acid or enzymes
Fermentation
Yeast, fungi, bacteria
Ethanol, Butanol, Acetone,
Methanol, Glutamic acid, 3-
Hydroxypropanoic acid, Malic acid,
Acetate, CO2, DDGS, Sorbitol,
Diesel, HMF, Furfural
Drying or dilution
Chemical catalysis
Extraction
Oilseed cake
DryingEsterification/
Transesterification
Biodiesel
Glycerine
SoapsSuccinic acid
1,3 PropanediolButyric acidAcetic acid
AcroleinOlefins
Polyols (Plastics)
BIOCHEMICAL ROUTES
CHEMICAL ROUTE
CHEMICAL ROUTE
BIOCHEMICALROUTE
Technology options – 2nd generation (Lignocellulose)C
ellu
lose
Lign
inP
rote
inA
shH
emic
ellu
lose
Fat
PretreatmentCrystalline cellulose
Cellulose fibres, polycarbonate
Pretreatment Hydrolysis Co -Fermentation
Chemical catalysis
Ethanol, Butanol, Acetone, Methanol, Glutamic acid, 3-Hydroxypropanoic acid, Malic acid, Acetate, CO2, DDGS, Sorbitol, Diesel, HMF,
Furfural
Acid dehydration Hydrogenation1,2 Propanediol
Methane
Extraction
Combustion
Chemical liquefaction
Polyols for polymers/plastics
Power, Heat
Extraction Proteins Amino acidsHydrolysis
BIOCHEMICAL ROUTES
CHEMICAL ROUTES
CHEMICAL ROUTES
CHEMICAL ROUTES
Technology options – 2nd generation (Lignocellulose)Li
gno
cellu
lose
Thermochemical liquefaction
Pyrolysis
Gasification or co-gasification
High quality biocharHHV 25-30 MJ/kg
High quality Bio-oilHHV 35-40 MJ/kg
Biogas
Low quality Bio-oilHHV 9-12 MJ/kg
Syngas
Fischer-TropschLiquid fuels and
chemicalsGasification
Hydroprocessing
Process heat, electricity
Bio-naphtha,Bio-kerosene
Renewable diesel
Biogas
Alcohols, Acids, Esters, Aldehydes,
Ketones
Drying
Drying
Soil remediationAdsorbent
Activated carbon
Technology options – 2nd generation (Oils and waste)
Pretreatment
Filtering, drying, acid wash
Esterification
Lipase, Acid
Transesterification
Lipase, Acid, Alkaline
Glycerol
Biodiesel
Used Cooking oil,Inedible oils
Municipal waste, sewage, landfill,
Manure, food waste
SoapsSuccinic acid
1,3 PropanediolButyric acidAcetic acid
AcroleinOlefins
Polyols (Polymers)
Hydroprocessing
Bio-naphtha,Bio-kerosene
Renewable diesel
Anaerobic digestion
Biogas
Methane
Hydrogen
Process heat,
electricity
Fertilizer
VFA
Biopolymers, esters, dietary supplements, food and perfume additives, vinyl
acetate, solvents
Technology options – 3rd generation (Algae)
Micro and Macro algae
Harvesting and Drying
Direct combustion
ExtractionPharmaceutical additives, colour pigments,
sugars, glycerol, enzymes
Process heat, electricity
Pyrolysis
Gasification
Thermochemical liquefaction
Anaerobic digestion Methane,
Hydrogen, Fertilizer
VFA Biopolymers, esters, dietary supplements, food and perfume additives, vinyl
acetate, solvents
Biogas Low quality oilBiochar
Biogas High quality oilBiochar
Alcohols, Acids, Esters, Aldehydes,
Ketones
Syngas Fischer-TropschLiquid fuels and
chemicals
Soil remediationProcess heat,
electricity
Hydroprocessing
Bio-naphtha,Bio-kerosene
Renewable dieselBiogas
Micro and Macro algae
Extraction
Transesterification
BiodieselGlycerol
1,3 Propanediol, VFA, AcroleinOlefins, Polyols (Polymers)