TT Flashcards
1
Q
What is biomass?
A
Biomass is organic matter derived from living or recently living organisms. It typically contains carbon, oxygen & hydrogen, and often nitrogen and small amounts of many other elements (Na, K, Mg, Cl, Si, P, S and many more).
2
Q
What are the main feedstock used?
A
- Sugar and starch crops (sugar cane, sugar beet, corn, wheat)
- Oil crops (oil palm, soy beans, rapeseed)
- Lignocellulosic crops/ woody biomass (pine, spruce, eucalyptus, willow, poplar)
- Agricultural and forest residues, manure, other organic waste streams
- In the future: aquatic biomass (micro & macro-algae)
3
Q
What is a BBE?
A
The circular & BBE is an economy drive by efficiency in using crops and biomass for food, feed, chemicals, energy and fuels (WUR).
4
Q
What can we do with biomass?
A
o Food, feed, energy
o Materials: fibers for paper and wood for timber
o Substances: starch for plastics and bio-oil for paints
o Chemical building blocks: lactic acid for additives and polymers, ethanol for plastics, furans for resins and fuels.
5
Q
Bio-based is not biodegradable
A
Biodegradable products decompose over time through biochemical processes. Not all bio-based plastics are biodegradable. In theory fossil fuels can also be used to produce biodegradable plastics.
6
Q
What are the drivers for a BBE?
A
Climate change (it is renewable, no or less GHG emissions than fossil economy, overall more sustainable than fossil economy), security of energy supply (depletion of fossil fuels) and rural development.
7
Q
The three definitions/examples of ILUC
A
- Firstly, when a direct displacement of pastureland, cropland or crop use results in livestock or crops being produced elsewhere to continue to meet demand.
- Secondly, when the diversion of the crop to other uses triggers higher crop prices, which results in more land being taken into agricultural production elsewhere.
- And lastly, when infrastructure is developed in support of bioenergy production and human migration.
8
Q
What do you know about measuring ILUC?
A
It is difficult to measure ILUC, because ILUC of for example biofuels is another product’s DLUC. Models cannot distinguish between DLUC and ILUC. A lot of models did research into the LUC-related GHG emission of corn ethanol. Only a research by Searchinger et al. 2008 found ethanol to emit more than fossil-based gasoline. All 13 other researchers found corn ethanol to emit less than 40% of the fossil-based gasoline.
9
Q
Why do ILUC needs to be addressed?
A
It needs to be addressed if we want bioenergy (or any other application of biomass) to meaningfully contribute to GHG emission reduction.
10
Q
How to mitigate the risk of ILUC?
A
- Use low ILUC-risk feedstocks: residues, dedicated energy crops, algae
- Increase productivity of existing agriculture: produce more per hectare, reduce losses
- Expand production only on currently un-used, low carbon land: abandoned agricultural land or degraded land)
11
Q
What are emissions related to BBE?
A
The emissions that are considered for bioenergy are the supply chain emissions and the direct land use change (LUC). Indirect land us change (ILUC) is no considered as emission yet.
12
Q
Explain the key premises of BBE?
A
- Climate Change: there are opportunities to mitigate climate change by replacing fossil fuels with biomass as feedstock for energy, materials and chemicals. A pro is the decarbonisation of the energy system (negative emissions using for example BECCS). A con is the increase in land use change and associated emissions. The size of ILUC impact the mitigation ability of BBE.
- Energy/resource security: locally produced biomass can replace imported fossil fuels for energy and thereby improve energy security. The diverse portfolio of energy & feedstock sources also improves energy security.
a. The concerns about imports/foreign oil dependence are geo-politics, supply disruption, finite resources and price fluctuations.
b. Trade-offs are the increased use of natural land for crop production, this leads to carbons tock changes, biodiversity loss, water quality and quantity. Also increased food prices due to using food crops for energy and materials, this reduces the food security. - Rural development: new economic activities in rural areas create jobs and increase farm revenue. For the EU BBE could be an alternative outlet and incentive to enhance production. For developing countries increase farm gate prices and agricultural employment could improve rural livelihoods. Higher crop/food prices are good for farmers that produce more than they need for themselves, but non-farming households can buy less food (this is also a part of the food vs fuel debate).
13
Q
What are the two perspective of the relationship between food and fuel prices?
A
One perspective is that there is a causal relationship between biofuel expansion and food insecurity. A second perspective is that both are affected by oil prices, policy and regulation instead of by each other. Scientists say that biofuels alone do not affect food prices but that there are many more causes: high oil prices, weather conditions, currency exchange rates, policies, speculation in food commodities and increase in demand of food and fuel.
14
Q
How do you measuring food (in)security?
A
Key indicators are food prices and food price index (often commodity prices are used). But note that international commodity prices are not the same as local consumer prices. The four pillars of food security are: availability, access, utilization and stability.
15
Q
What are country examples of BBE?
A
- Brazil: investment in sugarcane ethanol already in 1970’s, now globally 2nd biggest producer of ethanol. Currently the have a large fleet of flex-fuel vehicles.
- Indonesia: has a large trade deficit & high subsidy for transport fuels, at the same time globally largest producer & exporter of palm oil. They use palm oil for biodiesel for domestic consumption.
16
Q
What are opportunities and challenges for sustainability?
A
- LUC does not only cause carbon stock changes, but also affects biodiversity, soil fertility, water quality and quantity, land tenure conflicts and social unrest, …
- Land grabbing, the acquisitions of land
- GDP and trade balance
- Opportunities and challenges are closely intertwined
- Perspective: global vs local and micro vs macro
17
Q
How to ensure sustainability?
A
- Binding sustainability criteria (EU-RED and in the Netherlands the Cramer criteria)
- Other (inter-)national regulations on agriculture, forestry and biodiversity
- Voluntary sustainability certification schemes, general for all crops and crop specific
- Standardization bodies (ISO)
- Requirements by funding agencies (Climate Bonds Initiative)
18
Q
The criteria that are included in the Cramer criteria are:
A
GHG emissions, competition with food and other application of biomass, biodiversity, welfare, prosperity and environment (waste management, air quality, erosion, use of agrochemicals).
19
Q
Biomass use as renewable energy source in the EU, what are the shares of biomass and heat of biomass?
A
Biomass for energy is the main source of renewable energy in the EU, with a share of almost 60% The heating and cooling sector is the largest end user, using about 75% of all bioenergy.
20
Q
Why do we need biomass potential assessments?
A
Whether there is enough biomass to reach renewable energy and BBE ambitions and what it delivers in terms of sustainability goals. Whether there is enough biomass at an affordable cost/price. Whether policies measures are needed to mobilize or to constrain biomass production/harvesting. To support the development of roadmaps/BBE strategies at regional and national levels.
21
Q
What are the biomass categories?
A
- Primary by-products/residues: at the source, for example sugar beet tops
- Secondary by-products/residues: later in the production chain at the mill, for example sugar beet pulp
- Tertiary by-products/residues: has had use, for example UCO
- Primary dedicated biomass: Specific crops, for example trees from forest
22
Q
What are the definition of biomass potentials?
A
Theoretical potential > technical potential > economic potential > implementation potential > sustainability implementation potential
23
Q
What is theoretical potential?
A
The theoretical potential is the maximum amount of biomass theoretically available within fundamental bio-physical limits. It represents the maximum productivity.
24
Q
What is technical potential?
A
The technical potential is the available amount under the regarded techno-structural framework conditions with the current technological possibilities. It also takes into account the spatial confinements due to other land uses as was as the ecological.
25
What is economic potential?
The economic potential is the share of technical potential that meets criteria of economic profitability within the give framework conditions.
26
What is implementation potential?
The implementation potential is the fraction of economic potential that can be implanted within a certain time frame and under concrete socio-political framework conditions, including economic, institutional and social constraints and policy incentives.
27
What is sustainability implementation potential?
The sustainability implementation potential is the fraction that can be produces sustainable according the sustainability criteria.
28
What are the sustainability considerations and potential s of primary forestry production and residues?
Primary forestry production and residues have limited ILUC risks in the EU, more likely outside the EU when new plantation forest is established on agricultural lands. The loss of dead wood and stumps may negatively influence the species diversity and soil fauna. However, leaving them all may result in increased fertilization and negative impacts on vegetation. When overharvesting increased risk for soil erosion and carbon stock change could occur. Harvesting should not be larger than the average forest biomass increasement. The quantity of water could be in danger, particularly new plantations increase the risk. And lastly the quality of water could change due to increased risk in N-leaching.
29
What are the sustainability considerations and potential s of secondary residues from wood industries?
Secondary residues from wood industries have no ILUC, biodiversity and water risks. There are debates that using the wood in panel boards, creates a carbon stock in comparison to combustion of the wood.
30
What are the sustainability considerations and potential s of argicultural residues?
Agricultural residues have no ILUC risks. There could be biodiversity loss when harvesting too many crop residues. Stubbles left are feed for fauna, also harvesting of residues gives more disturbance. Also, a moderate risk to lose soil organic carbon when overharvesting crop residues, risk to lose nutrients when overharvesting with have machinery. The quality of water could decrease due to N-input increase but may also reduce nutrient leaching.
31
What are the sustainability considerations and potential s of manure?
Manure has no ILUC risks. It could have a risk on biodiversity when the manure is used as fertilizer. If it lowers fertilization it may lead to soil quality loss but generally digestate is brought back to land. It may also reduce N and P leaching into water streams.
32
What are the sustainability considerations and potential s of Secondary residues of food processing industry?
Secondary residues of food processing industry have no sustainability risks in the four groups.
33
What are the sustainability considerations and potential s of biodegradable municipal waste?
Biodegradable municipal waste has no ILUC risks. The biodiversity, soil, carbon stock and water quality are affected positively in regions where it avoids landfill.
34
What are the sustainability considerations and potential s of post-consumer wood?
Post-consumer wood has no ILUC risks. The biodiversity, soil, carbon stock and water quality are affected positively in regions where it avoids landfill.
35
What are the sustainability considerations and potential s of rotational/annual arable crops?
Rotational/annual arable crops have large risk on ILUC as it competes with food and feed. However also high productivity. Intensive annual crops require relative high inputs of N, pesticides and mechanization with risk for adverse effects on soil biodiversity and water quality, leading to pollution of habitats and eutrophication diminishing floristic diversity. Risks for soil erosion related to annual cropping. This type of crops is a more GHG intensive crop. If produced with irrigation in arid areas it leads to depletion of water.
36
What are the sustainability considerations and potential s of perennial lognocellulosic crops?
Perennial lignocellulosic crops have only ILUC risk when it grows in agricultural lands. It could reduce the biodiversity in the form that it provides winter shelter for birds. Because of its potential to grow on marginal lands it could increase soil quality and soil carbon stock. In arid regions ground water abstraction and depletion is possible because of the deep roots.
37
Cost-supply assessment for biomass potentials? (three types)
- Market prices for already trade biomass types.
- Road-side-cost for biomass for which markets are not developed yet. The cost depends on the level of waste. For example, dedicated biomass crops have all cost allocated to the biomass while waste has no costs allocated.
- At-gate-costs cover the costs at roadside + transport and pre-treatment until the biomass reaches the conversion plant gate. The costs that are allocated to biomass for this category are all the road side costs, the logistics costs between road side to plant gate which vary according to for example the type of transport and the pre-treatment.
38
What are methods to assess the potential role of the BBE?
- On the process scale an LCA or plot/technology scale could be made.
- On the sectoral scale an energy system, agricultural economy, land cover and use or biophysical environment could be made.
- On global interaction scale an integrated assessment model (IAM) could be made.
39
What are scenarios?
Scenarios are storylines which describe plausible alternative trends in the evolution of society and ecosystems over the long-term. Often it is a baseline scenario without governmental policies vs a scenario with mitigation policies.
40
What are the five Shared Socioeconomic Pathways (SSP) ?
- SSP1: Optimistic world (low challenges to mitigation and adaptation)
- SSP2: Middle of the road (current trends)
- SSP3: Pessimistic world (high challenges to mitigation and adaptation)
- SSP4: Inequality in the world (Adaption and challenges dominate)
- SSP5: Fossil-fueled development (Mitigation challenges dominate)
41
What is a Integrated Model to Assess the Global Environment (IMAGE)?
Model framework that simulates the global consequences of human activities. It represents the interactions between society, the biosphere and climate system. The model is used for global, long term (2050-2100) assessments.
42
Why do models have different outcomes?
Models are simplifications, different models have different results
o Future energy/agricultural demand
o Technological assumptions (availability, costs, etc.)
o Biomass resources
o Solution Method: Simulation vs. Equilibrium vs. Optimization
→ Model Intercomparison Projects (MIPs)
43
What are broad agreements among models?
o Biomass used significantly in future projections
o Importance of lignocellulosic feedstocks
o Use of BECCS
44
What are broad disagreements among models?
o Transport ↔ Power
o Supply regions
o Cost / Yield projections
45
What is a biorefinery?
A biorefinery is the sustainable processing of biomass into a spectrum of marketable products and energy. The spectrum of products consists of bioenergy, bio-oil, bioplastic and biochemicals just like the output of an oil refinery. But a biorefinery also has protein-rich animal feed, nutrients and healthy food ingredients as additional output. Another difference between an oil and biomass refinery is the needed pre-treatment of the biomass. Biomass has a lot of oxygen which has to be removed in order to produce energetic end products. If the oxygen is not removed the products will oxidize which will make CO2 instead of the end products.
46
What are the different conversion processes in a biorefinery?
- Bio-chemical
- Thermo-chemical
- Physical-chemical
- Others
47
What are the differences between first, second and third generation biofeedstocks?
1. First generation are the high energy bio-feedstocks; therefore, people often describe it as food products.
2. Second generation are the products in biomass to strength the biomass (lignocellulose), this is the reason that people often think that second generation biomass is the waste products from first generation biomass.
3. Third generation is biomass that does not interact with the food chain. An example is algae, because it grows on places where no food can grow.
48
Second and third vs. first generation biofeedstocks. Pro en cons?
- Pro: many different sources including waste, no competition with food, no direct land use change and more sustainable.
- Con: more difficult to convert, higher cost of production and require development of new conversion technologies.
49
What is the definition of a platform in a biorefinery?
The key intermediates between feedstock and final product. It can be a wide range of different products, ranging from a single carbon to large molecules. They can be converted to products with combination of thermal, biological and chemical processes.
50
What are the different platforms that you should remember?!
H2, Syngas, Biogas, C5 & C6 Sugars, Lignin and Pyrolytic oil / Bio-oil
51
What is syngas?
Syngas is a mixture of mainly CO and H2 produced by thermochemical process of gasification of various biomass sources. It is also called a Fisher-Tropsch process as the Germans used this process during the war to produce fuels from corn. The process is as follows:
1. Drying of biomass
2. Pyrolysis of dry biomass to produce tar gases and charcoal
3. Combustion and cracking of the tar gases and charcoal to cracked tar and hot reactive charcoal
4. Finally reduction makes from the products gasses in the form of H2 and CO.
52
What is biogas?
Biogas is a mixture of mainly CH4 and CO2 produced by biochemical process of anaerobic digestion of organic residues and crops. The 4 key stages of anaerobic digestion are hydrolysis, acidogenesis, acetogenesis and methanogenesis. Remember these stages by hard.
53
What are C5 and C6 sugars?
C5, C6 Sugars are produced by hydrolysis of crops and lignocellulosic feedstock. Lignocellulosic feedstock - Usually after pretreatment (previous lecture) to separate lignin. The treatment steps are different for sugar crops, starch crops and lignocellulosic biomass as some need pretreatment and some don’t.
54
Hydrolysis (conversion to sugars), 2 types :
- Acid hydrolysis – catalyzed by acids (i.e. sulphuric, hydrochloric)
o Concentrated acid – low temperature, atmospheric pressure
o Dilute acid – high temperature
- Enzymatic hydrolysis – use of enzymes (cellulase, hemicellulase)
o A advantage is that it is more effective, mild process conditions
o A disadvantage is the slow reaction, thermal stability, recovery
55
What is lignin?
Lignin, attained by pretreatment (physical, biological or chemical) of lignocellulosic feedstocks. A really big disadvantage that lignin can make a large variety of products except money, the process is really expensive.
56
What are pyrolytic liquid and bio-oil?
Pyrolytic liquid / Bio-oil is produced by thermochemical process of pyrolysis of various biomass sources. The pyrolysis process yields char, bio-oil (tar) and gasses. An advantage is that bio-oil has a high energy density and is therefore easy to store and transport. The end products are a mix of many oxygenated compounds. Flash, fast pyrolysis main product bio-oil.
57
What is H2?
```
Hydrogen attained by chemical/biochemical processes after various platforms:
- Water-gas shift reaction of syngas
- Steam reforming of biogas
- Fermentation of C5, C6 sugars
o 𝑪𝑶 + 𝑯𝟐𝑶 ⇄ 𝑪𝑶𝟐 + 𝑯𝟐
o 𝑪𝑯𝟒 + 𝑯𝟐𝑶 ⇄ 𝑪𝑶 + 𝟑 𝑯𝟐
Can also be attained by:
- Anaerobic digestion of organic residues
- Water electrolysis with electricity
o 𝟐 𝑯𝟐𝑶 → 𝑶𝟐 + 𝟐 𝑯𝟐
```
58
Why are there multiple technologies required for the conversion processes?
This is required due to the diversity of the biomass resource with a broad range of physical and chemical characteristics. The best process is needed for optimizing the biomass conversion. It is also depended on the desired output, the broad range of products.
59
What are the different types of biofuels?
Bioethanol, biomethane, biodiesel, synthetic biofuels (fischer-tropsch, Methanol, Methanol to gasoline, dimethyl ether, synthetic natural gas) and upgraded pyrolysis oil.
60
Biochemical conversion of bioethanol synthesis?
- Fermentation
o Anaerobic process, converts C5 & C6 sugars to ethanol
o Microorganism mostly yeast
- Distillation & Drying
o Separation of water to achieve required purity for automotive fuel
- Solid residues
o Used as animal feed
o Lignin – lignocellulosic feedstock, combusted for energy or valorized other ways
61
Biochemical conversion of biomethane synthesis
- Upgrading of biogas from Anaerobic Digestion
| - Can be fed to natural gas grid or used as vehicle fuel
62
Chemical conversion biodiesel by transesterification
- Feed oil from oil crops (rapeseed, palm), oil residues (animal fat, UCO) or algae.
- Transesterification
o Process of converting oils to fatty acid methyl esters
o Glycerin produced as by-product
o Most common biodiesel
63
Chemical conversion biodiesel (renewable diesel) by hydrotreating
- Feed Oil hydrotreated, hydrogen used to remove oxygen
- Straight chain hydrocarbons that are free of aromatics, oxygen and sulfur and have high cetane numbers
- Better product quality than from esterification
64
Thermochemical conversion syngas
- Chemical composition of syngas: (2n + 1) H2 + n CO
- Syngas from Gasification can be upgraded
o Fischer-Tropsch Synthesis: catalytic chemical reaction converting syngas to hydrocarbons of various molecular weights depending on operation temperature. Primarily diesel product, but further upgrading can make naphtha and kerosene.
o Methanol, Methanol to gasoline (MTG): Methanol synthesis is a chemical building block for a range of industrial chemicals. The end products can directly be used as fuel supplement in the form of a gasoline blend or other liquid fuels.
o Dimethyl ether (DME): This is produced by subsequent dehydration of methanol in the presence of a catalyst. It can be pressurized to store and transport as liquid like LPG.
o Synthetic natural gas (SNG or biomethane): This is produced by a catalytic methanation of syngas, followed by CO2 removal. It can be fed to the national grid or used as vehicle fuel.
- Syngas resource from wide variety of biomass
- Fuel obtained from syngas is called synthetic biofuel
65
Thermochemical conversion methanol-to-gasoline (MTG) process
It is a two-stage catalytic process where methanol is used to generate hydrocarbons of various molecular weights using zeolite catalyst. Contrary to FT technology require minimal end processing. The primarily end product is gasoline.
66
Thermochemical conversion, the bio-oil from pyrolysis can be upgraded
Hydrotreating is needed to meet quality specifications for fuels. In the process they remove oxygen, nitrogen and sulphur. The end product can be co-feted to a petroleum refinery for cracking to produce desired range of fuels.
67
What are integrated biorefineries?
The integration of different conversion technologies that process a wide range of feedstock and produce a wide range of products. The integrated biorefineries link high-added value with high volume.
68
What is the future of bio-based chemicals?
Due to government regulation the development of biorefinery is driven toward biofuels. Currently there a no regulation on bio-based chemical materials now. A promising approach is to co-produce for improved economics because there is a market potential that could reach 113 million tonnes by 2050 (38%).
69
What are the challenges on future bio-based chemicals?
1. Technical Challenges
a. Processing with solids
b. Complex biomass structure
i. Fundamental understanding of biomass structure and process chemistry, Closing carbon, mass & energy balances, Identifying coproducts, intermediates and residues and Understanding the effect of feed and process variations.
c. Need to improve process efficiency
i. Catalyst development, Genetic and metabolic engineering, Microorganism development, Reactor design and optimizing kinetics, Efficient solid handling and processing and Enabling flexibility to feedstock variation and different feedstock resources.
2. Commercial Challenges
a. Difficulty finding financing
b. High capital costs
3. Requirement of regulatory steering
a. Subsidies and mandates as incentive
b. Creating new markets
4. Need to establish biomass supply chain
a. Feedstock infrastructure
b. Product distribution network
70
Is the use of biomass 100% carbon neutral?
- Dedicated energy crops: energy inputs and GHG emissions due to fossil fuel input during production (fertilizer, use of tractors etc.), transport, possible refining (to e.g. liquid biofuels) and possible after end use (e.g. disposal of ashes).
- Residues do not require fossil fuel input during ‘production’, but collection may require energy (mainly of field-based residues) -> overall, much smaller GHG emissions.
- Land use change can cause additional emissions.
- Timing between C- emission and C -uptake can be an issue. The fact that bioenergy is ultimately renewable is not debated, but the time until the repayment of any potential carbon debt is repaid is under debate.
71
Carbon debt & parity points
- Carbon debt time= the time until the Cbalance of forest + fossil system is equal to t = 0
- Carbon parity time = the time until Cbalance of forest + fossil system is equal to the balance of a counterfactual scenario (what would have happened if we assumed no biomass would have been used for energy).
72
Burning biomass releases more CO2/kWh than natural gas or even coal
True but: The same biogenic C would have been emitted (sooner or later) when the tree dies, and through micro-organisms (bacteria, fungi) the Carbon is released again in the atmosphere. So, again, it is a matter of timing.
73
What is the carbon debt or credit discussion?
Carbon debt approach is taking the moment of harvest as reference point, while the carbon credit approach is taking the moment of planting as reference point. In the case of plantations established by men the often call it carbon credit.
74
What is the landscape-level?
That is the total carbon stored in the forests in the landscape. This carbon level should stay constant over time. This means that: amount of wood cutting down = amount of wood growing.
75
What is IWUC?
Indirect Wood Use Change
76
What are C-debt mitigation options?
1. New plantations on degraded/C-poor land -> imminent carbon credit!
2. For managed/commercial forests: Use of fertilizer and weed control (within SFM limits) – increases productivity strongly
3. Increased early stand density & use of pre-commercial thinning’s
Options 2 & 3 cause no additional land use and reduce any C-payback times strongly (+ additional output for pulp & timber), but all need incentives
77
What are bioplastics?
biodegradable: fully (PLA (polylactic acid), partially (Starch plastics), no (PBAT, PBS, PCL, PVOH)
Not biodegradable: fully (Bio-based-PE, -PP, -PA, -PUR), partly (Bio-based PET), no (PE, PP, PET, PUR, ABS…)
78
Overview of important commercialized bio‐based plastics:
- Starch plastics -> Direct use/modification of the natural structure
- Cellulose plastics -> Direct use/modification of the natural structure
- Polylactic acid (PLA) -> “New” structure, Via sugar fermentation (biochemical)
- (partially) Biobased PET -> “Drop‐in” chemical, via sugar fermentation
79
Starch
Feedstock: Potato, maize, wheat, soybean…
Direct use: food/feed, paper/board, pharmaceuticals and starch plastics
Indirect use: starch > sugar > ethanol, ethylene, lactic acid
Characteristics: oxygen and carbon dioxide barrier properties, it is biodegradable dependent on the copolymer, the melting point is 50-60 degrees.
80
Cellulose
Feedstock: wood pulp
Use: cellulose esters > lacquers, explosives and replacing ivory. Cellulose acetate > cigarette filters, textile fibres, packaging film, surface coating and pharmaceuticals.
Characteristics: high or no melting point
81
PLA (polyethylene terephthalate)
Feedstock: corn or sugarcane
Use: film, bottles, cups, packaging, fibres, injection moulding
Characteristics: biodegradable, high melting point
Synthesis of PLA: made from C6 sugars (sugars, molasses, sugar beet juice, sugarcane juice), Starch: (corn, whey, rice, potato, wheat, tapioca), second generation biomass.
82
In the 21st century… developments:
- 2001: PLA and starch plastics commercialized on large scale (for packaging)
- 2000s‐2010s: commercialization of bio‐ based PUR (remember Henry Ford and the soybean?)
- 2009 PET bottle recycling reached 40% in EU
- 2010‐today: large scale bio‐based PE, PVC, PET (partial), Nylon11, Nylon12, ECH, PHA and expanding of PLA and starch plastics
- 2018: Europe publishes the first Plastics Strategy
- Oct 2018: EU Parliament approves to ban top 10 single‐use items found on the sea shores
- Future: fully bio‐based PET, high performance Nylons (e.g. PA6, PA66)
- Future: furanic chemistry, cellulosic chemistry, oleochemistry, CO2‐based chemicals and fuels
83
What are the unfavourable characteristics and possible interventions of biomass for modern energy supply?
1. Dispersed nature of resources (low tonne/km2 and high €/GJdelivered) Efficient collection and (intermodal) transport.
2. Heterogeneity of biomass resources Pre-treatment, blending terminals & flexible conversion plants.
3. Inhomogeneous quality Meeting feedstock specifications and reduce downstream processing with pre-treatment.
4. Low energy density form pre-treatment early in the supply chain.
5. High moisture content Avoid transport of water with drying.
6. Seasonal availability Storage.
84
What is a biomass supply chain?
A supply chain consists of all parties (manufacturers, suppliers, transporters, warehouses, retailers, and customers) and, within each organization, all the functions involved, directly or indirectly, in fulfilling a customer request. A biomass feedstock supply chain covers all logistic operations needed to move biomass from the supply origin (field, forest, etc.) up to a) the conversion plant or b) ‘throat’ of the conversion unit (boiler, reactor, gasifier, etc.).
85
What are the variable and fixed costs in the transport cost curves?
- Variable cost:
o Linehaul cost: proportional to distance (manly fuel and labour)
- Fixed cost:
o Terminal cost: loading/unloading and intermediate transshipment cost
o Capital cost: cost applying to physical assets of transportation mainly infrastructures, terminals and vehicles.
86
Pretreatment density size biomass:
Logging residues < trees and tree sect’s < chips < pulpwood < pellets < oil
87
Moisture content is a key process variable:
- Energy content (LHV) depends on MC
- Varying feedstock MC increases complexity of feedstock control and conversion
- Stability during storage
- Pellet production need MC of 8-13wt%
88
Types of forced drying:
- Type: belt dryers, tube bundle dryers, drum dryers.
- (In)direct: directly heated with flue gas, indirectly heated with hot water or steam or thermal oil
- Heat source: often biomass but also natural gas is used
89
Why torrefaction?
- Significant cost reductions in transport and handling
- Broader feedstock basis - geographically + raw material
- Almost 0 biodegradation of product when stored
- Large variety of applications
- Reduces CAPEX & OPEX at end user – Immediate use in existing coal fired plants – grind ability, water resistance....
- Combusts cleaner, gasifies easier and cleaner
- Can be made to measure to client’s requirements
- Helps developing the market towards commoditization
90
What are the characteristics of Pyrolysis?
- Thermal decomposition of biomass at temperatures between 400 – 650 oC in ‘absence’ of oxygen
- Products:
o Biochar (process heat, activated carbon, soil amendment)
o Bio-oil
o Gas (syngas, light hydrocarbons, can be used to heat pyrolysis reacyor)
- Slow pyrolysis
o Slow heating rates: 0.1 -1 0C/s,
o Retention time: minutes – hours
o Yields equal quantities of char, liquids, gas
- Fast (or flash) pyrolysis
o Rapid heating rates 10 - 1000 0C/s
o Short residence time: < 2 s
o Yield higher amounts of liquids
91
Bio-oil is not crude oil, what are the differences?
- Higher water content
- Lower pH
- Higher weight density
- Les viscosity
- Lower HHV
92
Case study Sweden
1. Even with all 5 cost strategies, biofuel is more expensive than fossil fuel (in this spatiotemporal context for this technology)
2. Economies of scale provide the largest cost benefits (although upscaling for this technology is yet to be proven)
3. Distributed supply chain designs are only preferred when transport distance is high, or biomass density is low
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5 strategies to reduce the cost of biofuel production
- Smart site selection (biomass cost, supply and competing demand)
- Upscaling (trade-off: scale vs transport cost)
- Intermodal transport (road, rail, sea)
- Pre-treatment: distributed supply chains (trade-off: conversion cost vs transport cost)
- Integration with existing industries (trade-off: integration benefits vs location)
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What is the PAS 2050 method?
- Life cycle GHG emissions
- 100 years assessment period
- ISO 14040 and 14044 shall apply
- PAS takes precedence when it contradict to ISO
- NOT a British Standard, European Standard or International Standard.
- All emission except from use and disposal phase treated as single emission at the beginning of 100-year period.
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What are biogenic GHG emissions?
Biogenic greenhouse gas emissions are emissions directly resulting from combustion or decomposition of biologically-based materials other than fossil fuels. (combustion of wood, fermentation of biomaterial)
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What is carbon offsetting?
- Definition: A carbon offset is a reduction of GHG made in order to compensate for or to offset an emission made elsewhere.
- Examples: EU Emission Trading Scheme and investments in renewable energy.
- GHG emissions offsetting mechanisms shall not be used in PAS
- Use of low carbon intensity energy (renewable or fossil wit CCS) is not a form of offsetting
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Conclusion LCA bio-plastic:
- Using EU feedstock does not always offer benefits (fictional cases of EU-ethanol for PET, and EU-maize for PLA) : the logistics of shipping biomass is saved; but the saved impacts are not sufficient to overcome the more carbon-intensive (average) EU biomass cultivation.
- Using waste as the feedstock reduces the impact of feedstock production:
o Can be very beneficial when the conversion chains are straightforward: UCO-based PP (for drinking cups and packaging films)
o Does not offer visible savings for starch plastics (clips) because the impacts are dominated by the fossil fuel copolymers.
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What type of micro-economic indicators are there?
- LCOE: Production costs per energy unit
- Financial gap:Production costs minus market revenues
- NPV: Net value, with all benefits converted to present value
- IRR: Return on the entire investment
- ROE: Return on the equity part of the investment
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Private sector costs
Capital costs (Debt and equity: commercial)
Risk premiums
Taxes, subsidies
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National costs
```
Capital costs (Social discount rate)
Socialized costs (e.g. grid extension)
```
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What is a marginal abatement cost (MAC) curve?
The marginal abatement cost (MAC), in general, measures the cost of reducing one more unit of pollution.
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Key approach for setting up a MAC curve
1. Analyze current energy economy
2. Provide ‘baseline’ scenario for the future
3. Review extensive set of decarbonization options
a. Potential
b. Costs
c. Place in the energy economy
4. Set up ‘logical order’ of options
5. Construct MAC curve
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Conversion routes oil crops
- Feedstock: rape, sunflower, soya, waste oils, animal fats
- Conversion routes:
o Biomass upgrading + combustion
Heat and/or power
o Transesterification or hydrogenation
Biodiesel
Syndiesel/renewable diesel
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Conversion routes Sugar and starch crops
- Conversion routes:
o Hydrolysis + fermentation or microbial processing
Ethanol, butanol, hydrocarbons
Syndiesel/renewable diesel
o Anaerobic digestion + biogas upgrading
Heat and/or Power
Methanol, ethanol alcohols and biomethane
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Conversion routes Lignocellulosic biomass
- Feedstock: wood, straw, energy crop, MWS, etc.
- Conversion routes:
o Biomass upgrading + combustion
Heat and/or power
o Pyrolysis + secondary process
Heat and/or power
Syndiesel/renewable diesel
Other fuels and fuel additives
o Hydrolysis + fermentation or microbial processing
Ethanol, butanol, hydrocarbons
Syndiesel/renewable diesel
o Gasification + secondary process
Heat and/or Power
Ethanol, butanol, hydrocarbons
Syndiesel/renewable diesel
Other fuels and fuel additives
Biomethane
DME, Hydrogen
o Other biological/chemical routes
Other fuels and fuel additives
DME, Hydrogen
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Conversion routes MSW
- Feedstock: Sewage sludge, manure, wet waste (farm and food wastes), macroalgae
- Conversion routes:
o Hydrolysis + fermentation or microbial processing
Ethanol, butanol, hydrocarbons
Syndiesel/renewable diesel
o Gasification + secondary process
Heat and/or Power
Ethanol, butanol, hydrocarbons
Syndiesel/renewable diesel
Other fuels and fuel additives
Biomethane
DME, Hydrogen
o Pyrolysis + secondary process
Heat and/or power
Syndiesel/renewable diesel
Other fuels and fuel additives
o Other biological/chemical routes
Other fuels and fuel additives
DME, Hydrogen
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Conversion routes photosynthetic microorganisms
- Feedstock: microalgae and bacteria
- Conversion routes:
o Transesterification or hydrogenation
Biodiesel
Syndiesel/renewable diesel
o Bio-photochemical routes
Biodiesel
Ethanol, butanol, hydrocarbons
DME, Hydrogen
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How can bioeconomy increase the gender gap
women might be excluded from bioeconomy-related supply chains due to their role in small-scale agricultural production, lack of formal land tenure and involvement in decision-making process.
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Use of genetically modified (GM) crops can increase food security. What are the two main GM types exist? And what is the downside effect of one of those GMs?
modified to express a natural insecticide and modified to express herbicide tolerance. The last mentioned type does not per se increase yield, but decreases expenditure on agro-chemicals.
Environmental downside effects of herbicide tolerant GM are decreased biodiversity, potential gene flow to wild crops, impact on soil.
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What is the difference between carbon positive and negative biofuels?
- Carbon positive fuels: products of biomass that are cultivated carbon intensely
- Carbon negative fuels: remove more carbon from atmosphere than they put back in when combusted
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Cascading effect
“Cascading” can be applied to manage resources efficiently, but definition differ.
Generally = biomass should be re-used for high value products (chemical, construction) as much as possible before being burned.
However restrictions are: not all biomass can be used for high value products and, in countries without chemical industry, biomass might be more “valuable” as energy.
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SSP1: Low challenge to adaptation and mitigation.
- Population reaches a maximum by mid-century, decreasing thereafter, while global GDP per capita increases significantly.
- Conserve biodiversity.
- Change in diet behaviour (reducing meat)
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SSP2: Middle of the road development, extrapolation of current trends
- Population continues to increase, stabilizing towards the end of the century
- Moderate technological development and yield improvement
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SSP3: High challenge to adaptation and mitigation
- High population growth, small increase in GDP
- Diet: meat consumption
- Minor technological development
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Liquefaction (or hydro-pyrolysis):
- Thermochemical biomass conversion technology that produces high-quality bio-oil in the presence of catalyst at high pressures and controlled reaction rates.
- The bio-oil from liquefaction, initially called heavy oil, is a viscous liquid resembling tars. The heavy oil being difficult to handle because of its sticky and viscous nature is usually mixed with organic solvents in the reaction system.
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Syngas fermentation
convert gases to liquid fuels in the presence of catalysts ranging from metal to microorganisms.
Thermochemical conversion of syngas to liquid fuels is often termed as Fischer-Tropsch process.
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stand-level forest
Stand-level looks at singe land area which is disturbed at once (e.g. whole-tree harvest) and re-grows afterward (simple method).
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landscape-level forest
Landscape-level uses multiple harvest plots, suitable for modeling forest woody biomass containing time and space dynamics (complex method).
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Theoretical fixed and dynamic forest data:
Fixed theoretical data represents a theoretical forest inventory which is modeled under different scenarios. Theoretical dynamic data introduce actual, mostly geospatially explicit forest inventory data, is more accurate.
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Empirical forest data:
Empirical data: use of empirical measurements of CO2 exchanges between forest and atmosphere over time, from a tower located above the forest (instead of theoretical CO2 exchange rates)
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Carbon accumulation and impulse response functions:
carbon accumulation accounts for carbon fluxes without considering climate responses, whereas impulse response functions measure climate response (i.e. atmospheric decay) to a pulse emission
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Baseline construction forest management: 2 types are often used.
- Continued extraction of timber (business-as-usual, BAU) with only biomass outtake for energy as replacement of fossil fuel energy generation
- Land conservation where harvesting (with a certain share for bioenergy) is compared to forest protection.
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What are the main factors that influence carbon payback and parity times per scenario:
- Pre-harvest: plant growth rate (determined by biome, site productivity, tree species and management regime). Shorter payback time for intense regimes (e.g. plantations) and longer for extensive regimes (e.g. natural regeneration).
- Harvest: type of woody biomass, and herewith the size and sequestered carbon volume in biomass.
- Post-harvest: efficiency of biomass to energy, additional fossil fuel emissions, whether or not carbon storage in landfills is accounted for
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Time span for forest carbon recovering: absolute and relative carbon balance.
Absolute is indicated to the site itself, time until a site reaches its pre-harvest carbon level. Also referred to as payback time.
Relative is time span measured against a baseline, timeframe when a specific site reaches the same carbon volume as its reference case. Also referred to as parity time. This method accounts for alternative land or biomass use scenario (e.g. land use for pulp and paper, land protection), and provides insight in whether it is more beneficial from a net carbon perspective to keep biogenic carbon sequestered in plants or use it for energy purposes.
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Biobased polyethylene (PE)
Biobased polyethylene (PE) is produced from biobased ethylene. In nature, many plants produce ethylene when their fruit are ripening. Industrial biobased ethylene is produced from ethanol through a chemical dehydration process.
Production of biobased ethylene
At present, biobased PE is exclusively produced from sugarcane-based ethanol. In a sugar mill, the harvested sugarcane is cleaned, sliced and shredded, resulting in sugarcane juice as the main product and bagasse as the byproduct. In Brazil, the bagasse is typically combusted to generate heat and power to fuel the sugar mill. The power surplus from bagasse is usually sold to the grid. The sugarcane juice is then fermented to ethanol under anaerobic conditions.
Biobased ethylene as a building block
Ethylene is an important platform chemical in the chemical industry. PE is by far the most important product made from ethylene (Fig. 5). In addition, ethylene is an important intermediate to produce PVC, PET, PS and polyols for polyurethanes (PUR).
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PAS 2050 aspects from trial exam
a. Both carbon removals and emissions shall be taken into account. Consequently, for biobased
products the stored carbon (carbon embedded in the product) receives a credit.
b. When dealing with biogenic CH4 emission the CO2 removal should also be taken into
account.
c. Delayed emissions should be taken into account (optional according to PAS 2050)
d. Land use change occurred after 1 Jan 1990 should be taken into account.
e. ILUC is currently not included in PAS 2050 because the methodology and the databases are
still under development.
