Biorefineries based on lignocellulosics part 2....

Biorefineries based onlignocellulosics part 2. Analysis

CARLOS ARIEL CARDONA ALZATE M.S c PhD.

RESEARCH GROUP ON CHEMICAL , CATALYTIC AND B IOTECHNOLOGICAL PROCESSES

UNIVERS IDAD NACIONAL DE COLOMBIA SEDE MANIZALES

Outline 1

1. Types of Biorefineries and added value. Examples

2. Design of Biorefineries: Conceptual Synthesis

3. Energy analysis.

4 Technoeconomic analysis

5. Environmental assessments and Social analysis

6. Influence of the scale

Outline 2➢ Biorefinery concept

➢Types of biorefinery

➢Suitable feedstocks for a biorefinery

▪ Feedstocks classification

▪ Food Security

➢ Technologies in a biorefinery

▪ Technologies

▪ Hierarchization, sequencing and integration

▪ Green Biorefinery

▪ Biorefineries specification form

Feedstock separation in more treatable fractions

(Platforms)

Each platform → ProductLine

Different technologies allowthe conversion of biomass

into:• Commodities (Biofuels,

electricity, etc)• Specialties (Chemical

building blocks)

These combinations create a complex system able to exchange material (waste streams, platforms and products) and energy streams to supply their requirements and achieve self-sufficiency

General Biorefinery

Scheme

5

Combustion Gasification Pyrolysis Digestion Fermentation

Thermochemical Biochemical

Pretreatment

Biomass sources

Steam Syngas Oil/Charcoal Biogas Distillation

BIOFUELSELECTRICITYHEAT

Figura 5. Tipos de gasificadores

Figura 4. Tecnologías para la

conversión de biomasa

6

Figura 6. thermochemical processes

Figura 7. Products from gas

fermentation

Types of Biorefineries

Type I - Dry-milling bioethanol plantsusing wheat or corn

Type II - wet-milling plantusing corn and various processes with the capability to adapt multiple productions

Type III – These biorefineries are under extensive research and development

FOR THE SAME SYSTEMS :ENERGY DRIVEN OR PRODUCT DRIVEN

Energy driven or product driven

Energy driven most. Based mainly on biofuels and bioenergy production

Product driven …. Few. Based on products without priority in energy production

Energy driven usually low added value

Product driven usually higher added value

Biorefinery Feedstock

Biomass

Plant Location

PotentialAvailability

Starting point for planning and design of a biorefinery

Process Scale

BiomassNature

Platforms and Products

Processes

Biomass

“Any organic matter that is available on a renewable or recurring basis, including dedicated

energy crops and trees, agricultural residues, algae and aquatic plants, wood and wood residues,

animal wastes, wastes from food and feed processing and other waste materials usable for the

production of energy, fuels, chemicals, materials.”

CarbonNeutral

Capture CO2 fromthe atmosphere in the photosynthesis

Biorefinery is an effective way to alleviate climate change

Elemental analysis

Correlaciones teórico –experimentales

FC = Fixed carbonVM = volatile mat.

ASH = Cenizas

Easy method with good accuracy

Shen, J., Zhu, S., Liu, X., Zhang, H., Tan, J., 2010. Theprediction of elemental composition of biomass based onproximate analysis. Energy Convers. Manag. 51, 983–987.

Heating valueHigh (HHV) Low (LHV)

25°C, includes enthalpy of vaporization 150°C, no enthalpy of vaporization is considered.

𝐿𝐻𝑉 = 𝐻𝐻𝑉 − ℎ𝑓𝑔𝐹𝑎𝑔𝑢𝑎

𝐹𝐵𝑖𝑜𝑚𝑎𝑠𝑎

ℎ𝑓𝑔 = Enthalpy of vaporization𝐹𝑎𝑔𝑢𝑎

𝐹𝐵𝑖𝑜𝑚𝑎𝑠𝑎= water content

Experimental o teórico

High heating value (HHV)

Experimental

- proximal analysis

- Elemental analysis𝐻𝐻𝑉 = 0.335𝐶 + 1.423𝐻 − 0.154𝑂 − 0.145𝑁

- composition𝐻𝐻𝑉 = 0.1739 ∗ 𝐶𝑒𝑙𝑙𝑢𝑙𝑜𝑠𝑒 + 0.2663 ∗ 𝐿𝑖𝑔𝑛𝑖𝑛 + 0.3219 ∗ 𝐸𝑥𝑡𝑟𝑎𝑐𝑡𝑖𝑣𝑒𝑠

Theoretical

Heat pump

best correlation

Food Security Current Status

Food Crops = Corn, Wheat, Sugarcane

and oil seeds

Bioethanol and Biodiesel

¿Should be usedfood and feed for

biofuels?

Social ImpactEconomic

Impact

EnvironmentalImpact

Lignocellulosic residues as an alternativeEnsure Food

Security

Lignocelulosic biomass as a promising alternative

AdvantageDrawback

Technological barriersto break down theircomplex structure

• Cheap• No need additional

land for production

Pathways underdevelopment to reduce the

environmental footprint

Processes and Platforms

Fractionation and upgrading allows

an efficient use of biomass

feedstock and generation of value-

added products through

valorization.

Conversion Platforms

Biorefinery Products

Defining the product portfolio will depend

on their potential to generate revenues and

potential for avoided emission by replacing

similar functionality fossil-derived products.

Energy Carriers (biofuels, heat and electricity)

Materials for differentindustries (chemicals, foodingredientes, polymers, etc)

Design Strategies of a Biorefinery

Hierarchization

IntegrationSequencing

FeedstockProducts

Technologies

Technologies Hierarchy

Utilities

HeatExchangerNetwork

Separationand Recycling

Reaction

The hierarchy decompositionlevel is based on the processwhich has the highestimplication of the entirefacility.

Sequencing in a BiorefineryThe term sequence is used to establish a logical order to relate technologies and products. Last also considers the hierarchy definition described above. This leads to involve certain restrictions in the order and production lines.

Mechanical Sugar Extraction

Sugar for human consumption

Bioethanol Production

Non-convertedsugars

Ensure FoodSecurity

Integration in a Biorefinery

Integration makes reference to the maximum use of resources withinthe same plant. Integration can be performed between raw materials, technologies and even products.

The integration levels enhance the overallperformance of the entire biorefinery.

Integration in a Biorefinery

Green BiorefineriesPrinciples

Integrated technologies should have priority over separated technologies.

Feedstocks from Natural Sources, looking for first, second and third generation integration.

Reduce wastes, integrating products with feedstocks in multiprocessing biorefineries.

Preserve Ecosystems and biodiversity

Innovative Engineering Solutions

Social Impact and evaluation is essential

Adopt the term of Life Cycle.

Reduce as possible energy consumption and byproducts with low added value.

Use tools and strategies of analysis and evaluation for environmental, technical and economic impact.

Supply chain and logistics should be an essential part of a green biorefinery

Biorefinery Performance

Indicator Definition

Energy Conversion efficiencyRatio between net energy output (as valuable products, includingelectricity, steam, fuels and other streams contributing to energygeneration) to energy input (e.g., total biomass calorific value).

Land UseAmount of land used per unit biomass feedstock production.

Lignocellulosic feedstocks are chosen to reduce land use.

Water Use Amount of freshwater depletion, beyond recovery.

Greenhouse gases Gases causing greenhouse effect, i.e., with global warming potential.

Economic Margin Revenue potential of a biorefinery.

Methodology for Biorefineries design

1. Feedstock Selection

2. Products Selection

3. Potential Product Scenarios

4. Mass and Energy Integration

5. Generation of the superstructure

6. Techno-economic, energetic, environmental and social assessment

Feedstock Selection

Raw Material

FeedstockClassification

First Generation

Food Security?FeedstockAvailabilitySecond Generation

Thrid Generation

Decision Criteria

Feedstock Characteristics

Chemical Composition Heating Value

Proximate and Ultimate Analysis Density and Particle Size

Moisture Content Digestibility Parameters

Ash Content

Products

Based on the products and thehierarchical of the feedstock

Selection of the posible productsbased on the characteristics of

the feedstock

Potential Product Scenarios

Biorefinery Process• Mechanical/physical

• Biochemical• Chemical

• Termochemical

Which processes are required to convert feedstock in the selected

products?Hierarchization

Sequence of the Biorefineryscenarios

Biorefinery Schemes

IntegrationMass and Energy Integration

of process streams

Solid Residues for cogenerationPinch methodology for energy

integrationWastewater Treatment

SuperstructureGeneration

Techno-economic, environmentaland social evaluation

Optimization

Techno-economic Assessment

Economic Performance of thebiorefinery

Net Present Value (NPV)

Production Costs vs Maket Price

Economic assessment

Tasa de impuesto/Tax rate. Es el porcentaje de las ganancias pagado como impuesto, o el porcentaje del valor de un bien, servicio o activo pagado como impuesto. Para el contexto Colombiano es del 25%.

Tasa de interés anual/Interest rate. Conocida también como Tasa de Interés, Tasa de Interés Efectiva Anual, Tasa Efectiva Anual, es un monto de dinero que se cobra sobre una deuda prestada. Para el contexto Colombiano es del 17%.

Servicios o utilities. Conocida también como Fluidos de servicio, son fluidos ya sea de enfriamiento (Ej. Refrigerantes, agua, etilenglicol, etc.) o calentamiento (Ej. Vapor de alta, media o baja presión, aceites, etc.) que se usan en intercambiadores de calor, reactores enchaquetados, etc.

Periodo. Es el tiempo de operación de una planta y en Aspen Plus está definido como 8000 horas. Costo total (USD/periodo). Es la suma de Raw material costs, Utilities cost, Operating labor cost, Maintenance cost, Operating cost, Plant overhead, General and administrative cost y Depreciation.

Economic assessmentDepreciación (USD/periodo). Se refiere a una disminución periódica del valor de un bien material o inmaterial, en estecaso está asociado a la disminución del valor de los equipos considerados en el proceso.

Producción total (Kg/periodo). Es el flujo másico, molar o volumétrico del producto(s) principal(es) en el periodo deoperación. El flujo por corrida (kg/h) debe ser multiplicado por el periodo (8000h/periodo) para obtener el flujo total(kg/periodo).

Costo de producción (USD/kg). Es definido como la relación entre el Costo total y la Producción total.

Precio de venta (USD/kg). Es el valor monetario que se le asigna a un producto en el mercado.

Margen de ganancia (%). Indica la rentabilidad de un producto, servicio o negocio. Mientras más alto sea el número,más rentable es el negocio. En fórmula es: ((Precio de venta-costo de producción)/precio de venta)*100.

Valor Presente Neto (VPN). Es el método más conocido a la hora de evaluar proyectos de inversión a largo plazo. ElValor Presente Neto permite determinar si una inversión cumple con el objetivo básico financiero: MAXIMIZAR lainversión en un periodo de tiempo.

Tasa Interna de Retorno (TIR). Es aquella Tasa de Descuento que al utilizarla para actualizar los flujos Futuros deIngresos netos de un proyecto de Inversión, hace que su VPN sea igual a cero. Es decir, la Tasa Interna de Retorno (TIR)es una medida de la Rentabilidad de una inversión, mostrando cuál sería la tasa de Interés más alta a la que el proyectono genera ni pérdidas ni Ganancias

Process Scale

The optimum size of a biorefinery involves tradeoffs

between economies of scale with larger plants and

increased costs of feedstock transportation.

A critical component of economic profitability of biorefinery

processes is a secure and reliable feedstock supply system.

Ample feedstock should be available to biorefineries at the

appropriate time and at competitive prices, while assuring

reasonable, steady profits to the biomass suppliers.

Environmental Assessment

Environmental impactindicators

Human toxicity by ingestion (HTPI), human

toxicity by dermal exposition or inhalation

(HTPE), aquatic toxicity potential (ATP), Global

warming (GWP), Ozone depletion potential

(ODP), Photochemical oxidation potential (PCOP)

and acidification Potential (AP).

Required data for the biorefinery design

Content

Introduction

Feedstock

Mechanical pretreatment

Chemical pretreatment

Fermentation

Anaerobic digestion

Thermochemical methods

Purification step (Downstream processes)

Economic analysis

INTRODUCTION

The different researches being conducted worldwide provide a wealth ofinformation that can be used in conceptual processes design to obtain avariety of value-added products. Therefore, the use of different softwarehas become so important.

Through biorefinery concept, a full use of one or more raw materials isperformed. According to the American National Renewable EnergyLaboratory (NREL) “A biorefinery is a facility that integrates biomassconversion processes and equipment to produce fuels, power, andchemicals from biomass”

The use of different software is the most powerful tool that a designerhave to evaluate from technical, economical and environmental point ofview a new unit operation or even a new production process.

FEEDSTOCK

Exist a great variety of raw materials that can be used in a biochemicalprocess, however, any material must be characterized to know itscomposition and principal attributes. For that reason, aphysicochemical, ultimate and proximate analysis must beperformed.

The principal characteristics of a lignocellulosic biomass are:

✓ Cellulose, Hemicellulose, Lignin

✓ Extractives

✓ Ash content

✓ Elemental composition

✓ Heating value

FEEDSTOCK

The following tables show some parameters that must be taken into account to evaluate the best route of processing.

Specifications of main raw material

Item Value Unit

Flow (mass, volume, molar)

Cellulose

Hemicelluose

Lignin

Extractives

Moisture

Other components

Temperature

Pressure

Physico-chemical characterization of the raw

material

Item Value Unit

Total Solids

Moisture

Volatile Solids

Ash

Particle Size

Lipids (optional)

Proteins (optional)

Elemental analysis of raw material

Item Value Unit

C % w/w

H % w/w

O % w/w

N % w/w

S % w/w

Energetic information of raw material

Higher heating value (HHV) kcal/kg

Lower heating value (LHV) kcal/kg

MECHANICAL PRETREATMENT

Generally, the feedstock in a biorefinery is a solid waste that comes fromagroindustry sector and its size cannot be appropriated to subsequentsteps in the process, for this reason a mechanical pretreatment usually isemployed.

This pretreatment consist in a particle size reduction of the raw material using a crusher. Some crusher that can be modeled in process design software are:

Figure 1. Ball and impact mill

MECHANICAL PRETREATMENT

The tables present the required information for the mechanical treatment simulation

Crusher specification

Item Value Unit

Crusher type

Input particle diameter

Output particle diameter

Ratio of cut-off size to solids outlet diameter

Bond work index (J/kg, kJ/kg, kWhr/ton)

Particle Size Distribution (PSD)

Type of sieve (e.g Tyler, ASTM, etc.)

Sieve No. Mesh width (i.e inch,

milimeters)

Weigth

of sieve

Weigth of

solids

Ratio of the solids in each

sieve to total solids

Ratio of the

accumulated

solids to total

solids

1

2

3

n

n+1

Collector

CHEMICAL PRETREATMENT

In this step of the process the raw material is submitted to different types ofreaction that search increase the accessibility of microorganism in the nextstep (i.e fermentation) also this increase on the accessibility is evidencedthrough of amount of disposal substrate to fermentation (e.g sugars). Thesereactions and its objective are:

Acid/Alkaline reaction

Acid pretreatment is used to remove hemicellulose content in lignocellulosicmaterials, hydrolyzate the cellulose to increase the fermentable sugars anddecrease the crystallinity of the raw material.

Alkaline pretreatment is used to remove the lignin content in the raw materialto facility the next hydrolysis step. For these reactions are necessaryspecify: reactor type, temperature, pressure, amount of chemical (i.eacid or base) used, pH, agitation speed, etc.


Detoxification reaction

This reaction has as objective eliminate all components that could be inhibitory in the fermentation step;

generally, detoxification is performed by precipitation reaction. The information necessary to specify in

this procedure are: temperature, pressure, pH, agitation speed, precipitation agent, etc

Enzymatic reaction

This reaction has as objective break different polymers that are present in the raw material (e.g cellulose,

pectin, etc) to produce free monomers that can be assimilated by the microorganisms, in this

pretreatment is necessary specify the next conditions: pH, temperature, agitation speed, residence time,

charge of enzyme, type of enzyme, enzymatic activity, etc.


The following table present the input information to perform anacid/alkaline pretreatment:

Specifications of acid/basic hydrolysis

Item Value Unit

Reactor type

Temperature

Pressure

Valid phases

Basic or Acid Hydrolysis?

Reagent Sulfuric Acid, NaOH,…

Composition %wt

Solid to Liquid Ratio %

Amount of Acid or Basic g, kg, …


The following table present the input information to perform an enzymaticpretreatment:

Specifications of enzymatic hydrolysis

Item Value Unit

Reactor type

Temperature

Pressure

pH

Agitation (type)

Rpm rpm

Energy Consumption W, kW

Enzyme 1

Enzyme 2

Enzyme n

Activity Enzyme 1

Activity Enzyme 2

Activity Enzyme n


Do you use a

buffer solution?YES NO

Buffer Solution Citrate Buffer, …

CHEMICAL PRETREATMENTThe following table present the input information to perform andetoxification process:

Specifications of detoxification reaction

Item Value Units

Temperature

Pressure

pH

Agitation (Type)

Revolutions rpm

Energy Consumption W, kW, …

Detoxification Reagent Calcium hydroxyde, …

Amount g, mg, kg, ---


Feed Stream Concentration Units

Feed Component 1 g/L, g/g, …

Feed Component n g/L, g/g, …

Feed Component n+1 g/L, g/g, …

Products Concentration Units

Product 1 g/L, g/g, …

Product n g/L, g/g, …

Product n+1 g/L, g/g, …

FERMENTATION

Fermentation is a biochemical process that use a microorganism to produce different products. Exist many

types of fermentations (i.e submerged, solid, etc.), also, different kinetics equations are employed to describe a

fermentative process, but, regardless of the type of fermentation, the following information must be taken into

account:

✓ Operation type,

✓ Initial conditions (i.e biomass, substrate, products),

✓ Charge or working volume,

✓ Specific power consumption,

✓ Temperature,

✓ pH

FERMENTATION

Specifications of fermentation block

Operation type

Batch

Fed - Batch

Continuous

Initial Conditions

Substrate g/L

Biomass g/L

Product g/L

Temperature K

pH

pH

units

Concentrations of steady state (Cs)

Substrate g/L

Biomass g/L

Product 1 g/L

Product 2 g/L

Product n g/LDilution Rate (D) Total 1/h

Flow rate into reactor (Vo) Total m^3/h

Mass flow in outlet stream of each component

(Cs*Vo)

Substrate kg/h

Biomass kg/h

Product 1 kg/h

Product 2 kg/h

Product n kg/hMass flow in outlet steam (F) Total 0 kg/h

Yields of each component

Substrate N.A

Biomass N.A

Product 1 N.A

Product 2 N.A

Product n N.A

Summatory 0 N.A

FERMENTATION

In downstream process a hydrocyclone or filter are used to separate the biomass of the broth for dispose

or recycle it to fermenter. These equipments must be specify with the following information:

✓ Diameter of hydrocyclone

✓ Inlet diameter up flow outlet diameter

✓ Down flow outlet diameter

✓ Angle of cone

✓ Efficiency

Filter Specifications: the particle diameter, mass fraction in cake of particle solids must be specified.

ANAEROBIC DIGESTION

Anaerobic digestion (AD) is a biological process where a organic matter is converted to

biogas and digestate. Biogas is a renewable biofuel due to this is composed by methane

(50 – 70%), carbon dioxide (25 – 40%) and other gases as hydrogen sulfide and

ammonia.

The process is performed by several microorganism (i.e hydrolytic, acidogenic,acetogenic and methanogenic bacteria). However, due to the high complexity of thesystem this process is modeled as a first order kinetic. The experimentation of thisprocess uses a inoculum that comes from a wastewater plant or Upflow AnaerobicSludge Blanket reactor (UASB). The inoculum must be characterized minimum in volatilesolids terms

ANAEROBIC DIGESTION

Item Value Units

Temperature °C, °F, …

pH

Inoculum to substrate ratio

Headspace Gas N2, CO2, He,..

Incubation time min, days,..

Does the process require

stirring? YES NO

Type of Stirring

Energy Consumed W, kW, ---

C/N Ratio

Please, specify the method used in gas measuring

Volumetric or Manometric method

Experimental yield scum/kg VS

Inoculum

Microorganism

Concentration g/L, …

Pre-incubation

Time

min,

days, …

Feedstock

Substrates Concentration Units

Substrate 1

g/g,

g/L, …

Substrate 2

g/g,

g/L, …

Substrate 3

g/g,

g/L, …

Substrate n

g/g,

g/L, …

Substrate n+1

g/g,

g/L, …

THERMOCHEMICAL METHODS

“Thermochemical pathways for biomass conversion offer opportunities for rapid and

efficient processing of diverse feedstocks into fuels, chemicals and power.

Thermochemical processing has several advantages relative to biochemical processing,

including greater feedstock flexibility, conversion of both carbohydrate and lignin into

products, faster reaction rates, and the ability to produce a diverse selection of fuels”

Gasification and pyrolysis are the two most important thermochemical routes for

transformation of biomass (i.e lignocellulosic materials) into fuels with higher value-added

(e.g syngas) and utilities as heat and power

THERMOCHEMICAL PROCESSGasification

Item Value Units

Temperature

Pressure

Gasifiyng agent air, steam, oxygen, …

Gasifier Configuration downdraft, fluidized bed …

Pyrolysis

Item Value Units

Temperature

Pressure

Type of Pyrolysis Fast, moderate or slow

Product Yield

% Liquid %Char %Gas

Pyrolysis

Gasification

Feed Stream to the process

Item Value Units

Moisture Content %wt

Particle Size mm, cm, …

Energy Content Mj/kg, Mj/kmol

Components Composition Units

Component 1 %wt, % mol, …

Component n %wt, % mol, …

Component n+1 %wt, % mol, …

Products

Components Composition Units




Component n %wt, % mol, …

Component n+1 %wt, % mol, …

PURIFICATION STEP

The common downstream operations are:

Distillation (Azeotropic homogeneous, azeotrópic heterogeneous, extractive)

Absorption and stripping

Membranes

Molecular sieves

Decanters

Evaporators

ECONOMIC ANALYSIS

After completing the whole process of design, an economic evaluation

must be performed. This evaluation takes into account some economic

parameters of the region where the project will be located, furthermore

prices of the all raw materials must be specified.

Economic Aspects

Item Price Units

Operators USD/h, €/h, …

Supervisor USD/h, €/h, …

Tax Rate %

TIR %

Project Life years

Electricity USD/kW, …

Water USD/cum

Fuel USD/Megawatts

Low pressure steam USD/Ton

Medium pressure

steam USD/Ton

High pressure steam USD/Ton

Main raw material USD/kg, …

Reagent 1 USD/kg, …

Reagent n+1

Thank you for the attendance

Carlos Ariel Cardona Alzate M.Sc. Ph.DE-mail: [email protected] Nacional de Colombia Sede Manizales

Biorefineries based on lignocellulosics part 2....

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