1 Principles of Biorefinery

Biorefinery principles and

cascading use of biomass

Capacity Building Programme

small scale biorefineries24-25 June 2013 Putrajaya

istockphoto/anna kuzilina

Definition of IEA Bioenergy Task 42

Biorefinery is the sustainable processing of biomass

into a spectrum of marketable products

Biorefinery: concepts, facilities, processes, clusters of industries

Sustainable: maximising economics & social aspects, minimising

environmental impacts, fossil fuel replacement, closed cycles

Processing: upstream processing, transformation, fractionation, Processing: upstream processing, transformation, fractionation,

thermo-chemical and biochemical conversion, extraction,

separation, downstream processing

Biomass: wood & agricultural crops, organic residues, forest

residues, aquatic biomass

Spectrum: multiple energy and non-energy products

Marketable: Present and forecasted

Products: both intermediates and final products

(i.e. food, feed, materials, chemicals, fuels, power, heat)

http://www.iea-bioenergy.task42-biorefineries.com/

http://www.iea-bioenergy.task42-biorefineries.com/

GENERAL REMARKS AND PRINCIPLES BEHIND THE BIOREFINERY APPROACH

Biomass is a precious resource, renewable but also limited.

Prices and demand for biomass are increasing.

Biomass and bioenergy must be produced and processed sustainably and valorized to

their full potentials.

This way bioenergy can contribute significantly to feeding the growing global This way bioenergy can contribute significantly to feeding the growing global

population and providing a short cut to substitute for many of the products we now get

from fossil fuels.

Building new value chains from biomass (e.g. forestry and crop residues; waste and

byproducts from agroindustry; municipality waste) is the basic building blocks for

building the bioeconomy.

This area offers unique opportunities and potentials for the creation of new jobs

Source: L.Lange BE-Sustainable No.3

The biomass composition is highly complex;

it holds several types of components, which can be developed into many types of

products, not only in the bottom of the value pyramid, but also products higher up the

value chain.

Depending on the conversion process we can move from a downgrading (producing

low value products as electricity and heat) to an upgrade to higher value products (e.g.

food and feed ingredients, speciality chemicals etc).

GENERAL REMARKS AND PRINCIPLES BEHIND THE BIOREFINERY APPROACH

food and feed ingredients, speciality chemicals etc).

Currently most focus has been invested into developing logistics, equipment and

technologies for efficient combustion, increasing the percentage of renewables in the

energy system, but producing the lowest value products only.

However, we must already now start planning for how we can move towards

unlocking the full potentials of the biomass through optimized biorefinery

technologies.


The Biomass Value Pyramid: Biomass

holds potentials for being converted into

also higher level value chains.

Combustion for production of heat and

electricity gives the lowest value only,

while production of biomass based fuel,

Cascading principle

while production of biomass based fuel,

fine chemicals, functional biomaterials,

feed and food ingredients give higher

value.


Biorefinery

Bioproductbased (e.g.

pulp&paper)

Biofueldriven (e.g. bioethanol)

Classification: the 4 features to characterise a biorefinery

system IEA Bioenergy Task 42

1. Platforms 2. Products

Biorefinery

3. Feedstocks 4. Processes

Biorefinery

Source. IEA-Bioenergy task 42

Platforms

Platforms can be intermediate products towards products or linkages

between different biorefinery concepts or final products

Dominant platforms for biobased chemicals

C6 Sugar platform

Plant-based oil platform


1-platform (oil) biorefinery using oilseed crops for biodiesel, glycering and

feed via pressing, esterification and distillation Source. IEA-Bioenergy task 42

Classic 1G bioethanol plant


Integrated cane ethanol refinery


2G Ethanol refinery


Bioethanol from wood


Biomethane from grass and manure


Biomethane from wood


FT-fuels from Straw


FT-fuels from woodchips


14 Most Promising Biofuel-driven Biorefineries until 2025

New types of Biorefineries

There will be many types of biorefineries, designed to unlock the potentials of

different types of feed stock:

The Yellow biorefinery (Feedstock: cereal straw and stover)

The Green Biorefinery (Feedstock: fresh green leaves of e.g. grasses, after crops

and beet roots)

The Grey Biorefinery (Feedstock: sludge; wet, composite and dirty biomass)

The Blue Biorefinery (Feedstock: marine biomass; seafood waste, sea weeds and The Blue Biorefinery (Feedstock: marine biomass; seafood waste, sea weeds and

macro algae)

The White Biorefinery (Feed stock: agroindustrial waste)

Among these types of biorefineries, the most low hanging fruit is

probably the valorization of selected types of byproducts and waste from

agroindustrial food processing


BIOMASS CONVERSION ROUTES AND TECHNOLOGIES

1.Parts of each feedstock, e.g. crop residues,

could also be used in other routes

2.Each route also gives co-products

3.Biomass upgrading includes any one of the densitication

processes (pelletisation, pyrolysis, torrefaction, etc.)

4.AD = Anaerobic Digestion

Thermochemical value-chains

Source: European Biofuels Technology Platform

Biological value-chains


Thermo-chemical processes

Thermo-chemical conversion processes are sub-processes in a biorefinery, which aim to

convert raw materials to a uniform intermediate product which can be further processed

into a final value-added product using biochemical, catalytic or thermal methods.

Thermo-chemical biomass conversion processes can be broadly classified as

torrefaction,torrefaction,

pyrolysis,

gasification,

hydrothermal liquefaction

Combustion processes are applied for power, heat or combined heat and power (CHP)

production.

Torrefaction is a thermal process which operates at temperatures between 200 and

300C in the absence of oxygen.

In general, torrefaction is combined with pelletisation, giving torrefied pellets (TO P) as

the end product. Biomass is dried and partly decomposed to give a grindable,

hydrophobic solid with high energy value.

More like a pre-treatment than a conversion technology suitable for small scale

Torrefaction

More like a pre-treatment than a conversion technology suitable for small scale

TORREFACTION

Several technologies available. Not standardized yet

Benefits and advantages of biomass torrefaction

Torrefaction (+ densification) enables energy-efficient (>90%) upgrading of

biomass into commodity solid biofuels with favourable properties in view of

logistics and end-use

Favourable properties

higher energy density,

better water resistance, better water resistance,

slower biodegradation,

good grindability and flowability,

homogenised material properties

Enables cost savings in handling and transport, capex savings at end-user (e.g.

outside storage, direct co-milling and co-feeding), higher co-firing percentages

and enabling technology for gasification-based biofuels and biochemicals

production

Applicable to a wide range of ligno-cellulosic biomass feedstock, even mixed waste

streams

Fuel characteristics

Source: SECTOR project

State of the art of torrefaction technology development

Many technology developers (>50) due to strong market pull

Torrefaction technology is not yet fully commercially available for this application.

Often application of reactor technology proven for other applications (drying,

pyrolysis, combustion)

Often limited bench-/pilot-scale testing, limited attention to energy efficiency

and impact of exothermicity underestimated

Good process control is essential for good performance and product quality

control

Overall energy efficiency is strongly dependent on heat integration design

In general: torrefaction technology in demonstration phase with >10 demo-units

and first commercial units in operation and under construction

BIOMASS PYROLYSISPyrolysis is the thermal decomposition of biomass

occurring in the absence of oxygen (anaerobic

environment) that produces a solid (charcoal), a liquid

(pyrolysis oil or bio-oil) and a gas product.

The relative amounts of the three co-products depend on

the operating temperature and the residence time used in

the process.

High heating rates of the biomass feedstocks at moderate

temperatures (450C to 550C) result in oxygenated oils as

the major products (70 to 80%), with the remainder split

between a biochar and gases.

Slow pyrolysis (also known as carbonization) is practiced

throughout the world, for the production of charcoal.

Fast Pyrolysis and flash pyrolysis are more advanced

technologies and still under development.

FAST PYROLYSIS

Rapid thermal decomposition of organic compounds in

the absence of oxygen to produce liquids, char, and gas

Dry feedstock:

Pyrolysis

Use of various wood feedstocks has been demonstrated at a pilot scale. Many

lignocellulosic biomass types (including agricultural wastes like straw, food processing

residues etc.) may also be used as feedstocks, but some of them are more challenging

to use than wood

A number of fast pyrolysis technologies are all currently at various stages of A number of fast pyrolysis technologies are all currently at various stages of

development. Most processes employ fluidised- bed reactors, although other systems

have also been designed.

The largest existing commercial-scale units are

used to produce chemicals for the food flavouring industry.

However, these units would only be considered pilot-scale for fuel production.

Pyrolysis applications

Pyrolysis oil can be utilised in a large number of applications, which can be divided in

four main groups being heat, power, transport fuels and chemicals.

Pyrolysis oil combustion in a boiler or furnace for heat is the most simple and

straightforward application.

Pyrolysis oil can replace both heavy and light fuel oils in industrial boiler applications.

Pyrolysis oil co-combustion in an industrial, natural gas-fired power plant has been

successfully demonstrated.

Diesel engines and gas turbines for power production have been tested on pyrolysisDiesel engines and gas turbines for power production have been tested on pyrolysis

oil, but some development is still required. Commercially available engines and/or gas

turbines are stated to become available within several years.

Transport fuels can be derived from pyrolysis oil either by direct upgrading or by

gasification combined with gas-to-liquid synthesis to produce Methanol, Fischer-

Tropsch diesel or DME.

Potentially high-value chemicals can be extracted like adhesives for wood,

preservatives, browning/flavouring of food and more. Economic attractive recovery of

chemicals from pyrolysis oil needs further development.

POTENTIAL APPLICTIONS OF PYROLYSIS

Source: Biomass Technology Group

EMPYRO: COMMERCIAL DEMO PYROLYSIS PLANT IN EU

EMPYRO is a polygeneration plant that will produce

pyrolysis oil, process steam, and electricity from

woody biomass. The produced oil is the main product

and will be sold commercially on the market.

Steam will be delivered to the neighbouring factory of

AkzoNobel and electricity to the grid.

Developing and demonstrating the recovery of acetic

acid from biomass is part of the project.

www.empyroproject.eu

acid from biomass is part of the project.

The main aim of EMPYRO is the local commercial

demonstration of the fast pyrolysis concept from

biomass supply, through the pyrolysis conversion step,

to oil application.

Plant capacity: 120 ton of

wood/day

Plant feedstock: Local wood

residues

Plant output per year:

> Oil: 22,500 ton

> Electricity: 6,000 MWh

Steam: 80,000 ton

Location: Enschede NL

BTG constructed a 5 tonne/day pilot pyrolysis

unit in early 2000. Shortly after, a 50

tonne/day semi-commercial plant was built in

Genting Malaysia.

ROADMAP - PYROLYSIS

Source: Biomass Technology Group

GASIFICATION

Gasification is a high temperature (>700C) conversion of

solid, carbonaceous fuels into combustible product gas

which is used commercially in heat, power and CHP

production.

The gaseous intermediate fuel, consisting primarily of

carbon monoxide and hydrogen, which can be used for

the production of heat, power, liquid fuels, and chemicals.the production of heat, power, liquid fuels, and chemicals.

The gas made in this process is cleaned and processed to

form a so-called syngas, whose composition can be

controlled.

The importance of this technology lies in the fact that it

can take advantage of advanced turbine designs and heat-

recovery steam generators to achieve high energy

efficiency.

Example: NOTAR gasifier by Xylowatt

Source: H.Knoef BE-Sustainable issue 1

Since several decades biomass gasification offers the perspective of resource-

efficient production of energy and co-products in poly-generation systems.

More recently, biomass gasification has come to be seen as a central part of

integrated biorefineries.

The shift in interest to integrated biorefineries has led to an associated shift in the

targeted application of the synthesis gas that is produced in biomass gasification.

GASIFICATION FOR BIOREFINERIES

targeted application of the synthesis gas that is produced in biomass gasification.

Pure syngas is the building block for organic chemistry, and in principle all

products now being produced from fossil fuels can also be produced from syngas

made from renewable biomass.

Therefore, biomass gasification is becoming less focused on energy production but

more on the production of high-added value products including transportation

fuels, chemicals, Synthetic Natural Gas (SNG), etc.


The conversion of biomass in gasification processes is often combined with

pyrolysis, combustion or both like in multi-stage gasifcation concepts.

In these concepts, the gasification, pyrolysis and/or combustion processes are

Combination of gasification with other processes

Combined effect of the amount air supplied to the wood and the 3 Ts

(temperature, turbulence and time).

To explain and predict the gas composition an equivalence ratio is introduced. This is

the amount of oxygen used relative to the amount required for complete

combustion.

The exact amount of air needed for complete conversion of wood to carbondioxide

and water is called the stochiometric air.

In these concepts, the gasification, pyrolysis and/or combustion processes are

physically separated.


Gasification products at different ER


Producergas cleaning

Syngas from biomass gasification is used for power production and synthesis of fuels

and commodity chemicals.

Impurities in gasification feedstocks, especially sulfur, nitrogen, chlorine, and ash, often

find their way into syngas and can interfere with downstream applications.

Incomplete gasification can also produce undesirable products in the syngas in the

form of tar and particulate char. Several technologies for removing contaminants from form of tar and particulate char. Several technologies for removing contaminants from

syngas are available and are classified according to the gas temperature exiting the

cleanup device: hot (T > 300oC), cold (T < ~100oC), and warm gas cleaning regimes.

Cold gas cleanup uses relatively mature techniques that are highly effective although

they often generate waste water streams and may suffer from energy inefficiencies. The

majority of these techniques are based on using wet scrubbers.


Producergas utilization


synthetic natural gas applications (SNG)

Co-firing: percentages up to 10% (on energy basis) are feasible without the need for

substantial modifications of the coal boiler.

Combined heat and power (CHP): in CHP plants the product gas is fired in engines or

turbines.

Integrated gasification combined cycle (IGCC): for electricity production on larger

scales, integrated gasification combined cycles are preferred in which the gas is fired

on a gas turbine.on a gas turbine.

Fuel cells: for the production of electricity still in early development

Synthetic Natural Gas (SNG): SNG is a gas with similar properties as natural gas but

produced by methanation of H2 and CO in gasification product gas.

Transportation fuels: biosyngas important for the production of fuel from GTL

processes, Fischer-Tropsch diesel and methanol/DME.

Methanol: methanol can be produced by means of the catalytic reaction of carbon

monoxide and some carbon dioxide with hydrogen.

Finally, the product gas can be used in the chemical synthesis like ammonia for

fertiliser production, hydroformylation of olefins, hydrogen in refineries, mixed

alcohols, carbon monoxide, olefins and aromatics.Source: H.Knoef BE-Sustainable issue 1

IGCC Plant in Guessing Austria

Stable plant availability since many years

Harbore CHP Plant in Denmark

Hydrothermal Liquefaction (HTL)

The HTL process converts biomass to biocrude by means of water at a temperature

of 300-350C and at 120-180 bars pressure . Other products are gases (predominantly

CO 2), water and dissolved organics.

The fundamental biological building blocks are broken down and reformed during the

process. Initially, these macromolecules are broken down into their monomer units.

Oxygen and N, S, P are removed leaving behind the initial carbon and hydrogen atoms

in the form of low molecular weight compounds.in the form of low molecular weight compounds.

Biocrude may be utilised in co-combustion in coal- and oil-fired power stations or it

may be upgraded by catalytic hydro-de-oxygenation (HDO) processing, for example

into premium diesel fuel, kerosene and feedstock for chemical manufacturing.

Biochemical Conversion processes

Biochemical processes are based on the catalytic function of specific proteins called

enzymes.

Fermentation processes using living microorganisms (bacteria, yeast, etc.) are the

most common form of biochemical processing. The process typically takes place in a

contained reactor (a bioreactor or fermenter).

Enzymes can also be isolated from cells, and used either in processes such as the Enzymes can also be isolated from cells, and used either in processes such as the

conversion of starch to iso-glucose (the main sweetener used in soft drinks) or in end

products like washing detergents.

Today, biochemical processes are used in many parts of existing biorefineries.

Biochemical processing is used to make, for example, bioethanol and chemicals like

lactic and citric

acids. One of the main advantages is that processing is carried

out typically under very mild conditions (low temperature,

low pressure and moderate pH values). Biochemical

processes are also usually water-based.

Biological value-chains


Products obtained by fermentation


Biochemical processing is used to make, for example, bioethanol and chemicals like

lactic and citric acids.

One of the main advantages is that processing is carried out typically under very

mild conditions (low temperature, low pressure and moderate pH values).

Biochemical processes are also usually water-based. A bottleneck for biochemical

processes is the fact that product concentrations are typically relatively lowprocesses is the fact that product concentrations are typically relatively low

Also, it is common for several by-products to be produced during fermentation

processes.

These two factors make downstream processing (isolation and purification) of products

comparatively expensive and energy-intensive (e.g. distillation dehydration)

Source: star-colibri .eu

The general challenges for biochemical processes are therefore:

To increase yield and overall productivity.

Reducing material loss during the different processes to maximise their sustainability and

economic viability.

To develop processes working at high concentrations of both raw material and end-

product.


product.

To develop cheaper and more efficient processes for downstream processing (DSP) after

biochemical processes: DSP has a big impact on the economics of the system, in most

cases being the critical factor.

Source: star-colibri .eu

Documents

1 Principles of Biorefinery