Industrial Chemical Processes for BIobased and Speciality Chemicals - Appunti e domande

INDUSTRIAL

PROCESSES for

BIOBASED and

SPECIALITY

CHEMICALS

BIOREFINERY.........................................................................................................................2

WASTE VALORIZATION......................................................................................................... 5

PRETREATMENTS..................................................................................................................8

MECHANICAL PRETREATMENTS................................................................................... 8

PHYSICAL PRETREATMENT........................................................................................... 8

CHEMICAL PRETREATMENTS...................................................................................... 10

BIOLOGICAL PRETREATMENT..................................................................................... 13

THERMOCHEMICAL PROCESSING....................................................................................14

DIRECT LIQUEFACTION.................................................................................................14

DIRECT COMBUSTION...................................................................................................14

GASIFICATION................................................................................................................ 15

FISCHER TROPSCH PROCESS.................................................................................... 15

PYROLYSIS..................................................................................................................... 16

TORREFACTION............................................................................................................. 16

BIOLOGICAL PROCESSING................................................................................................18

FERMENTATION..............................................................................................................18

ANAEROBIC DIGESTION............................................................................................... 18

FEEDSTOCKS.......................................................................................................................21

SACCHARIDES............................................................................................................... 22

LIGNIN............................................................................................................................. 25

PHENOL PRODUCTION........................................................................................... 26

PROTEINS....................................................................................................................... 29

EXTRACTS...................................................................................................................... 31

TREATMENT CATEGORY.................................................................................................... 33

PLATFORM MOLECULES.................................................................................................... 35

SYNGAS - THERMAL TREATMENT............................................................................... 35

5 - CHLOROMETHYL FURFURAL (CMF) - CHEMICAL TREATMENT.......................... 36

n-BUTANOL - BIOLOGICAL TREATMENT......................................................................37

TRIGLYCERIDE - EXTRACTION.....................................................................................38

BIO-DERIVED CHEMICALS................................................................................................. 41

ADIPIC ACID....................................................................................................................42

ETHYLENE GLYCOL....................................................................................................... 46

BIOPOLYMERS............................................................................................................... 51

PULP and PAPER INDUSTRY.............................................................................................. 57

PAPER SHEETS MAKING...............................................................................................57

BLACK LIQUOR...............................................................................................................58

BIOBASED SPECIALITY CHEMICALS................................................................................60

SOAPS............................................................................................................................. 60

SURFACTANTS............................................................................................................... 61

PIGMENTS and DYES.....................................................................................................63

COATINGS.......................................................................................................................67

ENVIRONMENTAL and ECONOMIC SUSTAINABILITY of BIOCHEMICALS.................... 69

MULTIPLE-CHOICE and SHORT QUESTIONS................................................................... 72

OPEN QUESTIONS............................................................................................................. 105

1

BIOMASS

As the earth's capacity of resources is always the same, the environmental burden continues

to increase. A solution is the transmaterialization, i.e. see the waste as a resource of material.

Unlike solar or wind power, which provides only energy, biomass can be also converted into

chemicals.

Biomass corresponds to any organic matter which is available on a continuous basis and in

abundant quantities (like wood, crops, organic waste). It is considered renewable since it can

be continually regenerated within a closed loop.

The goal is to move towards an economy without any waste. For example, only the food

supply chain waste could be used to produce high value chemicals.

By the way, in Europe, there are some limitations to the biomass use:

●​ importance of avoiding the use of food crops, minimizing the competition with food

sector (except for creating chemicals used in food industries)

●​ the most used biomass is the organic waste

●​ other sources are lignocellulosic materials

BIOREFINERY

A biorefinery is a facility that converts biomass into chemicals or energy. It is based on the

maximization of the biomass conversion, minimizing also the waste generation.

It is quite different from the petrorefinery, which is based on the use of petroleum and other

fossil materials, despite the products being basically the same as the biorefinery.

The biorefinery can produce:

●​ low value high volume products (usually the products of a petrorefinery) like

biodiesel, bioethanol, plastics ecc)

●​ high value low volume products like speciality chemicals

In order to obtain these products, biorefinery could use:

●​ thermochemical processes, like combustion, to obtain for example syngas

●​ biochemical processes, like fermentation, to obtain for example bioethanol

●​ chemical processes, like a catalytic conversion to obtain biodiesel

●​ mechanical processes, like a mechanical extraction to obtain oils

TYPE I / PHASE I BIOREFINERIES

Type I biorefineries are based on a single type of feedstock that will be involved in a single

process to produce a single major product. An example could be the production of

biodiesel through the transesterification of rape seed oil and methanol.

Main characteristics:

●​ simple

●​ not versatile → for this reason it is used only for already proven and operational

processes

TYPE II / PHASE II BIOREFINERIES 2

Type II refineries allow only one type of feedstock, but it can be used to produce several

major molecules so it’s quite flexible. Examples:

●​ a plant in which starch (the only feedstock) can be converted into biodegradable

polyesters (Origi-Bi) and starch-derived thermoplastics (Mater-Bi)

●​ a biodiesel-only plant could become a type II biorefinery if it could develop

technologies to convert the glycerine (by-product of the process) into valuable energy

or chemicals

It’s economically advantageous because it’s possible to choose the product to synthesize

based on the actual demand and price.

We could convert a type I biorefinery into a type II biorefinery by converting side streams

into valuable products.

TYPE III / PHASE III BIOREFINERIES

Type III biorefineries allow more than one feedstock and can lead to the production of a

large variety of products. The diversity of feedstocks and products determines a high

flexibility of the plant towards demands and prices.

Moreover, the possibility to use different types of feedstock, secures consistent and

continuous supply (if one feedstock is not available, it can be substituted).

By the way, these types of plants are difficult to design so, at the moment, there are no type

III refineries.

LIGNOCELLULOSE FEEDSTOCK BIOREFINERY

In this type of biorefinery, the brown biomass (crops and wood) is used as feedstock. The

biomass should be fractionated into cellulose, hemicellulose and lignin.

After different treatments, we could obtain for example Adipic acid from hemicellulose.

WHOLE CROP BIOREFINERY

In this type of biorefinery, the whole crop is used (basically cereals like grain [grano],

straw[paglia]) as a feedstock. Grain, which is much easier to process, is separated from the

straw and after some treatments we could obtain, again, adipic acid from hemicellulose.

GREEN BIOREFINERY

In this type of biorefinery, grass is pressed to obtain:

●​ a green juice rich in nutrients, from which we can yield aminoacids or dyes [coloranti]

●​ fiber rich pressed cakes, that could be used to create bio-composities, insulation

materials ecc

TWO PLATFORM BIOREFINERY

In this type of biorefinery, the feedstock is separated into:

●​ a sugar platform stream, from which we could use biochemical processes to obtain

sugars

●​ a syngas platform stream, from which we could use thermochemical processes to

obtain fuels and chemicals

MARINE BIOREFINERY

An emerging concept using micro- and macro-algae for fuel and chemicals 3

COMPARISON between REFINERIES

Petrorefinery Biorefinery

present in the areas where widely distributed but the

there are rich deposits of density is not as high as the

crude oil and in those areas petrorefinery (higher

Location and density they are dense (efficient transportation costs)

transport between

refineries)

raw materials are highly oxygenated

hydrocarbons with low hydrocarbons (exception:

Type of raw material oxygen content (exception: limonene)

methanol)

Ethylene, Propylene, Saccharides, Proteins, ecc

Platform chemicals Benzene

Characteristic of the raw oil is continuous but finite biomass is not a continuous

material source but it’s renewable

oxidations, fully optimized reductions (oxygen is

so they present lower costs already present), which are

and higher quality products. not fully developed (need

Type of processes Does not use biochemical research), so they have

processes. higher costs and usually

lower quality products

largely available low availability, higher cost

Products and therefore low

competitiveness

Separation and purification Optimized Challenging, high cost

Carbon emission and waste high low if managed

generation

OBJECTIVES of the BIOREFINERY

●​ competitive price with petro-based products

●​ better quality of the petro-based products

●​ introduce new products with the same function of some petro-based products

●​ obtain protection and support of the government

●​ adapting its size with respect to the environment in which it is located:

○​ large if it needs a high capacity production

○​ small if connected only to local needs 4

WASTE VALORIZATION

Waste valorization is very important to reduce the actual amount of waste and the costs of

the disposal.

The biomass that can be used is both plant based or food based and the main type of process

that is used to obtain some value products from this feedstock is the extraction. Nowadays

the main focus is to improve these extraction methods, scale them up (increase the size of

equipment) or out (multiplying the number of equipment) to industrial use also finding some

greener techniques like using supercritical CO or microwave extraction.

2

The main problem of using biomass is that biomass degrades during time so we need to

stabilize it in order to study and design new processes to have advantages on using biomass

as feedstock.

AGRICULTURAL RESIDUES

Agricultural residues can be valuable feedstocks for biorefinery because they present a

mixture of hydrocarbons (basically lipids) named waxes that cover the plant surface.

These agricultural residues are divided into two big classes:

●​ sugarcane bagasse, which is the fiber residue of the sugarcane

●​ wheat straw, which is produced with a higher volume than wheat itself but it has a

much lower value

The production of these waxes is increasing since their applications are widening and the

petroleum waxes are starting to be less produced for the environmental impact.

The most important wax, which is extracted by straw is β-diketone because it can be used to:

●​ extract copper

●​ separate heavy metals

●​ bio-inspired application like self cleaning windows

●​ water resistant applications and coatings

Agricultural residues are made by lignocellulosic biomass, which consists of:

●​ lignin

●​ cellulose

●​ hemicellulose

Sugarcase bagasse is usually easier to process because of its lower content in lignin and

ash, following also its lower cost of processing.

The other main difference is their availability in the world: straw is available in more

temperate regions while sugarcane is common in tropical regions.

EXTRACTION PROCESS

The extraction process of waxes can be operated using:

●​ organic solvents like hexane

○​ more effective than CO 2

○​ toxic

○​ established extraction processes

●​ supercritical carbon dioxide 5

○​ widely available

○​ low temperature process (critical temperature is around 30°C)

○​ non flammable and non toxic solvent

○​ high pressure to reach

○​ its effectiveness can be improved with polar co-solvents

○​ used in decaffeination of coffee and extraction of plant waxes

○​ efficiency of the extraction can be optimized by changing temperature and

pressure

FOOD SUPPLY CHAIN WASTE

Food supply chain waste includes all the food that has been lost or discarded from the

production to consumption (so cultivation, processing, packaging, distribution, consumer

waste are included). Using such waste will:

●​ decrease disposal and waste treatment cost

●​ reduce waste

●​ obtain valuable chemicals

From the food waste we could obtain many important products, also with quite green and

revolutionary processes (like microwave extraction or fermentations).

The chemical extraction from FSCW is easier than the one from plant based waste because

of: ●​ the low lignin content

●​ high content of water

●​ they usually have a softer structure

The most important products that can be obtained from food waste are:

●​ limonene, for:

○​ flavoring

○​ natural solvent

○​ insect repellent

○​ botanical pesticide

●​ pectin (complex sugar coming from fruit peel)

○​ personal care products

○​ can be present in different forms (salt, free ecc)

●​ succinic acid obtained though fermentation:

○​ is the base monomer to produce poly-hydroxybutyrate (PHD), an important

biodegradable polymer

○​ used to produce bioethanol and bioalcohols through fermentation

●​ L-phenylalanine obtained from fermentation

○​ production of cinnamic acid (flavoring agent or base for cosmetics) thanks to

an enzyme

○​ production of styrene through decarbonylation and therefore polystyrene

●​ glutamic acid from the hydrolysis of proteinaceous food waste

○​ platform compound for the production of n-methylpyrrolidone (NMP) and

n-vynilpyrrolidone (NVP) 6

●​ lysine from the hydrolysis of proteinaceous food waste

○​ feedstock for commodity chemicals like

■​ 5-aminovaleric acid (AVA) through oxidative deamination

■​ 1,5-diaminopentane (DAP) through decarbonylation → biobased

nylon 5,6

■​ caprolactam through the catalytic cyclization of DAP → monomer

for nylon 6

PROCESSING of BIOMASS

The plant based biomass is composed by:

●​ hemicellulose is a branched polymer of sugars so it is amorphous and therefore

easier to degrade

●​ cellulose is a linear polymer so it is crystalline and therefore quite difficult to

degrade

●​ lignin is a crosslinked polymer with phenol cycles. It is amorphous but because of

cycles is very difficult to degrade

○​ it usually cover the internal part of biomass

Biomass contains energy (from the sun) inside chemical bonds.

Biomass is usually pretreated using mechanical, physical, chemical and biological processes

while platform molecules are converted into valuable chemicals using thermochemical or

biological processes.

SUMMARY - TYPES of WASTE

Agricultural waste Food waste

Type of biomass Lignocellulosic Non-lignocellulosic

Feature Quite difficult to process Easier to process because of

because of lignin low lignin content

Processing Extraction of waxes Extraction of amino acids

Advantages Reduce waste

Reduce waste disposal cost

Obtain valuable chemicals

Valuable products β-diketone from Wheat Caprolactam from lysine

Straw Styrene from

L-phenylalanine

Glutamic acid

Bioethanol from succinic

acid 7

PRETREATMENTS

MECHANICAL PRETREATMENTS

One problem of biomass is the low energy and carbon density so we need to densify these

feedstocks to reduce the cost of transportation and storage,

We need to eliminate every air pocket present in the biomass.

Another process is the breaking of long chains into smaller ones and then converting all the

crystalline structure into an amorphous mass which is easier to process.

Then, when it is easier, the total structure of the polymer is degraded to its monomers.<