La presentazione è in caricamento. Aspetta per favore

La presentazione è in caricamento. Aspetta per favore

GREEN CHEMISTRY Facoltà di Bioscienze e Biotecnologie

Presentazioni simili


Presentazione sul tema: "GREEN CHEMISTRY Facoltà di Bioscienze e Biotecnologie"— Transcript della presentazione:

1 GREEN CHEMISTRY Facoltà di Bioscienze e Biotecnologie
Università degli studi di Modena e Reggio Emilia Facoltà di Bioscienze e Biotecnologie GREEN CHEMISTRY Concetto di Bioraffineria Dr. Luca Forti Laboratorio di Biocatalisi Dipartimento di Chimica

2 7. Use of renewable feedstocks
A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable

3 Petroleum refinery Fuels Solvent Bulk chemicals Plastics Fibres
Present situation: organic industrial production from Petroleum refinery Fuels Solvent Bulk chemicals Plastics Fibres Petroleum feedstock Fine chemicals Oils

4 Organic feedstocks for the chemical industry
Ethylene Propylene Butadiene Benzene Toluene Xilenes Oil Natural gas Syngas Methanol Hydrogen Fossil resources Emerging feedstocks for the chemical industry Carbon Anthracene Nafthalene Natural polymers (cellulose, rubber) Fine chemicals Biomass

5 Organic industrial production from renewable resources (biomass)
The challenge Organic industrial production from renewable resources (biomass)

6 Chemical from renewable resources
Advantages New structural characteristics (stereochemical and enantiomerical) to be exploited in synthesis Structural complexity of building block: reduction of reaction side products, reduction of waste material Oxygenated building blocks: avoid the oxygenation process, which usually involve stoichiometric toxic reagents

7 Chemical from renewable resources
Advantages Extend the lifetime of available crude oil supplies Mitigate the build up of greenhouse CO2 in the atmosphere Feedstock supplies are domestic Feedstock is flexible, non-toxic, sustainable Products usually biodegradable

8 CO2 Biomass Oil Carbohydrate refinery Consumer Bio Crude oil refinery
Natural gas Coal > 106 years

9 Chemical from renewable resources
Disadvantages Current economic circumstances (comparison with petrochemicals industry) “Seasonal” supply Feedstock used as source of food: questioned Require space to grow Wide range of materials: detrimental if new processes are needed for each feedstock

10 Bio-refinery Fuels Solvent Bulk chemicals Plastics Grain Fibres
Fine chemicals Oils

11 Materiali biologici grezzi
Risorse rinnovabili Materiali biologici grezzi Alimenti Mangimi Intermedi farmaceutici Biomateriali Energia Carburanti Biochimici Additivi ossigenati per carburanti Fenoli e furfurale Acido acetico Acidi grassi Tensioattivi Prodotti per agricoltura Prodotti chimici speciali Solidi: carbone, lignina, bagassa Liquidi: etanolo, metanolo, olio combustibile Gassosi: syngas, metano, idrogeno Oli ed inchiostri Coloranti e pigmenti Vernici Detergenti Adesivi Biopolimeri Materiali compositi

12 Biomassa: materiale vegetale o animale di origine recente (nongeologica) che puo’ essere usato per produrre diversi composti chimici e carburanti U.S. President 1999; U.S. Congress 2000: “The term biomass means any organic matter that is available on a renewable or recurring basis (excluding oldgrowth timber), including dedicated energy crops and trees, agricultural food and feed crop residues, aquatic plants, wood and wood residues, animal wastes, and other waste materials.” La maggior parte dei materiali biologici grezzi e’ prodotta in agricultura, silvicoltura e sistemi microbici.

13 La biomassa ha una composizione complessa, simile al petrolio.
E’ quindi opportuna una separazione primaria nei principali gruppi di sostanze che la compongono. I trattamenti successivi di queste sostanze portano alla formazione di una “tavolozza” completa di prodotti. Un importante differenza col petrolio e’ che il petrolio deve essere estratto, mentre la biomassa esiste gia’ come prodotto, principalmente in seguito a trasformazioni agricole. La biomassa puo’ quindi essere modificata all’interno del processo con cui si origina in modo tale da adattarsi ai successivi processi di trasformazione per ottenere un prodotto target.

14 La bioraffineria combina le tecnologie necessarie per trasformare materiali biologici grezzi in intermedi o in prodotti finiti di interesse industriale. La biomassa vegetale e’ costituita principalmente da carboidrati, lignina, proteine e lipidi, oltre a varie sostanze presenti in quantita’ minori come vitamine, coloranti, aromi e fragranze.

15 materiale biologico grezzo
“bioraffineria”: un sistema simile alla raffineria del petrolio per produrre prodotti chimici, carburanti ed energia utilizzando biomasse. Granaglie Biomassa ligno-cellulosica (es. Graminacee, canne, arbusti, cespugli, residui di raccolti) Biomasse forestali (legname, sterpaglie, scarti della lavorazione del legno) Rifiuti solidi urbani (carta/cartone, fogliame…) Materie prime materiale biologico grezzo Bioprocessi (fermentazioni, bioconversioni) Processi chimici Processi termo-chimici Processi termici Processi fisici Processi di trasformazione Carburanti (etanolo, biodiesel) Prodotti chimici (intermedi, solventi, acidi grassi) Materiali (polimeri, inchiostri, vernici, lubrificanti) Prodotti Sostanze ed energia

16 Schema generale di bioraffineria
A technically feasible separation operation, which would allow the separate use or subsequent processing of all these basic compounds, has existed until now only in the form of initial attempts. Assuming that, of the estimated annual biosynthesis production of biomass of 170×109 t, 75% is carbohydrate, mainly in the form of cellulose, starch and saccharose, 20% is lignin and only 5% is other natural compounds, such as fats (oils), proteins and various substances the main attention should first be focused on an efficient access to carbohydrates, their subsequent conversion to chemical bulk products and the corresponding final products. Glucose, accessible by microbial or chemical methods from starch, sugar or cellulose, is among other things predestined for a key position as a basic chemical, because a broad palette of biotechnological or chemical products is accessible from glucose. In the case of starch, the advantage of enzymatic compared with chemical hydrolysis has already been realized In the case of cellulose, this is not yet realized. Cellulose-hydrolyzing enzymes can only act effectively after pre-treatment to break up the very stable lignin/cellulose/hemicellulose composites. These treatments are still mostly thermal, thermo-mechanical or thermo-chemical and require a considerable input of energy. The arsenal for the microbial conversion of substances out of glucose is large and the reactions are energetically profitable. It is necessary to combine the degradation processes from glucose to bulk chemicals with the building processes that give their subsequent products and materials. Among the variety of possible products from glucose which are accessible microbially and chemically , lactic acid, ethanol, acetic acid and levulinic acid are particularly favorable intermediates for the generation of industrially relevant product family trees. Here, two potential strategies are considered: either the development of new (possibly biologically degradable) products (e.g. followup products of lactic and levulinic acid) or the entry as intermediates into the conventional product lines (e.g. acrylic acid, 2,3-pentandion) of petrochemical refineries. The term green biorefinery was defined in the year 1997 as follows: green biorefineries represent complex (to fully integrated) systems of sustainable, environment- and resource-friendly technologies for the comprehensive (holistic) utilization and the exploitation of biological raw materials in the form of green and residue biomass from a targeted sustainable regional land utilization. The United States Department of Energy, in its Energy, environmental, and economics (E3) handbook, uses the following definition (U.S. Department of Energy 1997): a biorefinery is an overall concept of a processing plant where biomass feedstocks are converted and extracted into a spectrum of valuable products, based on the petrochemical refinery. There is (more or less) agreement about the goal, which is briefly defined as: developed biorefineries, so-called phase III biorefineries, start with a biomass feedstock-mix to produce a multiplicity of products by a technology-mix. An example of the phase I biorefinery is a dry-milling ethanol plant. It uses grain as a feedstock, has a fixed processing capability and produces a fixed amount of ethanol, feed co-products and carbon dioxide. It has almost no flexibility in processing. An example of the phase II biorefinery is the current wet-milling technology. This technology uses grain feedstocks, yet has the capability of producing various end-products, depending on product demand. A phase III biorefinery is not only able to produce a variety of chemicals, fuels and intermediates or endproducts, but can also use various types of feedstocks and processing methods to produce products for the industrial market. In the first step, the precursor-containing biomass is separated by physical methods. The main products and the by-products are subsequently subjected to microbiological or chemical methods. The follow-up products of the by-and main products can furthermore be converted or enter a conventional refinery. Therefore, the term biorefinery receives a double importance, on the one hand because of the biological genesis of the corresponding raw material and on the other hand because of the rising biological character of selected treatment and processing methods. Currently, three biorefinery systems are favored in research and development. First, the whole-crop biorefinery, which uses raw materials such as cereals or maize. Second, the green biorefinery, which uses naturally wet biomass, such as green grass, lucerne, clover, or immature cereal. Third, the lignocellulose feedstock (LCF) biorefinery, which uses naturally dry raw materials such as cellulose-containing biomass and wastes.

17 whole-crop biorefinery:
uses raw materials such as cereals or maize. green biorefinery: uses naturally wet biomass, such as green grass, lucerne, clover lignocellulose feedstock (LCF) biorefinery: uses naturally dry raw materials such as cellulose-containing biomass and wastes.

18 LCF-Biorefinery, Phase III
Among the potential large-scale industrial biorefineries, the LCF biorefinery will most probably be pushed through with highest success. On the one hand, the raw material situation is optimal (straw, reed, grass, wood, paper-waste, etc.) and, on the other hand, conversion products have a good position within both the traditional petrochemical and the future biobased product markets. An important point for the utilization of biomass as a chemical raw material is the cost of raw materials. Currently, the costs are U.S. $ 30/t for corn stover or straw and U.S. $ 110/t forcorn (U.S. $ 3/bushel; Dale 2002). An overview of the potential products of a LCF biorefinery is shown in Fig. 6. In particular, furfural and hydroxymethylfurfural are interesting products. Furfural is the starting material for the production of Nylon 6,6 and Nylon 6. The original process for the production of Nylon 6,6 was based on furfural. However, there are still some unsatisfactory parts within the LCF, such as the utilization of lignin as fuel, adhesive or binder. It is unsatisfactory because the lignin scaffold contains considerable amounts of mono-aromatic hydrocarbons which, if isolated in an economically efficient way, could add a significant value increase to the primary processes. It should be noticed that there are no obvious, natural enzymes to split the naturally formed lignin into basic monomers as easily as is possible for naturally formed polymeric carbohydrates or proteins (Ringpfeil 2002). An attractive accompanying process to the biomass–Nylon process is the already mentioned hydrolysis of cellulose to glucose, with the production of ethanol. Certain yeasts give a disproportionation of the glucose molecule during their generation of ethanol which practically shifts the entire reduction process towards ethanol and makes the latter obtainable in a 90% yield (w/w, regarding the formula turnover). Based on recent technologies, a plant was conceived for the production of the main products furfural and ethanol from LCF for west-central Missouri (USA). Optimal profitability can be reached with a daily consumption of about 4,400 t of feedstock. Annually, the plant produces 180×106 l of ethanol and 323×103 t of furfural (Van Dyne et al.1999). Ethanol may be used as a fuel additive. Ethanol is also a connecting product for a petrochemical refinery. Ethanol can be converted into ethene by chemical methods. As is well known for petrochemically produced ethene, today it starts a whole series of large-scale technical chemical syntheses for the production of important commodities, such as polyethylene and polyvinylacetate. Further petrochemically produced substances can similarly be manufactured by substantial microbial conversion of glucose, such as hydrogen, methane, propanol, acetone, butanol, butandiol, itaconic acid and succinic acid (Zeikus et al. 1999; Vorlop and Willke 2003).

19 Dehydrogenation Hydrolysis Hydrogenation Crystallisation Hydroxymethylfurfural Levulinic acid Polyols Glucose Hexoses Furfural Polyols (Xylitol) Xylose Dehydration Hydrogenation Crystallisation Hydrolysis (Chemical) Pentoses Hydrogenation Hydrolysis Oxidation Phenol derivatives, hydrocarbons Phenol derivatives, catechols Vanillin Lignin

20 5-(hydroxymethyl)-furfural
Levulinic acid 5-(hydroxymethyl)-furfural furfural 5-aminolevulinic acid

21 Meterie prime rinnovabili (fonti di carboidrati e lignina
USI UNITA’ C5/C6 Meterie prime rinnovabili (fonti di carboidrati e lignina lignina Glucosio da cellulosa e amido Ac. 3-chetoadipico Ac. 2-chetoglutarico Ac. glutammico Polimeri Nylon 4 Ac. glutarico Ac. 3-chetoadipico Nuovi poliesteri Nylon 1,2,5-pentantriolo

22 whole-crop biorefinery
The raw materials for the whole-crop biorefinery are cereals, such as rye, wheat, triticale, and maize. The first step is mechanical separation into corn and straw, which biorefinery. There is the possibility of separation into cellulose, hemicellulose and lignin and their further conversion within the separate product lines shown in the LCF biorefinery (Fig. 6). Furthermore, the straw is a starting material for the production of syngas via pyrolysis technologies. Syngas is the basic material for the synthesis of fuels and methanol (Fig. 7). The corn may either be converted into starch or directly used after grinding to meal. Further processing may be carried out in four directions: (a) breaking-up, (b) plasticization, (c) chemical modification or (d) biotechnological conversion via glucose. The meal can be treated and finished by extrusion into binder, adhesives and filler. Starch can be finished via plasticization (co-, mixpolymerization, compounding with other polymers), chemical modification (etherification into carboxymethyl starch, esterification, re-esterification into fatty acid esters via acetic starch, splitting reductive amination into ethylene diamine, etc., hydrogenative splitting into sorbitol, ethyleneglycol, propyleneglycol, glycerine) and biotechnological conversion (poly-3-hydroxybutyric acid; Nonato et al. 2001).

23 Industrial uses of starch
Fiber, hemicellulose, bran Germ oil Cereals/tubers Gluten Steepwater Starch Paper & corrugating Modified starches Hydrolysed Oxidised Esters Ethers Crossbondend Dextrins Thickeners Binders Cobuilders Thermoplastics Complexing agents Flocculating agents Coatings Maltodextrins Latex copolymers Fermentation feedstocks Hydrolysates Polyols Derivatives Surfactants Pharma & cosmetic aids

24 Green biorefinery Green biorefineries are multi-product systems which handle their refinery cuts, fractions and products in accordance with the physiology of the corresponding plant material, i.e. the maintenance and utilization of the diversity of syntheses achieved by nature. Green biomass for example includes grass from the cultivation of permanent grassland, closure fields, nature preserves and green crops, such as lucerne, clover and immature cereals from extensive land cultivation. Thus, green plants represent a natural chemical factory and food plant. Careful wet-fractionation technology is used as the first step (primary refinery) to isolate the green biomass substances in their natural form. Thus, green crop goods (or humid organic waste goods) are separated into a fiber-rich press cake and a nutrient-rich green juice. Beside cellulose and starch, the press cake contains valuable dyes and pigments, crude drugs and other organics. The green juice contains proteins, free amino acids, organic acids, dyes, enzymes, hormones, other organic substances and minerals. In particular, the application of biotechnological methods is predestined for conversions, because the plant water can simultaneously be used for further treatments. In addition, the lignin–cellulose composites are not so strong as those in LCF materials. Starting from green juice, the main focus is directed to products such as lactic acid and the corresponding derivatives, amino acids, ethanol and proteins. The press cake can be used for the production of green feed pellets, as a raw material for the production of chemicals, such as levulinic acid, and for conversion to syngas and hydrocarbons (synthetic biofuels). The residues of a substantial conversion are suitable for the production of biogas, combined with the generation of heat and electricity.

25 Ethylene Ethanol Ethylene glycol Acetaldehyde Acetic acid Acetone
Butadiene Acrylic acid Glycerol Propane Propylene butanol Butanediol Propanediols Lactic acid Succinic acid Butyric acid fermentation Hexoses Pentoses Hydrolysis biomass

26 Ethanol fermentation

27 ECONOMIA DELL’ETANOLO (C2)
CH3CH2OH CH2=CH2 CH3CHO CH3COOH Etil benzene Etil bromuro Etil cloruro Etilen cloridrina Etilendiammina Etilen dibromuro Etilen dicloruro Etilen glicole Etilenimmina Etilen ossido Dietil chetone Dietilen glicole Vinil acetato Polimeri Acido acetico Anidride acetica Prodotti aldolici Butil acetato Butil alcol Butirraldeide Cloralio Etilenimmina Piridine Acetammide Acetanilide Acetil cloruro Anidride acetica Dimetil acetammide Acetati di cellulosa Esteri

28 Commodity chemicals from ethanol
Some organic commodity chemicals from fermentation ethanol in Brazil

29 Lactic acid is produced by fermentation from sucrose or fructose
Products: Ethyl lactate: Biodegradable solvents chiral building block L-lactic acid: acrylic acid biodegradable polymers emulsifiers

30 Polylactic acid Polylactic acid (PLA) is not a new polymer, it has been known since 1932. Producing low molecular weight PLA is a simple process, however, making high molecular weight PLA is a more complicated affair. Cargill-Dow has developed a novel process involving selective depolymerisation of low molecular weight PLA to a cyclic intermediate (lactide), which is purified by distillation. Catalytic ring opening of the lactide results in continuous controlled weight PLA preparation. Lactic acid Polymerisation Low MW PLA Depolymerisation Separation by continuous distillation Lactide Catalytic polymerisation High MW PLA J. Lunt, Polymer Degradation and Stability, 59, (1998),

31 Properties and uses of Polylactic acid (PLA)
The PLA materials have mechanical properties that lie somewhere in between that of polystyrene and PET. Packaging Films Packaging foam Containers (biodegradable) Coatings for papers and boards Fibres Clothing Carpet tiles (Interface Inc.) Nappies Bottles Biodegradable bottles

32 Vinacce Trattamento enzimatico Acqua riciclata
Separazione solido sospeso Solido sospeso Refluo defenolato Concentrazione a membrana Recupero estratto grezzo fenoli concentrato Biotrasformazione Purificazione e isolamento dei fenoli Biomasse proteiche Formulazione di cibi fortificati Trasformazioni chimiche ed enzimatiche Formulazione di mangimi animali Chimica Fine

33 FROM BIOMASS TO CHEMICALS THROUGH
Physical methods Thermal methods Chemical methods Microbial methods

34 Physical methods They separate and isolate the different components of biomass leaving unmodified their structure examples the production of: Polysaccharides (cellulose, starch, agar alginate…) Disaccharides (lactose, sucrose) Triglycerides Natural rubber Flavour and fragrances, farmaceutical

35 Simple extraction of materials
Biomass Extraction Purification Usage Palm oil press

36 Pyrolisis Production of Bio-crude
Thermal Conversions Pyrolisis Production of Bio-crude Decomposition at temperature between °C in absence or with low amount of oxygen to produce liquid organic fractions similar those ones obtained from petroleum

37 Gasification Production of Bio-gas
Controlled combustion around 1000°C to produce synthesis gas

38 The syngas economy Current (fossil fuel) process CH4 + H2O  CO + 3H2
Nickel oxide catalyst, 300 °C, 30 atm CO H2  CH3OH CO H2  CH3OH H2O Cu and Zn catalyst, 300 °C, 100 atm Gas from biomass

39

40 Methanol economy O Surfactants Polymers Esters Ethers Oligomers C H C
/ A g 2 Esters Ethers - H O Oligomers C H C H 2 2 2 E t O H Syngas Biomass + H O 2 H O / R h / S e / T i O 2 2 aldehydes acids N Fisher-Tropsch alcohols N H 2 CO + H2 Gasoline 3 C O 2 C O / I r / R u C H C O H 3 2 Urea H C H O M e O H Alkanes HZSM-5 Pt / alumina C O , H Plastics 2 HCl Aromatics Alcohols M e C l C O H 2 Polymers Paints Adhesives

41 Chemical conversion

42 One step chemical modification
One step chemical modifications of components separated by physical methods Examples Cellulose and starch derivatives Glucose and fructose Glycerol Fatty acids

43 Two or more steps chemical modification
Examples Ethylene from ethanol Sorbitol and mannitol by hydrogenation of glucose and fructose Vitamin C in several steps from glucose Fatty alcohols and amines from triglycerides Alkyl polyglucoside from glucose and fatty alcohol

44 Industrial uses of sucrose
Sugar cane/sugar beet Beet pulp Bagasse Molasses sucrose Fermentation feedstocks Polycondensate (starter) Sucrose derivative Esters Ethers Acetals Building units (pharma) Surfactants Glucose + fructose Furan resins

45 Industrial use of fatty acid
Seed crushing and separation Surfactants in alternative to alkylbenzene sulphonates oil Lubricants in alternative to mineral oils High temperature hydrolysis Glycerol Solvents in alternative to chlorinated solvents Distillation Crude acid mix Crystallization Supercritical extraction Fatty acids Solvent extraction Fractional distillation

46 Biodiesel Short chain alcohol usually employed - methanol most common (NaOH soluble in MeOH) Catalyst used to improve yield (system loading 1 % w/w): Basic catalyst most commonly used (e.g. sodium hydroxide) - lower ratio of glyceride to alcohol required (6:1). Supported guanidines have also been used successfully Acidic catalyst can be used as well but higher ratio of glyceride to alcohol required (30:1) - however, system is water tolerant; wet substrate can be used Enzyme catalysts have also been used - require lower reaction temperatures.

47 Microbial conversion Dear God: I pray on bended knee’s,
That all my syntheses, Will never be inferior, To those conducted by bacteria Organic Chemists Prayer (unknown origin)

48 Biotransformation reactions
Fermentations Biotransformation reactions Biocatalysis and genetic engineering of microbial metabolism provide a new approach for the generation of building block for chemical synthesis and for the production of consumer goods

49 Fermentations Carbohydrates Plant-oils Methanol R-COOH R-OH Vit. B12
Some classical fermentation products… R-COOH acids R-OH alcohols Vit. B12 vitamins NH2-CR-COOH aminoacids … and some not so common products Natural carbon sources are used for production of biomass and for de novo synthesis of products Hexanoic acid Bioplastics Catechol

50 Biotransformation reactions
Biotransformation processes can be used for production of numerous fine and specialty chemicals Carbohydrates Plant-oils Methanol Precursor molecules Natural carbon sources are used for the production of the biocatalyst and for the subsequent transformation of the reaction precursor into the desired product

51 Polyhydroxyalkanoates (PHA’s)
Sunlight Sugar solution Crop Plastic product PHA Fermentation Biodegradation to CO2 and H2O

52 Produzione di bio-idrogeno
Basata sulla Modifica del metabolismo di alghe (rinnovabile e privo di inquinamento) Sunlight H2 luce solare + alghe + acqua H2 Idrogeno + celle a combustibile o generatore a turbina = elettricità

53 Draths-Frost biotechnological synthesis
Typical feed solution: In 1 litre of water 6 g Na2HPO g MgSO4 10 g bacto tryptone 3 g KH2PO4 1 mg thiamine 5 g bacto yeast 1 g NH4Cl 10.5 g NaCl 10 g glucose (62 mmol) Yield = 20.4 mmol % Yield = 33 %

54 Growing biomass Land usage: CAP (Common Agricultural Policy)
Fertilisers Pesticides/Herbicides Transportation/Infrastructure Reduced CO2???

55 THE FUTURE CHEMICAL INDUSTRY
Present Past Future ?


Scaricare ppt "GREEN CHEMISTRY Facoltà di Bioscienze e Biotecnologie"

Presentazioni simili


Annunci Google