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 EmiliaFacoltà di Bioscienze e BiotecnologieGREEN CHEMISTRYConcetto di BioraffineriaDr. Luca FortiLaboratorio di BiocatalisiDipartimento di Chimica
2 7. Use of renewable feedstocks A raw material or feedstock should be renewablerather than depleting whenevertechnically and economically practicable
4 Organic feedstocks for the chemical industry EthylenePropyleneButadieneBenzeneTolueneXilenesOilNatural gasSyngasMethanolHydrogenFossil resourcesEmerging feedstocksfor the chemical industryCarbonAnthraceneNafthaleneNatural polymers (cellulose, rubber)Fine chemicalsBiomass
5 Organic industrial production from renewable resources (biomass) The challengeOrganic industrial productionfrom renewable resources (biomass)
6 Chemical from renewable resources AdvantagesNew structural characteristics (stereochemical and enantiomerical) to be exploited in synthesisStructural complexity of building block: reduction of reaction side products, reduction of waste materialOxygenated building blocks: avoid the oxygenation process, which usually involve stoichiometric toxic reagents
7 Chemical from renewable resources AdvantagesExtend the lifetime of available crude oil suppliesMitigate the build up of greenhouse CO2 in the atmosphereFeedstock supplies are domesticFeedstock is flexible, non-toxic, sustainableProducts usually biodegradable
8 CO2 Biomass Oil Carbohydrate refinery Consumer Bio Crude oil refinery Natural gasCoal> 106 years
9 Chemical from renewable resources DisadvantagesCurrent economic circumstances (comparison with petrochemicals industry)“Seasonal” supplyFeedstock used as source of food: questionedRequire space to growWide range of materials: detrimental if new processesare needed for each feedstock
11 Materiali biologici grezzi Risorse rinnovabiliMateriali biologici grezziAlimentiMangimiIntermedi farmaceuticiBiomaterialiEnergiaCarburantiBiochimiciAdditivi ossigenati per carburantiFenoli e furfuraleAcido aceticoAcidi grassiTensioattiviProdotti per agricolturaProdotti chimici specialiSolidi: carbone, lignina, bagassaLiquidi: etanolo, metanolo, olio combustibileGassosi: syngas, metano, idrogenoOli ed inchiostriColoranti e pigmentiVerniciDetergentiAdesiviBiopolimeriMateriali compositi
12 Biomassa: materiale vegetale o animale di origine recente (nongeologica) che puo’ essere usato per produrre diversi composti chimici e carburantiU.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.GranaglieBiomassa 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 primemateriale biologico grezzoBioprocessi (fermentazioni, bioconversioni)Processi chimiciProcessi termo-chimiciProcessi termiciProcessi fisiciProcessi ditrasformazioneCarburanti (etanolo, biodiesel)Prodotti chimici (intermedi, solventi, acidi grassi)Materiali (polimeri, inchiostri, vernici, lubrificanti)ProdottiSostanze 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 realizedIn 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 materialand 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 immaturecereal. 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, cloverlignocellulose 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 itstarts 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).
21 Meterie prime rinnovabili (fonti di carboidrati e lignina USI UNITA’C5/C6Meterie prime rinnovabili(fonti di carboidrati e ligninaligninaGlucosio dacellulosa e amidoAc. 3-chetoadipicoAc. 2-chetoglutaricoAc. glutammicoPolimeriNylon 4Ac. glutaricoAc. 3-chetoadipicoNuovi poliesteriNylon1,2,5-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, branGerm oilCereals/tubersGlutenSteepwaterStarchPaper & corrugatingModified starchesHydrolysedOxidisedEstersEthersCrossbondendDextrinsThickenersBindersCobuildersThermoplasticsComplexing agentsFlocculating agentsCoatingsMaltodextrinsLatex copolymersFermentationfeedstocksHydrolysatesPolyolsDerivativesSurfactantsPharma & cosmetic aids
24 Green biorefineryGreen 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.
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 solventschiral building blockL-lactic acid: acrylic acidbiodegradable polymersemulsifiers
30 Polylactic acidPolylactic 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 acidPolymerisationLow MW PLADepolymerisationSeparation by continuous distillationLactideCatalytic polymerisationHigh MW PLAJ. 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.PackagingFilmsPackaging foamContainers (biodegradable)Coatings for papers and boardsFibresClothingCarpet tiles (Interface Inc.)NappiesBottlesBiodegradable bottles
32 Vinacce Trattamento enzimatico Acqua riciclata Separazione solido sospesoSolido sospesoRefluo defenolatoConcentrazione a membranaRecupero estratto grezzo fenoliconcentratoBiotrasformazionePurificazione e isolamento dei fenoliBiomasse proteicheFormulazione di cibi fortificatiTrasformazioni chimiche ed enzimaticheFormulazione di mangimi animaliChimica Fine
33 FROM BIOMASS TO CHEMICALS THROUGH Physical methodsThermal methodsChemical methodsMicrobial methods
34 Physical methodsThey separate and isolate the different components of biomass leaving unmodified their structureexamplesthe production of:Polysaccharides (cellulose, starch, agar alginate…)Disaccharides (lactose, sucrose)TriglyceridesNatural rubberFlavour and fragrances, farmaceutical
35 Simple extraction of materials BiomassExtractionPurificationUsagePalm oil press
36 Pyrolisis Production of Bio-crude Thermal ConversionsPyrolisis Production of Bio-crudeDecomposition at temperature between °C in absence or with low amount of oxygento produceliquid 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 atmCO H2 CH3OHCO H2 CH3OH H2OCu and Zn catalyst, 300 °C, 100 atmGas from biomass
40 Methanol economy O Surfactants Polymers Esters Ethers Oligomers C H C /Ag2EstersEthers-HOOligomersCHCH222EtOHSyngasBiomass + HO2HO/Rh/Se/TiO22aldehydesacidsNFisher-TropschalcoholsNH2CO + H2Gasoline3CO2CO/Ir/RuCHCOH32UreaHCHOMeOHAlkanesHZSM-5Pt / aluminaCO,HPlastics2HClAromaticsAlcoholsMeClCOH2PolymersPaintsAdhesives
42 One step chemical modification One step chemical modifications of components separated by physical methodsExamplesCellulose and starch derivativesGlucose and fructoseGlycerolFatty acids
43 Two or more steps chemical modification ExamplesEthylene from ethanolSorbitol and mannitol by hydrogenation of glucose and fructoseVitamin C in several steps from glucoseFatty alcohols and amines from triglyceridesAlkyl polyglucoside from glucose and fatty alcohol
44 Industrial uses of sucrose Sugar cane/sugar beetBeet pulpBagasseMolassessucroseFermentation feedstocksPolycondensate (starter)Sucrose derivativeEstersEthersAcetalsBuilding units (pharma)SurfactantsGlucose + fructoseFuran resins
45 Industrial use of fatty acid Seed crushingand separationSurfactants in alternative to alkylbenzene sulphonatesoilLubricants in alternative to mineral oilsHigh temperaturehydrolysisGlycerolSolvents in alternative to chlorinated solventsDistillationCrude acid mixCrystallizationSupercritical extractionFatty acidsSolvent extractionFractional distillation
46 BiodieselShort 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 successfullyAcidic 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 usedEnzyme 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 bacteriaOrganic Chemists Prayer (unknown origin)
48 Biotransformation reactions FermentationsBiotransformation reactionsBiocatalysis 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-COOHacidsR-OHalcoholsVit. B12vitaminsNH2-CR-COOHaminoacids… and some not so common productsNatural carbon sources are used for production of biomass and for de novo synthesis of productsHexanoic acidBioplasticsCatechol
50 Biotransformation reactions Biotransformation processes can be used for production of numerous fine and specialty chemicalsCarbohydratesPlant-oilsMethanolPrecursormoleculesNatural 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) SunlightSugar solutionCropPlastic productPHAFermentationBiodegradation to CO2 and H2O
52 Produzione di bio-idrogeno Basata sulla Modifica del metabolismo di alghe(rinnovabile e privo di inquinamento)SunlightH2luce solare + alghe + acqua H2Idrogeno + 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 MgSO410 g bacto tryptone 3 g KH2PO4 1 mg thiamine5 g bacto yeast 1 g NH4Cl10.5 g NaCl 10 g glucose (62 mmol)Yield = 20.4 mmol% Yield = 33 %
54 Growing biomass Land usage: CAP (Common Agricultural Policy) FertilisersPesticides/HerbicidesTransportation/InfrastructureReduced CO2???
55 THE FUTURE CHEMICAL INDUSTRY PresentPastFuture?