Meeting Malta. 5 November slide 1

Transcript

1 Meeting with Malta University La Valletta, November 5 th, 2008 PROCESS ANALYSIS AND SIMULATION FOR THE PRODUCTION OF BIOFUELS AND SYNFUELS Alberto Bertucco Dipartimento di Principi e Impianti di Ingegneria Chimica, Università di Padova Meeting Malta 5 November slide 1

2 Definition of sustainable development Humanity has the ability to make development sustainable, i.e. to ensure that it meets the needs of the present without compromising the ability of future generations to meet their own needs (The Bruntland Report, 1987) Meeting Malta 5 November slide 2

3 Where will we find the energy we need? in nuclear reactions in solar radiation in energy savings in renewable sources Meeting Malta 5 November slide 3

4 Renewable Energy Sources (RES) WOOD VEGETAL/ANIMAL OILS STARCH/SUGAR WASTES HYDRAULIC POWER WIND POWER GEOTHERMAL POWER OCEANIC WAVES POWER biomasses NOTE: hydrogen is NOT an energy source, it can be a tool to store and transport energy Meeting Malta 5 November slide 4

5 RES: solar energy the so-called thermal solar industrial photosynthesis (biomasses) chemical photocatalysis photovoltaic NOTE: solar energy is a huge amount, yet it is very diluited (1 kw/m2, at this latitude) Meeting Malta 5 November slide 5

6 A special problem: oil and transport fuels availability 60% of the oil produced is consumed as transportation fuel 98 % of transportation fuels is produced from oil (2% is Natural Gas) What shall we do without oil? What will come after oil? Meeting Malta 5 November slide 6

7 A crucial point: costs, i.e. economical sustainability The barrel price: what is ahead? (PLOT) Alternatives for the next 30 years SNG, LNG Synthetic fuels (GTL, CTL, BTL) biodiesel and bioethanol Biogas, RDF (solido) Reduction of fuel demand Meeting Malta 5 November slide 7

8 The oil price spot oil price: historical trend vs. actual price 120,000 historical trend actual price 110, ,000 90,000 80,000 70,000 60,000 50,000 oil price ($/bbl) 40,000 30,000 20,000 10,000 0,000 14/1/09 20/3/08 25/5/07 29/7/06 2/10/05 6/12/04 10/2/04 16/4/03 20/6/02 24/8/01 28/10/00 2/1/00 8/3/99 12/5/98 16/7/97 19/9/96 24/11/95 28/1/95 3/4/94 7/6/93 11/8/92 16/10/91 20/12/90 23/2/90 29/4/89 3/7/88 7/9/87 11/11/86 15/1/86 21/3/85 25/5/84 30/7/83 3/10/82 7/12/81 10/2/81 16/4/80 21/6/79 25/8/78 29/10/77 2/1/77 data Meeting Malta 5 November slide 8

9 Processes involved in alternative fuels production Combustion Gasification Pyrolysis Trans-esterification Fermentation Reforming Meeting Malta 5 November slide 9

10 The map of biofuels Zuccheri semplici BIOMASSA RACCOLTA SEPARAZIONE E PRETRATTAMENTO Polisaccaridi amido cellulosa emicellulosa Alcoli etanolo butanolo Metodi biochimici Lignina Idrocarburi ciclici Lipidi Acidi grassi e metilesteri TRATTAMENTI TERMICI Alcani lineari Metodi termochimici Oli di pirolisi idrocarburi Syngas Miscele alcoliche, carburanti di sintesi (FT fuels) Meeting Malta 5 November slide 10

11 Bioethanol: first generation process fundamentals sugar* Fermentation Recycle of H 2 O beer Distillazione distillation: stripping of alcohol, fractionation (3-5 columns, at different pressures) solids + H 2 O Evaporation Raw flour etanolo >92% corn* Milling Dehydration Drying ethanol >99% Animal food Steam consumption: kg/l EtOH H 2 O consumption : ~3 L/L EtOH Meeting Malta 5 November slide 11

12 The first plant in Italy (Triera S.p.A., Porto Marghera) Main features: maximum productivity: t/y Raw material used: t/y Agricultural land: ha Plant area: 6,5 ha Investment: 100 million Crucial factors raw material available in the surroundings close to the market (Refineries + public transpor fleets) Efficient logistics Plant integration Meeting Malta 5 November slide 12

13 the dry milling process: Block Flow Diagram (BFD) Liquefaction SSF CO kt/y steam Jet cooking Distillation stillage Centrifuge Evaporation EtOH >92% water Mashing Dehydration Dry house corn 340 kt/y Milling EtOH >99% kt/y DDGS 99.5 kt/y Meeting Malta 5 November slide 13

14 Ethanol recovery: an example of technical features from fermentation decanter steam beer colum n +H2O to recycle to molecular sieves rectifying column steam stripping colum n to recycle to dryhouse Meeting Malta 5 November slide 14

15 Energy duties of the process: technological alternatives The process requires about 6.5 MWe of electricity, 26.6 MW of steam, 11 MW of thermal power for DDGS drying Three alternatives were studied, all based on combined heat and power production, CHP): Gas turbine Fuel oil engine DDGS burner The three alternatives were compared to a base case where steam and electricity are supplied by an external source Meeting Malta 5 November slide 15

16 CHP: turbina a gas La stazione CHP a gas naturale è stata progettata per assicurare il completo fabbisogno di vapore. Il calcolo è stato eseguito sotto le seguenti ipotesi: P el (MW) 25.2 η el (%) 34.6 P term,in (MW) 72.8 Consumo di gas (kg/h) 6604 capitale investito (M ) L eccesso di energia elettrica è venduto ed immesso nella rete. I fumi di combustione potrebbero essere sfruttati per essiccare il DDGS. Meeting Malta 5 November slide 16

17 CHP: motore ad olio combustibile Il generatore CHP ad olio vegetale è stato dimensionato per soddisfare la sola richiesta di energia elettrica. Si sono assunte le seguenti ipotesi: P el (MW) 7.9 η el (%) 46.0 P term,in (MW) 17.2 oil consumption (kg/h) 1613 capital investment (M ) 7.41 Questo generatore produce soltanto 4 MW potenza termica. Il fabbisogno rimanente deve essere prodotto attraverso un bollitore a metano. In questo caso I fumi vengono utilizzati per l essiccamento del DDGS. Meeting Malta 5 November slide 17

18 CHP: bruciatore di DDGS Si è tenuto conto della possibilità di sfruttare l intera produzione di DDGS come combustibile per fornire sia il calore sia l energia elettrica necessaria al processo (Morey et al., 2006), e si è eseguito il calcolo sulla base delle ipotesi seguenti: P el (MW) 20.2 η el (%) 30 P term,in (MW) 67.3 capitale investito (M ) Il grande vantaggio di questa alternativa tecnica sta nella possibilità di ottenere Certificati Verdi (Green Credits, /MWh). Lo stesso discorso vale se si utilizza una centrale ad olio vegetale (ma questo da dove viene?). Meeting Malta 5 November slide 18

19 Bioethanol: Second generation processes From lignocellulose: biological process pretreatment for cellulose (glucose) and emicellulose (xilose) extraction Fermentation of glucose e xilose to ethanol Ethanol rectification treatment/combustion of solids and black liquor (recovery of energy) From lignocellulose: thermochemical process biomass gasification to produce syngas (H 2 e CO) Syngas fermentation to ethanol Electricity production Meeting Malta 5 November slide 19

20 Second generation Process: the basic idea Biomass collection several tecnical solutions for each step many possible integrations among steps Distillation and dehydration pre-processing pretreatment Separation of lignin + emicellulose energy hydrolysis production Enzymatic Release of cellulose and hydrolysis e C5 sugars acid or alkaline treatment steam explosion (with acid or NH 3 ) fermentation of conditioningo sugars (C5 C6) Meeting Malta 5 November slide 20

21 Biodiesel: BFD Meeting Malta 5 November slide 21

22 Process analysis, simulation and optimization by PTA Meeting Malta 5 November slide 22

23 Conclusions Chemical and process engineering techniques are well established to develop any biofuel processes Three steps involved: process analysis, simulation and optimization Quantitative informations can be provided on the process performances, including energy integration These calculations are the basis for: Economical-financial analysis of the process Plant design and construction Kinetic informations from biologists and biotecnologists are essential for a reliable result Meeting Malta 5 November slide 23

24 GReEn Development Group for Renewable Energy DIPIC Università di Padova Fabrizio Bezzo Ricercatore Universitario Alberto Bertucco Professore Ordinario Andrea Zamboni Dottorando Chiara Piccolo Dottoranda Giada Franceschin Dottoranda Maria Sudiro Dottoranda Meeting Malta 5 November slide 24

25 Thank You very much Meeting Malta 5 November slide 25