biofuels

 Biofuels
Fiche de présentation de la ressource Classe : 1ère STL Enseignement : LV et enseignements technologiques THEMES du programme : SOUS‐THEMES du programme : SPC : Chimie et développement durable SPC : chimie : enjeux sociétaux, économiques et environnementaux CBSV : Thème 1 : Les systèmes vivants présentent une organisation particulière de la matière. CBSV : 1.5. Les molécules des organismes vivants présentent des structures et des propriétés spécifiques Titre : Biofuels Extrait du BOEN CONNAISSANCES SPC CAPACITES SPC 1) Champs d’application de la chimie et évolution des techniques. Aspects historiques et économiques. 2) La chimie face à l’environnement. Rôle de la chimie dans des problématiques liées à l’environnement. Impact environnementaux des synthèses et des analyses. 3) Synthèses organiques. Acides et dérivés (estérification, hydrolyse) CONNAISSANCES CBSV 1) Les organismes vivants sont essentiellement constitués d’atomes de C, H, O, N, P et S 2) Ces atomes sont reliés entre eux par des liaisons covalentes pour constituer des biomolécules: lipides, protéines, acides nucléiques et polyosides. Les acides gras comportent une longue chaîne carbonée et une fonction acide carboxylique. 1) Citer : – l’intervention de la chimie dans divers domaines de la vie courante ; – l’évolution d’une technique au cours des siècles ; des choix opérés pour répondre à des besoins sociétaux et/ou économiques. Prendre conscience du lien entre science et technique. 2) Citer des implications de la chimie dans des études menées sur l’environnement ou des actions visant à le préserver. Choisir parmi plusieurs procédés, celui qui minimise les impacts environnementaux. 3) Reconnaître les réactions d’aldolisation, de crotonisation, d’estérification et d’hydrolyse. CAPACITES CBSV 1) Exploiter des ressources documentaires 2) Représenter la structure générique d’un aldohexose, d’un acide aminé et d’un acide gras. Biofuels
Compétences transversales et attitudes ƒ
Mobiliser ses connaissances Rechercher, extraire, organiser des informations utiles Raisonner, argumenter, démontrer Travailler en équipe Type de ressource Activité documentaire Réinvestissement et approfondissement Résumé du contenu de la ressource (et conditions de mise en oeuvre si besoin) : Il s’agit d’une séquence transversale car elle allie l’enseignement de SPC à la CBSV et à l’enseignement scientifique en langues vivantes. Il s’agit de découvrir à travers trois ressources documentaires (un MP3, deux vidéos) l’utilisation d’algues comme source d’énergie alternative. Une activité récapitulative est prévue en fin de séquence : un jeu de TABOO qui permet de revoir tout le nouveau vocabulaire abordé. Cette séquence permet le travail en binômes, par groupes de 4‐5 et en classe entière. Elle favorise l’utilisation de l’oral dans l’apprentissage des langues. Elle contient d’autre part les réponses en APPENDIX. Niveau requis et fichiers sources Langue cible Niveau requis Nombre de séances Anglais Compréhension écrite : B1 Compréhension orale : B1 Expression orale : B1 Prendre part à une conversation : B1 Niveaux définis dans le Cadre Commun de référence pour les Langues : http://fr.wikipedia.org/wiki/Cadre_européen_commun_de_référence_po
ur_les_langues 3 séances : 1) Etude du MP3 (en salle multimédia ou salle équipée d’enceintes audios) 2) Etude des deux vidéos (1h en salle multimédia) 3) Jeu de taboo en salle de cours classique Document 1 Document 2 Document 3 Documents choisis Making fuel from vegetable oil Site éducatif : The Naked Scientists http://www.thenakedscientists.com/HTML/content/interviews/interview/760/
Ecopolis biofuels Site éducatif : howstuff works http://videos.howstuffworks.com/science‐channel/34234‐ecopolis‐biofuel‐
video.htm Invention nation : algae biofuel Site éducatif : howstuff works http://videos.howstuffworks.com/science‐channel/37592‐invention‐nation‐
algae‐biofuel‐video.htm Mots clés de recherche : bioénergie, biocarburant, anglais, algues, CBSV, environnement Provenance : CANU Cécile, [email protected] Biofuels
BIOFUELS 1. KITCHEN SCIENCE : MAKING FUEL FROM VEGETABLE OIL Scientists at Bath University, UK, have a found a simple way to use vegetable oil as fuel for car engines for example. Here is an interview at Bath University by Azi, reporter from the Naked Scientists. STEP 1: Discover the recording http://www.thenakedscientists.com/HTML/content/i
nterviews/interview/760/ Listen to the MP3 without looking at the transcript at least two or three times. STOP at “glycerol, which is just a waste product of the biodiesel process » Source : http://commons.wikimedia.org/wiki/File:Bio
fuels.jpg Write down the keywords that you hear, then write them on the board: ________________________________________________________________________________ ________________________________________________________________________________ STEP 2: Rephrasing Get into groups of 4‐5 students. Using the keywords selected by the class, rephrase the main ideas in the MP3 : ________________________________________________________________________________ ________________________________________________________________________________ After having written your summary, one student from each group should read it or explain it to the rest of the class. STEP 3: Assisted listening After a couple of listenings without the text, you may listen to the MP3 again but this time, read the text at the same time. Biofuels
Note that the main keywords appear in bold lettering. Transcript: http://www.thenakedscientists.com/HTML/content/interviews/interview/760/ Kitchen Science ‐ Making Fuel from Vegetable Oil Prof. Matthew Davidson, Prof. Gary Hallway & Chris Chuck, University of Bath Azi ‐ Hello, welcome to Kitchen Science. This week, I’ve come to the historic city of Bath and Prof. Matthew Davidson, University of Bath I’m actually standing at the university of Bath’s Source: Chemistry Department, I’m joined by Professor http://www.thenakedscientists.com/HTML/c
[Matthew] Davidson and also Christopher Chuck ontent/interviews/interview/760/ who is a PhD student here. The question I’ve come to you guys with, and I’m really hoping you can help me out here, is can you run your car on cooking vegetable oil? Matthew ‐ That’s an interesting question as to whether you can run your car on vegetable oil, what’s chemically called a triglyceride, a molecule with three long fatty arms on it. What happens is they all just get entangled together, and that means it has a very high melting point. The two most important problems are; firstly the stuff would freeze in your tank, so on a slightly cold morning you would have a solid mess and the second problem is that it simply doesn’t burn very well. Azi ‐ Okay, so what’s the solution? Matthew ‐ Well the solution is actually quite a simple chemical process, and I can show you exactly how we do it. Before we do, I want you to put on some goggles, just to make sure we’re safe. Azi ‐ Okay, I’ve got my goggles on. Matthew ‐ Right, well what we’re going to do is were just going to take some vegetable oil that we bought at the supermarket, and we’re going to take this mixture here, which is methanol and sodium hydroxide. We’re just going to mix it with vegetable oil, you can see that the vegetable oil is stirring away with a stirrer in it, it’s heated up to about 60 or 70 degrees centigrade. Azi ‐ Okay, so you’ve got the vegetable oil in a flask, and you’re putting sodium hydroxide which is mixed with methanol, in the measuring cylinder and you’re going to tip it in… Matthew ‐ Yeah, we need to wait about half an hour and what we will see is the separate components; the biodiesel will separate out from the by‐product which is called glycerol, which is the other part of the fatty molecule that we started off with. Azi ‐ So what’s the chemical process that is happening inside that flask? Biofuels
Matthew ‐ Well the chemical process is something called transesterification, which is a bit of a complicated term for simply just changing the end of the long fatty molecule (molecule 1). So instead of just having 3 of the fatty molecules attached to one end, a bit like a piano stool with three legs, we’re changing the end, just capping off the fatty molecule with methanol (molecule 2). That give us individual fatty molecules, and that’s what is actually called biodiesel (molecule 3), that we could use in an engine; and another molecule called glycerol (molecule 4), which is just a waste product of the biodiesel process. STOP! STEP 4: Pair work on vocabulary Get into pairs. Here some definitions, try to match them with the correct words found in the text above: French or formula English moteur produit secondaire Résidu, déchet Corps gras Éprouvette graduée Agiter, mélanger Lunettes de protection geler Réservoir de voiture emmêlé Biofuels
2. REACTION Fill in the blanks, on the left handside, the reactants, and catalyst, on the right handside, the products and catalyst. Biofuel : 1) 2) 3) =
Temperature = 3. BIOFUELS FROM ALGAE Discover now how biofuel could be produced from algae: http://videos.howstuffworks.com/science‐channel/34234‐ecopolis‐biofuel‐video.htm Answer the following questions: In which state does biologist Glen Curts work? __________________________________________________________________________________ What can be used (in this video) to produce biofuels? __________________________________________________________________________________ Why do some environmentalists say that biofuels are an ecological disaster? __________________________________________________________________________________ __________________________________________________________________________________ If the US had to grow plants in order to produce enough biofuels for their energy needs, which percentage of the surface area of the country would they use? __________________________________________________________________________________ Which chemicals of interest do algae contain? __________________________________________________________________________________ Biofuels
4. INVENTION NATION : ALGAE BIOFUEL For further knowledge on algae biofuels, watch: http://videos.howstuffworks.com/science‐channel/37592‐invention‐nation‐algae‐biofuel‐video.htm Cross out the wrong answer: TRUE OR FALSE The three students are experts in algae biofuel: TRUE ‐ FALSE Dr. Patrick Hatcher teaches biology: TRUE ‐ FALSE The lab is developing an algae strain* with a maximum content of oil: TRUE ‐ FALSE * a strain = a race, a species The scientists want to heat the algae at 450°C in order to extract the oil: TRUE ‐ FALSE 5. PLAYING TABOO TO REVIEW THE ESSENTIALS On the next page, you will find taboo cards that will help you review the important vocabulary. Objective: you have to make your team guess the word on the card you randomly pick without using the word itself or three additional words listed on the card. A team that guesses a word gets one point. How to play: ‐
Get into two teams, decide on the teams’ names. ‐
Cut out the cards and place one set on the teacher’s desk. ‐
A student who gets a right answer gets to come to the front and make the others guess a word. He must first randomly pick a card from the pile. ‐
Students take turns to come to the front to make the others guess one word. ‐
The game stops after all 12 cards have been used. APPENDIX: Answers 1. KITCHEN SCIENCE : MAKING FUEL FROM VEGETABLE OIL STEP 4: Pair work on vocabulary French or formula English moteur engine produit secondaire By product Résidu, déchet Waste product Corps gras Fatty molecule Éprouvette graduée Measuring cylinder Agiter, mélanger To stir (or to mix) Lunettes de protection goggles geler To freeze Réservoir de voiture tank emmêlé entangled glycerol triglyceride 2. REACTION glycerol
Biofuel : 3 esters
triglyceride methanol Hydroxide ions =
Temperature = 60 to 70°C Hydroxide ions 3. BIOFUELS FROM ALGAE Discover now how biofuel could be produced from algae: http://videos.howstuffworks.com/science‐channel/34234‐ecopolis‐biofuel‐video.htm Answer the following questions: In which state does biologist Curts work? He works in Texas What can be used (in this video) to produce biofuels? They first refer to plants Why do some environmentalists say that biofuels are an ecological disaster? Biofuels could use soil that could not then be used to grow plants to feed the planet. If the US had to grow plants in order to produce enough biofuels for their energy needs, which percentage of the surface area of the country would they use? Over 100% would need to be used to that purpose! Which chemicals of interest do algae contain? Some strains of algae contain large quantities of lipids, ie fatty molecules. 4. INVENTION NATION : ALGAE BIOFUEL For further knowledge on algae biofuels, watch: http://videos.howstuffworks.com/science‐channel/37592‐invention‐nation‐algae‐biofuel‐video.htm Cross out the wrong answer: TRUE OR FALSE The three students are experts in algae biofuel: TRUE ‐ FALSE Dr. Patrick Hatcher teaches biology: TRUE ‐ FALSE The lab is developing an algae strain* with a maximum content of oil: TRUE ‐ FALSE * a strain = a race, a species The scientists want to heat the algae at 450°C in order to extract the oil: TRUE ‐ FALSE