La Biomassa

di Paola P. 42

Biomassa

Con il termine biomassa si indica il materiale di origine organica, vegetale o animale. Nel contesto della biomassa a fini energetici,  biomassa viene spesso usato per indicare il materiale a base vegetale, ma la biomassa può applicarsi sia a materiali derivati vegetali che animali.

Composizione chimica.
La biomassa ha una base di carbonio ed è composta da una miscela di molecole organiche che contengono idrogeno, atomi di ossigeno, azoto e spesso anche piccole quantità di altri atomi, tra cui alcalini, alcalino-terrosi e metalli pesanti. Questi metalli sono spesso presenti nelle molecole funzionali come le porfirine, che comprendono clorofilla che a sua volta contiene magnesio.

Materiale vegetale.
Il carbonio utilizzato per costruire la biomassa viene assorbito dall’atmosfera, come anidride carbonica (CO2), nel corso della vita delle piante che utilizzano l’energia dal sole.
Le piante possono poi essere mangiate da animali e così trasformate in biomassa animale. Tuttavia l’assorbimento principale avviene dalle piante.
Se il materiale vegetale non viene consumato è generalmente riassorbito da altri organismi oppure viene bruciato:

  • Se riassorbito il carbonio torna all’atmosfera, principalmente sia come anidride carbonica (CO2) che come metano (CH4), a seconda delle condizioni e dei processi coinvolti.
  • Se bruciato il carbonio viene restituito all’atmosfera sotto forma di CO2.

Questi processi fanno parte del ciclo del carbonio.

Combustibili fossili.

I combustibili fossili come carbone, petrolio e gas derivano da materiale biologico, con stoccaggio di CO2 assorbita dall’atmosfera molti milioni di anni fa.
I combustibili fossili offrono un’alta resa energetica, ma fare uso di questa energia comporta bruciare il combustibile, con l’ossidazione del carbonio in anidride carbonica e l’idrogeno in acqua (vapore). A meno di non essere immagazzinati questi prodotti di combustione sono normalmente rilasciati in atmosfera, rimettendo in circolo il carbonio stoccato milioni di anni fa e contribuendo così ad un aumento delle concentrazioni atmosferiche.

Differenza tra biomasse e combustibili fossili.

La differenza fondamentale tra biomassa e combustibili fossili è su scala temporale. La biomassa preleva carbonio dall’atmosfera mentre è in crescita, e la restituisce quando viene bruciata. Se è gestita in modo sostenibile, la biomassa viene prelevata come parte di un raccolto costantemente rifornito e dunque rinnovabile. Ad esempio nel processo di gestione dei rifiuti vegetali di un bosco o della potatura di colture arboree. Questo mantiene un ciclo chiuso di carbonio, senza un aumento netto dei livelli di CO2 nell’atmosfera.

Categorie di materiali di biomassa.

Nell’ambito di questa definizione, la biomassa per la produzione di energia può includere una vasta gamma di materiali.
Il legno è un materiale di alto valore e non è adatto, a livello di mercato, ad applicazioni energetiche su larga scala. Tuttavia ci sono enormi risorse provenienti dai residui, da co-prodotti e rifiuti che potrebbero diventare disponibili, in grandi quantità, a costi relativamente bassi, o addirittura ad un costo negativo, ad esempio laddove ci sia una richiesta di pagamento per lo smaltimento.

Ci sono cinque categorie di base del materiale:

  • Legno vergine, dalla silvicoltura, attività di arboricoltura o di trasformazione
  • Colture energetiche: le colture ad alto rendimento coltivate appositamente per la produzione di energia
  • I residui agricoli: scarti provenienti dall’agricoltura
  • I residui alimentari, dalla produzione degli alimenti e delle bevande e rifiuti post-consumo
  • Rifiuti da produzione industriale

Poiché vi è grande diversità delle caratteristiche e proprietà di queste diverse classi di materiali, e dei loro diversi sottogruppi, c’è anche una vasta gamma di tecnologie di conversione, che comprendono sia la conversione termica che chimica.

Per approfondire:

[Fonte: Biomassenergycenter]

Commenti (42)

  1. I just want to say I’m beginner to weblog and truly enjoyed this blog site. Very likely I’m want to bookmark your blog post . You absolutely come with wonderful writings. Thanks a lot for revealing your web-site.

  2. Sorry for the huge review, but I’m really loving the new Zune, and hope this, as well as the excellent reviews some other people have written, will help you decide if it’s the right choice for you.

  3. I’ve applied the valuable points from this page and I can definitely tell that it gives a lot of assistance with my present jobs. I would be very pleased to keep getting back in this web page. Thank you.

    http://www.repairloader.net/

  4. Pretty section of content. I just stumbled upon your weblog and in accession capital to assert that I acquire actually enjoyed account your blog posts. Anyway I’ll be subscribing to your augment and even I achievement you access consistently fast.

  5. I’ve been surfing online more than three hours today, yet I never found any interesting article like yours. It’s pretty worth enough for me. In my view, if all website owners and bloggers made good content as you did, the internet will be a lot more useful than ever before.

  6. I like what you guys are up too. Such intelligent work and reporting! Carry on the excellent works guys I have incorporated you guys to my blogroll. I think it’ll improve the value of my website 🙂

  7. Needed to put you a little bit of note to finally say thanks as before for your personal wonderful techniques you have featured on this website. It was certainly seriously generous with you to present freely all many people could have distributed as an electronic book to generate some profit for their own end, chiefly given that you could have tried it in case you considered necessary. These secrets also served to be the fantastic way to fully grasp that the rest have a similar dreams just like my personal own to find out significantly more in regard to this issue. Certainly there are some more pleasant periods ahead for those who looked at your blog post.

  8. I think this is among the most important information for me. And i’m glad reading your article. But want to remark on some general things, The web site style is wonderful, the articles is really excellent : D. Good job, cheers

  9. I’ve recently started a blog, the information you offer on this web site has helped me tremendously. Thank you for all of your time & work. “The man who fights for his fellow-man is a better man than the one who fights for himself.” by Clarence Darrow.

  10. I have been checking out many of your posts and it’s clever stuff. I will make sure to bookmark your blog.

  11. I think this is one of the most significant information for me. And i am glad reading your article. But want to remark on few general things, The web site style is wonderful, the articles is really excellent : D. Good job, cheers

  12. I think this is one of the most important information for me. And i’m glad reading your article. But wanna remark on few general things, The web site style is wonderful, the articles is really excellent : D. Good job, cheers

  13. Please let me know if you’re looking for a author for your weblog. You have some really great articles and I feel I would be a good asset. If you ever want to take some of the load off, I’d really like to write some material for your blog in exchange for a link back to mine. Please shoot me an email if interested. Many thanks!

    http://harman-enterprise.co.uk/?option=com_k2&view=itemlist&task=user&id=2214441

  14. Wow, awesome blog layout! How long have you been blogging for? you made blogging look easy. The overall look of your website is fantastic, let alone the content!

  15. Because the admin of this website is working, no uncertainty very shortly it will be famous, due to its quality contents.

    http://zrphp.com/comment/html/index.php?page=1&id=299975

  16. Divorcemind.com is a online divorce resource for divorce attorney, attornies and lawyers. You will find the best divorce information online. Divorce Mind will make your divorce or separation a quick, convenient and private.

    http://www.shortmyurls.com/divorcemind-divorces

  17. Unquestionably believe that which you stated. Your favorite reason seemed to be on the web the easiest thing to be aware of. I say to you, I certainly get irked while people consider worries that they plainly do not know about. You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people can take a signal. Will likely be back to get more. Thanks

    http://www.iyuelao.com/bbs/space-uid-583815.html

  18. I truly appreciate this post. I’ve been looking everywhere for this! Thank goodness I found it on Bing. You’ve made my day! Thanks again!

  19. I as well as my pals were looking through the good information located on your website while then developed a terrible suspicion I had not expressed respect to the website owner for them. All the people were as a consequence happy to learn them and have in effect surely been having fun with these things. Appreciate your actually being well accommodating and also for picking out this kind of beneficial guides most people are really desperate to know about. My personal sincere regret for not saying thanks to you sooner.

  20. Between me and my husband we’ve owned more MP3 players over the years than I can count, including Sansas, iRivers, iPods (classic & touch), the Ibiza Rhapsody, etc. But, the last few years I’ve settled down to one line of players. Why? Because I was happy to discover how well-designed and fun to use the underappreciated (and widely mocked) Zunes are.

  21. Divorcemind.com is a online divorce resource for divorce attorney, attornies and lawyers. You will find the best divorce information online. Divorce Mind will make your divorce or separation a quick, convenient and private.

    http://www.shortmyurls.com/divorcemind-divorce-attorney-comment-gen

  22. SacramentoCremation.us is one of the leading crematorium services in the Sacramento area. Feel free to contact us regarding any questions on Sacramento Cremation Services or concerns you might have. Our staff will respond to you as soon as possible.

    http://www.shortmyurls.com/sacramentocremation-services-comment-gen

  23. Do you have a spam issue on this blog; I also am a blogger, and I was wanting to know your situation; we have created some nice methods and we are looking to exchange solutions with other folks, please shoot me an email if interested.

    http://boulangerie-mechinaud.fr/?option=com_k2&view=itemlist&task=user&id=60984

  24. IMSC SEO is a Singapore SEO Company. They provide comprehensive Singapore SEO services to help SG businesses to gain traffic from search engine. Their SEO agency has many years of experiences working with overseas companies on more competitive grounds. They are the best seo company in Singapore you can find. Their SEO expert and consultant understand exactly what search engine optimization your company need to gain search engine traffic.

    http://www.shortmyurls.com/imsc-home-comment-general

  25. I’ll gear this review to 2 types of people: current Zune owners who are considering an upgrade, and people trying to decide between a Zune and an iPod. (There are other players worth considering out there, like the Sony Walkman X, but I hope this gives you enough info to make an informed decision of the Zune vs players other than the iPod line as well.)

  26. The new Zune browser is surprisingly good, but not as good as the iPod’s. It works well, but isn’t as fast as Safari, and has a clunkier interface. If you occasionally plan on using the web browser that’s not an issue, but if you’re planning to browse the web alot from your PMP then the iPod’s larger screen and better browser may be important.

  27. IMSC SEO is a Singapore SEO Company. They provide comprehensive Singapore SEO services to help SG businesses to gain traffic from search engine. Their SEO agency has many years of experiences working with overseas companies on more competitive grounds. They are the best seo company in Singapore you can find. Their SEO expert and consultant understand exactly what search engine optimization your company need to gain search engine traffic.

    http://www.shortmyurls.com/imsc-services-comment-exact

  28. It can be practically close to impossible to find well-informed individuals on this matter, although you look like you realize what you’re preaching about! Appreciate It

    http://www.seo08.info

  29. Undeniably believe that which you said. Your favorite justification appeared to be on the web the easiest thing to be aware of. I say to you, I certainly get annoyed while people consider worries that they just don’t know about. You managed to hit the nail upon the top and also defined out the whole thing without having side effect , people could take a signal. Will likely be back to get more. Thanks

  30. Hello.This article was really motivating, particularly because I was looking for thoughts on this matter last Wednesday.

  31. I actually wanted to jot down a simple remark to thank you for some of the awesome facts you are giving out at this site. My considerable internet lookup has finally been paid with useful facts to go over with my pals. I would suppose that many of us site visitors actually are rather lucky to live in a really good community with many outstanding people with very beneficial hints. I feel somewhat fortunate to have used your entire webpage and look forward to plenty of more awesome minutes reading here. Thank you once more for everything.

  32. fantastic issues altogether, you just received a emblem new reader. What could you recommend in regards to your publish that you simply made a few days in the past? Any certain?

  33. Great remarkable issues here. I am very happy to see your article. Thanks a lot and i’m looking forward to touch you. Will you kindly drop me a mail?

  34. You can certainly see your expertise in the paintings you write. The arena hopes for more passionate writers like you who aren’t afraid to say how they believe. At all times go after your heart.

  35. Wow! This could be one particular of the most helpful blogs We have ever arrive across on this subject. Basically Magnificent. I’m also a specialist in this topic therefore I can understand your effort.

  36. Thanks so much for providing individuals with a very splendid opportunity to read in detail from this blog. It is often very cool plus full of amusement for me personally and my office colleagues to visit your site not less than three times weekly to read the fresh things you have got. Of course, I’m also at all times satisfied with all the surprising things you serve. Certain two areas in this posting are unequivocally the simplest we have had.

  37. You made some good points there. I did a search on the subject and found a good number of folks will go along with with your blog.

  38. I don’t even know the way I finished up right here, however I thought this post used to be good.

    I do not recognize who you might be but definitely you are going to
    a famous blogger in case you are not already. Cheers!

  39. It抯 hard to search out knowledgeable folks on this topic, but you sound like you know what you抮e speaking about! Thanks

Lascia un commento

Il tuo indirizzo email non verrà pubblicato.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

Questo sito usa Akismet per ridurre lo spam. Scopri come i tuoi dati vengono elaborati.