Hi Folks, I've never posted to this list serve, but followed along for years. When I saw the discussion of Sweden's trash project, I had to weigh in.
In 2006, I traveled to Sweden as part of a Municipal Leaders Tour of Sustainable Sweden. As part of that tour we toured the Dava heat and electrical plant near the city of Umea. The Dava co-gen plant supplies the city of Umea with 85% of it's heat needs and a good portion of its electrical needs (I forget the exact amount). We we treated to a presentation about the DAVA plant and then got to tour the place. As a long time tinkerer, I was green with envy of all the intricate contraptions used to incinerate garbage and produce heat and power. see: http://www.umeaenergi.se/om-umeaa-energi/foeretaget/summary-in-english.ept I have lots of pictures of the plant, the .ppt the presenters used and also filmed of the tour and presentation. The presenters made a good case as to how the Dava plant actually cleaned up the air quality around Umea, a city that has frequent air inversions that can trap air pollutants near ground level. Before the installation of the Dava plant, air quality was often horrendous because of all the individual heat plants in homes and businesses, many of which were inefficient and polluting. The Dava plant improved air quality immensely, while creating heat and power and reducing waste. While it may not be perfectly clean, they made a good case about how clean it burned. It looked like a good deal to me. The did have a control room with banks of computers screens all monitoring various scrubbers and processes. We also got to tour the Helsingborg landfill, which diverted 76% of its waste stream into recyclable materials (21 categories of separation, a portion of that going into an anaerobic digester, which powered the extensive city bus fleet and the excess methane was sold on the open market to owners of bi-fuel cars ). 20% of the waste stream went into the incinerator, and the remaining 4% went into the landfill. Amazing! It was an eye opening experience for me. Thanks for letting me share it. Greg Greg David W4512 Riverdale Lane Watertown, WI 53094 (920)262-9996 home (920) 988-5629 On Nov 10, 2012, at 10:37 PM, Tom Miles wrote: > Mark, > > The Japanese unit looks like it might be a small rotary pyrolyzer that is > heated by burning the offgas. In that case we would expect to see a char > product and a clean stack. > > Ebara is the main waste to energy company that uses gasification in Japan. > Burn the gas directly into a close coupled boiler. > > Japan funded extensive waste gasification in the 1990s. They tried several > different types of gasifiers. Ebara is one of the few companies that still > used gasification for waste. There are several companies that make rotary > pyrolyzers. Last year in Kyoto we did not see evidence that they are used > much for biochar production. Most biochar seems to be made by very small > scale stirred bed rice husk gasifiers by Kansai Corporation.. The gas is > burned above the stirred bed and used to heat water for space heating or > process heat. The biochar (called “kuntan”) sells for about $0.40/lb. > > Tom > > From: Gasification [mailto:[email protected]] On > Behalf Of Mark Ludlow > Sent: Saturday, November 10, 2012 7:01 PM > To: 'Discussion of biomass pyrolysis and gasification' > Subject: Re: [Gasification] Sweden's trash project / Japanese trash project > > Tom, > The incinerators I’ve seen, operate with excess oxygen. This seems > antithetical to gasification. Perhaps a two-stage gasifier? > Mark > > From: Gasification [mailto:[email protected]] On > Behalf Of Tom Miles > Sent: Saturday, November 10, 2012 7:09 PM > To: 'Discussion of biomass pyrolysis and gasification' > Subject: Re: [Gasification] Sweden's trash project / Japanese trash project > > You could call it a pyrolytic incinerator. The gases must be burned in > conditions to completely destroy the dioxins. Even the poultry manure > gasifier in West Virginia had to be tested for dioxins. Poultry litter manure > has about 1% chlorine on a dry basis. Municipal waste also is loaded with > salts from foods and fertilizers. We found much higher concentrations of > salts in ash from MSW incineration than we expected. > > Tom > > From: Gasification [mailto:[email protected]] On > Behalf Of Lloyd Helferty > Sent: Saturday, November 10, 2012 4:49 PM > To: Discussion of biomass pyrolysis and gasification > Subject: Re: [Gasification] Sweden's trash project / Japanese trash project > > In answer to Mark Ludlow's question, Where does the rest of the “trash” go? > That would probably be "up the stack" ~ i.e. == air emissions ?? > > In answer to John Miedema's question about "chlorides involved in the trash" > and a possible dioxin problem? > Again, you might, depending on the TEMPS involved in the process. > > > You might expect that one good way to avoid Dioxins is to avoid burning > chlorinated plastics, i.e. PVC (Polyvinyl chloride), Chlorinated polyethylene > (CPE), Chlorinated polyvinyl chloride (CPVC) etc. > > Yes, most dioxins arise in the condensed solid phase by the reaction of > inorganic chlorides with graphitic structures in char-containing ash > particles, with copper acting as a catalyst for these reactions, therefore > the highest dioxin concentration is typically created by the pyrolysis of PVC. > > Large incinerators have mostly worked this out, however. The Japanese > [and German] tech is rather good at dealing with these things. > > I don't know what kind of "air emissions" controls have been put on this > particular system, if any. > > The single most important factor in forming dioxin-like compounds is the > temperature of the combustion gases. Oxygen concentration also plays a major > role on dioxin formation, but not the chlorine content. Several studies have > shown that removing PVC from waste would not significantly reduce the > quantity of dioxins emitted.** > > The design of modern incinerators minimize dioxins by optimizing the > stability of the thermal process. The EU emission limit is 0.1 ng I-TEQ/m3. > Modern incinerators not only operate in conditions that minimize dioxin > formation, but are also equipped with pollution control devices which catch > the low amounts produced. > > ** The European Union Commission published in July 2000 a Green Paper on the > Environmental Issues of PVC noted that, "there does not seem to be a direct > quantitative relationship between chlorine content and dioxin formation". > Similarly, another study commissioned by the European Commission on "Life > Cycle Assessment of PVC and of principal competing materials" states that > "Recent studies show that the presence of PVC has no significant effect on > the amount of dioxins released through incineration of plastic waste." > > Regards, > > Lloyd Helferty, Engineering Technologist > Principal, Biochar Consulting (Canada) > www.biochar-consulting.ca > 48 Suncrest Blvd, Thornhill, ON, Canada > 905-707-8754 > CELL: 647-886-8754 > Skype: lloyd.helferty > Steering Committee coordinator > Canadian Biochar Initiative (CBI) > President, Co-founder & CBI Liaison, Biochar-Ontario > National Office, Canadian Carbon Farming Initiative (CCFI) > Partner of Toronto Urban Ag Summit www.urbanagsummit.org > Manager, Biochar Offsets Group: > http://www.linkedin.com/groups?home=&gid=2446475 > Advisory Committee Member, IBI > http://www.linkedin.com/groups?gid=1404717 > http://www.facebook.com/group.php?gid=42237506675 > http://groups.google.com/group/biochar-ontario > http://www.meetup.com/biocharontario/ > http://www.biocharontario.ca > www.biochar.ca > > "It is the path, more than the arrival at the destination, that is important" > - Gandhi > On 2012-11-10 12:36 PM, John Miedema wrote: > I am curious about the chlorides involved in the trash (plastics)? Would not > there be a dioxin problem? > > > > John Miedema > BioLogical Carbon, LLC > > From: Gasification [mailto:[email protected]] On > Behalf Of Mark Ludlow > Sent: Saturday, November 10, 2012 2:24 AM > To: 'Discussion of biomass pyrolysis and gasification' > Subject: Re: [Gasification] Sweden's trash project / Japanese trash project > > Where does the rest of the “trash” go? Just, “Somewhere”? RE: Conservation of > Mass. > > Mark > > From: Gasification [mailto:[email protected]] On > Behalf Of Terry & Susan Layman > Sent: Friday, November 09, 2012 4:08 PM > To: [email protected] > Subject: Re: [Gasification] Sweden's trash project / Japanese trash project > > The Swedish are probably using the same system the Japanese invented. > > Leave it to the Japanese to perfect a system, that virtually elimanates > trash. Each day Iwamoto's "Super Stone Clean Waste Treatment'' processors > can take a 20 ton pile of common garbage, and reduce it to less than 8 gallons > of what they call biochar. > > Just watch their video. then you can see first hand the machine and the > process. > I, wouldn't classify it as BioChar, but it looks to me like ashes. > > Reduces waste volume from 1/100th to 1/3000th of original input: > 1,000kg waste →300g ashes ( 2,200 lbs waste to 10.58 oz's ashes ) > > This is probably the most advanced system for Gasification. > > > _______________________________________________ > Gasification mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org > > for more Gasifiers, News and Information see our web site: > http://gasifiers.bioenergylists.org/ > > _______________________________________________ > Gasification mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org > > for more Gasifiers, News and Information see our web site: > http://gasifiers.bioenergylists.org/
_______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
