Thomas,
Results have been mixed. One “gasifier char” had very high PAH which affected crop performance. Unfortunately the source and conditions of production were not identified. >From Sarah Hale: Quantifying the total and bioavailable polycyclic aromatic hydrocarbons and dioxins in biochars. Hale SE <http://www.ncbi.nlm.nih.gov/pubmed?term=Hale%20SE%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Lehmann J <http://www.ncbi.nlm.nih.gov/pubmed?term=Lehmann%20J%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Rutherford D <http://www.ncbi.nlm.nih.gov/pubmed?term=Rutherford%20D%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Zimmerman AR <http://www.ncbi.nlm.nih.gov/pubmed?term=Zimmerman%20AR%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Bachmann RT <http://www.ncbi.nlm.nih.gov/pubmed?term=Bachmann%20RT%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Shitumbanuma V <http://www.ncbi.nlm.nih.gov/pubmed?term=Shitumbanuma%20V%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , O'Toole A <http://www.ncbi.nlm.nih.gov/pubmed?term=O%27Toole%20A%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Sundqvist KL <http://www.ncbi.nlm.nih.gov/pubmed?term=Sundqvist%20KL%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Arp HP <http://www.ncbi.nlm.nih.gov/pubmed?term=Arp%20HP%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> , Cornelissen G <http://www.ncbi.nlm.nih.gov/pubmed?term=Cornelissen%20G%5BAuthor%5D&cauthor=true&cauthor_uid=22321025> . Source Department of Environmental Engineering, Norwegian Geotechnical Institute NGI, PO Box 3930 Ullevål Stadion, N-0806 Oslo, Norway. [email protected] Abstract Biochar soil amendment is advocated to mitigate climate change and improve soil fertility. A concern though, is that during biochar preparation PAHs and dioxins are likely formed. These contaminants can possibly be present in the biochar matrix and even bioavailable to exposed organisms. Here we quantify total and bioavailable PAHs and dioxins in a suite of over 50 biochars produced via slow pyrolysis between 250 and 900 °C, using various methods and biomass from tropical, boreal, and temperate areas. These slow pyrolysis biochars, which can be produced locally on farms with minimum resources, are also compared to biochar produced using the industrial methods of fast pyrolysis and gasification. Total concentrations were measured with a Soxhlet extraction and bioavailable concentrations were measured with polyoxymethylene passive samplers. Total PAH concentrations ranged from 0.07 μg g(-1) to 3.27 μg g(-1) for the slow pyrolysis biochars and were dependent on biomass source, pyrolysis temperature, and time. With increasing pyrolysis time and temperature, PAH concentrations generally decreased. These total concentrations were below existing environmental quality standards for concentrations of PAHs in soils. Total PAH concentrations in the fast pyrolysis and gasification biochar were 0.3 μg g(-1) and 45 μg g(-1), respectively, with maximum levels exceeding some quality standards. Concentrations of bioavailable PAHs in slow pyrolysis biochars ranged from 0.17 ng L(-1) to 10.0 ng L(-1)which is lower than concentrations reported for relatively clean urban sediments. The gasification produced biochar sample had the highest bioavailable concentration (162 ± 71 ng L(-1)). Total dioxin concentrations were low (up to 92 pg g(-1)) and bioavailable concentrations were below the analytical limit of detection. No clear pattern of how strongly PAHs were bound to different biochars was found based on the biochars' physicochemical properties. From: Gasification [mailto:[email protected]] On Behalf Of Thomas Koch Sent: Thursday, December 05, 2013 3:06 PM To: Discussion of biomass pyrolysis and gasification Subject: Re: [Gasification] AGT LTC process Are there anybody that have an idea of how much PAH biochar contains? Fra: Gasification [mailto:[email protected]] På vegne af darius_tamizi Sendt: 5. december 2013 23:36 Til: Discussion of biomass pyrolysis and gasification Emne: Re: [Gasification] AGT LTC process We are very interested in feeding poultry with biochar. Anybody can give us more info? Darius Terkirim dari Samsung Mobile -------- Original message -------- From: Tom Miles <[email protected]> Date: 06/12/2013 03:14 (GMT+07:00) To: 'Discussion of biomass pyrolysis and gasification' <[email protected]> Subject: Re: [Gasification] AGT LTC process IEA Task 33 country report (2012) by Reinhard Rausch gives the following information: AGT Agency for Green Technology Ledererg 3 A-4861 Schoerfling E-mail: [email protected] Web: http://www.agt-world.com Low Temperature Conversion (LTC) is a thermo catalytic decomposition process operating without air supply There is a presentation that is not too informative. http://www.agt-austria.at/downloads/AGT_DL3_072011.pdf You might contact the company and Reinhard at Vienna University of Technology. Tom From: Gasification [mailto:[email protected]] On Behalf Of Don Murray Sent: Thursday, December 05, 2013 11:03 AM To: [email protected] Subject: [Gasification] AGT LTC process Ref: AGT - Agency for Green Technology, Austria Process: LTC low temperature conversion gasification Is someone familiar with this technology - process? What is progressive thermal catalytic material gasification? Do we have here a pyrolysis reactor front-end; followed by a gasifier processing the char and the pyrolysis gases? Thank you for any insight. Don Murray, ing. EMISPEC Parc Techno du Québec Métropolitain 2750 rue Einstein, suite 390 Québec, G1P 4R1 Canada www.emispec.ca off: +1 418 266 0308 skype: emispec-don.murray de la fibre au <https://picasaweb.google.com/108399800724959588615/DropBox?authuser=0&feat=directlink> kWh ...
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