Dear Kevin, >From a broad perspective, it is very useful. Bill seems to be saying that there is no compact prescription for making this work; bur everything must be constrained by gasification chemistry and regulated by applicable process controls.
The "restricted throat" paradigm of the Imbert puts a lot of restrictions on fuel morphology that add to the complications of the chemical reactions that must occur. Who wants to spend a substantial portion of their energy output preparing fuel? What the World Needs Now is a gasification technology that is more catholic in its acceptance of fuels--from rice husks to dried MSW--with adaptive control algorithms that account for the variability that is encountered in real-world situations. Of course, I realize that I am stating the obvious. But more restrictions on fuel specifications amount to lower probability that gasification of biomass will ever have a measurable impact on anything but "niche" applications. Best, Mark -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, June 22, 2011 8:38 PM To: [email protected] Subject: Re: [Gasification] Any experience with Stak Properties 10K gasifier? Dear Bill Thank you for your reply. Hopefully, some list Members will find it helpful. Best wishes, Kevin Quoting Bill Klein <[email protected]>: > Hi, Kevin. > > So many questions, so little time. I shall attempt to give you some > answers, but they are subjective to linear hearth architecture. My > responses will follow your text and be preceded by "==>". > ### > > 1: For a given gasifier design, feed size is extremely important > > ==> I believe feedstock size is no more important than feedstock > preparation. There is no magic involved in the process, but there are > basic laws that must be observed if one is to make a good gas. Let's > face it, applied science still rules the roost. > ### > > 2: For an otherwise good gasifier design and feedstock selection, the > presence of leakage is extremely important. (Presumably, this means > air leakage IN, in a suction system, and gas leakage OUT in a > pressurized system. > > ==> I was taught that a cornerstone of making good gas is intake air > management. It controls the temperature which enables proper > conversion. If one does not have an airtight system, one cannot possibly manage air flow. > ### > > 3: Testing of the design and fuel selection, and final "tuning" is > extremely important. > ### > > : FUEL SIZE > The "Engine Grade Gas"(EGG) successes we see on this list seem to fall > into two categories: > A: Those who use chunkwood fuel (such as Wayne Keith, Mike Larosa, > Powerhearth, Vesa Mikkonen) > B: Those who have instrumented systems and do extensive testing and > utilize "on line controls." > C: Chip fueled gasifier systems, such as Greg Manning's system. Greg > has reported extensively on the use of screened wood chips being used > in his "Heating Grade Gas" (HGG) system, but I am not sure if his > system has produced EGG on a continuous basis. (Perhaps Greg could > clarify whether or not his system will produce EGG on a consistent > basis.) > > ==> The Powerhearth is easily able to gasify chunks, chips and > briquettes with equal success and without adjustments other than > calibration and setting the data points into the program/PLC. > > Personally, I like chunks for their char quality. > ### > > While chunkfuel is the preferred fuel size, what would you suggest as > the minimum size of fuel that teh "Home Gasifier Builder" should > consider, to avoid major problems, and to have some reasonable > expectation of success? > > ==> Kevin, it would be unfair of me to pretend to know the proper > answer. I have never built a gasifier outside of a sheetmetal shop, > with our own drawings and using uniform materials. I have, however, > seen many units made privately, all of round hearth architecture. My > response to similar questions has always been the same. I don't know, > but don't be afraid to experiment. Make friends with your gasifier and > learn what she likes. Never put the cart before the horse. > ### > > More specifically, what do you feel is the likelihood, and the > circumstances under which a Woodgas List Member could build an EGG > gasifier that ran reasonably well using screened wood chips that were > available free from a Tree Surgeon, or right-of-way clearing Contractor? > > ==> I have no experience in that area. We buy many tons of chips from > local sawmills and with our system, moisture content is a non issue. > ### > > 2: AIR LEAKAGE > Would you have any suggestions on the best way to test for leaks, and > to diagnose the probable area of leakage? Would you have any > suggestions on the amount of air leakage that would be acceptable? > > ==> Proper welds and proper gaskets, plenty of pipe dope at threaded joints. > Build airtight and, if done properly, it stays airtight. No amount of > leakage is acceptable if you are serious about good gas! > ### > > 3: TESTING and TUNING > Would you have any guidelines or suggestions for testing and > evaluating a home built gasifier, such as: > 3:1 What is a good way to measure tar content of gas? > 3:2 With the test you suggest, is there any way quantify it, so that > teh Builder would know if the tar content is low enough to allow a > typical engine to run for a minimum of say 1,000 hours? > 3:3 What would you recommend as the minimum requirement for test > equipment for the home builder? > 3:4 What tests would you suggest? > 3:5 When designing and building a gasifier, what are the minimum > provisions that the Back Yard Builder should make for testing and > tuning? (eg, Viewports, temperature and pressure measuring points, > etc) > > ==> Kevin, I don't know. I would think a backyard builder would have a > plan, an agenda and a budget. > > We shall be assembling and testing a model before shipping and > commissioning. The process lasts about a week and a half and is pretty > intense. If there is any interest in dropping in for the sake of > observing and/or learning, contact me off list. We would be pleased to > welcome you to a Vermont summer of long hours, but good coffee and tea. > ### > > Kevin, I'm sorry I couldn't be more helpful, but it seems an exercise > in futility to pontificate about that which one has a high degree of ignorance. > > Respectfully, > > Bill Klein > 3i > > > > > > > > > > > > > > > > > > > > > > Your helpful comments will be very much appreciated, and will go a > long way to preventing Home Gasifier Builders from wasting time on > gasifier and fuel combinations that are very likely to fail. > > Thanks! > > Kevin > > > Quoting Bill Klein <[email protected]>: > >> Hi, Kevin. >> >> Your question of feedstock size is rather interesting and one to >> which I can easily relate. That said, I hope the following provides a >> little bit of insight and doesn't aggravate the experts on this list. >> >> Before we ship our units, they undergo several tests. >> >> Test 1 is a 24 hour non stop test in which we push all of the limits. >> Said differently, we look for the weaknesses, leaks, etc. >> Test 2 is another 24 hour non stop test. It provides us with systems >> calibration. >> Test 3 is a 100 hour non stop test. During this period, all of the >> necessary data points are established for our automation and >> management system. >> >> Why am I describing an important phase of our unit fabrication, >> truncated as the description may be? >> >> I wanted to point out the importance of properly sized feedstock for, >> if there is a screw up with gas flow or aglomeration, the test is >> stopped and rerun. >> >> When we test, depending upon the customer's intended feedstock, we >> test and evaluate the gas from at least three feedstocks, one of >> which is a close approximation of that which the customer will use. >> Size of the feedstock is critical unless one really enjoys non stop >> runs, grumpy technicians and buckets of coffee. >> >> Pellets: We won't use them. They are seldom uniform (cross >> sectionally) in moisture content and generally sealed. With heat, >> they shatter magnificently, leaving a pile of sawdust. The exception >> seems to be pelletized switchgrass: a great feedstock. >> >> The chip size we like resembles an Oreo cookie, squared. As an >> approximation it works to gauge sizes. Overall length or width >> uniformity doesn't seem to be as critical as thickness. Still, there >> is a lot of flexibility and smaller sizes are okay to integrate, as >> an exception, not the rule. >> Gasifiers are not stoics. Built properly, they have some versatility, >> but you have to make friends with your unit before you learn her >> secrets. Then you merely have to respect them. . >> >> Charcoal briquettes as a feedstock too often creates a huge problem >> as they plug the grate with compacted fines. >> >> The best and my most favorite feedstock is still chunks. 2x4x4 - or >> briquettes of almost anything. >> >> Kevin, I would have gladly answered earlier, but you posted hours >> after my bedtime. We old folks need our beauty sleep. >> >> >> Respectfully, >> >> Bill Klein >> 3i >> >> >> >> >> >> ----- Original Message ----- >> From: <[email protected]> >> To: <[email protected]> >> Sent: Tuesday, June 21, 2011 10:13 PM >> Subject: Re: [Gasification] Any experience with Stak Properties 10K >> gasifier? >> >> >> Dear Bill >> >> Quoting Bill Klein <[email protected]>: >> >>> To underscore Greg's email, repeating what I was taught, "The >>> quality of the gas is in direct proportion to the quality of the >>> char." Larger feedstock makes great char! >> >> # OK!! Do you think one can make "Engine Grade Gas" using: >> 1: Wood pellets, 1/4" diameter, 1/4" to 1/2" long? >> 2: Wood chips screened to -1/4", +1/8"? >> 3: Wood chips screened to -1/2",+ 1/4"? >> 4: Wood chips screened to -1", + 1/2"? >> >> Thanks! >> >> Kevin >>> >>> >>> Respectfully, >>> >>> Bill Klein >>> 3i >>> >>> http://www.3iAlternativePower.com >>> >>> >>> -- Original Message ----- >>> From: Greg Manning >>> To: Discussion of biomass pyrolysis and gasification >>> Sent: Tuesday, June 21, 2011 7:40 PM >>> Subject: Re: [Gasification] Any experience with Stak Properties >>> 10K gasifier? >>> >>> >>> Pete, (and list) >>> >>> What, and how big, are the fuel chunks ? >>> >>> most gasifiers do NOT like wood chips, or really "fine" fuel, the >>> interstitial space the gasifier is designed to run with, is >>> generally much larger than that of chips or fine feedstock, using >>> the correct sized fuel, in-turn, lowers the reaction core >>> temperature, thus creating more, and more consistant amounts, of CO. >>> (the main flamable gas, in woodgas). (H2 and CH4 are simply "bonus" >>> gases.....) >>> >>> Greg Manning. >>> >>> >>> >>> >>> >>> >>> On Mon, Jun 20, 2011 at 6:01 PM, Pete & Sheri >>> <[email protected]> wrote: >>> >>> Has anyone here had any experience running an engine using the >>> Stak Properties 10K gasifier? >>> >>> >>> >>> They tell me that the JXQ-10 gasifier is a forerunner to this >>> machine. I have one of those. I?d like to be able to correspond >>> with others who have this style of machine. Currently I am having >>> mixed results getting a steady flow of good gas to run my 6.5 KW >>> Onan 1800 rpm genset from it. On Saturday, I got it to deliver >>> about 3.8 kw for about 12 minutes, but then the quality of the gas >>> deteriorated. On Sunday a similar test produced worse results, but >>> over about a one hour period, with gas quality again deteriorating >>> as the test went proceded. >>> >>> I am not writing to waste the time of senior members here by >>> asking them to troubleshoot my problems, without enough info. Just >>> want to show what kind of issues I have for those who might be >>> involved with similar equipment. >>> >>> My goals are to: 1. See how much power I can squeeze out of >>> the generator for an extended period of time with this gas source, >>> and 2. To get some actual experience making woodgas. >>> >>> >>> >>> Looking back over my videos and notes, I can see a dozen or two >>> things that I could do better next time. >>> >>> >>> >>> Pete Stanaitis >>> >>> >>> _______________________________________________ >>> 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/ >>> >>> >>> >>> >>> >>> -- >>> Regards, >>> >>> Greg Manning, >>> Brandon, Manitoba, Canada >>> >>> >>> >>> -------------------------------------------------------------------- >>> ---------- >>> >>> >>> _______________________________________________ >>> 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.b >> ioenergylists.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.b >> ioenergylists.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.bi > oenergylists.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.bi > oenergylists.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.bioenerg ylists.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/
