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.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/ _______________________________________________ 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/
