Posted by Zach Bouchard on February 22, 2009 at 17:22:03 from (64.136.27.226):
In Reply to: Biogas digester posted by Farmall_51 on February 21, 2009 at 20:51:27:
I don't know how cost effective it is but here's the story I found on a local dairy farm.
Vander Haak Dairy The Vander Haak Dairy is a family run farm operating in Lynden, Washington since 1968. It became the first dairy in Washington State to install a commercial anaerobic digester. The system utilizes a patented plug flow digester, designed by GHD Incorporated of Wisconsin, that handles manure from three dairies and up to 1500 dairy cows (as currently configured). In general, plug-flow digesters have few moving parts and work well with dairies, like Vander Haak, that collect cow manure by scraping instead of flushing the manure with water. The unprocessed manure is collected in a receiving pit and pumped directly into the anaerobic digester vessel where it undergoes a two-stage digestion process. In the first stage, raw manure is mixed and heated to 1000F, using the reclaimed waste heat from the engine/generator set. This facilitates the growth of acid forming bacteria that breaks down the raw manure into simpler volatile fatty acids and acetic acid. The slurry then gravity feeds into the second stage of the digester where methanogenic bacteria convert the volatile fatty acids into biogas. The second stage of the digester process takes about 20 days, after which the remaining materials flow into an effluent collection pit where they are further processed. The dairy is currently assessing the impact of other available feedstocks on the system processes. The biogas generated in the digester is collected and burned in a natural gas fueled reciprocating engine set modified to burn biogas. Waste heat from the engine set is 5 recovered and used to heat the digesters (30 to 60 percent is used), and could potentially be used in the future to provide for other thermal needs at the dairy. The engine genset produces about 285 net kW of electricity (parasitic load is 15 kW) which is sold to the power grid. This is enough electricity to serve approximately 180 average homes. The remaining digester effluent is separated into a solid and liquid stream for further processing. The separated solids are currently processed into bedding materials for the dairy or sold to other dairies for bedding. Additional work is underway to develop this material into a compost or soil amendment suitable for sale to commercial nurseries as a replacement to peat moss. The liquid stream from the digester is used as a high-value fertilizer, rich in phosphorous and useable nitrogen.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Torque Wrenches - by Curtis Von Fange. When working with fasteners a torque wrench can play an important role in the correct assembly of critical equipment components. Lets examine in detail some of the reasons for using a torque wrench along with how to correctly use the variety of wrenches available. Applying the proper torque to a fastener accomplishes a number of tasks. First of all correct torque will hold the parts together. This may seem like a trite statement but � think about it for a second. Engineers have designed
... [Read Article]
Latest Ad:
WANTED IH C200 gas engine — complete running motor Wanted complete used IH C200 gas engine in running condition for an International 574 gas tractor. My block has a hole in it and is dead, so a rebuild kit wont do it — need a whole running motor. The C200 also came in the 544 and 674 gas trac
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
