[Digestion] Digestion of Honey Waste

Wed Feb 16 22:42:49 CST 2011

The primary problem is the H2S. The Sulfur in diesel fuel is not H2S. The sulfur in diesel fuel actually acts as a lubricant and prolongs the life of diesel 
engines. The H2S will cut the life a  normal engine by 60- 75%. You can change to a higher heat thermostat say 210F and boil the acid that forms out
but the metal sulfides that form are highly abrasive to the entire engine. The real problem is the effect the H2S has on any parts that contain copper,
like bearings ,it just eats them up. Several companies make CHP gen sets designed to burn "sour" well head gas. 

I heard of several places that use engines out of wrecked cars and just through them away when they fail. Our personal experience is was not good.
We seldom got more than 6,OOO hours before standard automotive diesels or gas engines failed. What run time are your units able to reach?

Brent

  ----- Original Message ----- 
  From: Anand Karve 
  To: For Discussion of Anaerobic Digestion 
  Sent: Wednesday, February 16, 2011 6:03 PM
  Subject: Re: [Digestion] Digestion of Honey Waste

  Dear Brent,
  In India, biogas is used as cooking fuel and it is always used as it is.  We have two biogas plants at our training centre at Phaltan, Maharashtra State, India. We use food waste and kitchen waste from our hostel as the feedstock. The gas from one of the plants is used for cooking and that from the other is used for operating an internal combustion engine for generating electricity. The engine is started on petrol and then switched over to operate with biogas alone. We do not purify the gas, neither for the cooking nor for running the internal combustion engine. The H2S has so far corroded neither our cookstove nor our engine. I consulted a U.S.American Professor about the use of biogas in an internal combustion engine. He comes to my city (Pune, India), as a consultant to an automobile manufacturer. He said that the so called oxygen that the engine draws in contains 80% nitrogen. Biogas has about 40% CO2, which does not interfere with the functioning of the engine. The moisture in the biogas also does not harm the engine, as the external air being drawn into the engine also contains moisture, especially when it is raining. As to the H2S, he said that the whole world was using diesel with a high sulphur content until about 20 years ago. It never harmed the engine. We stopped using it to reduce atmospheric pollution. After seeing our example, there are now several farmers, who use biogas in their diesel engines (80% biogas and 20% diesel) for pumping water and for generating electricity.. Biogas has a lower calorific value than petrol and diesel. We overcome this problem by increasing the flow rate of biogas. 
  Yours
  A.D.Karve 

  On Thu, Feb 17, 2011 at 12:58 AM, bingham <bingham at zekes.com> wrote:

    Dear Anand,
    Are you saying you have an AD system that produces Biogas which does not require the expenditure of any energy?
    Alcohol can be burned in diesel and gas engines at 100 proof replacing $3.00++ automotive fuel. I do not understand
    your point about "use the fuel where it is generated" but one of alcohol's good points is it can be transported
    inexpensively or used "where it is generated". With the advent of vacuum operated alcohol distillation systems
    direct sun light  is all the external heat that is needed to produce alcohol at 190 proof.

    We do not know if the honey facility can even use biogas "as it is",  or has a need for it. Our natural gas boilers cannot use raw biogas
    "as it is", we must scrub out all H2S to prevent damaging another boiler and or most of the CO2  to avoid spending 
    thousands to modify the burners to burn both natural gas and biogas. I do not know where or how you use biogas 
    "as it is" we tried it in unit heaters in our livestock buildings and destroyed them in a year. 

    The fact is in the last 45 years, we have found almost no application for the long term use of biogas ,that H2S is not a factor.
    Cooking stoves, lighting, boilers, unite heaters, water heaters, inferred heaters all experienced significantly shorter lives from using 
    biogas "as it is". Some of the failures were out right dangerous. 

    Anand, I believe you are being misleading to the point of being untruthful. This could result in someone being hurt or killed,
    who might take what you said "Biogas can be burned as it is" as fact and use it with out precautions.
    Standard residential plumbing and appliances contain metals that do not stand up under long term exposure to H2S. Especially in high heat high
    humidity conditions. Steel plumbing is used in most places that were setup to use natural gas or propane. To suggest you can just pump
    biogas"as it is" in place of other fuels is just wrong on many levels. We are strong proponents of AD but the "Bad Press" the list is 
    currently discussing could be warranted in some instances. AD is not the "highest and best" technology for all applications.

    Highest and best use principles require the use of an energy audit and some study to determine which system is best suited to each situation. My father, grand father 
    and my uncles refused to believe that the effluent from the AD system was better for the crops than the runoff from the livestock buildings. It was only after the areas
    around the farms began to build up with new homes and the complaints of smell threatened to shut us down that they allowed me to build our first AD system. They then 
    could see an increase in crop yields in later years, (and the smell went away). I know corn farmers that use corn in there pellet stoves as fuel  to heat there house because fuel pellets cost more to buy than they were paid for their corn. 

    Brent

      ----- Original Message ----- 
      From: Anand Karve 
      To: For Discussion of Anaerobic Digestion 
      Sent: Tuesday, February 15, 2011 6:01 PM
      Subject: Re: [Digestion] Digestion of Honey Waste

      Dear Brent,
      for alcohol to be useful as fuel, it has to be distilled, which again requires expenditure of energy. Biogas can be burned as it is. So, if you want to use the fuel where it is generated, biogas is more advantageous than alcohol.
      Yours
      A.D.Karve

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  -- 
  ***
  Dr. A.D. Karve
  President, Appropriate Rural Technology Institute (ARTI)

  *Please change my email address in your records to: adkarve at gmail.com *

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  and the Biogas Wiki http://biogas.wikispaces.com/

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