DIY Gassification

Hi KJY/USA

What is the best method for producing electricity from this gas?

Tony

Thanks pradeep44

I assume this would have to run constantly, what sort of efficiency would you expect? What sort of cost for having 2kW available?

Tony

I don't think below 500 kW it's viable. I have not seen small steam/gas turbines. Effieciencies vary from 30 to 50%.

Hi Tony,

Sorry for the delay in responding to you.

The experience I have is, a few years back, I replaced a Cat - Biofuel 750KW gen-set at a local waste water treatment facility.

If my memory serves me, the facility mixed the digester gas with natural gas at a ratio of 40/60.

As far as methane to electricity, I did a switchgear replacement at a land fill. They were running 3 turbine gen-sets but here again, they mixed the methane with natural gas.

As far as the best method, I don't have enough data to provide an opinion.

With regards to heating with methane, my neighbor runs straight (without mixing), compressed methane to a modified forced air heater unit and it works great.

He has 70 head of cattle so fuel (poop) is abundant.

Regards - KJK

was there any sort of filtering to remove the sulfurous compounds?

Hi Garthh,

I do not know if they filtered/scrubbed the sulfurous compounds.

My work was in the generator room. All I had was a fuel pipe coming in to connect to the gen-set.

I did not see the fuel mixing/compression area of the plant.

Regards KJK

Hi KJK/USA

Most of the power consumption is used in heating and cooling, although in dry places like South Australia evaporative cooling works well. If there was indeed a small quiet generator that could run on natural gas and/or methane for just lighting and fans using the gas for refrigeration and heating it may offer a viable alternative to solar panels and the problems of storage.

Tony

Hi to all- I'm just wondering if there are obvious safety issues that would be in play. As the mother of 3, I'm happy to see intelligent questions being asked, but since I don't understand a lot of these concepts, I wish the danger aspects would be mentioned-(without making them possibly attractive!)

There have been a few instances of people trying to tap into pipelines to access various ingredients needed to manufacture certain substances, with unfortunate results to number of people- both the perpetrators and innocent bystanders ..

Google 'biogas for third world'. I have read they can build a system for about $300

Here is one link.

http://en.wikipedia.org/wiki/Biogas#In_developing_nations

That seems to have a bit of a green twist to it - such as pay no attention to details. From the Wiki,

Quote, 'Raw biogas produced from digestion is roughly 60% methane and 29% CO₂ with trace elements of H₂S, and is not high quality enough if the owner was planning on selling this gas or using it as fuel gas for machinery. The corrosive nature of H₂S alone is enough to destroy the internals of an expensive plant'

For a generator to burn this gas by itself it would need a specifically designed combustion system. Not to mention any H2S problems.

The 300 to 500$ mentioned would be to use the gas for cooking only I expect.

H2S is exactly what I'm talking about

you wouldn't want to throw raw biogas in a generator or stove

H2S is bad but the gas is also of low calorific value.

Hi, i forgot, i live in a cold areas also, so to have methane production you need that the temperature of your slurry inside of the digester be in the region of 25 degree Centigrade to 35 degree C. , so you need a heating jacket for the IBC (very expensive over 1000$) so i decided to use the heating blanket which are a 10 of the price, wrap it around your tank and put on top of that some insulation material.Another advantage of the heating blanket is that there is thermostat in it and it is the perfect heat require by the slurry to develop into methane gas. The only drag of this setup is that you have to put some roof over it. The lower the temperature the longer is going to take to make gas. once you have fill the tank with slurry you have to wait & wait around the 10 day gas will be produce but is not good its only CO2, but next come the methane, then and only then you start to recharge the digester. For my setup 60 kilos every 2 days (30 kilo of slurry-30 kilo of water mixed together) and ''BOB is my Uncle'' as we say here. Good luck.

Hi BC eng. There was a problem with the first part of the message, so here we go. I'm a industrial designer and i have made one DIY digester using IBC water tank. I connected them all together to make a continuous digester. I have used 4" sewage pipe to connect them and to feed it. I have drill the tank with 5" hole saw and inserted a rubber seal from Uniseal and stock the pipe into it. You need to build the system without leaks. Then i have drill the cap of the tank and inserted a 3/4" pipe for the collecting the gas. I have used Philmac pipe connector to connect them all together and connected them to a tractor tube to gather the gas (or you can use a truck tube or Puxin biogas bag). I am using cow manure mix with seaweed plus water. Then like i wrote on the precedent message you wait and it will work. Like i say i have used heating blanket to keep it warm this is the cheapest.It burn