How to measure biogas pressure
Equipment:
1. Hose
2. Water
3. Tree stump
4. Tall guy
Too cute by far
Making Charcoal
The experiment
CAT get everywhere
Sunny, MK, MK wife & Doug
The experiment
If you ever wondered what happend to the old falcon ambulances
Video of Diesel running on biogas
My final trip to the RTC this time around was to run an experiment on the diesel engine running on biogas to try to ascertain just how much gas was being used as apposed to diesel fuel. I bought a few odds and sods at the Chinese market including a large syringe to meter the amount of diesel going into the engine.
Unlike the propane I used last year the biogas will not self ignite, therefore it will always need some diesel fuel for both ignition and lubrication of the injectors. There are also some issues of the detrimental effect that the biogas (which contains I unknown amount of sulphur) will have on the engine.
The plan was to disconnect the diesel fuel tank and fill the syringe with diesel directly into the fuel inlet. We can now measure how much fuel the engine was consuming for a set speed. We could then run the engine with the biogas and see how much less fuel was being used. The gas was regulated by the valve at the opposed hose connection end to the mixing chamber, as apposed to the valve at the mixing chamber end. The reason for this was that we wanted to take a measurement of the flow of gas which would have been difficult with the mixing chamber. The valve was cracked open slowly until the engine started spluttering as the governor ran through its confusing cycles of not really knowing what to set itself to and then the valve was closed slightly. At this point we reckoned that we were running the maximum amount of biogas that we could get away with.
We ran the experiment at a number of different speeds and we concluded that we were running the engine on biogas however it was not a large percentage about 15% at the higher revs. And I have to admit to being a little disappointed. However we have to look at these things in perspective.
1. We know we have issues with the digester, there is manure/ water mix oozing out of the containment plates and the discharge chute is still bubbling with methane, therefore not all of the biogas is being extracted. We have no idea of the composition of the gas and no means of testing (there could be as little as 30% methane in it). I am bringing a sample back with me for testing and I will be looking for a testing kit of some form to take with me on my next trip. If anybody has any ideas I would be more than welcome to listen to them. Clearly improving the digester function will improve the biogas quality.
2. The gas was not scrubbed in anyway, so there is C02, water vapour and sulphur in various amounts in there, the C02 and the water vapour should cause too much of a problem but the sulphur could be an issue. My next step will be to construct a crude charcoal scrubber to try to remove as many impurities as I can prior to ignition.
3. The engine itself is in very poor state of repair and will soon be destined for the scrap yard. As I have mentioned in previous blogs the low compression caused by the bad condition of the engine can be seen as helping the process and did allow the engine to run on 100% propane. However, logic would dictate that as the tolerances in the engine start to degrade the running efficiency will also degrade, this maybe a benefit or a hindrance to the running on biogas, at the present I don’t know however it is a variable.
On the conclusion of the experiment we measured the pressure of the gas using a manometer ( yes there was tall man holding the open end) and the pressure measured at 37”H2O ( about 9.25 Kpa )and the flow rate was 6 litres/ min. We measured this by filling a 1 ½ Litre Pepsi bottle full of water and holding upside down in a bucket of water and inserting the biogas pipe into the bottle, turning on the valve to the set point and counting how long it took the gas to replace the water.
I am on my way back now and posting this blog in hotel in Bangkok, I have picked up a stomach bug in Laos and has been me some trouble for the last few weeks. I must have to admit that this trip has been a bit of a struggle for a number of reasons, nothing has seen to gone to plan and there have been a lot of disappointments. Seeing Vene again has been good and I can count the stuff I did at the RTC as some form of success. But it has been a sobering experience as I realise that if you choose to work in a country like Laos, nothing is going to easy, there is the Laos Laos way of doing things which when you first confront it is hilarious, but can be frustrating after a while, having you can’t let it get to you. Also there is the cultural sensitivity issue that you have to work with, this is an issue in Vientiane the capital, but in the countryside and poorer parts of the country can be a real struggle with local superstitions and mistrust of furlongs, there is also the endemic corruption which spans all of Asia but seems to be particularly bad in Laos. The simple truth of the matter is in the ‘big picture’ thinking of what I am doing here it is a remarkable opportunity, the country has huge potential and has a tenacious and dynamic people, there is a chance to do some real work here and really make a difference to peoples lives. Needless to say personally it is a huge adventure and a chance to do something which is totally ‘out there’ in my life. Of course the downside to this is you have to live it day in day out and you have to accept you will miss the creature comforts and look at the constant frustrations as part of the challenge and learning to live with them is part of the experience.
More on creature comforts:
1. Find somewhere to live other than a hotel, 8 weeks living in a hotel is just a dog, no being able to go to the fridge and make a sandwich when you want a snack gets to you after a while.
2. Next trip to Laos will include a trip to Udon Thani to buy a coffee maker
3. Missing a decent bike, the YZM 110 just does not cut the mustard
4. I miss the TV*( particularly the bike racing ), although I can download ‘The Daily show’ & ‘The Colbert Report’ and radio is no problem as I can stream RRR & Radio 4.
5. Boscastle Pies
6. Also my friends of course, I do have a number of acquaintances in Vientiane which is cool but it is a very different scene.
*The selection of TV channels you get in the hotels you stay in is usually a mixed bag, the Manohra hotel I am in a the moment which is the river end of the Sukhumvit road in Silom, Bangkok, which I must admit is an excellent hotel at a pretty reasonable rate and caters for mainly Indians, therefore there are a lot of Indian TV on the hotel TV, there is a RT ( Russian Times ) which is an English version of Russian magazine program which features constant Pro Russian anti USA propaganda which is far more subtle than the propaganda dished out by the English Chinese Magazine CCTV9, which last night explained how evil the Dali Lama was by ignoring one of the main tenants of Buddhism which is the love of the mother land, I am not making this up. The most disappointing is the Australian Network although you do get the ABC news and heavens be praised the footy the rest is what I term as ‘spiders & snakes’ which as a lot of people wearing hats and doing bogan bush things, This from a country where 99% of the population lives in cities.
Missed doing a number of things in my last few nights in Vientiane, I must take a video of the ride down the Dogphon road from Doug’s compound back to the city. Why would you want to buy a PS2 when you can ride down the Dogphon road on a step through? It’s the combination of being quite narrow, very busy and has a lot of side roads leading in at odd angles. Being Laos there are no traffic rules as such and things arrive in your vicinity form all angles. It’s not a fast moving road so there is usually plenty of time to do something about it, its just heaps of fun.
The Laos Laos way of doing things; It is taken me quite a while but I realised that along with Vientiane and Van Vieng , Vene also has a name with a ‘V’ in it but the Laos language ( as well as the Thai) does not have a ‘V’ sounding letter. It is seemed an obvious question, so I asked Vene, the Laos answer, “It is not interesting”.
Look forward to seeing a lot of you again soon
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