A Volkswagen Beetle that runs on methane produced from human waste in sewage sludge has been unveiled in Bristol.
Bath-based Greenfuel Company converted the ‘bug’ so it could run on biogas generated at the Bristol sewage treatment works in Avonmouth.
With support from the South West Regional Development Agency, GENeco, a Wessex Water-owned company, imported specialist equipment to purify biomethane in a way that doesn’t affect the vehicle performance.
If both tanks were filled up with methane the car would travel for 250 miles
The biogas is enough to power a conventional two-litre VW Beetle convertible to 114mph.
According to GENeco, waste flushed down the toilets of just 70 homes in Bristol is enough to power the ‘Bio-Bug’ for a year, based on an annual mileage of 10,000 miles.
Countries including India and China use compressed natural gas (CNG) to power vehicles and a number of companies in the UK are now using CNG mainly to fuel buses and commercial vehicles. In Sweden, more than 11,500 vehicles already run on biomethane produced from sewage plants.
But using biogas from sewage sludge is yet to take off in the UK despite a significant amount being produced everyday at sewage plants around the country.
In order to produce methane from sewage, it first must be treated with anaerobic digestion, a process in which microorganisms – in the absence of oxygen – break down biodegradable material to produce methane.
In an extra step to purify the methane, the GENeco engineers used specialist equipment to strip carbon dioxide from the biogas.
The methane is stored in two pressurised storage tanks in the boot of the Bio-Bug vehicle. If both tanks were filled up with methane the car would be able to travel for 250 miles.
Ingram Legge, director at Greenfuel Company, which converted the car, said filling it up with methane is fairly simple. ‘The storage tanks are pressurised to about 200 bar and you connect the vehicle up and it basically equalises pressure so the tanks in the vehicle are 200 bar with methane in them,’ he explained. ‘There’s no pump in effect, which is quite clever.’
The vehicle still depends on petrol but only for a moment after starting the engine. Once the engine’s temperature reaches 30ºC, the petrol injectors shut down and the methane ones open up. If methane runs out, the car will switch back to running on petrol.
While the Bio-Bug is being touted as environmentally friendly, Legge acknowledged that does not mean the vehicle produces no emissions. ‘It’s producing CO2 out the tailpipe but it’s important to know where that CO2 is coming from,’ he said. ‘Of course it’s not coming from yesterday’s CO2 buried in the ground as oil, it’s today’s CO2 from waste. So it’s very environmentally friendly.’
Mohammed Saddiq, GENeco’s general manager, said he was confident that methane from sewage sludge could be used as an alternative energy source and was an innovative way of powering company vehicles.
He added: ‘Our site at Avonmouth has been producing biogas for many years, which we use to generate electricity to power the site and export to the National Grid.
‘With surplus gas available, we wanted to put it to good use in a sustainable and efficient way.
‘We decided to power a vehicle on the gas offering a sustainable alternative to using fossil fuels that we so heavily rely on in the UK.
‘If you were to drive the car, you wouldn’t know it was powered by biogas as it performs just like any conventional car. It is probably the most sustainable car around.’
this is incredibly ingenious! i’m so estatic,
Hasn’t any one suggested a better name than Bio-Bug. What about the Dung Beetle?
Hope to see cars powered this way soon in the UK. There is also the ability to collect the methane from food waste and animal waste.
Is it true they are renaming it the Dung Beetle?
I believe that street lights in some towns were powered by gas from the town sewerage systems, perhaps it was discontinued because of the explosion hazard if gas from the sewerage system was not continuously vented to the atmosphere.
According to “Without Hot Air” biofuels can only be generated at a very low level per square m of land surface. The estimate is about 0.5W/sq m, which is only 1/6 the energy density of wind turbines, and we already know that covering the UK with wind turbines cannot provide all the energy we use now (it might provide all the electricity, but we need to replace all the oil, gas and coal we use now with renewable energy as well)
A panel was converted to methane operation by a local authority in the North west in the mid 1980s and was demonstrated at Gatwick Airport as a vehicle for servicing aircraft. The downfall was the duty free fuel for vehicles operating air side. There seemed to be no major attempt to market the technology of the concept which also had a diesel support option. Possibly methane from redundant coal mines might be a possible source of fuel for this sort of technology. The biggest problem will be adequate infrastructure for this type of fuel at a national level.
Come on, Siobhan Wagner and The Engineer, the obvious headline is Dung Beetle. Still, looking at the standard of the sub-editors’ imagination on The Engineer, one should not be surprised I suppose…
Brian Pollard made the important point. The article states that it takes the contributions of 70 homes to power the Beetle for a year. That is a 1.4% contribution to just portable energy use. If the infrastructure already exists and the conversion is free then by all means use the waste. But looking at this as a viable contribution to an energy equation seems a bit hopeful.
It’s been really a good leap into the eco-friendly technology….Hope it not only for the bug but also for the monsters…..
Gosh – so much ill-informed nonsense talked and written on an important subject, probably including some of my contribution! But a few suggestions anyway:
1. There are photographs of vehicles as far back as WW1 driving along with gas bags on the roof that were filled from chicken litter emissions, and presumably anything else that would digest but it is the chickens that I recall;
2. the water industry in which I work has been developing and exploiting anaerobic digestion for many decades, maybe a full century by now;
3. a lot of sewage treatment works (STW) sites have run partially or completely on their own power generated from burning digestion gas;
4. there are numerous peak lopping and power exchange schemes around the country making use of the digestion gas product;
4. where there can’t be a constructive swap, dual fuel engines have often been used as the rate of gas evolution cannot always be controlled to match availability to demand;
5. the servicing of those engines can be very costly due to contaminants in the gas, particularly sulphurous compounds that acidify condensates and deposition in the combustion products;
6. Mr. Pollard’s comment above about bio-fuel and energy intensity are only relevant in the context of bio-energy production from primary crops. It is completely separate from the sort of site as described in the article where a STW is converting a side stream product into a useful fuel.
John Douglas – thanks for a clear anlysis
This gas is no different to the natural fossil gas that most of us use to heat our homes and that is burned to produce 40% of our electricity. If we placed a big tax on natural gas from fossil sources then sewage plants and farmers would have an incentive to produce lots to pump into the grid.
Good to see potentially sustainable projects being operated.
The milage on two full tanks is also quite impressive, however what happens upon impact, either big or small? Perhaps I don’t understand the capabilities of the technology but is there not a huge risk associated given daily road accidents and fatalities?
brilliant,is there a chance this technology would be available here in the philippines. great savings especially in traffic.
Absolutely brilliant!
Ignore the jokers and the doubting-Thomas’s aside…
This is an incredible opportunity to importantly contribute to the issue of how we fuel our habits in the near and distant future.
C’mon people, stop pouring cold water on such ideas and encourage such innovation, because who knows where it can lead?
We people in the states could profit from this technology albeit on a larger scale. Once the current administration in Washington, D.C. is hooked up to the main feeder line it could be the end of the need for energy exploration as we know it.
During the years 1939 to 1945 – and maybe a bit longer – Croydon Council converted its modest fleet of refuse collection lorries and a number of vans to run on methane produced from their own sewage works. The gas was also used to heat the sludge digestion tanks so the plant was self-sufficient.
That was over 60 years ago, so its hardly new. I have a copy of an old magazine “Our Croydon?” that features this in text and photographs.