Cost Comparison: Bioethanol Liquid vs. Bioethanol Gel vs. Petroleum Fuel vs. Gas Canisters

 

Many sites and reviews talk about the low heat output of methylated spirits (meths) compared to alternative liquid fuels and gas cylinder for outdoor cooking systems. We thought we would take a different approach, focusing on the actual cost of each system to boil water.

In July 2013, the recipe for methylated spirits (meths) was replaced with a new European formula for denatured alcohol. Here at Ekofuel, we have taken those recipes and created a range of new products including a camping based bioethanol liquid fuel and a bioethanol based gel fuel see www.ekofuel.org.

Ekofuel 2013 Fuel range

1lt green1lt blue1lt orange

It is true that ethanol including bio ethanol has a lower calorific content that some other camping liquid fuels for example, ethanol has a calorific value of around 29.7 MJ/KG compared to gasoline and kerosene around 47MJ/KG and propane and butane around 50MJ/KG. For this reason a lot of the multi fuel systems are capable of running cleanly on these fluids.

As we are told so often, size is not everything. Granted bioethanol is at a disadvantage to start, but there are other benefits including an environmental benefit to burning bioethanol.

From the Primus literature it quotes that it takes theoretically approx 7.5g of Butane and propane to boil 1L of water compared to 9g of kerosene and 13.1g of bioethanol.

In reality the fuel consumption figures to heat a litre of water depend on the ambient conditions. If we assume that these conditions are static, then the actual amount of fuel used depends on the efficiency of the burner/pot system.

For a system to be efficient, the fuel must be burnt cleanly, and the transfer of heat from the burner to the pan and its contents be as efficient as possible.

Below we will discuss the relative costs of boiling water on various camping stoves.

Bioethanol Liquid Fuel

On a recent test of our EkoFuel bioethanol fuel in a Trangia alcohol burner system we used approx 22 to 23g of bio-ethanol to heat 1litre of water to 100C from 21C. The theoretical amount of bio-ethanol required was ((100C-21C) x  4184J(water/g))/29700J/g(ethanol) =11.13g.

From our calculations this equates to an approx efficiency of around 47 to 50% which seems pretty reasonable. It can be seen that although bio-ethanol may be at a disadvantage to start, greater losses are incurred through an inefficient heat transfer process.

EkoFuel sell 12 litres of liquid bioethanol fuel for £32 for 12 litres (£2.66/L) including vat and delivery. With approx 790g/litre, it can be seen that the cost of boiling 1 litre of water from 20C to 100C  in our recent trials cost around 7.7p/litre based on a 23g consumption.

Gas Cylinder Stoves

In contrast MSR in their You Tube video http://www.youtube.com/watch?v=5dFFU3x4pXQ report that their super efficient MSR Reactor stove will boil on average 22lts of water from an 8oz canister or 11L from a 4oz canister.  In contrast they also quote that their pocket rocket gas stove, will boil on average 16L of water from the same 8oz canister or 8L from a 4oz canister.

Looking across the net, a typical price for a 4oz gas canister is around £2.95.  Based on the efficient MSR reactor boiling 11L of water from a 4oz canister, the cost of boiling 1 litre of water is approx 26.8p/litre.

Bio-Ethanol Gel

In our latest online test, we evaluate our EkoFuel BBQ Fire Lighting Bioethanol Gel for boiling water on a Trangia. The results show that it took approx 33g of gel to heat 1 litre of water. With approx 825g of bio-ethanol gel per litre, it can be calculated that each litre of EkoFuel bioethanol gel will boil on average 25 litres of water from 21C. At £32 for 12 litres (£2.66/litre) including vat and delivery, it can be seen that the cost to boil 1 litre of water using Ekofuel gel is around 10.7p/litre using a Trangia.

In contrast another brand of bioethanol gel fuel is sold at £5.95 per litre in various outdoor shops. We have tested this bioethanol gel fuel and shown that it has a similar heat output to EkoFuel BBQ and Fire Lighting Gel. Using the same 33g fuel consumption figure from above, the cost to boil 1L of water on a Trangia from 21C would cost 23.9p per litre, a 220% price increase over EkoFuel.

Petroluem-Based Liquid Fuels

This is a difficult one to calculate. With no efficiency figures to hand, I have had to assume a similar efficiency to the figures used for ethanol. Some stoves can be run on proprietary fuels and some on standard unleaded petrol. The price for these fuels range for £1.29/litre for unleaded fuel to £5 to 6/litre for proprietary fuels.

The cost to boil a litre of water from 21C can therefore vary between approx 4p and 18.6p per litre depending on the fuel chosen and based on an efficiency of around 50%.

Summary

Although bioethanol based fuels are of a lower calorific fuel value than many competitor fuels, it can be seen that the cost of boiling water using EkoFuel bio-ethanol based liquid and gel fuels can be very competitive.

The table below summarise our approx calculated costs for heating 1 litre of water from 21C to 100C

Fuel Type

Cost to heat 1lt of water

Ekofuel bioethanol liquid

7.7p

Ekofuel bio-ethanol gel

10.7p

Competitors Bio-ethanol Gel fuel

23.9p

Gas canister stoves

26.8p +

Petroleum based fuels

4p to 18.6p

Coupled with the products being safer than petroleum based fluids, eco friendly and sustainable, bio-ethanol based fuels are certainly worth considering for your next camping trip. If you are attending a festival, you may also find that gas canister based stoves are banned, whilst bio-ethanol liquid and bio-ethanol gel stoves aren’t – more food for thought.

Rob @ekofuel

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