Expanded Use of Small Engines by the Application of Butane Fuel Canisters 2010-32-0055
To enhance the convenience of small engines and their current
range of application, we studied on the application of commercial
liquefied butane fuel canisters containing sealed liquefied
normal-butane (n-butane) and iso-butane (i-butane).
In processes for extracting a fuel mixture of n-butane and
i-butane in a vapor phase state, the discharge pressure dropped as
the fuel within the canister was decreased, due to the phenomenon
of prior discharge of the higher vapor pressure of i-butane. This
pressure loss from gas discharge had to be restored by raising
canister temperature which increased the butane vapor pressure.
However, in the liquid phase process, since there is no pressure
loss as a vapor, the canister holding temperature could be set
lower than that of the vapor phase process. Moreover, when the
ambient temperatures were the same or lower than the canister
holding temperature, the liquid phase process was superior in terms
of heat balance. However, there was superior heat balance in the
vapor phase process at ambient temperatures exceeding the canister
In the liquid phase process, the fuel supply system contained
residual non-volatile components. These nonvolatile components
could however be separated out and removed by utilizing a trap
structure in the fuel supply system.
A performance comparison using a 49.4 cm₃ test engine adapted
for butane canisters was carried out. Compared to gasoline, engine
output was 93%, energy efficiency and THC+NOX emissions were
equivalent, and CO₂ emission was reduced by 11%.
From these results, applying liquefied butane canisters to
various products is shown to be an effective means to enhance the
convenience of small engines and expand their potential use.