Page 229 - Biofuels Refining and Performance

212 Chapter Seven

Carburetor
EGR valve
Engine coolant
heat exchanger
Air pump

Intake
manifold

Exhaust
manifold

Stock motor Exhaust purifier
Figure 7.12 Modification provided to avoid the difficulty of cold starting.

7.8.4 Corrosion
Corrosion of the engine parts has been one of the main reasons for not
using alcohols as fuels. The problem of corrosion is severe during start-
ing and idling; but once the engine starts and gets heated, corrosion does
not take place. Severe corrosion is noticed with Zn, Pb, Cu, Mg, and Al.
This problem has been solved by using a methanol-resistant filter before
the carburetor. Corrosion by methanol has been prevented by using the
corrosion inhibitor LZ541 manufactured by M/S Lubrizol India. Being
solvent, it swells or softens many parts of plastic or rubber commonly
used for gaskets or floats in the carburetor. This is solved by using elas-
tomers instead of rubber or plastic. American Motors’ Gremlin model of
1970 has been used continuously for 9 years using pure methanol with-
out facing any difficulty of corrosion. Two 1972 Plymouth Valiants have
been used for 7 years: one using pure methanol and the other using a
methanol blend without any difficulty. None of these vehicles has had
a failure of engine components or fuel system components.

7.8.5 Toxicity of methanol
Methanol is more toxic as compared to petrol, which creates difficulty
in its handling. The toxicity of methanol is reduced by adding chemical
emetics.