Halogenated Compounds; Silicon Compounds; Residual Oils And Tar; Solid Particles - Kohler SFGLD480 Operation & Maintenance Manual

5.2.2. HALOGENATED COMPOUNDS ( F, CL, BR, I ) SUCH AS CL
Halogenated compounds may be very harmful to the engine, if they are present in the form of acidic elements in
the fuel gas or in the combustion products. They normally develop in landfill gases, and to a lesser extent, in
digester gases and in gases from thermochemical processes. Due to their chemical nature, the acids of this type
of constituents are extremely corrosive, they attack almost all the metallic parts of the engine and destroy the
additives of lubricating oil, thus reducing its life.

5.2.3. SILICON COMPOUNDS

Silicon compounds appear in fuel gases in either of two type groups:
a) inorganic silicon compounds, having their origin in mineral material introduced in the gas flow, such as
silicates and silica, and which can be classified in the group of gas-borne solid particles; or
b) organic silicon compounds, which include siloxanes as the most frequent ones, are hard to detect because
they require special analysis techniques, generally have their origin in the degradation of the many silicon-
based products used in the industry for manufacturing general-purpose products, paints, cosmetics, cleaning
products, etc.
Those compounds are present in the form of gas or vapor in the fuel flow and, generally, are harmless to the
engine until their combustion. Combustion transforms the silicon they contain into silicon dioxide, silicates and
other crystalline compounds that precipitate, forming abrasive particles inside the engine and jamming valves,
pistons and other parts essential to the operation of the engine.
Moreover, a portion of the silicon content migrates from the combustion chamber to the lubricating oil, reducing
the oil properties, which in turn affects engine parts that are not in direct contact with the combustion chamber.
5.2.4. AMMONIA (NH )
3
Ammonia is a chemical compound that can either attack different elements of an engine alone or combine with
other more acidic constituents to form ammonia salts that will abrade the engine components. Also, the NO
emissions of the engine may increase, as ammonia compounds pass through the combustion chamber, where
ammonia transforms itself into nitrogen oxides.

5.2.5. RESIDUAL OILS AND TAR

Oils and tar are usually carried along by the fuel gas. They are in the liquid phase or they condense when the gas
temperature decreases. Their presence is attributable to lubricant leaks in the gas compression equipment.
However, they are also present in large quantities in gases from thermochemical processes. Their effects on the
engine include plugging of filters and regulators, as well as a lower performance of the turbochargers and dirtying
of air coolers, etc.

5.2.6. SOLID PARTICLES

Solid particles act as abrasives on the engine components and they also give rise to failure when they
accumulate and block certain items of equipment impeding them to operate correctly. Solid particles are the major
source of inorganic silicon entering the engine with the fuel gas.
PRODUCT INFORMATION
IC-G-D-30-001e
FUEL SPECIFICATIONS FOR GAS ENGINES. GENERAL
4.1.16
INDEX DATE
D
March 2014
O&M_2.002211.810_A_10_2016
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Dep. 2
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