Fuel Cleanliness From the Microbiological Point of View Supply Chain Control

Transcription

1 Fuel Cleanliness From the Microbiological Point of View Supply Chain Control

2 Why do we talk about microbes in the fuel at all? In the early forties last century, storage tank explosions were for the first time connected with microbial anaerobic production of explosive gases methane, hydrogen and hydrogen sulphide. Until today in different industries many cases of tank explosion caused by microbial infection are known The hazards associated with fuel microbial contamination was underscored untill 1958 when a B-52 crash was directly attributed to the plugging of an in-line fuel filter.

3 Introduction of the fuel system icing inhibitor, ethylene glycol monomethyl ether (EGME) coupled with improved housekeeping, reduced the number of microorganisms in field fuel systems Many different additives developed since then have driven changes in the constitution of the microbial communities again Low sulfur content and diesel/biodiesel blending increased the likelihood of microbial fuel infections and degradation.

4 The major microbial problem in the petroleum refining industry in the world Contamination of stored products leads to: Loss of product quality Formation of sludge Deterioration of pipework& storage tank in the refinery and at the end-user Spending huge amount each year on equipment. Loss of reputation (customers are talking about))

5 Clean fuel is fuel without: Water Solids Chemical contaminants Also fuel without: microbial biomass microbial metabolic products such as: -biosurfactants -gases(hydrogen sulphide, methane) -acids.

6 Contamination of any kind can be introduced at different stages: Production Transportation Distribution Storage Handling

7 Laboratory analyses of samples from different sources Vechiles Boats Trucks Trains Storage tanks Methods ASTM D6974 D 6469 D 4057 E 1326 IP 472

8 FUEL Bottom sludge = water + biomass +corrosion particles

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10 Diesel microbial culture isolated from the middle of the fuel tank

11 Facultative anaerobes from The fuel sample

12 Microscopic picture of solid particle from the analyzed fuel sample

13 For example in modern diesel engines, dust just 2µm in diameter can cause fuel injector failure (the thickness of a human hair is 80µm). Dirt can cause deviations in the injector spray pattern which lead to jetting or dripping.

14 Over 120 different microbial species is determined in all kind of fuels depending on changes in the additives and different growth conditions

15 Fuel: Sources of the water Freshly refined fuel contains some water Atmospheric condensation Rain or snow During transport or storage in tankers-contmination by ballast water

16 The sources of microbial infection Water Air sources of the solids Water Air Corrosion processes(biological & chemical)

17 Consequences of fuel infections/degradation Fuel haziness-increasing water content because microbes produce biosurfactants result is increasing of water solubility Degradation of additives especially those with nitrogen or phosphorous- effect is lost Microbial induced corrosion-production of hydrogen sulphide by SRB

18 Sludge formation-debris deposition on the tank bottom-reservoir of infection Deposition and blockage of filters, pipes, valves Engine damage and in extreme complete failure Microscopic picture of solid particle from fuel bottom sample

19 Surfactant production-oil/water emulsification, entry of cells into the oil phase Production of suspended solids Degradation of hydrocarbons Shortened filter life Increased sulfur content of fuel Penetration of protective tank linings Workers health problems(endotoxin-producing bacteria, opportunistic pathogens, SRB)

20 Damaged fuel tank bottom by microbial metabolic products- pitting Damaged fuel tank by acid producing microorganisms

21 Fuel microbial standards ASTM D 6469,D402,D4057,D4412,D4454,D6974, D7463,D7464,D1259,E1326,IP385,IP472 And 50 referenced documents

22 Control of microbial contamination Prevention-cleanliness and frequent drainage of water Emptying storage system for thorough cleaning (removal of biofilm) Using of biocides (environment?) Biocorrosion avoidance-internal coatings Cathodic protection Ensure transport vehicle cleanliness to reduce contamination. Implementation of manipulation procedures control thorough production/transport/storage/retail chain Management and staff education Customer education

23 Implementation of supply chain management guidelines Strictly following default procedures against microbial infections continuous control of guidelines application

24 Problem recognition Problem admission Knowledge Solution