Characterization of Deposits Collected from Plugged Fuel Filters

Abstract

<div class="section abstract"><div class="htmlview paragraph">Fuel filters serve as a safety belt for modern compression ignition engines. To meet the requirements from environmental regulations these engines use the common rail injection system, which is highly susceptible to contamination from the fuel. Furthermore, the public awareness towards global warming is raising the need for renewable fuels such as biodiesel. An increased fuel variety brings a higher requirement for fuel filters as well. To better understand the process of filtration, awareness of the different possible contaminants from the field is needed. This study used several chemical characterization techniques to examine the deposits from plugged fuel filters collected from the field. The vehicle was run with a biodiesel blend available on the market. The characterization techniques included X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR) joined with attenuated total reflectance (ATR) sampling, gas chromatography-mass spectrometry (GC-MS), and lastly thermal gravimetric analyzer combined with FTIR and a GC-MS (TGA/FTIR/GC-MS). In addition the remaining ash from TGA was measured in energy-dispersive X-ray spectroscopy (EDX). Deposits were scraped from the used filter, and prepared for the different analytic methods. After cleaning the deposits with different solvents, GC-MS identified the traces of glycerol and sterols in the filter. After a transesterification reaction GC-MS could identify carboxylates corresponding to degraded biodiesel. The TGA/FTIR/GC-MS revealed the presence of polymeric compounds in the deposit. XRF did not require any previous cleaning, and was used to identify different metals present in the deposits. The mentioned deposits are characterized as soft particles, and could originate from the impurities of biodiesel, presence of engine oils, or degradation of the fuel. The presented results help to better understand the current concerns with the on-board filtration of fuels, and can help to create more robust fuel systems in the future.</div></div>

Solubility limitations of residual steryl glucosides, saturated monoglycerides and glycerol in commercial biodiesel fuels as determinants of filter blockages

“…In extreme cases, "soft" HPs can result in suddenly restricted or blocked fuel flows that interrupt vital transport operations or cause acute engine damage. Despite tightened US and European Union (EU) specifications adopted in (ASTM D-6751, 2012; European Committee for Standardization [CEN] 14214:2011[CEN] 14214: , 2019, concerns about precipitate formation resulting in filter blockages have continued (Cardeno et al, 2020;Csontos et al, 2019Csontos et al, , 2020Komariah et al, 2018;Na-Ranong & Kitchaiya, 2014;Plata et al, 2015) in concert with a dramatic rise in the volumes of biodiesel fuels entering the fuel supply (British Petroleum, 2020), nearly tripling between 2009-2019, globally. In the US production has increased by a factor of over 60-fold since 2004 (U.S. Energy Information Administration, 2020).…”

“…Other fuel related impurities, ostensibly originating in B100, are cited in various literature sources as contributors to blockage incidents, as well. Oxidation and thermally induced polymerization products (Ball et al, 2018;Csontos et al, 2019;Flitsch et al, 2014), fatty acid amides from certain animal derived feedstocks (Jovanovic et al, 2021;Madl & Mittelbach, 2005), and metal soaps (Cardeno et al, 2020;Chemical Research Council, 2014;Csontos et al, 2020) are mentioned. Processing, transport, and fuel storage can also add to the complexity of the impurity profile.…”

“…The polar GLY HPs also may contain residues of sodium or potassium-based transesterification catalysts and other metal carboxylate soaps that can leave an ash or carbon deposits on injectors (Csontos et al, 2019;). This deposition process can occur near hot combustion zones where temperatures often exceed 1000 C (Argachoy, 2007).…”

Development of Simplified and Efficient Sample Preparation Methods for the Analysis of Problem Material within the Diesel Fuel Delivery System

“…Recent publications have identified a number of common problematic species in blocked diesel engine fuelthese include SGs, SMGs, glycerol, metal carboxylates, and fatty acid sterol esters (FASEs) among others. ,,,, The scale of the problem is evidenced by a rise in the number of publications regarding blocked fuel filters. − ,,− In some cases, the techniques involve multiple stages that result in complex and time-intensive sample preparation steps. , …”

Comparison of Used Locomotive Fuel Filters after Using B20 and B0 Fuels

“…Testing of deposit characteristics was carried out by Csontos et al with analysis using GC-MS, XRF-EDX, FTIR, and TGA. They identi ed carboxylic acid (CA) as fuel degradation and unreacted CA from biodiesel production, oxidized polymer compounds, glycerol, sterol, other impurities, and contaminants [7,8]. Meanwhile, Barker et al identi ed the deposit or injector fouling as carbon in nature with C 16 -C 18 acid/ester [9].…”