AUTOMATIC WATER DISPOSAL FOR HEAVY DUTY AND … · drained water during the ISO 16332 water separation test for different fuel-water-separators during 2015-2018. The tests were run

AUTOMATIC WATER DISPOSAL FOR HEAVY DUTY AND

INDUSTRIAL APPLICATIONS – REMOVAL OF HYDROCARBONS TO

ENSURE ENVIRONMENTAL PROTECTION

Lars Spelter*, Jens Neumann

MANN+HUMMEL GmbH, Schwieberdinger Str. 126, 71636 Ludwigsburg

ABSTRACT

Modern fuel injection systems need to be protected from particles and water, causing

wear on the system. A state-of-the-art fuel-water separator can reliably ensure a high

purification by using multiple stages. The separated water is temporarily stored in

collection space and needs to be drained regularly.

A fully automatic drain system removes the water when the sensor detects a certain

level in the water collection chamber. Since the drained water is usually not collected

automatically (e.g. in an extra tank), it should be cleaned prior to the release into the

environment. A suitable adsorber removes the HC from the water phase.

The water that is separated by the fuel-water separator can be either clear or turbid.

Whilst low additivated fuels usually lead to a clear water phase, an ultra-low sulfur

diesel (ULSD) contains a high amount of additives and the drained water will be turbid

due to the formation of a diesel in water emulsion. Why is this important? The solubility

limit of diesel in water is reasonably low, approximately < 10 mg/l acc.

DIN EN ISO 9377-2 H53 but an emulsion contains in average > 200 mg/l HC with

levels up to > 2500 mg/l.

Activated carbon (AC) is the commonly used material in either systems that are already

running on the street or are in a concept status, but only little evidence is found in the

literature that activated carbon is actually suitable for this application. Experiments

show that AC is well suitable to reduce the dissolved HC content to < 0.2 mg/l but not

in the case when an emulsion is present as shown in figure below.

It is evident that no type of activated carbon is able to remove the HC from the water,

although the amount of emulsion, fed through the adsorber, was only 400 ml. Only the

Organoclay was able to remove the HC to a level < 2 mg/l which is considered as a

target value for safe disposal.

0,1

1,0

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100,0

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Upstream Blank value AC 1 AC 2 Organoclay

HC

co

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DIN

EN

ISO

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FILTECH 2019 - L19 - Liquid/Liquid Separation

FILTECH 2019 - 22-24 October - Cologne - Germany

Automatic water disposal for heavy duty and industrial applications

– removal of hydrocarbons to ensure environmental protection

Lars Spelter*, Jens Neumann

MANN+HUMMEL GmbH, Schwieberdinger Str. 126, 71636 Ludwigsburg

Modern fuel injection systems need to be protected from particles and water, causing

wear on the system. Whilst particles cause abrasion inside the injector and high-

pressure pump, water can lead to abrasion due to cavitation and to corrosion.

Therefore the particles and water needs to be removed from the fuel.

A state-of-the-art fuel-water separator can reliably ensure a high purification by using

multiple stages. First, the particles are removed by a filter medium. In the second stage,

the small water droplets are passing through a coalescer which results in coarse

droplets that can be separated by gravity. The third and last stage is a hydrophobic

barrier, preventing the droplets being dragged with the flow onto the clean side. The

separated water is temporarily stored in a collection space that could be a transparent

bowl on a spin-on filter cartridge or a volume inside a fuel filter module.

There are different possibilities to drain the water and for disposal as shown in figure 1.

The most commonly used method to remove the water from the collection space is the

manual drain, operated by the driver of the vehicle. A drain screw is opened and the

water is removed.

Figure 1: Different possibilities to drain separated water

A step towards automatization is the semi-automatic drain, in which the driver is

informed about the necessity to drain the water. Once the vehicle is at standstill and

Removal of water by taking water for particulate filter

regeneration from water bowl:

• E.g. regeneration of exhaust particulate filter each 20000 km:

200 ml water and > 3 L of fuel

• In case water level reaches maximum before regeneration is

necessary, it can be automatically disposed via the exhaust.

Cleaning of the water before disposing in the environment:

• Limit for hydrocarbons from the legislation point not regulated

• Cleaning by adsorption reduces contamination below 2 mg/l

• Responsibility of disposal: vehicle manufacturer

• Service of adsorber to be considered

Manual drain by driver or garage:

• Currently most popular system

• Responsibility of disposal: end customer

Diesel,

particles &

water

Clean Diesel

Water,

contaminated

with

hydrocarbons

(HC)

HCHCHC

Com

ple

xity o

f te

chn

olo

gy a

nd

cost



the engine switched off, the drain is activated by pressing a button in the vehicle. Both

methods, the manual and semi-automatic drain have a disadvantage: The water needs

to be collected and safely disposed because it is contaminated with hydrocarbons

(HC), coming from diesel fuel.

A smart way to automatically dispose the water is via the diesel dosing system used to

regenerate the particle filter of the vehicle. At a regeneration cycle, first the water enters

the exhaust which is negligible regarding the influence on the temperature and

emission and afterwards the diesel, which heats up the catalyst to burn the soot. The

advantage of this disposal is the avoidance of any additional mechanical or electrical

parts. In case the capacity of the water reservoir is reached in between two

regeneration cycles, the water can be drained through the dosing system without

starting the regeneration process. By doing so it is ensured, that there is always

sufficient capacity for water during the vehicle operation.

A fully automatic drain system that is independent of the exhaust emission treatment

system removes the water via a drain valve when the sensor detects a certain level in

the water collection chamber. Since the drained water is usually not collected

automatically (e.g. in an extra tank), it should be cleaned prior to the release into the

environment although there is no clear legislation for this case. A suitable adsorber

removes the HC from the water phase.

For the choice to the adsorber material it is important to know the kind and amount of

impurities that need to be removed. The water that is separated by the fuel-water

separator can be either clear or turbid. The reason lays within the used fuel: Whilst low

additivated fuels usually lead to a clear water phase, an ultra-low sulphur diesel (ULSD)

contains a high amount of additives and the water will be turbid due to the formation of

a diesel in water emulsion, containing highly stabilized and small diesel droplets. Why

is this important? The solubility limit of diesel in water is reasonably low, approximately

< 10 mg/l acc. DIN EN ISO 9377-2 H53, but an emulsion contains in average

> 200 mg/l HC, with levels up to > 2500 mg/l. Figure 2 shows a documentation of

drained water during the ISO 16332 water separation test for different fuel-water-

separators during 2015-2018. The tests were run using standard EN 590 fuel from a

gas station with the fuel only being used once. After the test the fuel is discharged. The

reason for the requirement of single use is the removal of additives during the test by



the water and filter medium. With multiple use of the diesel, the concentration of

additives is reduced which leads to better water separation results. This multiple-use

is not according field conditions (the diesel is burned by the engine and refuelling brings

always new additives) so single-use is necessary for realistic testing. The data shown

in figure 2 contains MANN+HUMMEL and competitor fuel-water separators. In all

cases a turbid water phase was observed. Based on this experience it is necessary to

develop and establish an adsorber material that is capable of cleaning such turbid

water. Considering a clear water phase with dissolved hydrocarbons is not reflecting

the real field conditions.

Figure 2: Occurrence of a turbid water phase during the ISO 16332 water separation

test

Activated carbon (AC) is the commonly used material in either systems that are already

running on the street or are in a concept status. Since several years, various

developments regarding automatic drain systems describe that material as adsorber,

but without the proof of function. Only little evidence is found in the literature, that

activated carbon is actually suitable for this application. The presentation shows details

about a novel adsorber material in comparison to activated carbons used to clean up

the water prior to disposal.

To be able to test the cleaning performance of a complete system as close as possible

to the field, a new test rig was developed and build by MANN+HUMMEL, see figure 4.

The emulsion is created by an ULTRA-TURRAX (2 l batch) with up to 5 l being used

for one test, see figure 3.

0

1

1 = Diesel in water emulsion0 = Clear water



Figure 3: Emulsion formation

By using the ULTRA-TURRAX it is possible to create an emulsion with a similar droplet

size distribution as it was determined in the emulsion created during the ISO 16332

water separation test. The concentration was set between 500 and 1000 mg/l diesel to

simulate heavily contaminated water.

The emulsion is stored in a stirred feed vessel and fed by over-pressure through the

adsorber, simulating the pressure in the low-pressure fuel circuit of the vehicle. The

flow rate is set by a needle-valve, the flow itself is started and stopped by a magnetic

valve. During the test the temperature is constant at room temperature. Tests at

elevated temperature showed a faster adsorption process (caused by the faster mass

transport), so that lower temperatures are considered as more critical.

Figure 4: Test setup

DI Water

Diesel

D/W Emulsion

Pressurized air supply

Valve

Adsorber

Scale

ULTRA-TURRAX

Treated water

Flushing/sampleFlushing/sample

D/W Emulsion

P

DI Water

Diesel

D/W Emulsion

Pressurized air supply

Valve

Adsorber

Scale

ULTRA-TURRAX

Treated water

Flushing/sampleFlushing/sample

D/W Emulsion

P



A cylinder contains the granular adsorber and the treated water is collected in a sample

flask. The flask itself is on a scale to that the drain cycles can be monitored (number

of cycles and amount of water drained per cycle). The treated water is then analysed

by means of TOC or DIN EN ISO 9377-2 methods. Prior to the tests the blank value is

tested to ensure reliable test results. The blank value is with < 0.5 mg/l at the detection

limit if the DIN EN ISO 9377-2 using a sample volume of 400 ml.

Activated carbon is well suitable to reduce the dissolved HC content from e.g. 5 mg/l

to < 0.2 mg/l, leaving only clear water. This behaviour has been evaluated using a feed

water with dissolved diesel only instead of an emulsion. However, once an emulsion is

present, the AC cannot reduce the concentration of HC effectively as shown in the

figure 5.

Figure 5: HC emulsion removal efficiency for different materials

It is evident that no type of activated carbon is able to remove the HC from the water,

although the amount of emulsion, fed through the adsorber, was only 400 ml. Only the

Organoclay [1] was able to remove the HC to a level < 2 mg/l, which is considered as

a target value for safe disposal. The reason for the poor cleaning performance of the

activated carbon is the effect of pore blinding of the carbon particle surface [2]. The

diesel molecules block the outer pores of the hydrocarbon, preventing the diffusion of

diesel molecules inside the structure of the carbon. Therefore the high inner surface of

0,1

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Upstream Blank value AC 1 AC 2 Organoclay

HC

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the adsorber cannot be facilitated. In contrast to this behaviour, the inner, layered

structure of Organoclays is accessible for the contaminants. Consequently the

cleaning performance and storage capacity for diesel is significantly higher.

Based on the experimental work a prototype has been developed that can be mounted

directly at the vehicle or at a fuel filter module. The different components of the

prototype are shown in figure 6.

Figure 6: Prototype for the water treatment using Organoclay, quick service concept

The Organoclay-granulate is contained in a cylindrical cartridge, the flow is from bottom

to top to avoid channelling and to ensure a sufficient de-aeration. A filter media is used

to hold back the granulate inside the cartridge. The HNBR foam compensates the

volume increase in the case of icing, similar to the compensation-elements used in

Urea-filters (AdBlue). The cartridge can be serviced from top, in the same direction as

the filter element of a fuel filter module. Solutions for the service from bottom are

possible.

Literature

[1] - Alexandre, Ferreira, Neumann, Spelter – 2019 – Obtenção de argila organofilica

e estudo de sua aplicação na adsorção de hidrocarbonetos emulsificados em agua,

XXVIII Encontro Nacional de Tratamento de Minérios e Metalurgia Extrativa Belo

Horizonte-MG

[2] – Alther – 2002 – Using organoclays to enhance carbon filtration, Waste

Management, Volume 22, Issue 5, Pages 507-513

Adsorber:

Organoclay

Outlet

InletHNBR foam to

compensate for icing

Service from top

Filter media to hold

back the granulate



Documents

AUTOMATIC WATER DISPOSAL FOR HEAVY DUTY AND … · drained water during the ISO 16332 water separation test for different fuel-water-separators during 2015-2018. The tests were run