PTQ Q2 2023 Issue

HDS-2 or, HDS-3 LH T GO

ADU-2

VDU-2

FCC PT

FCC

Euro-diesel

Blending

HDS-3 or / and HDS-5 HHTGO

ADU/VDU-1

SRLGO SRMGO SRHGO LVGO

H-Oil

Figure 1 Diesel fuel production scheme in LNB

Electrical conductivity of diesel fuel Final diesel fuel results from blending a definite per cent of light and heavy hydrotreated gasoils. Deterioration by hydrotreatment of gasoil properties can be improved by additives. LNB commodity diesel fuel consists of light, heavy hydrotreated gasoils and cetane improver, lubric - ity improver, antistatic additive, and cold flow improver for winter grade diesel. This study focuses on the electri - cal conductivity of LNB commodity diesel fuel to find dif - ferent ways to improve after HDS of gasoil fractions. As mentioned, LNB uses a typical approach for static charge of diesel fuel dissipation by applying SDA. Both winter and summer grade diesel fuels produced at LNB were evaluated. Figure 2 reveals the summer grade diesel fuel response to different SDA suppliers and SDA concentra - tion. It is obvious, and data confirm literature references, 4,5 that conductivity of ULSD is very low at 0-2 pS/m. Figure 2 results show that SDA concentration in LNB summer grade is below what is cited in4 typical values of 3-5 ppm. Two SDAs (from suppliers A and B) have the same effect (same slope of the straight lines describing the cor - relation between conductivity and SDA concentration), as every added ppm of SDA increases the electrical conductiv - ity with 143 pS/m. The third evaluated SDA (supplier C) is more effective as 1.0 ppm increases conductivity with 171 pS/m. It means that 1-1.5 ppm SDA from different suppliers can provide for summer grade diesel the required 150 pS/m at 20°C electrical conductivity, as per LNB specifications.

300 200 100 400 500 600 700 800 900

y = 170.86x R = 0.9983 y = 143.62x R = 0.9978 y = 143.1x R = 0.9996

Supplier A Supplier B, additive A Supplier C

World experience shows that adequate electrical con - ductivity, providing a relaxing of static charge and decreas - ing the possibility of fires or explosions caused by static electricity, is in the range of 50-450 pS/m.4 The same SDA was also evaluated for its effectiveness towards winter grade diesel fuel. Figure 3 presents two different LNB win - ter diesel fuels (a and b) treated with 3.0 and 3.5 ppm of SDA, respectively. These two types are blends of light and heavy vacuum gasoils (VGOs) with cetane improver, low- temperature additives (MDFI and WASA), and no SDA in order to evaluate the effect of adding the latter. Interestingly, a 3.0 ppm SDA from supplier A results in Figure 2 Electrical conductivity response of summer diesel_2020 to different static dissipator concentration 0 0.5 Static dissipator additive concentration in summer ULSD, ppm 0 5 2 4 4.5 3 3.5 2.5 1 1.5

300 200 100 400 500 600 700 800

600

500

400

300

200

100

ULSD wo SDA

Supplier A Supplier B, additive A Static dissipator additive supplier

Supplier B, additive B

ULSD wo SDA

Supplier A Supplier B, additive A Static dissipator additive supplier

Supplier C

(a)

(b)

Figure 3 Electrical conductivity response of two different winter diesel fuels to different static dissipator at concentration (a) 3.0 ppm (m/m) and (b) 3.5 ppm (m/m)

PTQ Q2 2023