Page 1 of 10

UTILIZATION OF ECAT GENERATED AT PANIPAT REFINERYIN CEMENT MANUFACTURE – LAB TRIAL AT ULTRATECH

*S.K. Chaturvedi, * D Yadav, *M.M. Ali ,**P Kasliwal, **K M Prabhu, **Brijesh Kumar **S Rajagopal, R.K Malhotra**

Anil Shukla&

National Council for Cement and Building Materials, Ballabgarh, India*

Indian Oil Corporation, R&D Centre, Faridabad, India**

M/s Ultratech Cement, Village Karad, Israna, Panipat&

ABSTRACT

The Spent Catalyst (E-Cat) is being generated as industrial waste in Indianpetroleum refineries at the rate of 15000 MT/annum. Investigations were carried outinvolving characterization of spent catalyst, its use in cement manufacture and theirleaching behavior in different curing mediums. The results of the investigations indicatethat spent catalyst waste (E-Cat) is a pozzolanic material and is very soft to grind. Thelime reactivity of as received E-Cat from Panipat refinery is 29 Kg/cm2 which increasesto 85 Kg/cm2 at the fineness of 4300 Blaine’s and to 97 Kg/cm2 at the fineness of 8400Blaine’s. The E-Cat has been found to be useful as a blending component in themanufacture of cement. Inter-grinding up to 10 percent spent catalyst with OPC clinkerhas resulted in improved cement performance. Subsequently, laboratory trials wereconducted at M/s Ultratech Ltd. Panipat at their grinding unit. The results of the lab trialsindicated that E-cat up to 5 % can be gainfully utilized along with 27% fly ash in themanufacture of cement. The results of performance evaluation indicated that the 3, 7 and28 days compressive strength were 29, 42 and 61 MPa respectively. The present paperhighlights the utilization potential of Ecat from Panipat refinery and the detailed results ofthe lab trials at M/s Ultratech Ltd. Panipat (grinding unit).

1. INTRODUCTION

Fluid Catalytic Cracking (FCC) is one of the largest secondary refining processespracticed in refineries for converting heavy feed into lighter products like LPG, gasolineand diesel. During this process, the catalyst gets rapidly deactivated due to variousreasons such as Cyclic operation between 500C in the reactor and about 700-800C inthe regenerator, presence of steam in the stripper which is responsible for reducing thecrystallinity of the catalyst and deposition of contaminant metals like Nickel, Vanadium,etc. on the catalyst particles.

In order to maintain the desired activity of the catalyst during the processing andget the required amount of cracking and the product yields, certain amount of catalyst hasto be withdrawn on daily basis and fresh catalyst has to be added. Indian FCC/RFCCunits have been generating spent catalyst (Ecat) at the rate of about 15,000 MT/annum.Use of oil cracking waste catalyst as active pozollanic material in cement mortar has beenreported by Kung-chung Shu, et al (1). Application of spent FCC catalyst as a cementkiln raw material has been reported by Simon et al (2), though exact composition and it’simpact on performance properties of cement is not reported. In order to establish thegainful utilization of Spent Catalyst, in the Cement industry and possibilities ofsubsequent leaching of heavy metals present in Spent catalyst, detailed investigations

Page 2 of 10

were carried out at NCB (3) with Ecat generated at Panipat refinery of Indian OilCorporation , The present paper highlights the utilization potential of Ecat waste in themanufacture of cement and the leaching behavior under different curing mediums.

2. CHARACTERISATION OF ECAT

The sample of Ecat was subjected to physico-chemical, and mineralogicalcharacterization. The chemical analysis of the Ecat sample from Panipat refinery indicatesthat it contains 1.64 percent LOI, 51.62 percent SiO2, 41.03 percent Al2O3 and 0.53percent Fe2O3 besides other minor impurities. The content of Ni and V was estimated tobe 0.22 percent and 0.93 percent respectively. The results of chemical analysis are givenin Table 1.

Table 1Chemical Analysis of Ecat from Panipat Refinery

Oxides % Wt%

LOISiO2Al2O3Fe2O3CaOMgOK2ONa2OSO3Cl-

TiO2NiV

1.6451.6241.030.530.740.40

-0.260.250.0071.910.220.93

The samples of Spent catalyst wase also examined using ICP technique to see thepresence of various other minor elements such as As, Ba,Cd, Co, Cr, Cu, K, Mn, Mo, Ni,Pb, Se, Sr, and Zn. The results of the ICP analysis are presented below in Table 2.

The X-Ray diffraction analysis was carried out to identify the mineral phases present inSpent catalyst. The investigations reveal that mineral phases present in spent catalyst areFaujasite, Andalusite, Mullite, Microcline, Anatase, Bayerite and Keatite. The X-RayDiffractograms of spent catalyst is given in Fig. 1 and the mineral identified along withtheir chemical formula are given in Table 3.

Page 3 of 10

Table 2Chemical Analysis using ICP for other metals, Non Metals and Transition

Metals present in Ecat from PanipatElement (%)

As 0.044Ba 0.80Cd --Co 0.012Cr 0.007Cu 0.009K 0.054

Mn 0.008Mo -Pb --Se 0.22Sr 0.008Zn 0.009

FIG. 1 : XRD PATTERN OF ECAT FROM PANIPAT REFINERY

Table 3Details of Mineralogical Analysis using XRD Technique

Spent catalyst XRD ANALYSISPanipat refinery Faujasite, Andalusite, Gehlenite, Bayerite, Microcline,

Anatase

The samples of spent catalyst were investigated under NIKON POL 600E Microscope inTransmitted light to study the Morphological features , Mineral phases, their grain sizesand their distribution . The investigation revealed that the sample is very fine grained innature. The Optical microscopy observations are given in Table 4 and the opticalmicrographs of Ecat from different refineries are shown below in Plate 1.

Page 4 of 10

PLATE 1: Panipat refineryOPTICAL MICROGRAPH OF SPENT CATALYST SAMPLES

The optical microscopy investigation revealed that most of the grains (glassy, semi glassyand non glassy grains) are rounded to sub rounded in shape with corroded grain margins.These grains are mostly clusters of numerous micrograins, which too are rounded inshape. These grains are highly perforated and brittle in nature. Quartz, zeolite andplagioclase grain are also present as tracers. The Optical microscopy analysis is given inTable 4:

Table 4Details of Grain sizes Analysis using Optical Microscope

Spent catalyst from Panipat refineryTypesof grains

GrainsizesMin. 1Max. 104Non

Glassy Grains Avg. 49Min. 3Max. 108Semi

Glassy Grains Avg. 39Min. 2Max. 96Glassy

Grains Avg. 42

The physical characterization revealed that the specific gravity of Ecat as received is2.53. The lime reactivity of as received Ecat is 29.07 Kg/cm2 which increases to 58.60Kg/cm2 at the fineness of 3140 Blaine’s, to 85.06 Kg/cm2 at the fineness of 4320 Blaine’s.The lime reactivities at different finenesses are given in Table 5.

Page 5 of 10

Table 5Physical Characteristics of Ecat

Spent CatalystProperties PanipatSpecificgravity As received 2.53

As received 29.07At 3150 + 50 58.60At 4350 + 50 85.06

Limereactivity(Kg/cm2)

8400 97.26

3. UTILISATION OF SPENT CATALYST IN CEMENT MANUFACTURE

In cement manufacture, the siliceous industrial waste and by products havingcompatibility with clinker in terms of their lime reactivity conforming to IS 1344 -1981 isknown to be used as blending component. A material having lime reactivity of 40 kg/cm2

is considered acceptable for use as blending component in cement manufacture. In fact,the Ca(OH)2 released during hydration of calcium silicates viz. the clinker mineral phasesis assimilated by the additional silica available from the blending components in theformation of calcium silicate hydrates ( C-S-H ) responsible for cement strength.Therefore cement containing pozzolanic additions often result in improved performance.Besides contributing to C-S-H phase formations, the blending components also providefiller effect in the cement matrix because of wider range of size gradations which alsohelps in improving the performance at lower level of additions.

3.1 Experimental Procedures

The experiment was designed to replace clinker by spent catalyst in the range of 1 - 25percent by weight. Seven cement blends for each refinery spent catalyst including twocontrol cement, namely OPC-1 and OPC-2, were prepared in the laboratory ball mill byinter grinding all the components. The details of various inter ground cement blendsprepared are given in Table 6. Samples thus prepared were studied for the physicalperformance such as fineness, setting time, consistency, compressive strength andsoundness.

Table 6Weight Composition of Interground Cement Blends

Weight Composition of various materials ( % )Blend No. Clinker Gypsum Spent Catalyst

Cement Blends prepared from E-Cat of Panipat RefineryP-0 95 5 NILP-1 94 5 1P-2 90 5 5P-3 85 5 10P-4 80 5 15P-5 75 5 20P-6 70 5 25

Page 6 of 10

3.2 Performance evaluation of cement blends3.2.1 Cement blends prepared using E-cat obtained from Panipat Refinery3.2.1.1 Control OPC

The control OPC was prepared using clinker and gypsum as per details given in Table 6 .The fineness levels of the control OPC was kept at 3200 + 100 cm2/g. The performanceevaluation of control OPC was carried out as per relevant IS procedures. The results ofthese evaluations are given in Table 7. The results indicate that the 3,7 and 28 daysstrength of control cement are 350, 365 and 454 kg/cm2 respectively. The initial and finalsetting times are 118 and 175 minutes. The Le-chatlier expansion is 3.5 mm.

Table 7Performance Evaluation of control cement

Properties ValuesFineness cm2/gm) 3200

Consistency (%) 25Setting Time (minutes) IST

FST118175

Comp. Strength (kg/cm2)3d7d28d

350365454

Soundness Autoclave (%)

Le-chatelier (mm)0.043.505

3.2.1.2 Cement blends containing Panipat Ecat

The results obtained indicate the addition of E-Cat has varying effect on the strengthdevelopment characteristics of different cement blends. The interpretation of 3 daystrengths of various cement blends containing 1,5,10,15,20 and 25 % E-Cat by weightindicate a remarkable gain in initial strengths of cement mortar when compared withcontrol cement upto 10 % addition level and at 15 % addition level the strength remainsmore or less in similar range as that of control cement

Page 7 of 10

Table 8Performance Evaluation of Cement Blends Containing E-Cat from

Panipat Refinery

Beyond 15 %, there is a decrease in 3 days strength at all the two levels i.e. 20 and 25 %.The strength development at 7 days follows more or less similar trend except that thedecrease in strength starts at 10 % level. Since the 28 days strength results are awaited,but looking at the trend of strength development is considered that that E-Cat upto 15 %can be added during clinker/gypsum inter-grinding and the cement blends meets therequirement of IS 1489 (part 2): 1991 for Portland Pozzolana Cement (calcined claybased)

4. LAB TRIALS AT ULTRATECH

Lab scale trials were carried out at the quality control laboratory of M/s ULTRATECHltd. Panipat. For the purpose of conducting trials, E-cat from Panipat refinery of IOC wereprovided to plant. Since M/s ULTRATECH is manufacturing Portland Pozzolana Cementat present, it was considered appropriate to see the effect of addition of 5 % E-cat duringclinker grinding on the performance of the resultant Portland Pozzolana cement blends.The clinker, gypsum and fly ash as available at the plant were used during lab trials. Thechemical analysis of clinker, purity of gypsum, flyash and Ecat as used during the trialsis given in Table 9.

P-1 P-2 P-3 P-4 P-5 P-6Properties

E-Cat1 %

E-Cat5 %

E-Cat10 %

E-Cat15 %

E-Cat20 %

E-Cat25 %

Fineness (cm2/gm) 3100 3222 3251 3134 3230 3220Consistency (%) 25.4 26.8 28.8 30.4 31.6 33.8Setting Time (Min.) IST FST

120178

105167

98180

93146

79129

82140

Comp. Strength(kg/cm2)

3d7d28d

320389467

313381464

265325441

231180372

185261366

149194304

SoundnessAutoclave (%)

Le-chatelier (mm)0.122.0

0.102.0

0.101.5

0.151.0

0.031.0

0.0011.5

Page 8 of 10

Table 9Chemical Analysis of Clinker, Gypsum, Fly ash and E-cat used during Lab Trials

Oxides % Clinker Gypsum Fly ash E-catLOISiO2Al2O3Fe2O3CaOMgOK2ONa2OSO3Cl-

TiO2NiV

Free Lime

0.1920.644.864.2261.844.52

--

1.120.05

---

1.10

--------

23.72-----

1.1657.8623.555.740.210.860.800.310.250.016

----

1.6451.6241.030.530.740.40

-0.260.250.0071.910.220.93

The experiments were designed using clinker, gypsum, fly ash and E-cat and the weightproportions of these materials are as given in Table 10 below:

Table 10Weight proportions of clinker, gypsum, fly ash and E-cat used during trials

Sample code Clinker%

Gypsum%

Fly ash%

E-cat%

BM-01 65.0 5.0 25.0 5.0BM-02 64.0 5.0 29.0 2.0BM-03 63.0 5.0 27.0 5.0

These materials were used in preparation of cement blends and the critical qualityparameters of these blends are as given in Table 11 below:

Table 11Critical quality Parameters of various Cement Blends containing E-cat

Sample code Blainefineness(m2/kg)

LoI %

CaO%

MgO%

SO3%

Insolubleresidue

%BM-01 424 0.85 39.32 2.56 2.61 28.87BM-02 372 0.70 39.62 3.73 2.56 29.32BM-03 372 0.93 41.36 3.76 2.47 29.14

The above cement blends were evaluated for their physical performance and the resultsare as summarized under:

Page 9 of 10

Table12Performance Evaluation of Cement Blends containing E-Cat

5. RESULTS AND DISCUSSIONS

Lab trials conducted at M/s ULTRATECH ltd. Panipat indicated that E-cat addition has apositive effect on the performance of the resultant cement blends. The comparison ofcement blends namely, BM-1 and BM-3 indicated that while maintaining similar additionlevel of E-cat and water of consistency, the 1 and 3 days compressive strength isimproved even at reduced level of fineness. While 7 days strength improved marginallyfrom 41.50 to 41.80, the 28 days compressive strength reduced by 2 MPa from 63.20 to61.20, which is attributed to reduced level of fineness in BM-03. The strengthdevelopment characteristics indicated that the cement blend BM-01 and BM-03, both arecapable of producing good quality of cement blends but considering fineness levels,cement blend BM-03 is preferable. BM-03 is also preferable from the point of view ofusing reduced level of clinker utilization by 2.0 % as compared to that of BM-01. In caseof BM-02, the addition level of E-cat is 2.0 percent and the fly ash level is at 29.0 %, thecompressive strength development at all ages is reduced when compared to that of eitherBM-01 or BM-03 and therefore the same if not preferable.

The above results indicate that the addition of spent catalyst upto a level of 5 % ishaving a positive effect on the setting and strength development characteristics of thecementitious system containing 27.0 % fly ash. The phenomena caused catalytic reactionsby way of increasing the hydration product development, thereby providing a higher gelsurface area and also by filling gel voids, which reduce the porosity and resulted in higherearly strength. From the interpretation of the performance evaluation results of variouscement blends it is clear that 5.0 % by weight of spent catalyst can be added at theclinker grinding stage in the manufacture of Portland Pozzolana cement.

BM-01 BM-02 BM-03Properties

E-Cat5 %

E-Cat2 %

E-Cat5 %

Fineness (cm2/gm) 4240 3720 3720

Consistency (%) 29.50 29.50 29.50

Setting Time (Min.) IST FST

155225

255320

170240

Comp. Strength(kg/cm2)

1d3d7d28d

14.6028.6041.5063.20

13.2026.9038.4058.30

15.8029.3041.8061.20

Page 10 of 10

6. CONCLUSIONS

Based on the lab trial results, the following conclusions are drawn:

1. E-cat as generated from Panipat refinery of IOC is possessing adequate limereactivity which increases upon finer grinding.

2. 5 % addition of E-cat during clinker grinding stage results in improvedcompressive strength characteristics at all ages upto 28 days in case of cementblends containing clinker, gypsum and E-cat.

3. Lab trials conducted at M/s ULTRATECH Panipat indicated that addition of 5% E-cat in Portland Pozzolana Cement also resulted in comparableperformance of cement blends containing clinker, gypsum, Fly ash and E-cat,even at reduced level of cement blend fineness with 2 % reduced use ofclinker.

7. ACKNOWLEDGEMENT

The authors have freely drawn the information/data from published literature and NCB/Indian Oil Corporation R&D project reports. This paper is being published with thepermission of the Director General, National Council for Cement and Building Materials,Ballabgarh, India and Director of Indian Oil Corporation, R&D Centre, Faridabad, India.

8. REFERENCES

1. Kung-Chung Hsu, Yun-Sheng Tseng, Fan-Feng Ku, Nan Su; “Oil crackingcatalyst as an active pozollanic material for superplasticized mortars”, Cement andConcrete Research, 31 (2001), pp 1815-1820.

2. William C. Simon et al, Symposium on regeneration, reactivation and reworkingof spent catalysts, 205th meeting of ACS, Denver, CO, March 28, 1993.

3. S.K.Chaturvedi, S. K. Agarwal, M.M.Ali, K.M.Sharma, K.Mohan, P.Kasliwal andS.K.Shah,“ Utilisation of spent catalyst waste from petroleum refineries in cementand Ceramic industries”, 9th NCB International Seminar, Nov’2005, New Delhi.

4. S.K. Chaturvedi, D.yadav, B.Rani, M.M.Ali, P.Kasliwal, M.Prabhu, S.K.Ray,Brijesh Kumar and S. Rajagopal,“Utilisation of spent FCC/RFCC catalyst incement manufacture and leaching behaviour of heavy metals”,12th NCBInternational Seminar, Nov’2011, New Delhi.