IN BRAZIL KUNIYUKI TERABE ** MECHANICAL ENGENEER ABSTRACT. according to estimates made by U.S. the PETROSIX Process has produced

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1 PR CEP 635 OIL SHALE INDUSTRIALIZATION IN BRAZIL ALTAIR R. DURSKI BATISTA * CHEMICAL ENGINEER CHIEF OF OIL SHALE SECTOR KUNIYUKI TERABE ** MECHANICAL ENGENEER CHIEF OF PROCESS DIVISION ABSTRACT Brazil has abundant oil shale resources, about 120 billion t.o.e (tonnes oil equivalent) oil according to estimates made by U.S. Geological Survey. The most important deposit oil shale is Irati Formation, Permian origin, that forms a part Paleozoic sediments Parana basin. It is located in South Brazil. Brazil is a country that invested continuously more than 500 million dollars on shale technology those last 34 years, mainly in development PETROSIX Process. A semicommercial plant using PETROSIX Process has produced more than 370 thousand t.o.e. shale oil, 35 thousand tonnes sulfur and operated continuously more than 95 thousand hours, achieving today an operating factor 94 per cent. A commercial plant, having a 11 m diameter PETROSIX Retort is being erected to produce from tonnes shale oil, 43 metric tonnes LPG, 70 metric tonnes fuel gas and 65 metric tonnes sulfur by processing t/d oil shale. Besides PETROSIX Process, used to retort coarse particles oil shale, PETROBRAS are developing or kind processes to retort oil shale fines, using entrained bed and spouted bed concepts, and to burn spent shale using circulating fluidized bed concepts. * Current adress: Petroleo Brasileiro S.A. DEPIN/DIFEA/SEXIS Av. Republica do Chile, 65 Rio de Janeiro Brazil ** Current adress: Superintendencia da Industrializacao do Xisto SIX Rodovia BR 476 Km Sao Mateus do Sul BRASIL

2 INTRODUCTION Brazil is well endowed in indigenous energy resources like hydroelectricity, oil shale, coal, nuclear fuels and biomass. Hydropower and wood (including charcoal) presently play a significant role in country's energy supply. The limited reserves crude oil relative to demand still constitute Brazil's major problem. Proven recoverable crude oil reserves in Brazil have practically tripled from 118 million t.o.e in 1970 to 299 million t.o.e in Most increase reserve came from fshore oil exploration. The measured reserves oil shale are 9 billion t.o.e. oil and 2.6 billion t.o.e gas. Brazil posses second largest resource oil shale in world with an estimate 120 billion t.o.e. oil. Hydropower resources is estimated in 27 million t.o.e/year potential electricity generation. Coal resources 2 billion t.o.e are classified as measured. Uranium resources are estimated at tonnes U308, equivalent to 2,1 billion t.o.e. Biomass supply 37% primary energy in Brazil with a production 23 million t.o.e sugarcane and 31 million t.o.e. forest product in Production fuel alcohol amounted to 6 million t.o.e in Natural gas measured reserves stood in order 85 million t.o.e in Brazil's consumption petroleum products (excluding fuel alcohol) amounted to 51 million t.o.e. in Crude oil production amounted for 34 million t.o.e. Shale oil and gas production amounted for 55 thousand t.o.e. All petroleum activities, including oil shale, in Brazil are carried out by or are under control State entities. The key institutions in petroleum sector are Ministry Mines and Energy (MME), National Petroleum Council (CNP) that regulates all petroleum activities and Petroleo Brasileiro S.A. (PETROBRAS) that is executing agency.

3 OIL SHALE ACTIVITIES IN BRAZIL Brazil's oil shale activities started between 1884 and 1949 when some small oil shale industries have been installed and operated by private companies. Since 1954 PETROBRAS oil shale Division (SIX) has been developing a methodical work on geological exploration oil shale, on research retorting processes and on processing oil shale. A scaleup program was established to select process to be used for retorting brazilian oil shale. PETROSIX concept basically emerged from idea to set apart operations retorting and combustion in different vessels. Preliminary economic evaluation on use this new process, at early time, for retorting Irati oil shale showed feasibility even without burning retorted shale. PETROSIX retorting results on pilot retort show yields as high as 115% based on Fischer assay. The semicommercial plant called in Portuguese Usina Prototipo do Irati (UPI), having a 5,5 m diameter PETROSIX Retort, started operation in The optimum throughput for Irati oil shale in this retort is 2,750 kg/h.m2. In 1982 was decided to first build a complete single industrial module, using a 11 m diameter PETROSIX retort, designed to produce "400 m3/d shale oil using deposit Irati oil shale in Sao Mateus do Sul with an average oil content 7,5% based on Fischer assay. This industrial plant, currently 70% erected, is located in same site semicommercial plant reby utilizing existing infrastructure and same oil shale mine. See photograph n9 1.

4 638 PHOTO 1 SEMICOMMERCIAL PLANT (RIGHT) 3. The six integrated an is The pieces shown heater for AND INDUSTRIAL MODULE (BACK) PETROSIX Process gravity moving bed external pyrolisis process principal a (CENTRE) PETROSIX TECNOLOGY PETROSIX Process retorting and MINE oil equipments heating shale into coarse comprises which retort. gas The set incorporates particles recycling a oil that scheme promotes RAW SHALE CONDENSER \ fx) PRECIPITATOR CYCLONE BLOWER PYROLYSIS OAS OIL? WATER RETORTED SHALE shale, in figure 1. IRATI OIL SHALE PETROSIX PROCESS FLOW DIAGRAM FIG. I

5 Feed 639 Pyrolisis releases organic material (kerogen) oil shale contains in form oil and gases. A high temperature stream gas (hot recycle) coming from gas heater and pushed by a recycling compressor enters retort at mid level. There, it is mixed with a second, colder stream, injected at bottom retort (cold recycle). The cold recycle recover residual heat from oil shale which has already been retorted. Those two gas streams are produced in process, comprising mainly shale oil vapor, gases and steam (from moisture and clay water oil shale contain). The upflowing mass gases exchanging its heat with descending bed oil shale condenses oil as a finely divided mist. The mist is collected in cyclones and electrostatic precipitators and constitutes heavy oil fraction. The mistfree gas is compressed into three different streams. One stream returns to bottom retort as cold recycle. The second is hot recycle that returns to mid level retort. The remainder flows to condenser where light oil is recovered. The effluent gas from condenser n flows to a DEAClaus plant, for fuel gas sweetening and sulfur recovery. The retorted shale is removed from bottom retort through a hydraulic sealing system after cooling and subsequently is conveyed to tailings. The Semicommercial PlantUPIPlant facilities include a number integrated units which now process 1,600 metric ton per day oil shale, yielding 120 ton shale oil, 16 metric ton sulfur and 35 metric ton high BTU fuel gas per day. It is located in city Sao Mateus do Sul, State Parana, South Brazil. The units are as follows: The Mine Two nearly horizontal uniform layers oil shale are removed by shovels that load trucks and overburden and intermediate layer are removed by an electric walking dragline. The retorted shale is deposited in mine pit area and is covered over with natural soil and revegetated. The Solids Handling for retort constituted particle size range 0,6 cm to 7,5 cm screening. is prepared using two crushing stages and

6 .ffftr M0.... _. _. Remove 640 The Retorting Comprises series PETROSIX process equipment with a 5,5 m diameter retort. Dessulfurization Gas and Sulfur Recovery sulfur compounds (H2S) from retorting gas producing fuel gas and recovers elemental sulfur. Since 1972 this semicommercial plant operated more than 95,000 hours presenting uninterrupted runs longer tham 5,800 hours. Current plant operating factor is controlled between 92% and 95%. Maintenance schedule include one shutdown 3 weeks per year. Improvement UPI operation can be seen in Fig. 2 ioo FIG.2 PETROSIX SEMIWORKS PLANTUPI OPERATING FACTOR i 80 tr o O < "60 W COMMERCIAL OPERATION 15 ac 40 ^w uj a. o IOO T I M E N TH ( ^COMPUTED 17 DAYS OF DISCONTINUOUS WORK DUE TO FLOOD The curve exhibits 4 distinct stages. The second stage between 20 th and 80 th months was spent in changing mainly aerodynamics PETROSIX retort to improve its throughput and efficiency. The third stage between 80th and 100th months was spent operating plant to obtain design basis for industrial plant. The last stage is operation plant in a commercial basis. The Industrial Module This industrial plant is located at same site UPI facilities reby using existing infrastructure.

7 641 The industrial module was designed for a nominal capacity four times that UPI, using one PETROSIX retort 11 m diameter. Operation this plant is sheduled for year The total capital investment to erect Industrial Module is estimated in 80 millions U$ dollar. The complex formed by industrial module and UPI has a nominal production capacity 3750 barrels shale oil per day, 43 metric ton LPG, 70 metric ton fuel gas and 65 metric ton sulfur per day. 4. RESEARCH AND DEVELOPMENT The UPI facilities also comprise one complete PETROSIX pilot plant with 2/3 ft retort diameter and a PETROSIX Demonstration plant with 6 ft retort diameter. Those two plants are used to test application PETROSIX process to a different oil shale. To study retorting oil shale fines a pilot plant using a vertical entrained bed reactor indirected heated has been in operation sine And a pilot plant using concept spouted bed reactor with one foot diameter is also operating since december A pilot boiler is being erected using a circulating fluidized bed combustor to burn retorted shale and oil shale fines. 5. ENVIRONMENTAL PROTECTION STUDIES While developing industrialization oil shale, it was carried out a number studies aiming at ensuring that environment shall suffer lowest possible impact. Leaching retorted shale disposed at mining site was studied to identify substances that may be leached out by percolating water. These studies permited definition mining scheme. Now is being made an inventory native animals and plants lives region, aiming to reitroduction se species in revegetated areas in mine. 6. OIL SHALE DEPOSITS In Brazil, oil shale resources have been found in many states Such as shown in fig. 3.

8 642 FIG. 3 BRAZILIAN OIL SHALE OUTCROPS I PERMIAN SHALES OF IRATI FORMATION 2 TERTIARY SHALES OF SAO PAULO 3 CRETACEOUS SHALES OF BAHIA 4 PERMIAN SHALES OF BAHIA 3 CRETACEOUS SHALES OF ALA60AS 6 CRETACEOUS SHALES OF CEARA 7 CRETACEOUS SHALES OF MARANHAO 8 DEVONIAN SHALES OF CURUA FORMATION The Irati Formation, Permian origin, is largest known shale oil deposit in Brazil. The outcrop runs from state Sao Paulo in Brazil to Uruguai over a distance aproximately 1500 kilometers. 7. CONCLUSION Tanks to all technological development, from Brazilian oil shale, PETROBRAS today has a mastery technique to prit our and foreign oil shale.