The Project

  Calcined Coke Demand Sectors

  Expected Markets

  Raw Material

  CPC Production Technologies

  Rotary Kiln

  Shaft Kiln

  Rotary Hearth

  Calcined petroleum Coke Quality

  Impact of Coke properties on Anode properties

  CPC bulk density

  Metals

  High Sulfur

  ADVANTAGES OF VERTICAL-SHAFT VS ROTARY KILNS

FOR CALCINING PETROLEUM COKE

  Product quality

  Process Advantages

  Lower Capital Costs

  The Process

  Green Coke ship Unload

  Green Coke Distribution on Kiln

  Calcination

  Coke Cooling

  Calcined Coke

The Projectintends to engineer, build and operate a Shaft Kiln Calciner to produce 500?000 metric tons per year of Calcined Coke (CPC). will be a new addition to the petrochemical, chemical and mineral industry and Saudi?s first Calciner that will provide a consistent high quality feedstock for the coming Aluminum industry in the kingdom of Saudi Arabia and the region. 

Calcined Petroleum Coke ?CPC? Demand Sectors Total world demand for Calcined Petroleum Coke in 2006 was 16.0 million metric tons, rising to approximately 23 million tons in 2012. The CPC demand sectors are aluminum, titanium dioxide, needle or graphitized electrodes coke, recarburizer, and other specialty markets. CPC is used also as a carbon source in a variety of other specialty applications, including corrosion prevention of metallic structures, in silicon carbide manufacture, refractory furnace linings, refining, deoxidizing agent in the glass industry, filtration agent in water purification, and cored wire production.Aluminum production is the primary driver for worldwide CPC production and the largest CPC demand sector, comprising approximately 85% of the world?s CPC demand. Calcined petroleum Coke?s major use is in the aluminum industry for the production of pre-baked carbon anodes used in the smelting process. There are over 200 smelters in 44 countries of the world, with a total primary aluminum annual capacity of roughly 37.3 million MT in

2006. Of these, China has over 100 smelters.Between 2007 and 2015, primary aluminum production increases are forecast for all regions, with the largest percentage increase in the Middle East (228%), followed by Africa (108%), Eastern Europe/CIS (88%), and China (65%). It is expected that by 2015 the Middle East production will reach 5.0 Million Tons/year and by the year 2020, the global Aluminium production will reach 70 million tons, with China?s share of production rising to 50 %. In terms of petroleum coke resources required to make this amount of aluminum, over 28.1 million MT of Calcined Petroleum Coke and 35.6 million MT of Green Petroleum Coke would be needed in 2020. The principal goal of all anode processing steps is to produce homogeneous anodes with properties that will meet the requirements concerning performance in the electrolysis cell. These requirements can be summarized as follows:  High electrical conductivity of the anode  High mechanical strength of the anode  Low carbon consumption: low CO2 & air reactivity  Sufficient purity to avoid contamination in the metal & emissions of SO2 All smelters require very stringent CPC quality with excellent physical and chemical properties, i.e. high density, low electrical resistance, low CO2 and air reactivity and chemical properties that meet smelters metal quality strategy. 

Expected Markets  Aluminum production in the Middle East region is projected to grow from 1.97 million metric tons in 2007 to 6.45 million metric tons in 2015. This level of aluminum production increase (4.48 million MT of primary aluminum) will create new annual demand for approximately 1.77 million metric tons of CPC by 2015.  Planned two grassroots smelters in Saudi Arabia (approximately 720,000 MT of primary aluminum between 2011- 2013) represent about 590,000 metric tons/year in-Kingdom demand for CPC.  All new Middle East demand for Calcined petroleum coke is expected to be a higher sulfur (3.5% S) CPC. Newer smelters are being designed with this in mind?that high quality low sulfur Calcined petroleum coke is already sold via contracts, and spot availability is scarce.  Western Europe and Western Africa are also potential markets for CPC from the planned GASAN Calciner, because these regions are expected to remain net importers of CPC.  These market opportunities are deemed attractive to support new Calcining capacity in the region. 

 Raw MaterialThe world?s supply of available calcinable and anode-grade coke in 2008 has been estimated 30 million MT, or 23% of the world?s supply, and was expected to increase to 31 million MT in 2012, primarily due to increases in supply from China. The feedstock for the project is the Green Petroleum Coke ?GPC? which is a byproduct of the oil refining industry. The quality and impurities of the product comes from the crude oil and depends mainly on the refining process parameters.After the delayed coking process, where oil residues are converted into coke, some volatile organic matters (VCM) remain in the coke. The VCM is removed in a Calcination process, where GPC is thermally treated in a Calciner  to produce a high grade carbon product.The resulting Calcined petroleum coke (CPC) is the raw material for anode manufacturing and contains all impurities such as sulfur and metals (V, Ni, Fe, Si, Na, Ca etc.). These impurities have an impact on the metal quality as well as on the anode behavior in the electrolysis cell. Therefore, the control of these impurities is of utmost importance in the selection and blending of GPC prior to Calcination. 

CPC Production TechnologiesWhile in the Western World the ?Rotary Kiln? is the major technology for Calcination of GPC, China uses the so called ?Shaft Kiln? Technology. Both technologies have their merits, but the Shaft Kiln allows Calcination of GPC, that is due to its high VCM and fines content not calcinable in rotary kilns. There are 3 major types of Calcining MethodsRotary KilnRotary kiln is a type of industrial dryer employed to reduce or minimize the moisture content of the material being handled by bringing it into direct contact with heated gas. The heart of the process is the rotary kiln. The rotary kiln is a refractory lined cylinder, with the diameter and length being set by the production rate and green coke properties. In general terms, the kiln will be 2 to 3 meters in diameter and about 50 meters long. In the kiln, the petroleum coke flows counter current to the hot combustion gas. The combustion gas is produced by burning natural gas or some other suitable fuel in a specially designed firing system. The constant abrasion of the coke particles results in the formation of coke fines and wear of the refractory lining. Maintenance of the refractory lining is one of the major maintenance activities. 

Vertical ShaftThe vertical shaft Calciner is a proven, simple, and efficient technology allows an economic production of quality CPC; with much less moving and rotating parts and has many advantages over the Rotary Kiln technology. In China more than 5 million tons of GPC are calcined in shaft kilns. The vertical shaft Calciner is composed of the following main parts:  Refractory lined shaft Calcining unit, where the Calcination process occurs at temperatures up to 1250 -1380 ?C. The coke moves through the kiln in 18-36 hrs where it is finally discharged from the bottom of the Calciner into the cooling zone for quick cooling by the cooling water sleeve underneath of the Calcining unit.  The cooled Calcined coke drops off at the discharge end in batches or continuously through a sealed discharger. Typically four units form a Calcining group. Most of the shafts Calciners operate in a 3 ? 6 groups.  The Calcining units are surrounded by the flues with baffles to ensure constant air flow  A combustion air adjustment allows insertion of air to ensure total combustion of the volatiles.  The hot waste gases flow through a recuperation unit to recover the heat, which typically can be utilized in various processes if proved feasible.  At the discharge end an indirectly water cooled steel sleeve allows to cool the coke to ambient temperature.Rotary HearthThe fundamental principle of using hot combustion gas to remove moisture and volatile material in the rotary kiln is also used in the rotary hearth. The main difference from the rotary kiln is how the hot combustion gases are produced in the rotary hearth and how the coke and hot combustion gases are contacted.

 Calcined petroleum Coke QualityCalcined petroleum Coke quality is critical to anode performance. Petroleum coke's low ash content is a primary reason for its use in anode manufacture.All smelters require very stringent CPC quality with excellent physical and chemical properties, i.e. high density, low electrical resistance, low CO2 and air reactivity and chemical properties that meet smelters metal quality strategy. 

Impact of CPC properties on anode propertiesCPC bulk density (which measures coke porosity) is critical to anode stability and electrical conductivity. An anode is more stable and efficient when the bulk density is higher and the porosity is lower. Since power conservation is critical to the energy intensive aluminum industry, bulk density is a primary quality factor. In addition, since anodes are of a fixed size, a higher density means less change-outs and thus less use of butts2.Metals

In coke particularly vanadium, nickel, sodium, and calcium contribute to alloying, increased power consumption, and catalytic oxidation of the anodes. Iron and silicon in the coke also affect aluminum quality.High Sulfur

 content is undesirable because of environmental concerns. Control of sulfur dioxide emissions can be achieved either by limiting the sulfur in the Calcined petroleum coke used to produce the anodes, or by installing scrubbing equipment. Scrubbing equipment is also required to limit fluoride emissions. We are committed to produce consistent quality, continually improve and deliver total customer satisfaction through:  competitive advantages  Reliability  Customer focused Solutions  Leadership with innovation and growth

We will follow the standard specifications for the Calcined coke. This product typically has the following specifications

Physical

Properties %/min

VBD

g/cm3

Density

g/cm3

El. Resistivity

??m

Grain stability

%

CO2 Reactivity

%

Air Reactivity%/min

0.75 min 2.06 min 500 max 75 min 12 max 0.3 max

 

Chemical Properties

S % Si (ppm) Fe (ppm) V (ppm) Ni (ppm) Na (ppm) Ca (ppm)

3 max 250 max 350 max 250 max 200 max 120 max 150 max

 ADVANTAGES OF VERTICAL-SHAFT VS ROTARY KILNS FOR CALCINING PETROLEUM COKE

  PRODUCT QUALITY

         Better coke structure - lower porosity, higher bulk density, harder (lower grindability)

         Better sizing - less generation of fines due to agglomeration and higher grain stability

         Good overall uniformity

 PROCESS ADVANTAGES

         More ability to use marginal, lower-quality green cokes (finer, higher VM) resulting in more purchasing

flexibility  and hence lower ongoing operating costs

         Higher yield factor –

          Less combustion loss of solid coke fines and dust

          Less loss of evolved volatiles due to re-condensing and agglomeration

          Roughly 0.85 vs. 0.75, depending on VM, Moisture, sizing

         Simple and easy control of product quality and process, including indirect product cooling 

         No fuel consumption, even at high Lc & real density and low resistivity targets

         Lower maintenance requirements and costs, and less downtime due to less-sophisticated equipment with fewer

moving parts

 LOWER CAPITAL COSTS     

         Simpler equipment and construction requirements (leads to less implementation time also) 

         No incinerator required, and smaller secondary gas treatment system(s)

         Improvements for safety and internal environmental control, and to minimize manpower needs, are expected to

be inexpensive to make via mechanization and automation involving basic and simple equipment

  The Process

 Green Coke Ship UnloadThe shaft Calciner will be located south of the port facility, where vessels with green coke (typical size 25?0?00 to 30?000 metric tons) are unloaded by means of a grab shell ship unloader, which has an unloading capacity of 650 tons per hour. The Grab Shell releases the green coke to a Grizzly to separate the coarse GPC lumps > 150 mm which are crushed in a shredder. The combined green coke is transferred to the plant by means of a conveyor belt with a maximum capacity of 650 tph. The cokes are stored based on type and quality, where blending different qualities of green coke to meet customer requirements before the Calcining process begins.

       Green Coke Distribution on KilnFrom the blending bed green coke passes a crusher to reduce the size to < 70 mm. The crushed material is filled into a day bin of 200 tons for each kiln. By means of a bucket elevator the coke is brought on top of the kiln where it is distributed with drag chain conveyors to each of the 32 shafts. The shafts are always filled to the top, where a thermocouple measures the coke temperature. Each shaft produces approx. 120 kg/h CPC or 3.8 tph for all 32 shafts respectively 92 tons per day and kiln.

    CalcinationThe Green Petroleum Coke feed on top of the shaft kiln, the coke moves downward through the kiln, where due to the slow movement of the coke through the Calcining unit, all coke particles reach maximum Calcination temperature resulting in consistent physical properties, such as resistivity, real density, and high Hardgrove index. The necessary heat for the Calcination process comes from the combustion of the volatiles inside the

flues, and conducted through the refractory walls to inside the kiln where the temperature reaches around 1250?C, this process controlled through adjustment of the air inlet and by the baffles.The Calcined Coke discharge from the bottom of the kiln after being cooled to a temperature around 100?C, by indirect cooling in the cooling part located below the shaft.Due to the fact, that prior to Calcination some of the volatiles glue the coke grains together; the resulting grain size is relatively high with little or no Coke fines. The vibrated bulk density is typically high.Green Coke with high volatile matters ? 12% can be calcined without having negative effect on the coke quality; this cannot be achieved in a rotary kiln technology. Even green Cokes with 14 % can be calcined by adding Calcined material to the green coke feed. This naturally has a negative impact on productivity, but not the quality.

          Coke CoolingCalcined coke needs to be cooled from approx. 1?200 ?C to 60 ?C. On the bottom of each shaft a cooling sleeve for indirect cooling is installed.

 Calcined CokeAfter Calcination and cooling the Calcined coke is removed via a vibratory conveyor to the central conveyor. The combined CPC passes a crusher to reduce the coke lumps to < 30 mm. With a bucket elevator the CPC is brought on top of the two 20?000 tons silos. From there it is either moved to the adjacent smelters or to the harbor to fill the vessels, which transport the coke to the smelters in the Middle East.Calcined Coke will be returned on the same conveyor belt from the CPC silos to the harbor to load ships of various capacities.

 

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