Lube-Tech PUBLISHED BY LUBE: THE EUROPEAN LUBRICANTS INDUSTRY MAGAZINE Figure C Evergreen Desulphurisation R-303
desulphurisation of 75% is predicted during the whole life of the catalyst.
Economics of Re-Refining
All of the changes made above make the re-refining business more attractive in terms of profitability. As one considers to build and operate a re-refinery, one must have enough used oil feedstock available to feed the plant without interruption. CEP recommends a minimum annual capacity of 20 thousand metric tons (20,000 MTA) of feed in order to generate a reasonable profit. The graph below shows the capital cost required for various capacities for a CEP technology re-refinery.
Capital Cost vs Capacity for a Grassroots Re-refinery CEP Reactor Design
Having developed the mathematical model that matches the real operations, CEP uses this model to design the optimum hydrotreating reactors for any new re-refineries. The optimum process conditions and reactor sizes are determined using this model to ensure all specifications of the API Group II base oil are met. A typical example of a reactor design is presented in Figure D. This is a design graph for a last reactor. Designs for other reactors are quite similar.
Figure D Performance Reactor 3
No.84 page 3
While these costs are just estimates, it is clear that the relationship between the capital cost and the capacity is not linear (as shown by the deviation from the dashed line). The higher the capacity of the plant, the less the capital cost is required per metric ton of used oil processed. It truly shows ’Bigger is Better!’
The parametric charts below show the relationship between the used oil prices and the rate of return at various base oil prices.
Note that the product sulphur value is 293 ppm, less than the 300 ppm required for Group II lubricants.
From models such as shown in Figure D, CEP can predict the optimum operating temperature for each reactor through the catalyst life cycle. In addition, metals loading as well as degree of desulfurisation are determined for the life cycle of the catalyst.
In this example, the design temperature increases from Base + 10°F (Base is the temperature used at the start of the catalyst life) at the beginning of the life cycle, to Base + 90°F at the end of the useful catalyst life. At the end of the catalyst life cycle a metals loading of about 7.5% has been calculated. The indicated sulphur retention is quite low, i.e. a high degree of
LUBE MAGAZINE No .111 OCTOBER 2012 25
Grassroots 40,000 MTA Re-refinery Internal Rate of Return at Various Feed & Base Oil Prices
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49
