Using the Bottom of the Barrel as Refinery Fuel

Presented at the ERTC Conference, Vienna, 13th November 2012
Using the Bottom of the Barrel as Refinery Fuel
By Joe Gelder, CANSOLV Technologies Inc (an affiliate of Shell Global Solutions BV)
The MARPOL Annex VI Regulation reduced the sulphur content in marine bunker fuel oil to 1.0wt% maximum in 2010 in SOx Emission Control Areas (SECAs) and this limit will reduce to 0.1wt% maximum in 2015. These SECAs include Northern Europe and US coastlines.
The demand for heavy fuel oil is expected to fall dramatically and the future outlet for residue streams is reduced. Refiners which supply into the marine market, impacted by the regulation, without a sufficient degree of residue upgrading and de‐sulphurization capacity, must change crude diet, invest in residue (hydro) conversion capacity, rely upon blending high value distillates into the residue streams to meet the new sulphur specifications or continue to sell heavy fuel oil at an economic penalty.  As a more economical alternative, refiners could use residue as refinery fuel oil, particularly in gas constrained regions, provided that they can meet local flue gas SOx emission targets.
Cansolv Technologies Inc., an affiliate of Shell Global Solutions International BV, provides a proven technology to reduce SOx from flue gases to environmental limits and produce a pure, water saturated SO2 stream. This can either be recycled into the refiner’s Sulphur Recovery Unit (SRU) or converted into sellable Sulphuric Acid. This paper takes a typical European refinery configuration and discusses the refinery economics of burning refinery fuel oil in its existing units. The paper very briefly introduces the CANSOLV SO2 Capture and Recycling System and compares its capital and operating costs, to treat the flue gas produced when burning refinery fuel oil, against other non‐regenerable flue gas de‐sulphurization systems.
Introduction
The refining industry continues to be subject to supply side pressures to process more difficult crudes, while being forced to respond to ever tighter limitations on product sulphur content. It is expected that after 2015, a large percentage of the marine bunker fuel oil market in North America and Europe will move from high sulphur residue fuel oil to lower sulphur distillate material, because of the Marpol Annex VI Regulation. Investment in the bottom of the barrel hydrocracking or coking systems is economical for large volumes of residue, but options are limited when smaller volumes of high sulphur products must be accommodated. In addition to burning residue in Co‐generation Power Projects (1), of which CANSOLV has two projects under construction, mechanical conversion of certain refinery furnaces and boilers to burn residue, in addition to gas, provides flexibility to the refiner to take advantage of higher price differentials between natural gas and high sulphur residue. These projects require some minimal investment to the burners etc., to enable the burning of high viscosity material and they also require investment to install SO2 scrubbing, to meet SOx emissions limits to atmosphere.
Combustion of modest quantities of residue streams inside the refinery reduces the refiner’s reliance on external, purchased balancing fuels, such as natural gas. It also increases the refinery planner’s ability to fill the refinery crude slate with cheaper, high sulphur crudes, to maximize margins, since the residue can be burnt rather than incurring the penalty of producing high sulphur Marine Fuel Oil (MFO), with a limited and low market value. Finally, the refiner will use less valuable cutterstock to achieve MFO viscosity and sulphur specifications, if there is less residue to sell.
Free Full Text Source: http://www.cansolv.com/cn/media/Papers/2012%20ERTC%20-%20Using%20the%20Bottom%20of%20the%20Barrel%20as%20Refinery%20Fuel'%20Paper-%20Joe.Gelder.pdf