Stringent EPA and global environmental regulations are demanding dramatic reductions in sulfur levels in fossil fuels to less than 15 parts per million (PPM) from several hundred PPM. Currently, desulfurization occurs in a process called Hydro-Desulfurization that uses hydrogen gas, high temperatures (300 to 400 degrees Celsius) and high pressures (30 to 130 atmospheres) to modify sulfur bearing compounds so they can be removed. However, this process is limited to large refineries owned by companies such as BP and Shell as the capital and operating costs are too high for smaller refineries. In order to meet the needs of small refineries and pipeline end users, APT has investigated methods to provide a cheaper method of reducing the sulfur content of fossil fuels.
APT has shown that its leading edge emulsion technology provides a positive method of controlling reagents used in Oxidative Desulfurization and is fully capapable of economically achieving the mandated decrease in sulfur. This results in a more valuable fuel with the same hydrocarbon quality as the original high sulfur fuel. APT has two patent-pending processes that use chemical Oxidative Desulfurization (ODS) that combine high sulfur fuel with water containing a catalyst (either solid or liquid), an oxidizing material (for example hydrogen peroxide) and other reagents as needed. The resulting mixture of the water-borne reagents and the hydrocarbon forms an emulsion at high mix rates. This emulsion allows the reaction to proceed in a timely and economic fashion. The catalyst serves the dual purpose of a catalyst and a transfer agent, thus increasing the rate of the oxidation of the sulfur-bearing compounds in the fuel. Once these sulfur compounds are oxidized, the water and fuel are separated, and the sulfur is removed from the fuel.
To date, APT’s laboratory, pilot plant, and small scale industrial plants have resulted in as much as 99.9% reductions of all sulfur compounds found in existing high sulfur fuels and middle distillates sourced from various refineries. APT has treated 20 different types of diesel and gasoline fuels including U.S. Navy JP-5 jet fuel, U.S. Marine F-75 diesel fuel, high sulfur kerosene, and middle distillates. In addition to dramatically decreasing sulfur levels, APT’s process can simultaneously remove other contaminatns such as dirt, water and polar chemical contaminants to comply with EPA regulations.
The main cost-saving advantage of APT’s patent pending approach is that the fuel is not processed under high temperatures and pressures. It also does not need large amounts of ancillary equipment. These items are both capital and operationally expensive. ODS is also operationally much simpler and thus much safer.