Versatile systems for continuous in-line blending of butane and petroleum
A system and method are provided for in-line processes of blending butane into gasoline streams, and for blending butane into a gasoline stream at any point along a petroleum pipeline. The invention additionally provides a method for measuring the vapor pressure and vapor to liquid ratio of the gasoline, both upstream and downstream of the blending operation, as well as the sulfur content of the butane entering the blending operation. The blending operation can be controlled to ensure that the blended gasoline meets EPA requirements for vapor pressure and sulfur content of gasoline. The invention further provides a method for accessing and monitoring the operation off-site.
1. A system for in-line blending of gasoline and butane comprising:
a) a gasoline stream having a volumetric flow rate that varies over time;
b) a butane stream;
c) a blending unit for blending said gasoline stream and said butane stream at an actual blend ratio and an actual blend rate to yield a blended gasoline stream;
d) an upstream vapor pressure sensor in sensory communication with said gasoline stream upstream of said blending unit; and
e) one or more information processing units (IPUs) in informational communication with said upstream vapor pressure sensors, logically programmed to calculate a calculated blend ratio and calculated blend rate based upon vapor pressure and volumetric flow rate of said gasoline stream, and for communicating said calculated blend ratio and calculated blend rate to said blending unit;
wherein said blending unit periodically receives said calculated blend ratio and calculated blend rate from said one or more IPUs, and adjusts the actual blend ratio and actual blend rate to coincide with said calculated blend ratio and calculated blend rate.
2. The system of claim 1 further comprising a downstream vapor pressure sensor in sensory communication with said gasoline stream downstream of said blending unit.
3. The system of claim 1 further comprising one or more informational databases in informational communication with said downstream vapor pressure sensor, wherein said one or more informational databases periodically access and store vapor pressure measurements from said downstream vapor pressure sensor.
4. The system of claim 1 wherein said one or more IPUs are further logically programmed to calculate said calculated blend ratio based upon the date.
5. The system of claim 1 wherein said blending unit comprises:
a) an on/off valve between said gasoline stream and said butane stream; and
b) a modulating valve that modulates rate of flow of said butane stream toward said on/off valve.
6. The system of claim 1 further comprising:
a) one or more informational databases on which is stored seasonal data that prescribes:
(i) allowable vapor pressures on two or more prescribed dates or ranges of dates, or
(ii) whether butane blending is allowed on two or more prescribed dates or ranges of dates; and
b) one or more information processing units (IPUs) in informational communication with said upstream vapor pressure sensors and said informational databases, logically programmed to retrieve the date and to calculate a calculated blend ratio and calculated blend rate based upon the stored seasonal data and vapor pressure and volumetric flow rate of said gasoline stream, and for communicating said calculated blend ratio and calculated blend rate to said blending unit;
wherein said blending unit periodically accesses said calculated blend ratio from said IPU, and adjusts the actual blend ratio to coincide with said calculated blend ratio.
7. The system of claim 1 wherein said gasoline stream has a volumetric flow rate and comprises a plurality of batches of gasoline, each batch of gasoline being associated with a batch code, the system further comprising:
a) one or more informational databases on which is stored data that prescribes allowable vapor pressures for one or more batch codes; and b) one or more information processing units (IPUs) in informational communication with said upstream vapor pressure sensors and said informational databases, logically programmed to retrieve the batch code and to calculate a calculated blend ratio and calculated blend rate based upon the stored data and vapor pressure and volumetric flow rate of said gasoline stream, and for communicating said calculated blend ratio and calculated blend rate to said blending unit.
8. The system of claim 1 further comprising a butane sampling unit for periodically or continuously withdrawing butane from said butane stream, wherein:
a) said butane sampling unit is under the command of one or more information processing units (IPUs), wherein said one or more IPUs command said butane sampling unit to withdraw into a reservoir at least one sample of butane from said butane stream at least every 500,000 gallons of butane; and
b) said reservoir is manually withdrawn periodically from said butane sampling unit, and any butane contained in said reservoir is tested for sulfur content.
9. The system of claim 1 further comprising:
a) a butane storage unit;
b) underground piping for transmitting said butane stream from said butane storage unit to said butane blending unit;
c) a first butane pressure sensor in sensory communication with said butane stream at or near said butane storage unit;
d) a second butane pressure sensor in sensory communication with said butane stream at or near said butane blending unit; and
e) a remote information processing unit in informational communication with said first and second butane pressure sensors, for remotely monitoring and displaying butane pressures detected by said first and second butane pressure sensors.
10. The system of claim 1 further comprising:
a) a butane storage unit;
b) a temperature gauge for measuring the temperature of butane in said butane storage unit; and
c) a remote information processing unit in informational communication with said temperature gauge, for remotely monitoring and displaying temperatures detected by said temperature gauge.