The cost to produce and deliver gasoline to consumers includes the following major components: crude oil, refinery processing, taxes, and marketing and distribution. Each major cost component fluctuates for one reason or another over time. For example, in January 2005, marketing and distribution accounted for about 9 percent of the cost of a gallon of regular-grade gasoline, according to the Energy Information Administration. In January 2007 the same cost associated with marketing and distribution jumped to 15 percent.
 

 There are several factors that can be attributed to the rise in marketing and distribution costs for gasoline. Ironically enough, the rise in the cost of gasoline could be one of these factors. No matter what the actual cause or causes for the increase, the costs associated with the marketing and distribution of gasoline, diesel and ethanol are a major factor in the final price to consumers.
 
 A state-of-the-art loading arm system can assist in increasing distribution efficiencies and decrease the overall cost of producing and shipping ethanol. Top- and bottom-loading arms are designed for bulk fluid transfer out of bulk plants, terminals and holding tanks and into railcars, tank cars and tank trucks. The various chemical products—such as ethanol, gasoline, diesel fuel, biodiesel and other chemicals that are loaded or unloaded by top- and bottom-loading arms—are considered hazardous and expensive, therefore the best available loading arm technology should be considered for these applications. Loading arms are self-balancing, articulated piping systems typically designed with three sections—inboard and outboard arm sections, and a drop section connected by swivel joints.
 
 Decreasing Loading Times
 Typical loading arm diameters range from two to eight inches. Depending on the required reach, loading arms with diameters of four inches and smaller can generally be easily maneuvered manually. However, a trend in the ethanol industry is the use of six-inch loading arms for increased flow and decreased loading times. However, due to their large size, these arms can be heavy and create stress on elbows and piping. These larger and heavier loading arms may necessitate the use of pneumatically controlled systems for raising and lowering.
 
 "Most ethanol producers want to load rail cars at very high rates like 600 to 800 gallons per minute," says Dave Morrow, product manager for loading systems for Lebanon, Ohio-based OPW Engineered Systems. "That gets you up into six-inch loading arms, which can introduce ergonomic, safety and storage concerns. To safely and efficiently handle arms of that size, we're manufacturing a lot of arms with pneumatic cylinders to assist with maneuvering and counterbalancing the arms."
 
 Choosing a Loading Arm
 Nearly 100 percent of railcar loading in the ethanol industry is performed via top-loading arm systems through the dome of a railcar. Top-loading railcars and trucks provide an efficient and cost-effective loading method. A top-loading system should have sufficient horizontal range to reach the farthest compartment without re-spotting the vehicle. Also necessary are sufficient vertical movement and drop-pipe lengths capable of reaching vehicles of various heights. Three of the most popular styles of top-loading arms in the ethanol industry are the single-arm fixed reach, unsupported and supported booms.
 
 Primarily used to load railcars through open domes in installations where the cars can be accurately spotted, the single-arm configuration can also be used for tank truck applications. This type of arm requires accurate vehicle spotting and incorporates three swivel planes of rotation. It's designed for use in top-loading installations where the vehicle is located at a fixed distance from the riser pipe. The two swivel planes at the inlet permit up-and-down and side-to-side movement of the assembly, and the third swivel plane allows the drop pipe to remain vertical. The single-arm loader is adaptable to tight-fill or closed-system loading when equipped with additional swivel planes of rotation and/or drop hose, including the outboard coupling, union or fitting.
 
 The unsupported boom arm is an alternative for variable reach applications, especially in larger sizes where the outboard components are relatively heavy. It can be modified for closed-system loading and unloading, and is available in various design configurations to meet the needs of virtually any installation. This popular loader style is designed for those installations where it's undesirable or impractical to mount a supported boom arm. For example, many loading sites have no support columns or overhead structures to which a supported boom can be attached. The unsupported boom arm offers many of the same advantages as the supported boom arm, but maximum reach can be significantly less due to the stresses in the loading arm and facility piping. It provides flexibility in the event the vehicle mis-spotted, and can be folded back against the rack for convenient, compact storage.

 
 The supported boom arm consists of a single-arm loader mounted on a swiveling boom attached to a supporting structure by means of a flange bearing or pillow block bearing. This type of loading arm provides maximum flexibility for mis-spotting of vehicles and allows longer reaches from the loading rack to the railcar or tank truck. The arm and boom can be folded for convenience and safety from traffic flow. The supported boom requires low maintenance and offers dependable service.
 
 Supported boom-style loading arms are the sturdiest and safest loading arm system used in the ethanol industry. Since this style of boom arm is supported via additional structure and flange or pillow block bearings, there is very little load or stress on the swivel joint components of the loading arm, thereby minimizing wear and increasing component life. With the larger and heavier loading systems, pneumatic controls are sometimes recommended to allow operators to easily maneuver the arms.
 
 Materials of Construction
 Loading arms are manufactured using a variety of materials such as aluminum, and stainless and carbon steel. Loading arms used for handling aggressive chemicals and acids are constructed with high alloy materials such as alloy 20, the trademarked material hastelloy as well as polytetrafluoroethylene-lined piping.
 
 Certain materials commonly used with gasoline may be incompatible with high-level ethanol blends, causing them to degrade and contaminate the fuel. Metals that have been shown to degrade over time in the presence of high-level alcohol blends include brass, lead, zinc and lead-based solder. Degradable nonmetallic materials include natural rubber, polyurethane, cork gasket material, leather, polyvinyl chloride polyamides, and certain thermoplastic or thermoset polymers.
 
 Black iron, bronze, and unplated, nickel-plated and stainless steels have shown resistance to ethanol corrosion. Nonmetallic materials like reinforced fiberglass, Neoprene rubber, polypropylene, nitrile rubber, Viton and Teflon meet acceptable usage standards.
 
 In the railcar or tank-truck loading and unloading processes, Morrow says that when it comes to ethanol material compatibility, "We really haven't had any problems. Most bulk plants have specified the use of carbon steel or stainless steel materials of construction with aluminum sub-components. We have seen some concern over the use of aluminum, but most users do not seem concerned with this material being used as a sub-component on a loading arm."
 
 As for seal selection, Morrow follows the producer's recommendations but has had great success with Viton GFLT high-grade fluorocarbon elastomers in ethanol service. With more ethanol being shipped, Morrow says he has seen a significant change in the flow rates being used to load and unload the fuel.
 

 Safety Issues
 As is the case with all liquid fuels, it's very important that proper fuel-handling techniques be practiced and the best available technology be considered when choosing and using a loading system. As previously mentioned, the larger loading arms used in the ethanol industry are heavy and cause stress on the elbows and piping. Therefore, pneumatically controlled, supported boom-style loading arms are ideal for providing increased loading flow rates with added safety for the operator and ethanol plant.
 
 Another issue with higher loading rates is the potential for static generation. Static electricity can build up and pose potential danger for the loading arm operator. In order to limit the potential for static buildup, ethanol producers should use ground verification equipment and long drop tubes that reach to the bottom of the railcar.
 
 "We stress the importance of a properly grounded loading system and recommend utilizing a ground verification package to ensure that the system is properly grounded prior to loading," says Simon Hill, director of engineering for Kansas City, Mo.-based Civacon and Knappco Corp.
 
 The other issue that many shippers face is vapor recovery. As mentioned earlier, most of the ethanol being loaded into railcars at the ethanol plant is being top loaded through an open hatch. To address vapor recovery concerns, most loading arms are equipped with a vapor recovery attachment such as a flat hatch plate or inflatable hatch seal, allowing the vapors to be collected and reclaimed during the loading process.
 
 In addition to ground verification and vapor recovery equipment, a final safety feature is overfill protection equipment. Cane probes can be used in instances where a permanent sensor can't be properly affixed to a tank or railcar and provide a portable solution to various types of overfill prevention requirements.
 
 Improved performance, speed and safer technology make pneumatically controlled, supported boom loading arms the clear choice for top loading ethanol into a railcar. There are several factors that go into making this important decision, such as space constraints and expected production volume. Ethanol producers should weigh the available options and make sure that all of the proper safety procedures have been followed to ensure an efficient and secure loading system is in place for many years.
 
 Gary Schriever is the biofuels market manager for Riverside, Mo.-based OPW Fluid Transfer Group. Reach him at <a href="mailto:gschriever@opwftg.com">gschriever@opwftg.com</a> or (513) 696-1550.

 
 The claims and statements made in this article belong exclusively to the author(s) and do not necessarily reflect the views of Ethanol Producer Magazine or its advertisers. All questions pertaining to this article should be directed to the author(s).

Reviewing the Capabilities of Ethanol Loading Systems

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Carbon Capture & Storage Summit

North American SAF Conference & Expo

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Reviewing the Capabilities of Ethanol Loading Systems