Maintaining Safety and Value

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The development of a solid maintenance and safety program is imperative to running a safe and efficient biodiesel plant. These programs also need to be continued-often in a slightly altered form-even when the plant is idle. Ensuring that safety standards continue to be met, and that maintenance activities are performed in a timely manner, can help maintain the value of a plant while helping to ensure a smooth and seamless restart.

While maintenance activities must be performed on an ongoing basis at all biodiesel facilities, the specific requirements for idle plants are markedly different than those for operating facilities. The requirements for facilities operating below capacity are largely the same as those operating at full capacity, however.

"If you are running a drop, you are running," says Brad Albin, Renewable Energy Group Inc.'s vice president of manufacturing. "From a safety and maintenance perspective, if you are running at all-whether you are running at a low capacity or a high capacity-most of the day-to-day work really doesn't change."

Plants running at below capacity may employ a skeleton crew, which is fine so long as the required maintenance and safety standards are met. When the crew is reduced to the extent that these activities cannot be performed properly, it's a problem, Albin says. "Then you are operating an unsafe facility and you're probably close to having someone get hurt," he continues. "When you are running a skeleton crew, you can't cut back so far that maintenance and safety activities aren't getting done, because they are non-negotiable-or should be."

Complying with applicable OSHA regulations and staying on top of maintenance needs does more than just provide a safe working environment, it also allows other elements of plant operation, such as product yield and quality, to fall into place. "This is because [these facilities] will have good corrective action processes in place to help them find root causes and correct things," Albin says.

While some facilities may consider a stop-and-go solution to below-capacity operation, Manfred Baumgartner, BDI-BioEnergy International AG's technical director, advises against it. "If there is capacity needed at lower production rates we suggest very much not to do a stop-and-go operation," he says. "We suggest running the plant at lower capacity, but running it continuously." This is important because repeatedly starting and stopping the facility is more likely to result trouble in terms of maintenance needs, cleaning issues and mechanical problems.

Most pieces of equipment within a biodiesel plant have a set capacity range for optimal production, which is generally between 50 and 110 percent, says Baumgartner. These guidelines should be adhered to. Running outside the guidelines can lead to inefficient operation and quality problems.


Idle Facilities

When it comes to maintaining an idle facility, plant management has to make a decision on how long the shutdown is likely to last. In the event of a long-term shut down, hazardous material removal should be a primary concern. "There is no reason to have methanol vapors around if it's not necessary," says Derek Masterson, Crown Iron Works Co.'s product sales manager. "There have been a lot of accidents in the past years because of maintenance work done on vessels that contained methanol vapors. So, that's definitely a priority for safety reasons."

This might be easier said than done, however. Plants are designed to take in these hazardous substances, not offload them, Albin says. For this reason, it is important to get the right people and equipment involved to ensure a safe and complete removal of these substances.

After the hazardous chemicals are offsite, the next step should be a complete cleaning of the facility, including the flushing of all lines. Special attention should be paid to lines that might contain salt, such as glycerin lines. If these lines aren't flushed and cleaned properly, it will lead to problems down the road. "[The salt] could harden and cause things to be very difficult to clean upon startup," Masterson says. "If you were to try to startup the plant again without cleaning it first, there would be significant problems, so our general suggestion is to clean upon shutdown. Then you won't need to worry as much when the plant is started up again."

Baumgartner agrees that special attention should be paid to glycerin lines, but also notes that at all applicable machines, such as those made from carbon steel, should be filled with a conservation fluid during a long-term shutdown. "Basically they are mineral oil-based fluids," he says, noting that several are available on the market. It is also possible to use pure biodiesel for this purpose, Baumgartner says, so long as it is treated with an oxidation stabilizer. If the biodiesel is not stabilized, it can degrade and get gluey.

Facilities located in cold climates also need to ensure that all water lines are properly drained to prevent damage from freezing, Baumgartner says. "Freezing water can cause huge issues," Albin agrees. "It will freeze up a pipe, a valve, a pump. It will bust it open and you won't know until later."

In addition, all bearings with squeeze lubrication should be filled completely with grease to prevent air from reaching the metal and causing corrosion, Baumgartner says. Actions should also be taken to protect carbon steel components from corrosion. This can be done by covering all areas that may be exposed to air with a corrosion inhibitor, he continues. Electrical components must also be protected from moisture in the air. "Electrical equipment should be sealed, and it's recommended to use silica get packets," to protect these elements from moisture, Baumgartner says.

It is also a good idea to get in touch with the manufacturers of a facility's boiler and water treatment systems for advice on how to store these pieces of equipment so they don't seriously degrade over time, Albin says.

Whether an idle plant keeps an employee onsite, or hires a contractor, it is also important to have someone regularly turn pumps, motors and bearings because these components can degrade if left in the same position for a significant period of time. "It's just like if you have a tire on your car and it sits there for five or six years on that tire, it will flatten on one side," Albin says.

Even when greased properly, moving parts that are left sitting stationary for an extended period can displace the grease due to pressure. This can cause pitting, Baumgartner says. Suppliers offer recommendations on how often these parts should be rotated. It is best to abide by their recommendations.


Maintaining Quality

Taking these kinds of protective actions at an idle facility can go a long way towards maintaining the value of a plant, which is important regardless of whether a company intends to retain the facility or sell it. According to Albin, approximately 20 facilities have approached or interacted with REG regarding possible sales, upgrades or technology partnerships. "The level of upkeep runs the gamut on those plants; from some people who didn't know that they were doing to start with, to some that had plants that were running and have kept them very well, to some people who at the end, when they were running out of capital, didn't keep them very well," Albin says. "It really runs the gamut on what you see out there."

Regarding facilities that REG has considered acquiring, Albin says proper upkeep of maintenance and safety standards does play a significant role in the decision to purchase. "If [a facility] is not kept well, then that's a cost to purchase or to startup that has to be taken into consideration," he continues. "They can be significant costs."

REG recently acquired and restarted its Seneca facility, which had been idle for more than a year. "We had to take a long time going through that one with the people who had been there before, using our experts to come up with a startup plan that we probably worked on-including that deal-for four or five months, to figure out exactly what it was going to cost to startup," Ablin says. "That plant has got two of three lines already past the performance guarantee. It is running quite well, but it takes a lot of planning and expertise to do that."


Restart

As economic conditions improve and federal lawmakers continue the effort to pass an extension of the biodiesel tax credit, it is likely that more and more idle biodiesel plants will restart operations. When restarting a plant, Masterson says it is probably best to take the same steps that were taken when the facility was started for the first time. This includes checking all electrical connections, checking mechanical connections and running each piece of equipment individually. It may also be beneficial to run water through the entire system to make sure everything is working properly before vegetable oils and chemicals are introduced into the system, Masterson continues.

"If I were a new owner taking over a plant, I would check everything as if it never ran before and as if I were starting it for the first time," Masterson says. "But if the owner is the same and the plant has simply been idle for awhile, I would still do a lot of checking."

In chemical pipelines, such as those delivering methanol, Baumgartner says he recommends that gaskets be changed out and that increased safety measures be taken until the system has been checked for leaks.

It is also necessary to reverse many of the protective actions that were taken while the plant was idle, Baumgartner says. Any bearings that were filled with excessive grease to protect them from corrosion need to be cleaned to remove the extra lubrication. Restarting equipment with too much grease in the bearings can cause overheating, which could cause damage. In addition, all elements that were filled with corrosion inhibitors must be drained. We also highly recommend that all stopped rotors are manually turned before they are filled with media and restarted, Baumgartner continues.

He also notes that some necessary maintenance activities, such as the replacement of seals and gaskets, should be completed right before restart. Once a plant is restarted, it should not be shut down again in the short-term for maintenance reasons, he says. In addition, all lubrication and hydraulic fluids should also be changed out prior to restart.

"Biodiesel plants aren't unique in having to be shut down and restarted," Masterson says. "The No. 1 aspect, I think, is safety in terms of methanol. No. 2 is in terms of salts and other residues, and No. 3 is general maintenance issues."
No matter what a facility's status, Albin says it is never okay to compromise on safety or environmental issues. "You need to make the right decisions on how long you are going to be down, and make some good decisions on whether you are going completely down-and if you are, cleaning everything out and doing that the right way."


Author: Erin Voegele
Associate Editor, Biodiesel Magazine
(701) 850-2551
evoegele@bbiinternational.com