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Biodiesel Feedstocks – Lesquerella Oil & Linseed Oil 150 150 Star Oilco

Biodiesel Feedstocks – Lesquerella Oil & Linseed Oil

We’re continuing our deeper look into different types of feedstock that Renewable Energy Group (REG) studied in 2009 in the Feedstock and Biodiesel Characteristics Report. This posts two feedstocks are Lesquerella Oil & Linseed Oil.  Here is a link to the main page of feedstocks we have examined so far.

Lesquerella fendleri Oil

Lesquerella fendleri, also known as Physaria fendleri, is part of the mustard family. (Lesquerella) Physaria Fendleri part of the mustard familyThe common names of this plant are popweed and Fendler’s bladderpod. This silvery-gray perennial has four-petaled yellow flowers that grow on a plant that is about 1 to 16 inches tall. Found in plains and mesas in the southwestern United States, it requires low water usage and is one of the first of the flowering wildflowers in the spring (Source).

Lesquerella produces hairless capsules called siliques which contain 6 to 25 seeds. These seeds contain 20-28% oil with around 62% lesquerolic acid. Lesquerella oil is a source of hydroxyl unsaturated fatty acids, and is useful as a replacement for castor oil in some applications.

While there are benefits from using this seed oil, the dark reddish-brown color of the oil is a potential limiting factor. Potential selective breeding and domestication of the plant may solve this issue, but there haven’t been much momentum at this time. That being said, there have been some studies about growing this plant for its oil and the natural gum in its seed coat for commercial use.


Lesquerella Oil and Lesquerella Biodiesel

Lesquerella BioDiesel Certificate of Analysis



Linseed Oil

Linseed (Linum usitatissimum) is also known as flax in North America. The plant is an annual and can grow in large range of climates. Linseed Oil and SeedsFor example, it grows in Argentina, India, and Canada. Linseed oil has been traditionally used as a drying oil. According to REG report, these seeds contains 37-42% oil. The crude oil contains 0.25% phosphatides, a small amount of crystalline wax, and a water-soluble resinous matter with antioxidant properties.

As one the earliest cultivated field crops in the US, it has found many uses for its oils. Linseed oil can be used as a varnish, pigment binder or to manufacture linoleum. These applications have seen reductions in use due to synthetic options that resist yellowing. Other uses for this plant are as nutritional supplements and foods, although raw linseed oil can become rancid unless refrigerated.  After the oil has been pressed out of the seeds, the leftover residue makes great animal food.

As some of the traditional uses of the plant are replaced with other options, use of this crop for a feedstock in biodiesel is an option.

Linseed Oil and Linseed biodiesel


Last article for biodiesel feedstocks was Jatropha Oil, Jojoba Oil, & Karania Oil.

BioDiesel Feedstocks – Jatropha Oil, Jojoba Oil, & Karania Oil 150 150 Star Oilco

BioDiesel Feedstocks – Jatropha Oil, Jojoba Oil, & Karania Oil

Jatropha Oil, Jojoba Oil, & Karania Oil

We are continuing our deeper look into different types of feedstock that Renewable Energy Group (REG) studied in 2009 in the Feedstock and Biodiesel Characteristics Report. If you would like to see what feedstocks we have talked about, this is the main page and it links to the ones we have examined.

As a reminder, B20 biodiesel (B20 stands for 20% biodiesel and 80% petroleum diesel) is the drop-in solution for reduced emissions in today’s modern diesel engines. To understand some of the alternate feedstocks that can be used for biodiesel, we are examining a report that Renewable Energy Group (REG) produced in 2009. All certificates of analysis and results are for B100.

This post is a bit different as we have only one successful biodiesel created and two failures. The oils are jatropha oil, jojoba oil and karanja oil.

Jatropha Oil

Jatropha oil comes from the shrub Jatropha curcas, also known as physic nut, Barbados nut, poison nut, bubble bush or purging nut. This plant is a succulent that loses its leaves during the dry season. It is best adapted for arid and semi-arid conditions. The resistance to high degrees of aridity allows it to grow in deserts. This shrub can thrive on only 10 inches of rain for a whole year. It is native to Mexico, Central America, Brazil, Bolivia, Peru, Argentina, and Paraguay. Jatropha curcas is considered a shrub or small tree and can reach a height of 20 ft. or more.Top of a Jatropha plant as part of a hedge

 “Shrubs begin to produce when only 4 – 5 months old, and reach full productivity at about 3 years Under good rainfall conditions, nursery plants bear fruit after the first rainy season, while directly seeded plants bear for the first time after the 2nd rainy season. With vegetative propagation, the first seed yield is higher. At least 2 – 3 tonnes of seeds per hectare can be achieved in semi-arid areas.” (Source)

The seeds contain 27% to 40% oil (Source) and develop in 90 days from the flower to the seed. Trees can have a productive life of 40 to 50 years without tending.

Uses of the plant include medical, edible and as a source of oil for biofuels. The young shoots and even young leaves can be cooked and eaten as a vegetable. The nuts can be eaten but they are purgative and, if eaten in large quantities, can be poisonous.

Medicinal uses include uses the juice from the bark as a treatment for malarial fevers and or using it to treat external burns, scabies and ringworm (Source).

The low maintenance and high oil content makes this plant attractive as a biofuel feedstock. In addition to its use for biodiesel, the oil has been made into jet fuels. In 2008, Air New Zealand flew a plane on 50/50 mix of jatropha oil fuel and jet A1 fuel (Source).

Currently biodiesel is being produced from this plant in the Philippines, Pakistan and Brazil.


Jatropha Oil and the biodiesel it produces

Jatropha biodiesel certificate of analysis

Jojoba Oil

Golden jojoba oil was produced from the plant called jojoba (Simmondsia chinensis), an evergreen perennial shrub grown in Arizona, Mexico, and neighboring areas. Some of the common names of this are goat nut, deer nut, pignut, wild hazel, quinine nut, coffeeberry and the gray box bush (Source). The dehulled seeds of jojoba contain 44% of liquid wax ester, which is not a triglyceride.

Seeds on a Female Jojoba BushThis shrub grows to 3 to 6 feet tall and some can get as tall as nearly 10 feet. The fruit is acorn-shaped and .4 inches to .8 inches long.  The seed is dark brown.

Uses of the plant include forage for wild animals such as deer, bighorn sheep and some livestock. In large quantities, the seed meal is toxic to many animals. The oil is different than many of the feedstocks we have discussed.

“Jojoba is unique in that the lipid content of the seeds, which is between 45 and 55 wt.%, is in the form of long-chain esters of fatty acids (FA) and alcohols (wax esters) as opposed to triacylglycerols (TAG) encountered in other vegetable oils and animal fats” (Source).

Because of this, the Jojoba oil wasn’t made into a biodiesel for this study. According to the REG Report:

“The purpose of this project was to transesterify all the feedstocks using the same procedure and if jojoba was done differently, comparisons could not be made with jojoba methyl esters. Jojoba can be transesterified and used as a fuel using a different process.”

Jojoba Oil as a biodiesel feedstock

Karanja Oil

Pure, cold pressed karanja oil was purchased from The Ahimsa Alternative, Inc.Karanja Tree source for Biodiesel Karanja (Pongamia pinnata) is a medium sized evergreen tree, and usually about 25 ft. tall but can grow as large as 80 ft tall (Source). The tree has dark green leaves and the very fragrant flowers of lavender, pink and white.  The tree grows in the humid tropic and can be found in India, China, and Japan. The seed contains 27-39% oil.

Karanja is used for oil production and has some successes in India as a feedstock. In regards to this study, they weren’t able to create a biodiesel fuel using the same procedure as the rest of the feedstocks and therefore there isn’t a sample created to test.

REG’s notes about this oil are as follows:

“Esterification was only able to reduce the FFA (Free Fatty Acid) of the oil to 0.7 wt %. Since 0.5 wt % was the maximum amount of FFA allowed in the feedstock, karanja was not made into biodiesel using the standard procedure. A small scale experiment was performed to see what would happen to the karanja when it was transesterified. A 20 gram sample of karanja oil was used, along with the standard ratios of chemicals as in the other feedstocks for the project. After the water wash step, the karanja formed an emulsion with the water and the phases would not separate. No further refining experiments were done to make karanja suitable for transesterification.”

Karanja Oil

Last article for biodiesel feedstocks was Hemp Oil & High IV and Low IV Hepar

Oregon Diesel Fuel
Diesel Fuel in Portland, Oregon 530 530 Star Oilco

Diesel Fuel in Portland, Oregon

What is the difference between diesel fuel in Portland, Oregon and the rest of the Pacific Northwest?

Oregon Diesel Fuel

Star Oilco delivers and sells diesel fuel in Portland, Oregon.

We are ready for your diesel needs be they off-road, on-road, biodiesel, renewable diesel, or anything else you want.

Star Oilco has simple fuel solutions to keep your business moving.

On the West Coast, expect biodiesel blends to be in all diesel fuel. B5 biodiesel being the most commonly found fuel. Be aware though, in Oregon,  B20 biodiesel (a 20% blend of biodiesel mixed with petroleum diesel) is extremely common at retail throughout the state. B5 through B20 blends of biodiesel are becoming more common as Oregon’s legal framework regulates CO2 emissions requiring diesel sellers to blend biodiesel or charge substantially more for every gallon they sell.

On top of that, Oregon has a 5% biofuel blend mandate that can include a number of fuels, most commonly biodiesel and renewable diesel. Washington state also has a mandate for 5% biodiesel though it isn’t as specific as the Oregon mandate.

That’s Oregon Diesel. What about Portland?

The city of Portland has a stand-along city fuel tax due to its policy goals (which cause it to codify rules for low CO2 fuels and the sources of diesel in particular), as well as its own budget needs.

Portland, Oregon Diesel Fuel Mandates

A little known fact is that Portland, Oregon has its own biofuels mandate and fuel tax structure on diesel. This mandate affects all diesel equipment both on and off-road use. It does not affect boilers or HVAC systems though most people selling heating oil and boiler fuel are still handling a 5% biodiesel product to ensure they don’t cross fuel in violation of the law.

Functionally, the city of Portland’s mandate and Oregon’s specific mandate do not make a huge difference. Your biggest noticeable difference is the higher price due to the diesel fuel tax, given that Portland’s biofuel mandate now overlaps with Oregon state’s fuel mandates.

For more on the actual code for biofuel mandates in Portland, see the Portland City Code.

Until 2019, Portland had a 5% biodiesel “methylester” mandate. This meant that Portland mandated that all diesel fuel sold inside the city must contain 5% of biodiesel or sellers of fuel inside city limits would face a fine. For years, Portland actually checked every seller of diesel for a 5% biodiesel blend in person annually. This mandate also included feedstocks and did not allow for palm oil sourced biodiesel, as palm oil is responsible for a large amount of deforestation in Indonesia and other places. The Portland mandate required that half of all biodiesel blended to meet the 5% mandate must be derived from canola and waste vegetable oil sources, as Oregon can produce them.

In 2019, the city of Portland suddenly lined up their mandate to match the state of Oregon’s, which allows for renewable diesel to be used as a feedstock. Anything derived from palm is still a barred feedstock for the fuel to meet Portland mandate requirements (which is distinctly different than Oregon’s biofuel mandate).

Onsite Diesel wethose service Portland
Portland, Oregon Diesel Fuel Taxes

(NOTE: Read this article by Star Oilco for more on Oregon Fuel Taxes Explained.

In 2016, the city of Portland, Oregon created its own diesel tax of $.10 a gallon. This tax is on both gasoline and diesel fuels sold at retail or commercially.  If you are operating vehicles over 26,000 GVW that are exempt from Oregon road tax, Portland also has a weight mile for those tax exempt vehicles.

If you are fueling inside the Portland city limits, that diesel tax will be charged at the pump when you fill up unless you are a P.U.C. tax exempted vehicle in Oregon.

Find a list of every diesel and gasoline tax by city and municipalities in Oregon see the Oregon Fuel Tax Group.

If you have any questions about Portland, Oregon diesel fuel standards please feel free to call or message Star Oilco for more information.

Star Oilco is here to be your Bulk Fuel Supplier in Portland, Oregon.

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For more on the subject of Diesel fuel please read these other posts by Star Oilco on the subject:

Every Question Star Oilco has been asked about Biodiesel

Every Question Star Oilco has been asked about Off Road Diesel

About Diesel Fuel – Star Oilco’s Diesel Fuel FAQ

Oregon Biodiesel Tax Breaks for Retail Stations

BioDiesel Feedstocks – Hemp Oil & High IV and Low IV Hepar 150 150 Star Oilco

BioDiesel Feedstocks – Hemp Oil & High IV and Low IV Hepar

In this post we are going to continue our deeper look into different types of feedstock that Renewable Energy Group (REG) studied in 2009 in the Feedstock and Biodiesel Characteristics Report. The feedstocks we are looking into are Hemp Oil & High IV and Low IV Hepar. Here is a link to the main page of feedstocks we have examined so far.

As a reminder B20 Biodiesel (B20 stands for 20% biodiesel and 80% petroleum diesel)  is the drop in solution for reduced emissions in today’s modern diesel engines.   To understand some of the alternate feedstocks that can be used for biodiesel, we are examining a report that Renewable Energy Group (REG) produced in 2009. All certificates of analysis and results are for B100.

Hemp Oil

Hemp seed oil comes from the plant Cannabis sativa and contains significant amounts of linolenic acid. The hemp oil in this study was sourced out of Canada and these seeds have an oil content of 33 percent. Cannabis sativa male picture of flowers

Based on Industrial Hemp Regulations in Canada:

“Industrial hemp includes Cannabis plants and plant parts, of any variety, that contains 0.3% tetrahydrocannabinol (THC) or less in the leaves and flowering heads.

Industrial hemp also includes the derivatives of industrial hemp plants and plant parts. These do not include the flowering parts or the leaves.

Examples of derivatives that are considered industrial hemp include: hemp seed oil (oil derived from seed or grain) and hemp flour.”

THC is the chemical that has psychoactive properties and is what makes the cannabis Marijuana vs Hemp.

This biodiesel sample was created with seed oil that contained less than .03% THC.

Cannabis sativa is an annual flowering plant that originates in Central Asia and is now spread world-wide. The uses of the plant include seed oil, food, recreation, medicine and industrial fiber. (Source)

The centuries of early human cultivation of these plants has created a large variety of strains that look, grow and act different.  Pictured is an example of what a Hemp or Marijuana plant looks like in bloom.


Hemp Oil and hemp Biodiesel

Hemp Oil Biodiesel Certificate of Analysis



Hepar, High Iodine Value and Low Iodine Value (IV)

In this situation, Hepar is a byproduct of the heparin manufacturing process. Pharmaceutical grade heparin is derived from the mucosal tissues and of animals, such as pig intestines or cow lungs. (Mucosal tissues are part of the immune system it is the barrier between potential pathogens and the body.) Heparin is a medicine that is used as an anticoagulant.  Since the creation of Heparin is a industry secret, it is difficult to find much information about the byproduct Hepar.

High IV Hepar and Biodiesel

High IV Hepar Biodiesel Certificate of Analysis Low IV Hepar BioDiesel Certificate of Analysis


Last article for biodiesel feedstocks was Evening Primrose Oil & Fish Oil

Biodiesel Handling and Use Guide (5th Edition 2016) 150 150 Star Oilco

Biodiesel Handling and Use Guide (5th Edition 2016)

Where to start when fueling your fleet with  biodiesel.


The U.S. Department of Energy’s Biodiesel Handling and Use Guide (Fifth Edition)

If you are a fleet seeking to reduce your CO2 footprint and biodiesel is your drop in solution, this book is your guide.  The Biodiesel Handling and Use Guide is the definitive user’s manual for fleets seeking to field biodiesel and blends as a substitute for petroleum diesel (available from the US Department of Energy’s Alternative Fuel Data Center).

Biodiesel is diesel-rated fuel manufactured from animal fats and vegetable oils by way of a chemical reaction. It is not diesel fuel but it has extremely similar properties, allowing it to be blended with petroleum diesel.

As a drop in fuel, it substantially reduces tailpipe emissions and cuts CO2 emission by more than half when used as a substitute for petroleum diesel. Many states and the federal government have financial incentives to encourage its use. Several states also have mandates for the use of biodiesel as a blend component with diesel fuel.

In the last twenty years biodiesel has come a long way and it is now a mainstream fuel around the United States. In just the last ten years, a great deal has changed with the complexity of diesel engines, the sources of crude oil refined into ultra-low sulfur on road diesel, and the complexity diesel fleets will encounter in operating day-to-day. This book is a scientific and easy-to-read manual to help you navigate success with modern diesel.

The Biodiesel Handling and Use Guide covers the technical aspects of biodiesel and how it differs from petroleum diesel. It also provides advice on higher blends and storing fuel onsite. This guide goes in-depth about equipment compatibility for your refueling infrastructure as well as maintenance concerns you want to get ahead of. There are also checklists included for fleets seeking to move from petroleum diesel to higher blends of biodiesel.

If you have questions or want help in using higher blends of biodiesel in your fleet, don’t hesitate to contact Star Oilco. Even if you are not in our service area, we will be here to help. Star Oilco has been helping fleets succeed with biodiesel blends since 2003.

B20 Biodiesel A PROVEN FUEL

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For further reading on Biodiesel please see the following Star Oilco pages:

Every Question Star Oilco has been asked about Biodiesel

B20 Biodiesel; a Proven Fuel

Oregon Biodiesel Tax Breaks for Retail Stations

In-Depth look at Biodiesel as a Heating Fuel


B20 Biodiesel, a Proven Fuel 150 150 Star Oilco

B20 Biodiesel, a Proven Fuel

Using Biodiesel in the Pacific Northwest.

(NOTE: B20 refers to 20% biodiesel blended with an 80% petroleum diesel percentage. B5 refers to 5% biodiesel blended with petroleum diesel which is the legally required blend percentage in Oregon state. For more on biodiesel basics, visit the US DOE.)

Biodiesel is the “Drop In Solution” used in the Pacific Northwest to reduce CO2 emissions in diesel equipment.

If you are looking to use Biodiesel in a fleet or a personal vehicle it is as easy as just asking for it.  In Oregon the fuel is everywhere.  From an Oregon and Washington state requirement for a minimum 5% of biodiesel blended with every gallon to large financial incentives this low carbon diesel fuel is ready for you if you want it.

It’s not just the Pacific Northwest.  For years B20 has been a defacto blend at some of the biggest names in fuel. When you pull up to the pump on the west coast you are likely getting B5 or B20 as a blend. In Oregon, B5 biodiesel is the required fuel by law. Oregon also has a B20 incentive for a waiver of state on road taxes.  Washington as well has requirements that biodiesel finds its way into retail and commercial diesel throughout the state.   Additionally, Oregon and California have “Clean Fuel Standard” programs which heavily incentivize low CO2 fuels like biodiesel.  Washington state is expected to pass their own Clean Fuel Standard as well this year.  Biodiesel has been a fact of life in fuel for over a decade in the United States and Pacific NW and it is not going away.

Due to a mix of federal and state incentives to use biodiesel, there can also be financial advantages for a fleet dedicated to making B20 biodiesel its fuel of choice. You can see evidence of this at truck stops and other retailers making B20 available in Oregon and Washington, as well as in the trucking lanes of the United States. America’s largest fleets are choosing B20 biodiesel in order to reduce their cost per mile. So can you.

In an effort to deliver the best value to truckers, many U.S. truck stops are blending biodiesel up to 20% when the market enables them to pass along a lower cost yet high quality ASTM specified diesel fuel to their customers. Most prominent is Pilot/Flying J, who lists where and when their sites are serving up B20 or lower blends. Pilot/Flying J buys biodiesel directly and blends on site in order to give their customers the best value possible. Loves Travel Centers also sell biodiesel blends around the U.S.

In Oregon, due to a diesel road tax waiver on B20 sales, gas station retailers Safeway, Leathers Fuel, Spaceage, and others are offering B20 biodiesel as their retail diesel offering. Oregon’s system requires the biodiesel be sourced from used vegetable oil refined biodiesel products. Biodiesel has been in Oregon’s fuel supply since 2006 when the city of Portland mandated B5 biodiesel blends within its city limits. The state of Oregon followed Portland with its own statewide mandate not long after.

(NOTE: If you operate a retail gas station and are curious about Oregon’s fuel tax breaks for biodiesel blends here is a more in depth article Oregon Biodiesel Tax Breaks for Retail Fuel Stations that explains these rules for retailers of fuel).

Biodiesel has been in our fuel system since 2006 and the technology that goes into making it has vastly improved. It is proven in diesel engine performance while also creating a diversified supply for energy and significantly reducing emissions from the working fleets of the world. Biodiesel substantially reduces emission coming out of your stack without a major impact on price because it helps to offset high diesel prices.

B20 Biodiesel A PROVEN FUEL

If you want to look at using B20 blends in your fleet, we are here to help. Star Oilco carries B20 blends for mobile onsite refueling every day of the week. We also have dyed/off-road/heating oil blends of B20. If you are an over the road fleet we can provide B20 at our cardlocks as well as help you procure it with a fleetcard over the road. Let us know if we can be of help.

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About Diesel Fuel 150 150 Star Oilco

About Diesel Fuel

Bulk Diesel Fuel Frequently Asked Questions

Ultra Low Sulfur Diesel is 15 PPMDyed Off-Road Diesel

Where your diesel comes from and what you need to know about ASTM Diesel Standards and ISO cleanliness code.

Where do Pacific Northwest vendors get their fuel?

In the Pacific Northwest, diesel is fungible. Everyone buys their fuel from each other in some way or another.  

This means that every refiner is typically expecting to mix their diesel and gasoline products. The real difference is in the care a vendor takes to filter the fuel, additize and continuously check their fuel quality. If you are buying at the absolute lowest price possible, know that there is an incentive to skip any added value of quality assurance.

Through its Pacific Operations unit, Kinder Morgan operates approximately 3,000 miles of refined products pipeline that serves Arizona, California, Nevada, New Mexico, Oregon, Washington and Texas. With roots dating back to 1956, it is the largest products pipeline in the Western U.S., transporting more than one million barrels per day of gasoline, jet fuel and diesel fuel to our customers. The company-owned terminals also provide additional services, such as liquid petroleum product storage and loading facilities for delivery trucks.

Diesel Fuels

In the United States, diesel fuel is controlled according the American Society for Testing and Materials Standard D975-97.  This standard describes a limited number of properties that diesel fuels must meet.  It should be noted that the requirements are all performance- based.  They do not mandate the composition of the fuel, only the specific performance related requirements demanded of a fuel for a diesel engine.  The requirements of D975 are described below. 

ASTM Specifications for Diesel Fuel Oils (D975)*

* You can go to the source of ASTM HERE if you have an interest in really getting in depth.

Diesel fuel is characterized in the United States by the ASTM standard D975.  This standard identifies five grades of diesel fuel. We are only going to talk about the two most popular commercially diesel fuel used — No 1 and No. 2 diesel. The ASTM D975 standard is made up of a series of different tests that check the characteristic ranges of a fuel to confirm it is adequate to operate in your equipment. In simple terms, they are checking for specific gravity, the vapor point (when it turns into a gas), the flash point (when it catches fire), the dirt content, water content (how much microscopic entrained water), and a host of other requirements diesel must meet in order to be legal to be sold for use in your engine.

Grade No. 1-D and Ultra-Low Sulfur 1-D: This is a light distillate fuel for applications requiring a higher volatility fuel to accommodate rapidly fluctuating loads and speeds, as in light trucks and buses. The specification for this grade of diesel fuel overlaps with kerosene and jet fuel, and all three are commonly produced from the same base stock. One major use for No. 1-D diesel fuel is to blend with No. 2-D during winter to provide improved cold flow properties.  Ultra Ultra-Low sulfur fuel is required for on-highway use with sulfur level < 0.05%. 

Grade No. 2-D and Ultra-Low Sulfur 2-D:  This is a middle- or mid-grade distillate fuel for applications that do not require a high volatility fuel. Typical applications include high-speed engines that operate for sustained periods at high load. Ultra-Low sulfur fuel is required for on-highway use with sulfur level < 0.05%.

RecologyDealing with Dirty Fuel and Today’s Tier 4 Engines

Water and dirt are the biggest concerns for fuel quality. Why? Because no matter how perfect fuel is refined, these two elements can find their way into fuel and crash its performance. Water and dirt often build up in tanks just from the temperature change between night and day, causing a bulk fuel tank to breathe. Condensation and dust can also find their way into a bulk storage tank. If not addressed, they build up and will cause mechanical failures.

Dirty fuel will cause premature parts failure in equipment of any age. But newer equipment has far tighter tolerances than what we saw in previous decades. Today’s new and improved Tier 4 rail injector engines are more efficient, they burn cleaner, and run better, they are more powerful than ever before. But there are things that make fuel quality more important than ever. Because of the extremely high pressures (upwards of 35,000psi at the injector tip), the possibility of damage from dirty wet fuel is more prevalent than ever. This damage is much more pronounced in newer equipment with High Pressure Common Rail (HPCR) fuel systems. Hard particulate is commonly referred to as “dirt,” but is in fact made up of a wide variety of materials found at job sites (coal, iron, salt, etc.), generated by fuel tanks and lines (rust, corrosion, etc.) and inside engines (carbonaceous materials and wear particles).

Frequent diesel fuel filter changes — as well as the expensive, and time consuming, task of cleaning diesel fuel tanks — have become acceptable periodic maintenance, instead of a warning signal, for diesel engine failure. Diesel fuel filter elements should last a thousand hours or more, and injectors should endure 15,000 hours. However, since diesel fuel is inherently unstable, solids begin to form and the accumulating tank sludge will eventually clog your diesel fuel filters, ruin your injectors and cause diesel engines to smoke.


  • Clogged and slimy filters
  • Dark, hazy fuel
  • Floating debris in tanks
  • Sludge build up in tanks
  • Loss of power and RPM
  • Excessive smoke
  • Corroded, pitted injectors
  • Foul odor

The solids that form as the result of the inherent instability of the diesel fuel and the debris formed in the natural process of fuel degradation will accumulate in the bottom of your fuel tank. The sludge will form a coating or “bio-film” on the walls and baffles of the fuel tank, plug your fuel filters, adversely impact combustion efficiency, produce dark smoke from the exhaust, form acids that degrade injectors and fuel pumps, and impact performance. Eventually, fouled diesel fuel will clog fuel lines and ruin your equipment.

The Bigger Picture: ISO (International Standardization Organization)ISO Chart 1

In today’s world, the definition of what constitutes clean or dirty fuel is critically important and, as such, fuel cleanliness levels are now measured and reported according to the ISO Cleanliness Code 4406:1999. The International Organization for Standardization (ISO) created the cleanliness code to quantify particulate contamination levels per milliliter of fluid at three sizes: 4μ, 6μ, 14μ. Microns.

Fuel Cleanliness vs. Engine Technology

Fuel cleanliness levels using the ISO4406:1999 method were officially documented as a global standard only as recently as 1998 with the development of the Worldwide Fuels Charter (WWFC). Since its inception, the charter has established a minimum cleanliness level for each of the diesel fuels under various available categories around the world.

Most mainstream engine OEM’s now subscribe to these standards. Interestingly (and somewhat troubling to note), however, is that fuel cleanliness levels as specified by engine OEM’s and the WWFC have not changed since their inception in 1998, despite the enormous advances in fuel injection technology. This relationship is best represented in the previous table that identifies the advances in fuel injection systems and clearly highlights how OEM’s and the WWFC have not responded to reduce fuel cleanliness in accordance with advancements in technology.

Diesel Fuel Injection – Advancing Technologies & Cleanliness Levels

ISO Chart 4This table  identifies that, over time, fuel injector critical clearances have halved and fuel pressures have doubled, yet the level of fuel cleanliness being specified has not changed in accordance with such advancements. In fact, the same cleanliness levels specified in 2000 are still being used today despite these magnificent technological design advancements by engine manufacturers worldwide.

Leading fuel injector manufacturers around the world have clearly identified and communicated that they require ULSD fuels with ISO fuel cleanliness levels as low as ISO12/9/6 to maintain ultimate performance and reliability. It is here where we see an enormous mismatch in what the fuel injection OEM desires as a fuel cleanliness level, to what the engine OEM’s and the WWFC are advising the industry. The following table identifies the discrepancies in fuel cleanliness levels.

Diesel Cleanliness Levels

 ISO Chart 3                        






WWFC Diesel Category Fuel Cleanliness Standards                                                                                                      ISO Chart 5





Damage Caused by Hard Particulate

Hard particulates cause problems with moving parts in the fuel system. This can lead to starting problems, poor engine performance, idling issues and, potentially, complete engine failure. All too common, hard particulates damage engines.

The spray pattern generated by the HPCR injector is critical for proper combustion and overall fuel system performance. (1) sm-injector-with-red-light-Bosch

It must be extremely precise in terms of quantity, distribution and timing. Ball seat valves are sealed with balls that are only 1mm in diameter. A good seal is absolutely necessary for proper injection. Damage from erosive wear, such as shown below, will cause over fueling, leading to decreased fuel efficiency and eventually shut you down altogether.

hpcr injector damaged by hard particulate(3) high-pressure-fuel-system-wear

Pump performance can also be compromised by scoring and abrasive wear. These issues are magnified by tighter tolerances and extreme pressures in HPCR engines. In these circumstances, it is the smallest particles (1-5 microns in size) that cause the most damage, virtually sand blasting part surfaces.

Allowable Levels of Hard Particulate 

(4) dirt-in-vs-allowed-in-1000-gal-dieselIn some parts of the world, 10,000 gallons (38,000 liters) of “typical” diesel contains 1-1/2 lbs (700 grams) of hard particulate; this is 1000 times more than the 1/4 oz. (0.7 grams) per 10,000 gallons (38,000 liters) that is allowed by the cleanliness requirements of high pressure common rail fuel systems. In reality, there is no “OK” level of hard particulate. Injector manufacturers are very clear that damage caused by hard particulate reaching the engine is not a factory defect, but rather the result of dirty diesel that is not fit for use in HPCR fuel systems. At the end of the day, the end user is responsible for the fuel he puts into his equipment, and the consequences thereof.

How Dirt Enters Fuel

Dust and dirt are all around us, especially on job sites. Diesel fuel is fairly clean when it leaves the refinery but becomes contaminated each time it is transferred or stored. Below you will find some of the key contributors of fuel contamination:

Pipelines: Most pipelines are not new, and certainly not in pristine condition. Corrosion inhibitors are added at most refineries to help protect pipelines, but rust and other hard particulate is nevertheless picked up by the fuel that flows through them.

Barges and rail cars: How often are they drained and scrubbed out? What was in the last load? Where did it come from? How much of it was still in the tank when your load was picked up? How long was it in transit? Is the tank hermetically sealed? There are many opportunities for contaminants to make their way into the fuel.

Terminal tanks: Terminal tanks usually see a high rate of turnover, so there is not much time for the fuel to pick-up contamination from outside ingress. Has the tank ever received a “bad load” from a pipeline or a barge? Has larger dirt had a chance to settle on the bottom of the tank? How often has it been cleaned out? Was it just filled? Did the bottom get churned up in the process? How full was the tank when your fuel was loaded into the delivery truck? There are many variables that can affect fuel cleanliness.

Delivery trucks: All the same issues that apply to stationary tanks also apply to tanker trucks, except that truck tanks never get a chance to settle. In addition, have you ever considered how much dirt gets into that tanker while it is delivering fuel to a customer, potentially a customer in an extremely dusty environment? As fuel flows out, air is sucked in to displace it. Is there anything protecting the inside of the tank from all the dust in the air? Generally not. Venting is typically completely unprotected, as seen in the image to the right.

Storage tanks: Onsite bulk storage tanks typically see less rapid turn-over than terminal tanks. In addition to those issues, yard and jobsite tanks can also develop serious problems with other sources of contamination, such as the ingress of dirt and water, condensation, rust, corrosion, microbial growth, glycerin fall-out and additive instability. Time and temperature become big factors affecting fuel quality.

Dispensing process: How far does your diesel need to travel between the bulk tank and the dispenser? The more pipe it runs though, the more potential there is for contamination. Are your dispenser nozzles kept clean? Are they ever dropped on the ground? Then what? What about the vehicles’ fuel tank inlets, are they clean? Think about the extremely tight tolerances in your fuel system, then take another look at housekeeping issues. You will see them through new eyes.

Onboard fuel tanks: Contamination continues even after the fuel is in the equipment. What has that tank seen in the past? Has it been left stagnant for long periods? What kind of protection is there on the equipment’s air intake vents? Heavy equipment does hard, dirty work.

Engines: Unfortunately, even if the fuel in your tank could be perfect, additional contamination is generated by the fuel system itself. Wear particles are created by mechanical friction. High heat and extreme pressure generated inside the modern engine, lead to coking and the creation of carbon products at the injector. Much of this internally-produced particulate is returned to the fuel tank, along with the unburned diesel.

The Bottom Line

No one gets special fuel, no one has better fuel, no one has cleaner fuel. Diesel fuel vendors get the same fuel, from the same pipeline, delivered to the same terminals. We all wait in the same lines with our tank trucks to get that same fuel. So ask yourself: Given that the fuel is the same, what sets one vendor apart from all the others? Star Oilco Premium Diesel fuel is treated with Hydrotex PowerKleen® additive running through Donaldson filtration systems.

Clean, dry, premium diesel


Read about Star Oilco’s approach to Fuel Quality Assurance: Star Oilco – Precision Fuel Management

Read about dealing with biological growth in your diesel tank: Bioguard Plus 6 biocide treatment for diesel

Get Chevron’s Technical Manual to Diesel Fuel (essentially an easy to read text book on diesel): Chevron’s Fuel Technical Review

Get a white paper from Donaldson Filtration on tier 4 engines and fuel cleanliness: Donaldson on Tier 4 Engine Fuel Contamination

Read more about Donaldson Desiccant Breathers for bulk diesel tanks: Why use a Donaldson Desiccant Breather for a bulk diesel storage tank.

Bulk diesel desiccant filters, dry fuel, and keeping your diesel fuel clean. 150 150 Star Oilco

Bulk diesel desiccant filters, dry fuel, and keeping your diesel fuel clean.

Bulk diesel fuel delivery and storage best practice.

Use Desiccant Breathers and Premium Diesel additives to improve your diesel performance and reduce maintenance cost.


Save tens of thousands on fleet maintenance costs!

How? Clean, dry, and premium-treated diesel.

Reduce injector wear and particulate trap service needs with simple steps focused on fuel quality. Get the water and dirt out of your fuel with aggressive filtration and then upgrade the fuel’s lubricity, detergency, cetane, and performance with Hyrdrotex Power Kleen premium diesel.

Call Star Oilco if you want to permanently solve bulk diesel quality issues with our Precision Fuel Management program.

Do you have a bulk diesel storage tank?

Does that tank seem to have water in the bottom of it and you can’t seem to figure out where it’s coming from?

You call your diesel supplier and they say they know it isn’t them. If that’s your experience, Star Oilco can explain where that water is probably coming from. With the help of Hydrotex, Star Oilco can also lab test your fuel quality and prove we are in improving it as well.

desiccant filter in field

All storage tanks are different. But for the most part, if your tank seems to take on water randomly. It’s probably from the tank breathing. Especially if you have a large above ground tank. In fact, if you tracked it on a calendar it probably happens the same time of year in conjunction with a weather pattern your tank responds to.

How it works is as the temperature changes the tank’s space that is not filled with fuel will breathe in and out. The temperature and air pressure move air in and out of the tank. As does dispensing fuel out of the tank and then refilling the tank. When that happens, especially if you have a significant amount of humidity in the air or misting rain, water makes it’s way into your fuel supply. As temperatures change, moisture is drawn into the tank, condenses on the inner wall of the tank, and then deposits itself on the bottom of the tank.

This water not only poses a risk to your engines, but if your fuel isn’t treated for stability and performance, that fuel is guaranteed to start growing bugs and algae that will spread throughout your fleet and will have your mechanics spinning filters and dealing with random problems due to this diesel biological growth.

This problem is also exacerbated by ineffective fuel additives trying to keep your fuel dry, clean and safe for your injectors to process, which ensures that water does not get absorbed by your diesel. A single drop of water falling out of solution in today’s high pressure fuel rails and your engine can blow an injector.



Desiccant diagram

Star Oilco recommends Donaldson desiccant filters, given their excellent full line of products and support. More on the full Donaldson Clean Dry Fuel program here: Donaldson Clean Diesel Kits Brochure.

The Donaldson desiccant breaker mounts to the top of a tank at it’s vent point. This addition seals the point of failure for water to get into your tank. Though in some cases it doesn’t stop 100% of water from ending up in your fuel tank, it definitely guarantees you know where it won’t be coming from, the environment around your tank.

(NOTE: If dealing with underground storage tanks also be aware that if you seal the vent with a desiccant filter and you still have incident’s of water, it might be a leak in the bottom of the tank where rain water is making its way into the tank.)

By using Donaldson filters, Star Oilco also gains the benefit of support from Hydrotex PowerKleen diesel fuel lab to analyze fuel to guarantee that the before and after samples of the fuel are moving as expected and the problem is solved. Running diesel samples can cost as much as $200 each time–having a partner that backs up our solutions with ASTM and ISO measured verification is a must.

The first step in getting better performance from your diesel fuel is to test your bulk diesel storage tank.

To get a complementary ASTM diesel fuel test, contact Star Oilco for assistance.

Clean, dry, premium diesel

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BioDiesel Feedstocks – Evening Primrose & Fish Oil 150 150 Star Oilco

BioDiesel Feedstocks – Evening Primrose & Fish Oil

The two feedstocks we are looking into this time are Evening-Primrose Oil and Fish Oil. Here is a link to the main page of feedstocks we have examined so far.  As we continue our deeper look into different types of feedstock that Renewable Energy Group (REG) studied in 2009 in the Feedstock and Biodiesel Characteristics Report.

Evening-Primrose Oil

The Common Evening-primrose (Oenothera biennis) is also known as evening star, sun drop, German rampion, weedy evening primrose, hog weed, King’s cure-all, or fever-plant.  This plant is native to North America and grows throughout most of the continental US and in Canada. Oenothera biennis (common evening primrose). Flowers and buds

A unique aspect of this plant is that it has a bright yellow flower blooms that is open in the evening and then is closed at noon.(source)  This plant can grow up to 6 feet tall and is a biennial, meaning it lives for 2 years flowering the second year. The plant has leafy branched stems that are ridged and usually has fine white hair.

According to Friends of the wild flower:

“The leaves are both basal and stem. Basal leaves taper to short stalks and form a rosette in the first year of growth. The stem leaves develop the second year when the flowering stem rises; they are alternate, lance-like, wavy edged, slightly toothed, slightly hairy on both surfaces, with one main central vein and fine laterals. They can be up to 8 inches long near the base and 1/4 as wide, but become considerable shorter near the top of the stem.”

A simple google search shows that this plant has medicinal uses, known by some of the indigenous tribes of North America for hundreds of years. Some of the common uses were to treat bruises with a poultice and use the leaves in a tea as a stimulant. The drug in the plant can be used as a sedative and and as an astringent. The oil the plant produces is full of fatty acids and is sold as a dietary supplement.

The roots of the plant can also be boiled and eaten if they haven’t flowered yet. The leaves of the plant can be used before flowering in salads. Even the flowers can be eaten and are said to have a sweet taste.

The ability of the plant to grow in arid conditions and not need a lot of water adds potential of this plant to provide nutrients, oil and medicinal material for drier locations.


Evening Primrose Oil and the Bio-Diesel it produces

Evening Primrose Certificate of Analysis



Fish Oil

The Fish Oil that REG used simply says “Fish oil was obtained from a commercially available source in Peru.”  The types of fish that are used to make fish oil in Peru are anchovy, herring, menhaden or sardines.

This source was likely the same that would be purchased to produce fish oil nutritional supplements or other food products. In the production of biodiesel there is a large potential for this product. Many of the toxins and imperfections that need to come out for human consumption wouldn’t effect the creation of biodiesel.  Fish oil that is produced in the process of fish processing has potential of removing waste from going to landfills. Several scholarly papers have been written on it.  If you would like to know a little more this article was written on the waste from salmon processing in Canada.

Fish Oil and the Fish Bio-Diesel that it produces

Fish Oil Bio-diesel Certificate of Analysis


Last article for biodiesel feedstocks was Coconut Oil and Coffee Oil.

Keep and make your diesel fuel cleaner 700 394 Star Oilco

Keep and make your diesel fuel cleaner

Clean, dry, premium diesel

What is Clean Diesel? 

Clean diesel is free of the contaminants that harm modern diesel engines. Today, there is a gap between ASTM diesel standards and the ISO cleanliness standards needed for use in high pressure common rail engines. Anyone operating a modern clean diesel engine is seeing the effect, including injector replacement, DPF regeneration, and a host of other fuel quality related maintenance concerns we never saw twenty years ago. On top of all of that, today’s refined diesel fuels are less storage stable then ever before. What is on the bottom of your bulk tank can also complicate matters further. When diesel is bought wholesale it typically meets and exceeds ASTM required industry standards, but almost always requires additional filtration to avoid excessive engine wear and premature part failures.

Having clean diesel requires an additional amount of care. Namely, you need to make sure that the fuel is aggressively filtered at 4 microns to catch the microscopic particles that are big enough to damage your modern diesel engine’s high pressure fuel rail system. Furthermore, clean diesel is fuel that is free of water and stabilized with Premium Diesel to guarantee no bacteria, yeast and other creatures can grow and further contaminate the saddle tanks on your trucks.

For more on clean diesel, see Donaldson’s description of “The New Clean” for an in-depth explanation of what ISO cleanliness and filtration mean for your diesel fleet.

Making Diesel Cleaner!

Knowing the quality of your fuel is the first step. This is done by taking samples off of the bottom of your bulk storage, as well as a representative sample from your fuel dispenser. Lab tests of those samples will tell you if you have water, biological growth, or dirt issues with your storage. The contaminants in the tank being sampled are almost always visible, which is to say that they look horribly ugly. If your fuel quality assurance has been on autopilot, do not be surprised if you find this. After gathering knowledge about your fuel, the next step is to get your fuel quality clean.

Filtration and tank bottom sampling is the start. Beyond that, the only way to improve your fuel quality performance is to filter your fuel, ensure water is not getting into the tank through condensation, and additize it with a Premium Diesel additive to upgrade the performance of the fuel. Many fleets today are seeing injector wear and continual problems with particulate trap maintenance. This is a combination of water in fuel and microscopic particles not captured by a 10 or 30 micron filter used at most diesel dispensers. You have to filter more aggressively than this.

Clean, Dry, and Premium Diesel!  Where To Start?

The first step is sampling your bulk diesel tank. We check your bulk tank for water and dirt, and make sure to meet the specifications your engine is built for. Star Oilco can help by providing a complementary diesel test for those fleets interested in taking control of their fuel quality assurance. Usually when testing fuel, we take a sample off of the tank bottom as well as a representative sample out of the fuel dispensing nozzle.

What we usually find is ASTM specification diesel fuel (it meets ASTM spec) that is higher than you’d want (still in spec) for water with far more dirt than the OEM’s would want to see in your engine. This dirt fails to be within the “ISO Cleanliness” specifications recommended by engine manufacturers. Usually we also see water on the bottom of the fuel tank, which is a likely source for future or current biological growth in your fuel tank.

Star Oilco can help you fix this! The first step is to sample your fuel tank.

NOTE: If you have a current biological growth problem in your bulk fuel tank or fleet, your first step is to treat that effected fuel with a diesel microbiocide to kill the bugs growing in your tank. For more on this, see our Valvtect Plus 6 Diesel Microbiocide page.

Tank Testing Form

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