Technology

How Eni green diesel was born

 By RP Siegel

RP Siegel looks at the joint development of the Ecofining process that Honeywell UOP’s Renewable Energy and Chemicals business has undertaken in conjunction with ENI. The process was just recognized with the 2015 Platts Industry Leader Award for Biofuels. Author explains how ENI made the decision to revamp its Venice refinery, which was becoming redundant, from petroleum to biofuel and how new green diesel could bring a turnaround to the industry…

Back in 2003, the European Union came out with a directive in response to climate change, requiring that a growing portion of all transportation fuels be produced from biological sources. According to the directive, that number will need to reach 10% by 2020. Eni, the integrated energy company based in Rome, Italy, decided to confront the challenge with a new high quality biodiesel using an approach that had been in development for some years. The approach was called Ecofining. The process can provide an alternative to traditional biodiesel, known as fatty acid methyl ester or FAME.

the challenge

“By 2020, the EU aims to have 10% of the transport fuel of every EU country come from renewable sources such as biofuels. Fuel suppliers are also required to reduce the greenhouse gas intensity of the EU fuel mix by 6% by 2020 in comparison to 2010.”

-european commission

TM

ECOFINING

PROCESS

BIODIESEL

CONVENTIONAL PROCESS

BIOLOGICAL

FEEDSTOCK

BIOLOGICAL

FEEDSTOCK

+

+

METHANOL

HYDROGEN

hydrotreatment

transesterification

BIODIESEL

(FAME)

GREEN

DIESEL

+

+

GLYCEROL

PROPANE

The use of traditional biodiesel, while greener than petro-diesel, involves a number of compromises: NOx and Sox emissions, a cloud point that is dependent on the feedstock used, reduced fuel economy, filter clogging, and the need to be blended with conventional diesel in order to be used in unmodified engines. Other issues listed on Eni's website include, “low levels of chemical stability, inadequate cold reactions, fouling and low levels of energy content per unit of fuel." Many car manufacturers now advise using no more than a 7% blend of biodiesel in their engines.

performance comparison

GREEN

DIESEL

FOSSIL DIESEL

BIODIESEL

lower emissions of nitrogen oxides

standard

+10%

-10% to 0

NO

EMISSIONS

x

40-55

50-65

70-90

CETANE

it improves performances*

COLD FLOW

PROPERTIES

baseline

poor

excellent

OXIDATIVE

STABILITY

baseline

poor

excellent

*high-cetane fuel improves performances: fluidity of gear shift, cold start,

carburization in the first 15 minutes, less noise, less fuel consumption ( up to -4%)

GREEN

DIESEL

FOSSIL DIESEL

BIODIESEL

standard

+10%

-10% to 0

NO

EMISSIONS

x

lower emissions of nitrogen oxides

40-55

50-65

70-90

CETANE

high-cetane fuel improves performances: fluidity of gear shift, cold start, carburization in the first 15 minutes, less noise, less fuel consumption ( up to -4%)

COLD FLOW

PROPERTIES

baseline

poor

excellent

OXIDATIVE

STABILITY

baseline

poor

excellent

At the time of the directive time, Eni was having regular meetings with UOP, a division of Honeywell from whom they license refinery technology. The companies discussed the possibility of working together on the development of this new type of biodiesel, and in 2005 an agreement was reached. UOP applied its expertise to Eni's catalytic process and made some further refinements.

European refineries were undergoing financial challenges at that time, due to shrinking margins resulting from price differences between West Texas Intermediate and Brent Crudefrom the North Sea.

Eni made the decision to revamp its Venice refinery, which was becoming redundant, from petroleum to biofuel. This was the first such conversion in the world.

the steps of biofuel conversion

2nd half 2005

ENI and Honeywell UOP

started a joint R&D project

on innovative biofuels

2007

ENI/Honeywell UOP

Ecofining TM patent

2nd half 2005

ENI and Honeywell UOP started a joint R&D project on innovative biofuels

2007

ENI/Honeywell UOP Ecofining TM patent

In this way, according to Giacomo Rispoli, Executive Vice President of Portfolio Management & Supply and Licensing for Eni, the company was able to reduce its excess capacity without closing a plant. Converting a traditional oil refinery into a “green refinery” saved a considerable amount of time and money. The conversion process was granted a patent in September 2012. According to Rispoli, the turnaround started in September 2013, and was up and running by May 2014. The cost was somewhere between 20-25% of what a brand new Ecofining TM facility would have cost.

COST OF A BRAND

NEW BIOREFINERY

20-25%

COST OF VENICE REFINERY

CONVERSION TO A BIOREFINERY

2012

“Refinery conversion

to a biorefinery”

Eni patent

2013

First Green Refinery

Project starts

May 2014

Green fuels production starts from Venice Green Refinery

2012

“Refinery conversion

to a biorefinery”

Eni patent

2013

First Green Refinery

Project starts

May 2014

Green fuels production starts from Venice Green Refinery

Jim Andersen, Business Director for Green fuels at UOP, says the chief merit of the Ecofining technology is its ability to work with a wide variety of feedstocks ranging from fats, oils, greases, and algae, to a variety of oil seeds — and to meet any fuel specification for either diesel or aviation fuel with any of them. The process, which became commercially available in 2007, also achieves a 20 percent reduction in greenhouse gas emission levels.

Paramount, CA

Norco, LA

To get from that point to a new refinery was a lengthy process that involved establishing the supply chain, testing the process with the various feedstocks, getting agency certification for the fuel produced, and obtaining financing. At the same time Eni had to do a lot of upfront design work to plan the conversion of the petro plant into a biofuel plant.

In the interim, UOP designed and completed the Diamond Green refinery based on the same process. It is located in Norco, Louisiana, and jointly operated by Valero’s Diamond Alternative Energy subsidiary and Darling Ingredients. More recently, AltAir converted an existing petroleum refinery to one that produces renewable jet fuel using the same process in Paramount, California.


In December of 2015, Honeywell/UOP and Eni received the Platts Industry Leader Award for Biofuels in recognition for its role in multiple renewable fuel technologies through the Ecofining process. From Eni’s perspective, unlike FAME-type biodiesel, which contains oxygen, this new Green Diesel is a pure hydrocarbon, which means Sulphur and nitrogen-based pollutants will be low. It can be used in unmodified diesel engines at full strength or at any blend ratio. In the industry, that's known as a “drop-in fuel”. But the Green Diesel produced by Ecofining, also referred as a hydrotreated vegetable oil (HVO), is not merely a cleaner, no-compromise alternative to FAME-based biodiesels.

2014

Agreement with the Italian Navy to formulate and produce a new military ship fuel containing at least 50% of Green Diesel

2015

Honeywell/UOP and Eni received the Platts Industry Leader Award for Biofuels

2014

Agreement with the Italian Navy to formulate and produce a new military ship fuel containing at least 50% of Green Diesel

2015

Honeywell/UOP and Eni received the Platts Industry Leader Award for Biofuels

“New Green Diesel is a pure hydrocarbon, which means Sulphur and nitrogen-based pollutants will be low. It can be used in unmodified diesel engines at full strength or at any blend ratio...”
green diesel

GREEN

DIESEL

FOSSIL DIESEL

BIODIESEL

the absence of oxygen in the compound eliminates the risk of bacterial

contamination, this excludes the chance of filter clogging

0

11

0

OXYGEN, %

0.840

0.880

0.780

SPECIFIC GRAVITY

<10

<1

<1

SULPHUR, PPM

reduction of sulphur oxides, one of the causes of acid rain

the heating value describes the energy

released during the combustion

43

38

44

HEATING VALUE, MJ/KG

the liquid crystallizes/fixes at lower temperatures,

thus improving resistance to cold temperatures

-5

from -5 to +15

up to -20

CLOUD POINT, °C

standard

+10%

-10%

NOX EMISSIONS

lower emissions of nitrogen oxides

high-cetane fuel improves performances: fluidity of gear shift, cold start,

carburization in the first 15 minutes, less noise, less fuel consumption (up to -4%)

51

50-65

70-90

CETANE

ENI DIESEL +

contains 15%

of green diesel

FOSSIL

DIESEL

GREEN

DIESEL

BIODIESEL

0

11

0

OXYGEN, %

the absence of oxygen in the compound eliminates the risk of bacterial contamination, this excludes the chance of filter clogging

0.840

0.880

0.780

SPECIFIC GRAVITY

<10

<1

<1

SULPHUR, PPM

reduction of sulphur oxides, one of the causes of acid rain

43

38

44

HEATING VALUE, MJ/KG

the heating value describes the energy

released during the combustion

-5

from -5 to +15

up to -20

CLOUD POINT, °C

the liquid crystallizes/fixes at lower temperatures,

thus improving resistance to cold temperatures

standard

+10%

-10%

NO

EMISSIONS

x

lower emissions of nitrogen oxides

51

50-65

70-90

CETANE

high-cetane fuel improves performances: fluidity of gear shift, cold start, carburization in the first 15 minutes, less noise, less fuel consumption (up to -4%)

ENI DIESEL +

contains 15% of green diesel

FOSSIL

DIESEL

GREEN

DIESEL

BIODIESEL

the absence of oxygen in the compound eliminates the risk of bacterial contamination, this excludes the chance of filter clogging

0

11

0

OXYGEN, %

0.840

0.880

0.780

SPECIFIC GRAVITY

reduction of sulphur oxides, one of the causes of acid rain

<10

<1

<1

SULPHUR,

PPM

the heating value describes the energy released during the combustion

43

38

44

HEATING VALUE,

MJ/KG

the liquid crystallizes/fixes at lower temperatures, thus improving resistance to cold temperatures

-5

from -5 to +15

up to -20

CLOUD POINT,

°C

lower emissions of nitrogen oxides

standard

+10%

-10%

NO

EMISSIONS

x

high-cetane fuel improves performances: fluidity of gear shift, cold start, carburization in the first 15 minutes, less noise, less fuel consumption (up to -4%)

51

50-65

70-90

CETANE

ENI DIESEL +

contains 15% of green diesel

Cetane is analogous to octane value in gasoline. A high-cetane fuel enables engines to operate more effectively, and can be blended with low-cetane diesel to meet transportation requirements. Some of the challenges in the development of this new fuel, beyond optimizing the catalyst, was in developing the know-how associated with such an unconventional supply chain, including fats rendered from meat, used cooking oil, oil from seed crops, and so on. The company had to learn to identify the fuel sources, their composition and their contaminants, and understand how to tune the process to be able to accommodate all of them, while maintaining the ability to predict yield and guarantee performance.

Says Andersen, “the process continues to be refined each year, primarily expanding the range of feedstocks that can be used. Feedstocks are plentiful even as more sources continue to be developed.” The pinch point is the capacity, which, while being utilized at 100%, still only accounts for 0.1% of total fuel consumption.

Says Rispoli, the Green Refinery idea is part of the “Eni Green Strategy,” based on the “make option.” “Eni has entered the biofuels market with a new generation of very high quality biofuels from renewable feedstocks. Eni was able to turn a critical situation into a great opportunity by investing in the innovative Green Refinery project. Green diesel, in particular, will be distinctive of Eni diesel fuel, assuring premium quality for stronger competition. Moreover, by this strategy, Eni can reduce traditional refining capacity without losing technical and scientific know-how and largely keeping the national refining industry structure.”

It is in fact a fuel that is superior to even conventional petroleum based-diesel in the areas of heating value, sulphur content, cloud point, NOx emissions, polyaromatics and most important of all: cetane value, where it is nearly double that of conventional diesel.

2017/2018

Green fuels production increase in Venice and starts from new Gela Green Refinery

2017/2018

Green fuels production increase in Venice and starts from new Gela Green Refinery

Given the success of the first conversion, Eni has decided to increase capacity at the Venice plant and convert a second refinery, located in Gela (Sicily), based on the same model.

In January 2016, Eni launched a new diesel fuel called Eni Diesel+, containing 15% of HVO. The use of Eni Diesel+ reduces CO2 emissions and other pollutants such as CO and particulate. The increase in the cetane number (from 55 to 70-90) helps to improve the combustion efficiency, and improve the acoustic comfort level (-2dB). Initial market data is showing a significant increase in sales.

Porto Marghera

Gela

consumption of vegetable oils

710 kton/year

expected production

530 kton/year

about the author
RP Siegel
Skilled writer. Technology, sustainability, engineering, energy, renewables, solar, wind, poverty, water, food. Studied both English Lit.and Engineering at university level. Inventor.