Technology

The future of biofuels

 By RP Siegel

In the efforts to decarbonize the transportation industry, vehicles with varying degrees of electrification get most of the attention. But liquid fuels will predominate a while longer thanks to the delivery infrastructure circling the globe, dispensing fuels that contain significantly more energy per kg than batteries. That leaves a gap for a clean liquid fuel which is quietly being filled with biofuels. They are clearly controversial, but are they getting the respect they deserve? Given how much is at stake here, perhaps it’s time to take a closer look…

In the efforts to decarbonize the transportation sector, vehicles with varying degrees of electrification get most of the attention. But liquid fuels will predominate a while longer thanks to the delivery infrastructure circling the globe, dispensing fuels that contain significantly more energy per kg than batteries.

That leaves a gap for a clean liquid fuel which is quietly being filled with biofuels. According to the Renewable Fuels Association, biofuels have eliminated 232 million metric tonnes (255 short tones) of carbon, the equivalent of taking 5 million cars off the road since 2007. Yet, it is reportedly not even being mentioned by the US delegation at the COP21 in Paris. Biofuels are clearly controversial, but are they getting the respect they deserve? Given how much is at stake here, perhaps it’s time to take a closer look.

First-generation biofuel, also known as starch-based ethanol, represents the vast majority of biofuel that is being added, as a 10% blend, into gasoline today. For the most part, in the US, it is derived from corn. Corn sugars are distilled into ethanol the same way that whiskey is made.

At present, corn production volumes have grown enormously, as has the efficiency of conversion. The supply chain is well prepared to keep pace with increasing goals. However, the distribution infrastructure has not kept pace, citing concerns about a blend wall.

Corn ethanol has a lot of detractors with a variety of objections: everything from the fact that it’s a big government program, to opponents of big Ag on environmental grounds, to petroleum interests who see it as a competitor. But when all is said and done, corn ethanol, is the first step in a journey that will lead to clean, renewable liquid fuels that can play an enormous role in rapidly reducing carbon emissions.

Here are a few things that are not commonly known about ethanol. Ethanol has a very high octane rating. This means that blending ethanol into gasoline eliminates the need to blend in costlier and more toxic additives to raise the octane level to the required minimum of 87, a fact overlooked in most cost comparisons.

While ethanol contains less energy per gallon than gasoline, its high octane rating actually allows it to generate more power in an engine with a high compression ratio. That is why Formula 1 racing cars use ethanol as their fuel of choice. Unfortunately, those engines cannot run regular gasoline without harmful “knocking.” As Wolfgang Warnecke, Shell’s Chief Scientist for Mobility said, “As engine engineers, what we’d like to see is an engine that can vary its compression ratio. That way, depending on the fuel you are running, the compression ratio would adapt.” No such engine is yet on the market.

Those concerned that using corn for fuel could be taking food off the table may not realize that only the starch from the corn is used. The protein fraction, which is 40% of the corn, is returned as animal feed known as distiller’s dry grain (DDG).

(Biofuel dream come true for in India)

Newer processes also separate out corn oil, which can be used for food or to make biodiesel. As the levels of corn being produced increase to keep pace with increasing gasoline consumption, more of these food products also become available. Says Jack Rogers, Biofuel Global Marketing Manager for Novozymes, a Danish producer of enzymes used in ethanol production, “People and animals are starch rich and protein poor.”

While people argue that when all the energy required to grow corn is factored in, corn ethanol is barely net positive; that equation continues to improve as both farm productivity and conversion efficiency grow (thanks to high performance enzymes). Says Rogers, “since 2005, the number of gallons of ethanol per acre, has increased from 409.7 to 489, close to a 20% increase.” Costs have fallen as well.

These improvements, however, pale in comparison to the reduced carbon footprint enabled by second-generation, or cellulosic ethanol. Cellulosic, refers to the woody parts of the plant, such as the leaves and stalks, which have little or no food value. It also includes wood chips, grasses, and forestry residue. This opens the door to far less energy-intensive plants that can grow without fertilizers or cultivation.

But while starch-based ethanol uses age-old distillation techniques, extracting sugars that are biochemically locked into cellulose, was not something that people knew how to do. So, cellulosic ethanol, which was the prize all along, for which the whole corn ethanol program was largely used to create an infrastructure, became a challenge, to the biotech industry.

According to Thomas Schrøder, Head of Biomass Conversion at Novozymes the results stack up something like this. If we look at carbon footprint, and give gasoline a reference rating of 100, we find that corn ethanol, depending on how it is produced, will have a footprint in the range of 50-70. Cellulosic ethanol, on the other hand, can be produced with a footprint ranging from 30 to zero.

Though the industry is in its infancy, the technology has arrived. DuPont recently opened the world’s largest cellulosic plant in Nevada, Iowa. It will produce 30 million gallons of ethanol from 375,000 metric tons (413 million short tons) of corn stover provided by local farmers. The company plans to license its technology in several countries including China. All told, there are currently two commercial plants in Brazil, three in the US, two in Europe, and one in China, representing a total investment of $2 billion. While the chemistry has been solved, says Schrøder, there are still issues associated with the mechanics of the process that are holding things back. In short, “how do you push through 30-50 metric tons (33-55 short tons) of biomass per hour without jamming up the works?”

Numerous biotech startups are building demonstration plants utilizing various approaches. Says Schrøder, “Most plants that are out there today are there because someone wanted to demonstrate the viability of the technology.”

Algae feeds directly on CO2, which means it could play a dual role in the climate battle. Not only could it displace hydrocarbon fuels, but it could also be coupled with an emission source, such as a power plant to capture CO2

One such startup is Sweetwater Energy of Rochester NY. They have patented technology for producing low-cost sugars and clean lignin fiber from multiple non-food plant materials. Both the sugars and the lignin can be used in a wide variety of commercial products. Another company working on advanced biofuels is Red Rock Biofuels. They leverage a commercially proven Fischer-Tropsch technology to convert sustainably harvested biomass residues from forests and sawmills into jet fuel and diesel products. The company is preparing to begin construction of its first refinery in Lakeview, Oregon in early 2016. Both Red Rock and Sweetwater are also working on advanced biofuels.

Others, like Maryland-based Fiberight are looking at creative ways to utilize cellulosic production as part of an integrated process. Fiberight is a waste-disposal company that has launched a business of extracting maximum value from the waste stream. Separating food and organic matter from pulp from cardboard, the company produces both compressed gas, which is used to run their trucks, as well as cellulosic ethanol. The company has projects underway in the UK, in Maine and a cellulosic facility in Iowa that takes in 650 metric tons (717 short tons) of trash per day and produces 8 million gallons of ethanol per year.

As promising as these second-generation biofuels are, they are not the end of the story. Third-generation and even fourth-generation biofuels are in the works. Third-generation biofuels use a feedstock that is potentially less expensive and far easier to work with than corn, wood, sawgrass or sugarcane. That would be microalgae. According to biofuel.org, “When it comes to the potential to produce fuel, no feedstock can match algae In terms of quantity or diversity… First, algae produce an oil that can easily be refined into diesel or even certain components of gasoline. More importantly, however, is a second property in it can be genetically manipulated to produce everything from ethanol and butanol to even gasoline and diesel fuel directly.”

Algae feeds directly on CO2, which means it could play a dual role in the climate battle. Not only could it displace hydrocarbon fuels, but it could also be coupled with an emission source, such as a power plant to capture CO2. Pond Biofuels has partnered with a cement plant in Canada to produce biodiesel from algae. Over 30 companies are currently involved in the production of oils from algae. A number of them, such as Sapphire Energy and Solazyme are producing high value oils for food and pharmaceuticals as they transition into a higher volume biofuel business. Algenol plans to announce a commercial production facility in the US this year capable of 8,000 gallons of fuel per acre at $1.30 per gallon.

Last, but certainly not least, are the fourth-generation fuels. Sweetwater Energy is working with Naturally Scientific of Nottingham, England to develop an engineered biological process that can create oil for biodiesel, directly from carbon dioxide, not using algae, as others are trying, but rather through the use of an embryogenic cell culture.

Says Dr. Sarad Parekh, Sweetwater’s CTO, “The flexibility of this process is that you can convert sugars into oil. This is totally different from the conventional seed processing where you have to grow the seed, cultivate, harvest, dry, crush, extract and refine. The beauty of this process is that it eliminates many of these steps, just as plants will do in the field, but we are doing it in a contained tank.”

Eni's new Venice biorefinery

Finally, cellulosic producer Red Rock Biofuels recently announced a merger with Joule, inventors of a “reverse combustion” process that can connect to a CO2 exhaust stream, and using only engineered bacteria, non-potable water, and energy provided by solar panels, produce liquid hydrocarbon fuels. Says Tom Jensen, Executive VP for Joule Unlimited,“We believe it’s possible to develop sustainable solutions for hydrocarbon combustion.”

Instead of burning a fuel with oxygen and producing energy plus CO2, they take CO2, add energy, which they get from solar panels, and use it to produce either ethanol or diesel. They do it using photosynthetic micro-organisms called cyanobacteria, some of the oldest living organisms on the planet. Last year they commissioned an end-to-end integrated plant in New Mexico, co-located next to industrial carbon dioxide emitters which provide the “fuel.”

One acre of bacteria, using Joule’s process, can make as much as 25,000 gallons of ethanol. That’s ten times as much as can be made from forest residue and fifty times that which can be grown from corn.

Combining Joule with Red Rock will provide some powerful synergies. The waste CO2 from the Red Rock process can be input to the Joule process, while the depleted bacteria from Joule can be used as biomass for Red Rock. It’s too early to calculate the overall efficiency of this system, but, says Jensen, the results will be accretive. It’s not unlike adding cellulosic capabilities to a corn ethanol plant, or a combined heat and power system, where additional output is derived from the same level of input. Says Joule CEO Serge Tchuruk,”I don’t think anybody can claim to be carbon-neutral, but I think we are close.” The company plans to build a 1,000 acre facility in 2017.

Eni, the Italian company that sponsors this publication, has also been quite active in biofuels. In Europe, the emphasis there has been on diesel which is more widely used compared to the US. The EU Renewable Directive (similar to the RFS), calls for a 10% blend by 2020, with most of that going into diesel fuel. Eni has, in collaboration with the American company UOP, developed a proprietary EcofiningTM process.

According to Carlo Perego, Director of Eni’s Research Center for Non-Conventional Energy, the process accepts a variety of feedstocks including, rapeseed, soybean, carinata, palm, pennycress, jatropha, camelina, tallow, lard, used cooking oils and algal oil. This green diesel can be blended with conventional diesel in any amount without adverse effects. The process can also produce green LPG, naphtha, and jet fuel as byproducts. The company has a green refinery online in Venice, which has been producing 300,000 metric tons (330,000 short tons) per year since April 2014. They are also building a green refinery in the town of Gela, Italy that will have an annual capacity of 750,000 metric tons (827,000 short tons), and are conducting a demonstration of algae-based oil and lignino- cellulosic based microbial oil, both suitable for EcofiningTM.

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.