Early-stage, Breakthrough Technologies: Biofuels, 10 of the Best

By Lorenz Bauer and Gerald Kutney, Lee Enterprises Consulting

Special to The Digest

The concept of early stage, breakthrough technologies is a bit of an oxymoron: at an early stage how do you determine if it is a breakthrough technology? The only way is for experts to give their opinion, and, usually, they are wrong, as reality seldom matches, or even comes close to, the hype. There are many exotic which receive press attention but are not close to being commercially viable. In this report, we are focused on bioenergy and biofuels (and not bioproducts) that are moving from the lab to initial commercial demonstrations and that potentially solve significant barriers to commercialization.

Often the proponents have focused on the biomass conversion step and not a comprehensive technology process. There is an incorrect assumption that waste biomass is free and that side products can simply be burned to produce electricity without an economic penalty. As the effort to leverage the billions spent on biofuel research continues, the approaches have become more sophisticated and the various conversion strategies are becoming more carbon efficient. If these incremental improvements in efficiency eventually lower the cost of biomass derived feed to below that of fossil fuels, they will constitute a major breakthrough technology.

Never-the-less, to date there are no commercial technologies that meet the target of producing transportation fuel or large volumes of commodity chemicals at a cost close those of fossil derived materials.   Commercial focus has been shifting to higher value products.   However, the demand for these bioproducts is not large enough to support a biofuel industry that achieves the greenhouse gas reduction targets and they can have viewed as supplemental method for reducing the cost of fuel production. Separation and purification of the products increases operating and capital costs of these projects. True breakthrough technologies will directly lower the cost of fuel production, produce large quantities of commodity chemicals and/or improve the carbon utilization of the biomass. We have identified the following technologies as having the potential to significantly lower the costs of biomass conversion:

1. Advanced Fermentation
2. Biochar
3. Bioenergy Carbon Capture & Utilization (BECCU)
4. Catalytic fast pyrolysis
5. Ethanol conversion to other products
6. Gasification
7. Hydrothermal Carbonization/Liquefaction (HTC/HTL)
8. Upgrading Volatile Products
9. Solvent and ionic liquid pretreatment methods
10. Tars

Advanced Fermentation Technnology

New fermentation technologies based improvements in the microbes used continue to move towards commercial viability. There are recent reports of strains capable of efficiently coprocessing of xyloses (C-5) and hexoses (C-6) that will greatly lower the cost of cellulosic ethanol; see, for example, Biofuels Digest – “What’s New and Important about C5 and C6 Sugars?” (July 10, 2016). Organisms more tolerant to lignin and lignin derived products are being discovered. Acid tolerant microbes that allow processing more concentrated solutions that lower reactor sizes and facilitate product recovery are also reaching the demonstration scale. An overview of one such firm, Leaf Resources, recently appeared in Biofuels Digest on July 25^th (“Cellulosic Sugars Heading to Scale”).

Biochar

Biochar is not usually a fuel, but it is a co-product of processes that are, such as fast pyrolysis and gasification. The use of char as agricultural soil supplement is often cited, however, the value of the carbon in these applications is low.   Generating high value absorbent materials for a variety of applications is being developed.  Battelle has shown interest in the area of finding higher value uses for biochar.  Battelle, Proton Power, and Avello Bioenergy

have all been reported to developing biochar as adsorbents (Biofuels Digest on April 3, 2015 (“The Pyromaniax, Class of 2015: The Top 10 Pyrolysis projects in renewable fuels”).

BECCU

Carbon, capture and storage (CCS) has been promoted for decades, and was naturally suggested for bioenergy facilities early in the new millennium. The technology has evolved one step further, going beyond storage to utilization. BECCU can take a power-generation facility into the realm of carbon negative. On the June 27^th issue of Biofuels Digest, Jim Lane wrote (“The 20 Hottest Carbon Capturing Technologies of 2016”): Well, you can’t just capture carbon these days. That’s mundane. You have to use it, in a sustainable and novel way that makes carbon capture more affordable and cycles carbon more effectively through the industrial system. IEA Biofuels has a project in this rea (Task 41, project 5). In the USA, the Department of Energy is funding a number of projects aimed at CO2 utilization for production of chemicals and polycarbonate polymers. In principle the chemicals can be converted to liquid fuels, however, none of these are close to commercialization. CO2 utilization that are closest to reality use algae or other microbes to convert it to higher carbon compounds including ethanol. Companies included in this category that were listed in the “Top 50 Hottest in the Advanced Bioeconomy” by Biofuels Digest (February 17, 2016) were Lanzatech (#2), Algenol (#20), and Liquid Light (#50).

Catalytic Fast Pyrolysis

Three decades ago, fast pyrolysis would have been on this list, but a few high-profile demonstration facilities met with failure. A problem was the properties of the main product of the process, namely pyrolysis oil.   The technology went back to the research stage, and a new series of catalytic fast pyrolysis processes were developed for cracking or hydroprocessing the pyrolysis oil, improving its fuel properties. The January 5^th issue of Biofuels Digest reviewed one of the leading ventures in this sector, the IH² process of CRI (“IH2 Deep Dive: Breakthrough Technology has Commercial-scale in Sight”). IEA Bioenergy Task 34 works in this sector.

There are several new technologies that could greatly enhance the efficiency of catalytic pyrolysis. There are new catalysts being evaluated that can improve the yields. These include metal substituted zeolites along with less expensive options. Pretreatment methods that remove catalyst poisons from the biomass and greatly decrease catalyst deactivation are under development.

New methods for upgrading the pyrolysis oil are also moving forward.   Most upgrading technologies to date have focused on hydrogen addition to the pyrolysis oil to remove oxygen to allow water separation and make it compatible with traditional hydrocarbon feed for further processing in the existing refinery or blending infrastructure.   However, the cost of the hydrogen and high pressures required for the process is a major barrier. More recently mild oxidation has been receiving more attention as an upgrading method. The oxidation activates the biomass or pyrolysis oil and facilitates downstream processing. Efforts to use steam cracking as an alternative upgrading process have moved to the demonstration scale.

Stabilization of the oil via partial upgrading and processing the stabilized oil in a commercial refinery FCC reactor is being pursued by UOP and Ensyn. They have demonstrated that the commercial process was not effected by the addition of the pyrolysis oil. Ensyn has made a recent announcement for a new facility in Canada (Biofuels Digest, “Ensyn breaks ground on new 10 million gallon advanced biofuels project in Quebec,” July 13, 2016).

Ethanol Conversion

Ethanol production continues to grow because of introduction of cellulosic derived materials and commercialization of technologies like LanzaTech’s CO2-to-ethanol biological process. There are a number of projects underway that anticipate that ethanol production will exceed market demand for the use of ethanol as a blending component with current fuel supplies. Conversion of ethanol to butanes, higher hydrocarbons and aromatics via chemical conversion is coming close to a commercial reality. Several companies are proposing to integrate Clariant’s ethanol to olefins and aromatics technology into their technology.

Gasification

Gasification technologies continue to be improved and are providing a practical methods for using mixed biomass and other wastes to make electricity. The breakthroughs in this area is in the use of the light gas products as sources of hydrogen and liquid fuels. Small scale Fischer-Tropsch reactions, reforming and other techniques for upgrading the products are being developed.   These applications are not yet commercially viable because of product quality and separation issues that prevent the use of off the shelf technology.   However there has been continued progress in this area and technologies are emerging that improve the biomass conversion process and/or produce products that can be used in downstream process. materials.

Hydrothermal Carbonization/Liquefaction (HTC/HTL)

Although developed over a century ago, this technology had been the least investigation of the major thermochemical pathways to biofuels. However, in the past decade or so, there has a surge in ventures in this sector, though still small compared to the other thermochemical processes, such as torrefaction and pyrolysis. On the March 29^th issue of Biofuels Digest, a major project announced for Australia was reviewed (“Queensland Greenlights Advanced Drop-in Biofuels Project for Military, Aviation, Marine”). Hydrothermal liquefaction is included in the mandate of IEA Bioenergy Task 34. Hydrothermal liquefaction is also been heavily promoted by Battelle who along with other partners is planning larger scale demonstrations.   Extensions of the technology to processes operating at supercritical and near subcritical conditions are also being evaluated by a number of groups; one of these companies, Licella, recently announced a demonstration project with Canfor (Biofuels Digest, July 4, 2016, “Canfor to Invest $70 Million in 400,000 bpy Licella Biocrude Plant”).

Upgrading Volatile Products

A number of biomass conversion processes produce significant quantities of carbonaceous molecules that boil below the temperature required for use a transportation fuel. These lights are currently burned to provide heat for the conversion process. Typical heat produce exceeds the process needs and coproduction of electricity at a net loss is included to use this carbon and avoid a problem meeting life-cycle carbon reduction targets. There are a number efforts underway to convert these light products to fuel either in separate reactors or by recycling them to the conversion process. An example is Virent’s BioForming® platform is based on a novel combination of Aqueous Phase Reforming (APR) technology with modified conventional catalytic processing.

Solvent and ionic liquid pretreatment methods

The use of solvents to liquefy biomass continues to move forward. The liquefaction improves the selectivity and yields of the conversion process, which could be pyrolysis, gasification or fermentation. It facilates separation of cellulose and lignin allowing separate processing. A wide variety of organic solvents have been proposed for this purpose and efficient systems for reducing the cost are being developed. Ionic liquids, which are organic salts, are being evaluated because they are highly effective at lignin and cellulose degradation. They can be easily separated from the product stream for recycle. However, one of the more intriguing proposal is the recycle of pyrolysis oil or partially upgraded oil for this purpose. A venture in this sector, BIOeCON, was reviewed in Biofuels Digest (April 26, 2015).

Tars

Many biomass conversion processes produce carbon char and/or high molecular weight materials (tars) unsuitable for transportation fuel.   Managing these tars during processing and finding outlets for them that do not negatively impact life cycle estimates of GHG reduction is a continuing developing area. One of the technologies that is emerging involve using the high molecular products in asphalt manufacturing and recycling.

Conclusions

While many specific examples discussed above will not be successful, the fact that major efforts to scale up and commercialization are underway demonstrate that these are fruitful areas for future development.   Reducing greenhouse gas continues to be a societal imperative. This need is driving research and development efforts throughout the world and numerous technologies will begin to emerge.   The harsh realities of the commercial marketplace will dictate which ones will be successful.

About the authors

Lorenz Bauer and Gerald Kutney are both members of Lee Enterprises Consulting. Lee Enterprises Consulting is the world’s largest bioenergy and biofuels consulting group, who have consultants and experts worldwide, including in the technologies discussed in this report.  The opinions expressed in the report are those the authors, and do not, necessarily, express the views of Lee Enterprises Consulting.