Commentary

Bio products from bio refineries - trends, challenges and opportunities

Bhima Vijayendran

A recent study estimates that, by 2025, over 15% of the three trillion dollar global chemical sales will be derived from bio-derived sources. Many of these bioproducts would be manufactured in bio-refineries by the deployment of rapidly emerging industrial biotechnology. It is expected that bioderived chemicals will come from three sources: direct production using conventional thermochemical and catalytic process, biorefining, and expression in plants. Direct production is already a reality, as evidenced by the production of propane diol and polylactic acid from corn-derived glucose and others. There has been recent commercialization of bio-derived plasticizers for polyvinyl chloride, polyester resins for coatings and inks, biopolyols for urethane foams and others based on vegetable oil and carbohydrate renewable sources. Chemical biorefineries, on the other hand, based on various platforms such as carbohydrate/ cellulose, oil, and glycerin, a co-product of biodiesel production, and algae are in the pilot stage. Chemicals expressed in genetically enhanced plants to accentuate target functionalities such as primary hydroxyls, oxirane and others are in the discovery phase and furthest from commercialization. This paper highlights some of the recent developments and trends in each of the three waves for bioderived chemicals. Further, it also covers some of the successes in the commercialization of bioproducts, lessons learned, and challenges ahead for the nascent chemical biorefineries.

 

Introduction

A recent report (C&News, 2009) estimates over $100 billion of the current global chemicals market, about 3%, are derived from either bio-based feedstock or fermentation or enzymatic conversion or combination of them. This report projected that the share of bio-derived chemicals would grow to about 15% of global chemical sales by 2025. There are several drivers for the interest and growth of bio products in the marketplace. A few that are worth mentioning include the availability of cost effective technologies including novel functional building blocks and improved processes, concerns about long term sustainability and price volatility of fossil-based feedstock, a more benign footprint on the environment, and consumer interest in green products and public policy. Many large and established chemical and biotechnology companies as well as numerous smaller startup and venture companies are actively involved in the development and commercialization of bioproducts from a variety of renewable biomass sources. These companies are trying to follow a bio-refinery model, similar to current petrochemical refineries, which co-produce large volume commodity fuels and high value chemicals.
This paper covers the following topics related to these emerging technologies:

  • Various bio refinery models
  • Conversion technologies
    • First wave of bioproducts by thermo chemical/catalytic conversion of bioderived feedstock
    • Bio feedstock platforms
    • Second wave of bioproducts by biochemical conversion technologies
  • Third wave of bioproducts from genetically engineered plants with designed functionality of bio-monomers/building blocks
  • Some challenges and opportunities for bio refineries


Various bio refinery models

There are various bio refinery models under development, most of which differ based on the biomass source. A palm plantation-based bio refinery is shown in Figure 1.

 

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The concept of palm-based bio refinery (and others such as corn wet mill, sugar cane, and soybean) is quite simple and similar to the current petroleum refineries. Biomass is converted to fuels (biodiesel from palm oil and bioethanol from lignocellulosic contained in the feedstock, in this case empty fruit bunches, fronds, etc. that are residues from palm oil processing) and value added chemicals. In a typical palm plantation, besides the oil and lignocellulosic biomass sources, there is some activity to convert palm oil mill effluent (POME) to high value chemicals and biogas. In the case of corn wet mill and sugar cane plantations, biomass is converted to fuel (mostly bio ethanol) and chemicals such as polyols, acids, and others. One major difference between a bio refinery and petroleum refinery is that one of the main product from a bio refinery—at least for the first generation ones based on palm, corn, and sugar cane—is food for humans and animals. This is an important consideration and challenge and has created a serious debate as to the sustainability of first generation bio fuels in particular, and to a lesser extent for smaller volume bio products. Technologies are being developed to use co-products from the first generation bio refineries that are not targeted for food and feed. To address this problem more directly, the trend is to develop non-food energy crops such as jatropha, switch grass, and others as the biomass source for future bio refineries. The general consensus is that the bio refineries will initially focus on large volume fuels followed by high value chemicals similar to the evolution of petrochemical refineries.

First wave bioproducts

Many first wave bioproducts are already in the marketplace and are finding applications in myriad end uses. These bioproducts are derived from thermochemical conversion of new bio monomers or building blocks. Products often fall in two categories, namely, the ones that are chemical replacement for petroleum-derived chemicals such as ethylene or lactic acid or functional equivalent of existing chemicals. The main driver for successful first wave bio products is the competitive cost of bio-derived feedstock compared to the current petroleum counterpart that is being replaced. This is very true for bio products such as bio ethylene derived from sugar cane or bio 1,3-propanediol that are targeted to replace corresponding petroleum derived products.
A few of the first wave bio product initiatives are captured in Figure 2.
It is worth noting that there are other projects such as the propylene glycol plant to be commissioned by Archer Daniel Midland (ADM) shortly and the polyvinyl chloride (PVC) by Solvay Indupa in Brazil from bio based feedstock (Martinz and Quadros, 2007).

 

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Bio feedstock platforms

The bio feedstock platform for the production of bio products is mainly focused on the following chemical functionalities.

Vegetable oil/fatty acid esters of glycerol

Vegetable oils and fats provide useful chemical functionalities such as unsaturation and ester groups for further modifications using conventional schemes such as hydrogenation, selective oxidation, epoxidation , meta thesis reaction and others to introduce functionality of value in diverse applications such as plasticizers, coatings, adhesives, polymers, composites, etc. Several bio products such as bioplasticizers for PVC (Vijayendran,  2005), bio toners (Vijayendran, 2008), biopolyols (Benecke et al.; 2008) based on this approach have been commercialized recently.
   
Sugar-based platform

Platforms based on sugars (Werpy and Petersen, 2004) have been deployed to create acids such as succinic acid and convert the acid to high value chemicals such as 2- pyrrolidone, 1,4-butanediol, tetra hydrofuran and others. 
More recently cellulosic feedstock (Zhang et al., 2009) has been converted to 5-hydroxymethyl furfural (HMF) using some novel catalysts and ionic liquids as platform chemical to make a variety a high value chemicals derived from petroleum sources, as shown in Figure 3.

 

Glycerine Platform

Figure 4 shows bio products derived from crude glycerine, a co-product of biodiesel production.
There have been recent activities to convert abundant and low cost lignin to value added chemicals and fibers (Baker, 2009).

 

 

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Recent commercialization efforts of first wave bioproducts have clearly shown that it is important that the technology is proven at the pilot scale and the economics are competitive with the petroleum products. In many cases, such as in bio plasticizers for PVC and biotoners for office copiers and printers, the bio product replacements have functional attributes that are of value and not available from current petroleum products. In the case of bio plasticizers, it is shown that one of the new bio plasticizers, reFlexTM 100, has significantly better thermal stability, lower plasticizer migration, and improved plasticization efficiency compared to industry standard (butyl benzyl phthalate [BBP]) and a petroleum-based phthalate replacement (DINCH from BASF), as shown in Figure 5.

 

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Plasticization efficiency and thus lower use level with no known health concerns compared to the petroleum based phthalate plasticizers, besides being “green” and environmentally friendly. See Table 1 for some comparative data of reFlex™ 100 bioplasticizer from PolyOne and the industry control, butyl benzyl phthalate (BBP).
In the case of bio toners, the bioproduct replacement has lower fusion temperature and easier recycling of office waste paper (Vijayendran, 2008). The message that is becoming clear is that any new bio products that are targeted to replace existing petroleum-derived products should be able to compete on cost and performance. Just being “green” and bio-derived from a sustainable source are not enough to be accepted in the marketplace.

 

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Second wave bio products

The second wave bio products involving the conversion of bioderived sugars, cellulosics and oils by biochemical routes are in the advanced R&D and early pilot scale phases. Biochemical processing using advances in metabolic engineering and separation technologies to produce high value chemicals have made great strides in the last few years. Bioprocessing tend to have the following attributes compared to conventional thermo chemical conversion technologies:

  • Lower yields
  • Fairly dilute solutions with lower concentrations of actives
  • Most reactions are done at ambient temperature and pressure thus offering processes with potential lower capital and operating investments
  • Microorganisms have several pathways to make the same products and rapid screening tools have helped to design metabolic pathways to achieve high yields of target molecules
  • Most of the initiatives in the second wave bio products are in the advanced R&D or pilot scale. Major milestone is to demonstrate commercial viability of many of the technologies that have shown R&D feasibility in the laboratory scale.


A few of the players that are active in the second wave bio product development and commercialization are shown in Table 2.

 

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It will be interesting to watch over the next several years how successful the second wave products from these companies are going to be in the marketplace.
It is worth mentioning here that there are several algae-based initiatives to make biofuels and high value chemicals such as acids, alcohols, esters etc (Solix Biofuels.com). It should also be mentioned that there is a joint venture between ADM and Metabolix to produce poly hydroxyl alkanoates, a polyester biopolymer with some interesting properties (Chen, 2010).

Third wave bio products

Third wave bio products derived from plant expression through genetic engineering to produce chemicals with designed functionality are still in the early discovery stage and furthest from commercialization. The work on high oleic acid oils is perhaps furthest along in terms of commercialization. There are several patents describing the use of such high oleic acid oils in several industrial applications such as inks, lubricants, etc. (Knowlton, 1999). Some early work has shown the feasibility of introducing primary hydroxyl functionality in vegetable oils such as canola. About 12% riconelic acid has been expressed in conventional canola seed (Grushcow, 2007).  Primary hydroxyl functionality from such modified oils has several useful functionalities and attributes of interest in lubricant, coating and polymer applications. Recent work at CSIRO, Australia (Green et al., 2009) has shown the feasibility of expressing high levels of epoxy functionality in some native oil seeds. A crop producing epoxy oil would be an interesting replacement for epoxidized oils produced by the convention per acid route. The same group has also expressed acetylinic functionality in plant oils with the potential provide useful reactivity and functionality of value in several high value chemical applications.

Summary

Use of bio products is growing with the first wave products derived from thermochemical conversion of bio-derived building block taking the lead in commercialization. Second wave bio products produced by metabolic engineering and bioprocessing technologies are in the pilot scale. Third wave bio products based on plant expression are in the discovery phase. Bio refineries based on a variety of biomass feedstock are still in the nascent stage and will require some time to fully develop. Continued R&D investment to improve the technologies to provide cost effective solutions is very much needed. Also, establishment of supply chain of feedstock as well as compatibility with existing infrastructure of the well established petrochemical industry is expected to facilitate commercialization of bioproducts. It is expected that bio products from bio refiners will continue to grow and compliment the petrochemical refineries to serve the global chemicals markets.

 

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References Baker,F.S., Low Cost Carbon Fiber from Renewable Resource., EERE, U.S. Dept of Energy Project ID # lm_03_baker

 

Benecke, H., Vijayendran, B.R., Garbark, D. and Mitchell, K. (2008): Low Cost Highly Reactive Biobased Polyol—A Co-Product of Emerging Bio Refinery Economy., Clean Journal, 36 (8), p. 694.

 

C&News, July 2009, p. 26-28.

 

C&News, Bio Refineries, Oct 12, 2009, p. 28-29.

 

Chen, G.Q., Industrial Production of PHA., Plastics from Bacteria., Microbiology Series Vol. 14, 121-132,

 

Choi, W.J. (2008): Glycerol Based Bio refinery for Fuels and Chemicals, Recent Advances on Biotechnology, 2 (3), p. 174.

 

Gray, J. (2009): Personal communication from PolyOne, Cleveland, OH.

 

Green, A., O’Shea, M., Lawrence, L. and Begley, C. (2009): Beyond Biodiesel., Inform, 20 (6), p. 345.

 

Grushcow, J. (2007): New Opportunities in Oil Seed Engineering., available at http://www.linnaeus.net, accessed, 2009

 

Knowlton, S. (1999): U.S. Pat 5981781, Du Pont Company.

 

Martinz, D. and Quadros, J. (2007): Presentation at Brighton Conference, Brighton, U.K.

 

Vijayendran, B.R. (2005): Emerging Opportunities and Challenges for Soybean oil –derived Industrial Products., Inform, 16 (10), p. 659.

 

Vijayendran, B.R. (2008): Presidential Green Chemistry Award Invited Lecture, Washington, June 2008.

 

Werpy, T. and Petersen G. (2004): USDOE’s Top Sugar Derived Building Blocks, available at http://www.nrel.gov/ docs/fy04osti/35523.pdf, accessed 2009.

 

Zhang, Z.C. (2009): Single Step Conversion of Cellulose to 5- Hydroxyl Methyl Furfural (HMF) - a versatile Platform Chemical., Applied Catalysis. A 36, p. 117

 

 

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