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Harnessing : A Practical Guide Biotechnology is increasingly proving its ability to address challenges. An engineering-focused approach — bioengineering — is vital to successful industrial application

Steve Weiss Genomatica

In Brief Whole-Process design

Extend techno- economic analysis

Rethink economics

Bioengineering is different

Evaluate Services

CLosing thoughts

Figure 1. At Cargill’s biorefinery in Blair, Neb., companies such as Corbion, Evonik and Natureworks produce bio-based products

or those undertaking overall process panediol biologically, after DuPont deter- design and implementation for in- mined that bio-based production would cost termediate and specialty chemicals, less than chemical routes to that product. Fthe incorporation of biotechnology- BASF SE (Ludwigshafen, Germany; www. based processes has become a viable op- basf.com) produces vitamin B2 (riboflavin) tion for the industries (CPI). biologically and has replaced its established Bioprocesses have the potential to deliver chemical route. Lysine is another example of benefits in cost, quality and sustainability. a large-volume chemical produced biologi- Many well-known chemicals are already cally. And 1,4-butanediol (BDO) is the next produced biologically. For example, Cargill bio-based commercial process on the ho- Inc. (Minneapolis, Minn.; www.cargill.com) rizon: BASF and Novamont Sp.A. (Novara, produces lactic acid for polymer applications Italy; www.novamont.com) have licensed at petrochemical scale at its Blair, Neb. site technology from the author’s company to (Figure 1) using a proprietary, low-pH, yeast- produce BDO biologically. Note: based process. DuPont Tate & This article is not intended as an introduc- is the exclusive publisher and Lyle Bioproducts Co. (Loudon, Tenn.; www. tion to , nor a recap of bioprocess ad- distributor of this article. duponttateandlyle.com) produces 1,3-pro- vantages or case studies (see Chem. Eng.,

38 Chemical Engineering www.chemengonline.com april 2016 November, 2015, p. 40). Rather, the article Table 1. Better process performance through is intended as a practical guide for how to whole-process thinking think about, plan for, and integrate biopro- cess technologies into chemical production “Bio-centric” approach “Whole-process” approach facilities. To do this, the article highlights sim- Focus: Maximize microorganism performance Focus: Design microorganism and overall pro- (for example, titer, rate and yield) cess to minimize total production cost, meet ilarities and differences between bioprocess all specifications and maximize operational and conventional chemical process designs, robustness equipment and operations, while strongly Priority: Laboratory-scale strain and fermenta- Priority: Choose microorganisms and meta- emphasizing cost economics and overall tion development is prioritized, supported by bolic pathways that are compatible with the process analysis. computational tools and iterative strain de- lowest-cost operating conditions (for example, sign, testing and metric optimization pH, , aerobic versus anaerobic, co-product value). Design the microorganism Principle 1: Whole-process design for the process, not the other way around A well-known idiom states: “begin with the Process design: Process is designed sub- Process design: Pay close attention to manag- end in mind.” This suggestion — in the cur- sequently to fit the needs, capabilities and ing process impurities (raw material residuals, rent context, designing a process with the limitations of the microorganism metabolic byproducts, prod- whole system in mind — is appropriate. ucts) that could otherwise increase capital and operating costs, or compromise product The first part of our framework recognizes quality a key idea: chemical engineers had it right Process performance: Performance in the Process performance: Develop the microor- all along. Chemical engineers have decades laboratory may not be realized at large scale ganism and process at laboratory scale under of experience in designing and optimizing due to overlooked, scale-dependent param- anticipated large-scale conditions (time and integrated, large-scale processes to convert eters. Or, high performance at large scale may temperature profiles, mixing times, , raw materials into useful products. In its best require special (expensive) operating condi- recycles). Characterize key process sensitivi- tions, be more sensitive to process upsets ties. Demonstrate the whole process at an ap- application, considerable effort is invested (less robust), more subject to contamination propriate scale to document its performance upfront, in the form of conceptual designs, by foreign microbes (plant shutdown), or incur with engineering data. Use those data as the even before the associated experimental higher costs basis of detailed plant design program is launched. Downstream processing: Downstream pro- Downstream processing: Microorganism is By contrast, many of the headlines as- cessing is not addressed until the late stages designed for the process, to enable least of development (when the microorganism expensive operating conditions (includes pH, sociated with the rise of biotechnology- and fermentation are nearly finished). It is aerobic versus anaerobic, fermentation time based processes have focused on specific the responsibility of downstream processing and so on) technologies, tools and advances. Among to identify and solve any problems that have the favorite topics are the tools for design- arisen upstream. This invariably adds cost. ing microorganisms (sometimes referred to Plant: Large-scale plant is designed and built Plant: The whole-process approach translates informally as “bugs”). For the purposes of to accommodate the laboratory-scale process directly to design of large-scale plant, mini- mizing changes and added costs this article, the specific biology is not impor- tant — these engineered microorganisms can be thought of as fancy, biology-based “super-catalysts” that can perform multiple We refer to this whole-process discipline unit operations, such as all the steps needed as bioengineering. This approach better to convert into a desired target chemi- captures the intimate intertwining of, and co- cal with high specificity and minimal byprod- optimization across, multiple disciplines. ucts. While the progress has been impres- While everyone can surely appreciate — sive in using new biological tools to shorten and even marvel at — the continued ad- the timelines to engineer an organism suit- vances in specific parts of the biology toolkit, able for a proof of concept, the reality is that the best practice is to take a whole-process commercializing a bio-based technology is view when exploring how to harness bio- not just about the bug. based processes as a component of a plant Instead of thinking about bio-based pro- construction project. Product customers cess design as a linear sequence (first, de- may also marvel at the science underlying sign the bug, then figure out the unit opera- a particular microorganism, but ultimately, tions to best separate and purify its output, they are really looking for ways to lower and then loop back to tune the design of the costs, raise product quality and improve the microorganism), a better approach is to “co- sustainability profile. develop” and “co-optimize” the microorgan- ism in conjunction with the overall process. Principle 2: Extend TEA Table 1 illustrates the differences between The second principle in evaluating and de- these two approaches — the “bug-first” ap- ploying biotechnology is to apply one of the proach is designated as “bio-centric” in the most favored tools from conventional pro- table, and the co-optimization approach is cess technology: techno-economic analy- designated as “whole-process.” sis (TEA).

Chemical Engineering www.chemengonline.com april 2016 39 Table 2. Capital Costs per Ton of product for Conventional and feedstock price for a bio-based process. Bio-based Plants (Examples) The first line to draw is where total produc- Conventional Bio-based Comparison tion costs are equal for the two competing process technologies. The region on one 100,000-ton/yr plant $300 million total $230 million total Bio is 23% lower $3,000 per ton $2,300 per ton side of that line shows all the feedstock price combinations where one process 50,000-ton/yr plant $200 million total $140 million total Bio is 30% lower $4,000 per ton $2,800 per ton technology is lower cost; and the other side of that line shows the price combinations Source: Genomatica estimates, based on industry analyst data, company data and discussions where the other process is favored. Next, with chemical producers. Assumes scaling exponent of 0.6 for conventional and 0.7 for bio-based at these ranges of capacity map historical data points, and see which process technology would have delivered Many readers are likely already familiar with lower costs given actual feedstock prices TEA, and may use it to better understand over time (as shown by the Xs and circles the overall economics of potential process in Figure 3). Lastly, draw additional lines to designs for conventional chemistry-based highlight the relative feedstock pricing when processing. The idea is to apply the same one process delivers, for example, a 25% concepts of TEA to bio-based processes cost advantage. By doing so, you can get a (see sidebar, p. 41). Some of the individual feel for how processes compare over time, line items of the TEA will be different, but the even when using different feedstocks. overall goal remains the same — to gener- Interestingly, some bio-based processes ate an all-inclusive picture of the total capital may offer lower total process costs even investment and production costs for a po- with the current low prices of fossil-based tential process. feedstocks. And many analysts believe that An important recommendation at this point petroleum-based feedstocks will eventu- is to create a management dashboard to fa- ally return to higher, more traditional prices, cilitate internal discussion and decisions (Fig- which may provide a truer point of compari- ure 2). If biotechnology is a new area for your son for when a new plant begins operation. organization, then this kind of dashboard will help your team become more comfortable Principle 3: Rethink economics with how process economics change under Economics is not just about total production varying conditions (for example, historical cost (or even the economic cost of goods data, forecasts, competitive processes, al- sold, which includes consideration for a ternative feedstocks and geography). return on capital employed (ROCE)). Bio- Similarly, you can expect questions based processes can bring additional po- about the competitiveness of bio-based tential economic advantages, including de- processes, especially given the current ployment flexibility, greater price stability and low prices of crude petroleum in 2016. A lower safety and operations risks. helpful way to approach this is by creating Let’s start by looking at the forces act- indifference curves (essentially, sensitivity ing on capital expenditures. First, the capi- analyses), which provide an unbiased per- tal cost per ton may be significantly lower Figure 2. Management spective on overall process economics. For (sometimes 20–40%) for bio-based process dashboards, such as the one shown here, can facilitate in- example, as shown in Figure 3, the x-axis technologies than for conventional chemical ternal discussions of techno- corresponds to the feedstock price for a processes using fossil feedstocks — espe- economic analyses conventional process and the y-axis is the cially for mid-sized plants (Table 2). This is because a single bio-based (fermentation) frequently replaces multiple conventional unit operations. Additionally, capital equipment for that process may be less expensive (for example, with bio- based operations running at near-ambient temperature and and near-neutral pH, versus the more challenging conditions often required in a conventional chemical process). Generally, only the largest con- ventional plants will not be disadvantaged in capital cost per ton. Second, the plant- scaling exponent is higher for bio-based processes, and this increases the cost-per- ton advantage for bio-based processes as

40 Chemical Engineering www.chemengonline.com april 2016 Techno-Economic Analysis for bio-based processes: New examples The use of techno-economic analysis (TEA) is all about understanding tradeoffs — the interplay between process design decisions and both capital and operating expenses. TEA can be used when implementing a bio-based process in the same way it would be used for a conventional process. In the bio-based process, however, some new types of unit operations and equipment are in play, and they have different trade-offs compared to conven- tional processes. TEA can be used the same way, just with some substitutions. As an example, consider fermentation. At first blush, it seems to be just a big tank, but in fact, process design — and tank design — can have a significant impact on capital and operating costs. Is it better to use a smaller number of large fermentation tanks (for instance, 1,000 m3) or a larger number of smaller tanks (100 m3)? Other questions also must be answered, including whether the process will use aerobic or anaerobic microorganisms; whether a bubble column or stirred-tank reactor should be used; whether to control temperature with a cooling jacket, internal coil or external loop; and whether the process will be run as a batch or continuous process. For separation and purification, considerations include feedstock quality (for example, more impurities at the start likely mean more effort and cost later); handling of both upstream (for example, biomass pretreatment and handling) and downstream ( and ); and the properties of the target chemical (such as , , permeability, target purity). The net effect of these factors can be significant. For example, designing a bio-based process for lysine will tend to have higher capital costs per ton of annual production capacity (about $3,000 per annual ton), as compared to a process design for ethanol (approximately $600). Successful lysine processes have been aerobic; aseptic; use jacketed fermenters with chilled water; use semi-refined feedstocks; and need extensive downstream separations. Ethanol processes work well with large fermenters; are anaerobic and sanitary, and use ex- ternal cooling loops and unrefined feedstocks. Ethanol processes also have easier separations due to its higher volatility. These factors can also shift the balance of capital and operating expenses, with one type of process design being better at larger scale and another at smaller scale. smaller plants are built. commitments, or reduce the discounts For decades, the chemical industry it needs to offer to customers (espe- has moved in the direction of building cially during times of weak demand) ever-larger plants, in part to increase — both of which improve the true eco- efficiency by reducing capital expendi- nomic performance, offering a more ture per ton. Now, with the capital ad- comprehensive view than a TEA. vantages of bio-based processes, the Additional considerations in the industry can gain the option to go the broader economic picture are safety other way — to economically deploy and operations-related risks. Accidents smaller, “right-sized” plants. This can happen. And accidents at conventional allow entry into a local or regional mar- plants, operating at high temperature ket, and can allow capacity expansion and pressures and sometimes with without the large outlays needed for a toxic chemicals, can be very costly. By mega-sized plant or the risk of disrupt- contrast, the less severe conditions of a ing the supply-and-demand market bal- bio-based process, combined with the ance. It can also enable users of chemi- aqueous-based environment of fermen- Figure 3. Indifference curves can help cals to backward-integrate and produce tations, reduce process-safety risk. compare process economics of two alter- their own supplies, as Novamont is Lastly, the chemical industry has de- native processing pathways doing with bio-based 1,4-butanediol in Italy, with a planned start-up in the sec- Bio-based processes may be competitive, even at low oil prices ond half of 2016. (example: GENO BDO, 50,000 tons) Readers should also consider the Equivalent cost line 25% cost advantage line potential for better overall economic performance of a plant because of Average monthly price GENO 0-25% the greater sustainability of the chemi- Trailing (-3 yr average price) Advantage zone cal being produced and sold there. Current price While this article’s discussion so far has treated plant output as a direct substitute (that is, as a commodity), a bio-based plant may deliver a product with a smaller environmental footprint — and may be seen by customers as a

more sustainable and desirable option. Corn prices (from CME Group) This is not the same as assuming a GENO >25% “green premium” based solely on sale Advantage zone price. Selling a more sustainable ver- sion of the same product may enable a North American butane price supplier to gain longer-term customer

Chemical Engineering www.chemengonline.com april 2016 41 veloped strategies to manage many eco- gen-containing byproducts, such as 2-pyr- nomic risks, including those tied to feedstock rolidone. Strain modifications reduced this costs. Increasingly, similar tools are available significantly, thereby reducing downstream to support bio-based projects. For example, processing costs. This ability to produce a Cargill, the global agricultural products and targeted chemical with high selectivity can services firm, has among its core compe- be a strong advantage. tencies the ability to manage the pricing and Managing for variations in feedstock is supply risks tied to agricultural commodi- different. Making a plant or process that is ties — which may be used as feedstock for robust under varying inputs is a fundamen- bio-based production plants. In addition, tal task for process engineers that impacts Cargill is now offering a range of production- both capital and operating costs. The tech- support services to companies interested niques for managing variations in feedstocks in specific bio-based process technologies, for bio-based processes are different than including fully outsourced production, ser- for conventional processes, and may include vices and feedstock supplies. feedstock testing (to determine attributes), collaboration with feedstock suppliers to Principle 4: Bioprocessing is different optimize consistency versus cost, rethink- While bioprocess engineering and conven- ing the design of your microorganism to ef- tional process engineering are disciplines ficiently handle greater variation in feedstock that share a similar overall approach, there properties, and adjusting fermentation or are important differences in the specifics of other operating parameters. the two, as well as some specialized skills Requirements for sterility are different. associated with bioprocessing. The following Contamination is a concern in any produc- items represent some examples. tion plant, but the manner in which it is real- Downstream processing is different. ized for a bio-based process, and the rigor Chemicals made from fossil feedstocks have with which it must be maintained, are differ- characteristic impurities, while those made ent. In particular, it is most often necessary biologically have different impurity profiles, to design, build, and operate a bio-based even if both types of process technologies process to exclude viable foreign microbes. offer end products at the same purity level. This is particularly demanding and critical For example, the feedstock for bio-based in the fermenters and associated systems, processes is often carbohydrates. These and, depending on the product, can extend can lead to product-quality issues, such as into downstream processing as well. The color and odor, if not addressed during pro- penalty for cutting corners on sterility can cess design. The bioprocess engineer must be severe. be familiar with carbohydrate chemistry and Managing for the weather is different. For nitrogen (, amino acids) chemistry, as example, large-scale can be well as methods for separating color and sensitive to the effect of outside odor-causing compounds. Similarly, sepa- on cooling-tower capacity. Insufficient cooling rating the desired chemical product from capacity can ruin a fermentation batch due the fermentation broth may require different to temperature run-up, with consequences techniques and equipment. Fermentation- that can extend into downstream process- based processes operate in an aqueous ing. This risk can be addressed through environment (required for microbial life to operating procedures that adjust process thrive). Effective handling and purification parameters to slow down the fermentation of aqueous streams often dictates special- rate to maintain temperature control of the ized unit operations. Key concerns include fermentation process. Fermentation plants energy-efficient techniques to remove water are often constructed with minimal enclosure and the ability to recycle and reuse water. and exposed piping. Given their lower oper- The tools to minimize byproducts are ating temperatures and aqueous streams, it different. Removing byproducts is expen- may be necessary to account for the pos- sive, both in capital and operating costs. sibility of . Bioengineering techniques generally allow So what is the overall lesson here? Take the elimination of many byproducts from advantage of people and firms that have bio- the outset, by designing a microorganism process expertise as an integral part of your so that the byproducts are not produced project planning and implementation. Missing in the first place. For example, initial strains this can be (and has been) a critical point of of bacteria engineered by Genomatica to failure, just like trying to build your first-ever produce 1,4-butanediol also formed nitro- plant in a new part of the world without local

42 Chemical Engineering www.chemengonline.com april 2016 knowledge and resources. Coupled with Prin- knowledge, experience, and best practices, ciple 1, this puts a premium on collaborating from which all can benefit. with partners that have proven experience in Our trade is tasked with planning for proj- biotechnology, in bioengineering, and in tak- ects that start up three or more years from ing a whole-process perspective. now. That means that now is the right time The good news is that despite all these to learn how and where to integrate bioengi- differences, large-scale commercial fermen- neering and bring it into active consideration tation-based processes have been running for your upcoming projects. n for decades to make products like organic Edited by Scott Jenkins acids and amino acids. Recent advances in microorganism engineering have simply Author expanded the opportunities for employ- Steve Weiss leads marketing efforts for ing bioengineering to develop cost-com- Genomatica, Inc. (4757 Nexus Center Drive, San Diego, Calif., www.genomatica.com; petitive, robust bioprocesses for a greater Phone: 858-824-1771; Email: sweiss@ number of products and for a wider range genomatica.com or alternatively, of product types. [email protected]) as a consultant. Genomatica is a widely recognized leader in bioengineering for the chemical industry. The Principle 5: Evaluate services firm is the recipient of the 2013 Kirkpatrick Award for Chemical Engineering Achieve- If you have never bought a motorcycle be- ment. Weiss is co-founder of Grey Heron (San Francisco, Calif.; fore, it is important to learn the most impor- www.greyheron.com), a management and marketing consulting tant questions to ask and what tires to kick. firm that helps executives and investors turn technologies into substantive businesses. Fields include energy, cleantech, ad- To successfully harness biotechnology in vanced materials, the Internet of Things and cloud software. Re- your projects, here are some key consider- cent examples in the chemical industry include the launch of Beta ations in evaluating potential technology or Renewables and Light. Weiss has held research, develop- ment and marketing/business development roles at Serious En- project partners. ergy, IBM, HP and multiple startup companies. Weiss holds mas- Design processes to operate at your ter’s and bachelor’s degrees in computer science from the targeted commercial scale. Technology Massachusetts Institute of Technology (MIT). should be demonstrated under large-scale conditions and piloted at a scale and to an extent necessary to mitigate scale-up risks. The best practice is to prioritize those tech- nologies and partners that have “been there and done that” — they know what the end result should look like. Invest in comprehensive integrated solu- tions. Do not take a piecemeal approach, where microorganism development, process development, TEA and large-scale plant de- FREE On Demand sign are disconnected activities. Overprepare for technology transfer and take nothing for granted. It is easier to re- Webinars duce resources later because technology transfer has gone smoothly, than to add re- sources to “fight fires.” Prospective partners may offer validation of their technologies View On Demand based on a plant that they have built, and Webinars at now own and operate. Look for those that chemengonline.com/ have successfully transferred their technol- ogy — ideally to multiple locations around webcasts the world — and possess documented, sys- tematic approaches for doing so. If finding such a situation is difficult, look harder and persevere; they do exist.

Closing thoughts Biotechnology brings increased options for many chemical-production businesses and offers more tools to harness where appro- priate. There is a fast-expanding body of

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