After completing all of the presentations and breakout sessions, the workshop held a final panel discussion to summarize the day’s findings. The panel consisted of William Hitz of E. I. du Pont de Nemours, Emily Carter of Princeton University, and Rina Singh of the Biotechnology Industry Organization (BIO). Paul Bryan, the workshop co-chair, asked each panelist to identify one to three new and important ideas gleaned from the workshop.
Hitz said that he was excited about the possibility of using ethanol as the primary fermentation output but then using ethanol as the starting material to make other chemicals more reduced than ethanol. Carter was encouraged by the idea of using natural gas as a bridge technology to move from coal to biomass as the primary fuel for generating electricity. She thought that this route would develop a biomass industry that would eventually scale enough to make a final transition to producing fuels economically from biomass.
Singh was impressed by the potential of thermochemical conversion technologies and was encouraged that biological and thermochemical conversion were on equal footing in terms of research interest. She noted, though, that she was disappointed by the overall lack of discussion of the economics of any of the technologies discussed at the workshop. She also remarked that the 2012 Farm Bill before Congress calls for funding research on technologies for conversion of biomass to renewable chemicals that stress energy efficiency.
In the ensuing open discussion period, Mark Barteau followed up on the subject of bridge technologies by noting that Delaware enticed Bloom Energy to construct a natural gas-fired fuel cell power plant in the state by passing legislation that counts natural gas-powered fuel cell-generated electricity as part of the state’s renewable portfolio. While that may be a stretch, he added that it was his belief that the real interest lies in having biomass be the ultimate source of gas for those fuel cells rather than fossil natural gas. The take home lesson, he said, is that as the biomass community thinks about bridging and transitions it should think not just about technology but also policy and legislation. Carter agreed with this comment and added that discussions that she has been having with the leadership of Public Service Gas and Electric Company (PSG&E), New Jersey’s largest publicly owned utility, raised the issue that there is a need for a national policy about electricity. Power grids, she said, are regional and on an interstate basis one electron is no different from any other electron. What happens as a result, she explained, is that PSG&E ends up idling expensive plants that use renewables and that are better for the environment because these plants cannot compete economically with dirty coal plants feeding electricity into the regional grid.
Charles Anderson, from the Pennsylvania State University, commented that the solar energy industry is looking at combining natural gas and solar power plants as a way of being able to produce electricity consistently. Another possible bridging approach might be to combine biomass-fed plants with solar as a way of moving both technologies forward. Continuing on the theme of coupled plants, Thomas Richard, also of Penn State, wondered what became of an idea that was popular five to ten years ago of the integrated biorefinery that would produce high-value chemicals as a means of supporting the production of lower value fuels. Hitz responded that industry may have moved away from this idea because the drive to produce low-cost biofuels has become the dominant push. But he agreed that the idea of using a common feedstock to make high-value chemicals might create enough demand for that feedstock to get the front end of the infrastructure going to then make cheap biofuel.
Hitz added that the field needs to continue to evolve its ideas and work on both the supply and demand side together. In other words, a feedstock infrastructure that generates a shippable, densified feedstock will not develop unless there
is already an end use for it and vice versa. His recommendation was that the community focus on developing a front-end to back-end solution that would demonstrate the viability of taking biomass and making an economically viable product. Once that happens, he said, then parties might jump in who are interested in developing the supply side or the processing supply. The challenge is figuring out how to evolve that system. Carter added that small companies that she has talked with are looking primarily at making high-value chemicals as a way of getting into the larger biodiesel business eventually.
In a cautionary note, Bryan said that the high cost of separation and purification technologies presents a challenge for the integrated biorefinery idea. Each product needs its own separation, purification, storage, and distribution infrastructure, he explained, and so every product being made needs to pay off at least that part of the process, which in his experience, he said, is often the most costly part of a continuously operating refinery operation. This approach may be more feasible with batch processing.
Helena Chum added to this thread by describing how the Brazilian ethanol industry is evolving. It started largely by converting sugar cane to sugar, using ethanol to maximize profits and eventually to produce electricity. Over the past three years, however, Brazil had shifted its output and is now using 10 percent of its sugar production to make higher value products such as polyethylene and other chemicals. There is a major emphasis in Brazil now to develop the biorefinery concept. The point is that by building a biomass-to-fuels infrastructure, biomass is now a commodity with potential as a feedstock for chemicals and other applications. She added that RFS2 is creating the same situation in the United States. The point that she wanted to make, she said, was that chemists need to think more about the whole system of agriculture and forestry, energy and other products, and the biomass landscape as a whole.
Singh noted that while there are some integrated refineries in the petrochemical industry, these are a number of companies that focus on specialty chemicals. These companies are not vertically integrated, but are instead capitalizing on one aspect of the value chain, something that she thinks could take place in the biomass world with the development of commodity sugars that would be analogous to commodity oil. She added that there are 10 BIO member companies that are working on producing cheap, sustainable supplies of feedstock sugars.
Robert Greene, from DOE’s Office of Basic Energy Sciences, asked what a more ideal biomass would look like, and Hitz responded that in his opinion, the biggest improvements today would be on the transportation side, that is, making bigger bales of material rather than in increasing the sugar content of the biomass by a few percent. From an economics perspective, increasing the volume of material that could be hauled on a truck would be the place to have the biggest impact. However, he added that it is still important to continue studying how to increase sugar content and change the structure of plant carbohydrates and lignin to make them more easily converted into sugars. But those efforts will take time to yield advances. Jeff Steiner added that the key thing that has to happen is that people working in the process side need to be talking more to the people working on the supply side to make sure everyone’s needs and interests are aligned. Hitz agreed and cited an illustrative example. Grasses may become a good feedstock, but it would be a better one if it stood erect in the field until it was totally dry. Those kinds of mundane features need to be communicated.
Throughout the workshop, speakers made general observations about the issues associated with large-scale biomass utilization and the role of the chemical sciences in addressing these issues. These observations are gathered here to capture the broad themes emerging from the workshop. These themes should not be seen as consensus conclusions of the workshop and are associated with the speaker who made that observation.
- Total global production of cereal grains as a feedstock cannot meet even a fraction of the demand for renewable fuels and chemicals. Doing so will require making use of lignocellulosic materials. (Bryan)
- Solving the “tyranny of distance,” seasonality, and feedstock variability problems will require the development of technologies that can convert a wide variety of biomass sources at local depots into a uniform, transportable feedstock for further processing at centralized biorefineries. (Bryan and Stokes)
- With sufficient research and development, the United States has enough available land to produce biomass in sufficient quantities to meet the demand as a renewable source of fuel, chemicals, power, and heat in a manner that is sustainable and that does not compete with food. (Stokes)
- It is not possible to replace a multi-trillion-dollar petroleum-based infrastructure with a biomass-based infrastructure overnight. Economics must be the driving force behind this transition, but policy can help ease this transition. (Duff)
- Tapping into the enormous value of petrochemicals and specialty chemicals is a place where chemistry can play a huge role in realizing value from biomass conversion, particularly since these are high value added products that would use very little of the available biomass. (Duff)
- Both thermochemical and biochemical conversion of biomass into a feedstock for fuel and chemical production is promising, but there is a significant need to create catalysts that can remove contaminants from this
feedstock and that are more tolerant of contaminants in downstream processing. (Duff and Brown)
- Algae have potential as a source of lipids that could be used as a feedstock for fuel, chemical, and energy production, but a great deal of basic research is needed to realize this potential. (Duff)
- To achieve cost-competitive biological conversion of biomass into ethanol or other feedstocks will require moving from batch to continuous-flow processes, a transition that will require a substantial amount of chemical and chemical engineering research, particularly with regard to the development of catalysts and separation technologies. (Somerville)
- Basic research on the chemistry of thermal conversions, via both gasification and pyrolysis, is needed to better tailor these processes to the meet the demands of working with biomass feedstocks. (Brown)
- The lack of a national policy on the use of biomass in power and heat generation is impeding developments in this field. (Steiner, Barteau, and Carter)
- The economics of biomass-to-power systems may benefit from the development of small-scale systems as opposed to large-scale power plants. (Steiner)
- Methane may serve as an important bridge technology between oil/coal and biomass. (Hitz)
- Production of high-value chemicals is an area worth exploring in detail as it represents a potentially viable approach of creating demand for a biomass feedstock. (Hitz, Carter, Chun, and Singh)
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