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Posted: Jun 10, 2017
Fueling a sustainable future
(Nanowerk News) Imagine a future in which agricultural, animal and even human waste is used to produce fuels and high-value chemicals. This may seem far-fetched, but researchers at the Department of Energy’s Pacific Northwest National Laboratory are working hard to make it a reality. They are reinventing chemical conversion processes to turn once-forgotten waste into more efficient and sustainable fuels and chemicals with minimal environmental impacts.
This research could also help consumers save money as the fuel and chemical industries move to new processes that are less energy-intensive and cost less than the processes used today. The petroleum industry, for example, is responsible for about 6 percent of the country’s annual energy consumption. In fact, the energy it uses to refine and produce fuels and other products in just one year could power all the homes in Washington for eight years. This energy usage drives up costs and produces greenhouse gases like carbon dioxide.
PNNL is bringing its hallmark fundamental science and applied engineering capabilities to bear on this challenge. As researchers look to produce carbon-neutral fuels and chemicals from waste carbon and low-cost electrical energy, they are exploring ways to increase the efficiency of existing chemical conversions. They also are working with catalysts — substances that increase the rate of chemical reactions — and discovering new catalytic reactions that produce zero carbon emissions. In particular, they are developing new ways to control catalysts so that reactions happen more quickly, at lower temperatures and lower pressures, and with greater precision.
PNNL chemist Molly O'Hagan and her colleagues explore different catalysts inspired by nature, looking for one that runs fast and efficiently.
To do this, our researchers turn to nature for inspiration. They are building processes that mimic the fast and efficient reactions that take place in biological systems, where enzymes act as catalysts. In biological systems, reactions take place in constrained spaces, reaction sites serve more than one function and there are pathways or channels that steer the right molecules to the right places at the right time. Researchers are finding that by combining and applying some of the same rules, they can increase reaction rates and selectivity while also operating at lower temperatures, which helps bring down costs.
For example, by studying how nature stores energy in chemical bonds, PNNL researchers recently developed the fastest-known catalyst for producing hydrogen. Capable of producing 45 million molecules of hydrogen per second, this catalyst uses nickel at its core, which is a less expensive, more abundant alternative to metals like platinum often used in catalysts. This new catalyst could ultimately lead to an environmentally friendly, affordable way to make hydrogen fuel.
In another effort, researchers are using molecular engineering to build tiny, three-dimensional structures that could serve as building blocks for efficient catalysts. Their novel approach to vary the size, structure and composition of particles is similar to the way proteins direct the growth of complex structures, such as shells, bone and tooth enamel, without defects that can hamper catalyst performance.
PNNL researchers also are exploring ways to convert biomass and waste carbon into fuels. By developing a process that eliminates the need to dry raw materials like sewage sludge before processing, they have overcome a common barrier to using these materials to produce biofuels. Our technology, called hydrothermal liquefaction, breaks down human waste into simpler chemical compounds and produces a material similar to petroleum pumped out of the ground. This biocrude can then be refined using conventional petroleum refining operations. Utah-based Genifuel Corporation has licensed the process and is working with Metro Vancouver in British Columbia to build a demonstration plant.