13 research outputs found
Policy mixes for incumbency: the destructive recreation of renewable energy, shale gas 'fracking,' and nuclear power in the United Kingdom
The notion of a âpolicy mixâ can describe interactions across a wide range of innovation policies, including âmotors for creationâ as well as for âdestructionâ. This paper focuses on the United Kingdomâs (UK) ânew policy directionâ that has weakened support for renewables and energy efficiency schemes while strengthening promotion of nuclear power and hydraulic fracturing for natural gas (âfrackingâ). The paper argues that a âpolicy apparatus for incumbencyâ is emerging which strengthens key regimebased technologies while arguably damaging emerging niche innovations. Basing the discussion around the three technology-based cases of renewable energy and efficiency, fracking, and nuclear power, this paper refers to this process as âdestructive recreationâ. Our study raises questions over the extent to which policymaking in the energy field is not so much driven by stated aims around sustainability transitions, as by other policy drivers. It investigates different âstrategies of incumbencyâ including âsecuritizationâ, âmaskingâ, âreinventionâ, and âcapture.â It suggests that analytical frameworks should extend beyond the particular sectors in focus, with notions of what counts as a relevant âpolicy makerâ correspondingly also expanded, in order to explore a wider range of nodes and critical junctures as entry points for understanding how relations of incumbency are forged and reproduced
Prozessentwicklung zur Produktion von 2-Keto-l-GlulonsÀure, einer Vitamin C-Vorstufe
In this study a process for the continuous production of 2-keto-L-gulonic acid was developed. This compound is a precursor of vitamin C and therefore of great industrial interest. 2-Keto-L-gulonic acid (2-KLG) was produced from D-glucose in a two-step reaction: Glucose was first oxidized to 2,5-diketo-D-gluconic acid (2,5-DKG) with cells of , 2,5-DKG was then reduced to 2-KLG with the enzyme 2,5-diketo-D-gluconate reductase. Both reactions were carried out in separate reactors; 2,5-DKG was transferred into the second reactor without any further processing or purification. Resting cells of could successfully be applied in batch and continuously stirred tank reactors (CSTR) for the production of 2,5-DKG. In both cases, sufficient supply of oxygen is crucial; in a specially constructed batch reactor the activity of the cells was increased threefold compared to the activity in shaking flasks. Thus, yields of up to 97% were achieved in the batch reactor. In a CSTR, yields of about 80% could be kept for several days, in that case the space-time-yield was 92 gLd. The enzyme 2,5-diketo-D-gluconate reductase (2,5-DKGR) was isolated and purified from recombinant cells in good yields of 0.31 mg. In kinetic investigations it accepted NADH as a cofactor but showed a much higher preference for NADPH (K = 500 · K). Cofactor regeneration worked best with the alcohol dehydrogenase from . The two enzymes were successfully applied in an enzyme membrane reactor to produce 2-KLG from 2,5-DKG with yields of up to 100%. The highest space-time-yield was 329 gLd with product yields of 81%. After coupling the two reactor systems, 2-KLG could be produced continuously from D-glucose with yields of 68% and space-time-yields of 41.5 gLd for more than eight days. This study showed that the yields in this two-step reaction can be improved if the two steps are carried out in separate reactors. This way, the best reaction conditions for both oxidation and reduction can be adjusted
Prozessentwicklung zur Produktion von 2-Keto-L-GulonsÀure, einer Vitamin C-Vorstufe
In this study a process for the continuous production of 2-keto-L-gulonic acid was
developed. This compound is a precursor of vitamin C and therefore of great industrial
interest. 2-Keto-L-gulonic acid (2-KLG) was produced from D-glucose in a two-step
reaction: Glucose was first oxidized to 2,5-diketo-D-gluconic acid (2,5-DKG) with cells of Gluconobacter oxydans, 2,5-DKG was then reduced to 2-KLG with the enzyme
2,5-diketo-D-gluconate reductase. Both reactions were carried out in separate reactors; 2,5-DKG was transferred into the second reactor without any further processing or purification...
Technische Anwendung von Enzymen: WeiĂe WĂ€sche und GrĂŒne Chemie
In the laboratories of Mother Nature, enzymes, the most efficient and specific catalysts, have been developed. These proteins have been used by mankind since millennia, e.g., for cheese-making. By now, enzymes have captured a huge market in industry and handicraft, and even more expansions are certain. Applications range from detergents and textiles to food, animal feed and drugs. Stone-washed jeans, antibiotics, improved wine corks and ice cream - all these products make us live a very enzyme-filled life