Novel Reactor Technology

This chapter deals with basic fundamentals of novel reactor technology and some of green reactor design softwares and their applications. Basic understanding of flow pattern in stirred-tank reactor by computational fluid dynamics and simulation of CSTR model by using ASPEN Plus were mainly presented in this chapter. 

---

The chemical route a potential decrease in manufacturing costs is roughly proportional to the reduction in number of processing steps. B2C is therefore attractive if it is an enabler for a chemistry that carmot be carried out in classic batch equipment. This is the opportunity for novel reactor technologies. The economic impact is, however, hard to define quantitatively [34, 60]. 

U Zardi et al, A Novel Reactor Design for Ammonia and Methanol Synthesis , IV Intern Conference Fertilizer Technology, London 1981, Hydrocarbon Process, 1982, 61 (No 8), 129-133... 

The next steps involve the development and build of an optimized pilot plant (100 kWth) for solar Hydrogen production based on this novel reactor concept, involving further scale-up of the HYDROSOL technology and its effective coupling with solar platform concentration systems, in order to exploit and demonstrate all potential advantages. Specific challenging problems currently addressed include ... 

While the aforementioned and other novel membrane reactors hold great promises, many material, catalysis and engineering issues need to be fully addressed before the inorganic membrane reactor technology can be implemented in an industrial scale. This is particularly true for many bulk-processing applications at high temperatures and often harsh chemical environments. Those issues will be treated in the subsequent chapters. 

ABSTRACT A novel reactor configuration has been developed in our laboratory which addresses the heat transfer limitations usually encountered in vacuum pyrolysis technology. In order to scale-up this reactor to an industrial scale, a systematic study on the heat transfer, the chemical reactions and the movement of the bed of particles inside the reactor has been carried out over the last ten years. Two different configurations of moving and stirred bed pilot units have been used to scale-up a continuous feed vacuum pyrolysis reactor, in accordance with the principle of similarity. A dynamic model for the reactor scale-up was developed, which includes heat transfer, chemical kinetics and particle flow mechanisms. Based on the results of the experimental and theoretical studies, an industrial vacuum pyrolysis reactor, 14.6 m long and 2.2 m in diameter, has been constructed and operated. The operation of the pyrolysis reactor has been successful, with the reactor capacity reaching the predicted feed rate of 3000 kg/h on a biomass feedstock anhydrous basis. 

Carbon-based catalysts and in particular their kinetics have been intensively studied [41 3], because they should reduce the disadvantages related to metal-based catalysts. Carbon materials are more available, have the potential of cost reduction, do not require periodic regeneration because it is not necessary to separate the carbon-product from the catalyst. The fluidised bed reactor technology represents the optimal choice for this kind of hydrocarbon cracking process as it can withdraw the carbon particles evermore, permitting a reliable storage of produced carbon for further use [44 46]. A novel technological solution aimed to improve activity and stability of carbon catalysts has been recently proposed [47]. The presence of small amount of O2 in an autothermal approach seems to be the best solution to minimize CO2 emissions in the overall process. 

Process Intensification offers an interesting incentive for the assessment of existing chemical processes. By comparing a number of established technologies as well as novel reactor set-ups, some distinctions can be made. 

The separation of soluble PTC is a matter of concern in the industry not only due to environmental considerations, but also due to contamination of the product with the catalyst. Further research should be oriented towards development of novel catalyst separation techniques and of novel reactor-separator combo units. As outlined before, the development of a membrane reactor with PT catalyst immobilized on the membrane surface seems to be a novel and viable candidate for accomplishing PTC reactions on an industrial scale. Another aspect of PTC which needs urgent consideration is the development of engineering technology for immobilized PTC. This would require the development of supports with low diffusional limitations and with the right hydrophilic-lipohilic balance to ensure adequate contact of the aqueous and organic phases with the supported catalyst. 

This paper describes the development of BP s Fischer-Tropsch (FT) catalyst from the early days of laboratory scale preparations and micro-reactor tests to commercial scale manufacture and operation at BP s Gas to Liquids (GTL) demonstration facility in Nikiski, Alaska. A detailed description of the catalyst development activities, preparation methods, and experimental facilities is provided by Font Fieide and eoworkers [1]. The initial research was focused on eatalyst development for a fixed bed reactor design. Recent activities inelude the eommereial seale fixed bed tests in progress at Nikiski and development of a novel slurry-based reactor technology. 

Susceptibility to product inhibition This is a serious shortcoming but can be overcome by the use of novel reactors such as membrane reactors (Matson and Quinn, 1986 see also Chapter 24), nonaqueous media (Dordick, 1989 Rethwisch et al., 1990), and recombinant DNA technology (Arbige and Pilcher, 1989). 

James is also an active postdoctoral researcher. His research interests centre on clean synthesis with focus on asymmetric induction in enantiose-lective catalysis, utilization of CO and CO2 as a sustainable source of chemicals, heterogeneous catalysis and novel reaction technologies including cold plasma reactors and continuous flow synthesis. 

The problems associated with conventional biodiesel production can be solved by PI technologies that involve the use of novel reactors or coupled reaction/separation processes. These technologies can cause an improvement in the rate of reaction reduction in residence time (Qiu, Zhao, Weatherley, 2010). 

Such a trend would give a substantial stimulus to integration methodologies which have yet, with a few exceptions, to fully incorporate the novel PI technologies emerging into the marketplace. One example is the current work on fluidised-bed reactors in the Netherlands and Germany (Deshmukh et al, 2007). 

---