First painting in life

 First painting in life

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Feeding Spent Coffee Grounds into Reactors: TFM Simulation of a Non-Mechanical Spouted Bed Type Feeder

Link for 50 days' free access https://authors.elsevier.com/a/1b2ZF,LlFP9xwn

Feeding Spent Coffee Grounds into Reactors:

TFM Simulation of a Non-Mechanical Spouted Bed Type Feeder

Lucas Massaro Sousa^{1, 2}, Maria C. Ferreira², Qinfu Hou^[1]*and Aibing Yu^{1, 3}

¹ARC Research Hub for Computational Particle Technology, Chemical Engineering Department, Monash University, Clayton, VIC 3800, Australia

²Drying Center for Pastes, Suspensions, and Seeds, Chemical Engineering Department, Federal University of São Carlos, P.O. Box 676, 13565-905 São Carlos, Brazil

³Centre for Simulation and Modelling of Particulate Systems, Southeast University−Monash University Joint Research Institute, Suzhou 215123, PR China

* Corresponding author. E-mail address: qinfu.hou@monash.edu

ABSTRACT

Due to the increasing coffee production, Spent Coffee Grounds’ (SCGs) generation has grown dramatically, hence appropriate management of this solid biomass waste is imperative. SCGs can be used as feedstocks for renewable energy and fuel generation provided that a stable feeding of powders to reactors is maintained. Recently, a non-mechanical spouted bed feeder proved itself an excellent alternative in feeding SCGs to a pilot-scale circulating fluidized bed reactor. Nonetheless, further studies are necessary for the feeder’s implementation in commercial applications. Here the feeding of SCGs with the spouted bed feeder is addressed by using Computational Fluid Dynamics. Firstly, a Two-Fluid Model (TFM) is validated against experimental data, and then the effects of five operating and design parameters were analyzed aiming at improving the handling of SCGs. The solids flowrate (W_S) in the reactor could be stably controlled from 4 to 30 g/s depending on the settings. The feeder performance is enhanced by operating it under high gas flowrate (Q), high entrainment length (z), and high mass of solids in the feeder (H_S). Using feeders with low cone angle (γ) or reactors with large diameter (D_R) increases W_S, which is appealing for the operation of medium-to large-scale units. The proposed TFM is a cost-effective tool for implementing spouted bed feeders in commercial applications. With the feeder coupled to the process, SCGs are treated continuously in the reactor for energy generation, thus reducing the disposal problems associated with this waste and improving the management of SCGs globally.

Keywords: feeding device; spent coffee grounds; two-fluid model; spouted bed; CFD.

'Postdoc'

"An individual who has received a doctoral degree (or equivalent) and is engaged in a temporary and defined period of mentored advanced training to enhance the professional skills and research independence needed to pursue his or her chosen career path"

• Period of service: Postdoctoral appointments for a given postdoctoral researcher should total no more than 5 years in duration, barring extraordinary circumstances.
• Career Development: Host institutions and mentors should, beginning at the first year of graduate school, make graduate students aware of the wide variety of career paths available for Ph.D. recipients, and explain that postdoctoral positions are intended only for those seeking advanced research training. Career
• guidance should include, where feasible, the provision of internships and other practical experiences. The postdoctoral position should not be viewed by graduate students or principal investigators as the default step after the completion of doctoral training.

Some of the work now being done by postdoctoral researchers might more appropriately be done by permanent research staff, who receive the salary, benefits, and job security commensurate with full-time  employment. Such research staff positions are common in government, industrial laboratories, and outside the United States. The postdoctoral experience itself should be refocused, with training and mentoring at its center.

From a report from the US on the Postdoctoral experience

"the best research funding" reviewed

Performance of funding by NSFC #China is reviewed by an international committee. Some main suggestions (comments in the brackets are mine):

1 substantially more staff to process huge applications, at the same time reduce the number of applications submitted (good to cut applications)

2 International problems, to attract international researchers (good for many overseas researchers)

3 extend the peer-review model to other funding agencies in China (good suggestion, however…)

4 improve the review of inter-disciplinary research (where I am in this dilemma: metallurgy, chemical engineering, material science)

5 promote early career researchers (too many PhD in China, who should be considered)

6 increase flexibility in spending the fund (should avoid corruption at the same time)

 

Feed: Science: Current Issue
Posted on: Friday, 28 October 2011 4:05 AM
Author: Richard N. Zare
Subject: [Editorial] China's Science Funding

 

Authors: Richard N. Zare, Ernst-Ludwig Winnacker

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Academics unhappy in Australia

Australian academic researchers are rallying behind a report that laments their working conditions. The government-funded study, out in September, surveyed 5,525 academics across all career stages and fields at 20 universities. It found that nearly half of academics under 30 want to leave the country or the profession owing to low pay and lack of job security. Researchers are frustrated by teaching obligations that cut into research time; low grant success rates; and 70- to 80-hour working weeks. Emmaline Bexley, a lecturer in higher education at the University of Melbourne and lead author of the study, says she hopes that her research will "help government and universities to work together to replenish the academic workforce".

Academics unhappy Nature (2011). doi:10.1038/nj7370-549c Low pay, low grant success and job insecurity add to researchers' miseries in Australia.

 

[News & Analysis] China: Foreign Researchers Begin to Make Their Mark

中国的人才政策

Science 8 July 2011: 
Vol. 333 no. 6039 p. 144 
DOI: 10.1126/science.333.6039.144

CHINA

Foreign Researchers Begin to Make Their Mark

Jane Qiu

BEIJING—As one of the country's poorer provinces, Yunnan in southwestern China has struggled to balance economic development and conservation. "Few researchers in China are equipped with the necessary expertise or perspective" to help Yunnan officials craft sound environmental policies, says Xu Jianchu, a conservation biologist at the Kunming Institute of Botany of the Chinese Academy of Sciences (CAS). That's where Edward Grumbine comes in. With more than 2 decades of experience as an environmental policy expert, Grumbine came to Kunming from Prescott College in Arizona on a 1-year fellowship and just reupped for a second year. He and Xu are trying to persuade local officials to take a holistic approach toward land-use management and to enlighten them on the perils of unrestrained hydropower development.

China has been going all out to persuade ethnic Chinese researchers stationed abroad to return and bolster science in their motherland (Science, 31 July 2009, p. 534). Conditions in China are improving so quickly, research chiefs say, that labs are now wooing top overseas scientists, no matter their ethnicity. Last month, CAS held a workshop here to assess a pair of fellowship programs launched in 2009 to bring non-Chinese scientists to CAS labs. Thus far the programs have supported 179 postdocs and 477 professors, paying annual stipends as high as 500,000 yuan ($77,000).

At the meeting, Grumbine and 69 other foreign researchers on long-term stints hailed the fellowships. China, they say, offers a number of attractions. Some scientists came here because there is ample funding for research and new instruments. Others followed partners to China or say they are curious about the rising power.

UK jobs not secure

英国经济困难，好多职位薪资较低，安全性降低。不知道温总理的大单生意，能否给英国注入活力？

对了，温总理讲话还提到，解决贪腐的根本是推进政治体制改革，不知道他代表的是个人还是中央政府？推进的过程，步伐究竟是怎么样的？拭目以待！

 

UK jobs not secure Nature 474, 7353 (2011). doi:10.1038/nj7353-669a Survey suggests scientists' job security is suffering as a result of austerity measures.

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