| Author | Vu Quang Vinh |
| Call Number | AIT Thesis no.ET-93-3 |
| Subject(s) | Coal slurry.
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| Note | A thesis submitted in partial fulfilment of the requirement for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ET-93-3 |
| Abstract | This report is concerned with some aspects of the fluidity and combustibility of several types of torrefied wood (TW) slurries which could be used as oil substitute in industrial facilities. Experimental study on TW grindability was performed to choose the suitable operating conditions (torrefaction temprature and holding time). The reduction ratio was used to determine the grindability of the TW produced at different torrefaction temperatures and holding times. A set of operating conditions for torrefaction (280°C and 11 hrs) was chosen based on the best grindability for slurry preparation and an appropriate mass yield. Experimental study on sedimentation and rheological behaviors of TW slurries reveals the possible effects of a number of governing factors, such as TW particle size analysis, TW loading, chemical additive (Cab-0-Sil M5) and addition of a second liquid on the slurry properties. TW particle size distribution was governed by different milling procedures using a number of available milling machines in AIT. Due to high porosity of TW paticles, the maximum TW loading of a workable slurry of TW is limited to 40 to 45% by weight depending on the type of TW powder. Adding a second liquid significantly changes the viscosity and makes the resulting slurry much more stable. The viscosity of the resulting slurry is reduced only when the addition is done at low initial loading (e.g. 30% less). The resulting slurry remains stable for a long time if the initial loading is more than 30% and the percentage of second liquid addition is less than 15%. It should be noted that the viscosity of the resulting slurry is independent of particle size distribution. The combustibility of TW slurries is better than charcoal slurries due to high volatile content of TW. TWOM burns faster than COM. The experiments on combustion of TW slurry droplet show a strong micro-explosion phenomenon in case of droplets of TWOM in which a small quantity of water had been added. Thus TWOM (40 to 45% loading) with 10 to 15% water addition can burn faster than diesel oil. Due its poor calorific value, there is still a problem in reducing the combustion delay of TWWS even with diesel oil addition. Positive effect of microexplosion on combustion of TWWS with oil additive is expected to be limited by strong particle agglomeration resulting from high viscosity of the resulting slurry. |
| Year | 1993 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ET-93-3 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Bhattacharya, S.C. |
| Examination Committee(s) | Surapong C.;Mohanty, B. |
| Scholarship Donor(s) | The Government of France. |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993. |