科研之友
微信
新浪微博
Facebook
分享链接
摘要
Chars formed during air and oxygen blown gasification processes have a low reactivity. This is due to changes that occur in the structure and morphology of the original coal during heating. In part, the changes depend on conditions prevailing during the pyrolysis stage and partly on the length of time spent at peak temperature. Previous work in this laboratory has highlighted that the gasification reactivity of a char depends on the conditions of its formation. This means that chars must be prepared under realistic conditions when conducting laboratory scale reactivity studies that are intended to support a larger scale development. This is not easy to do and requires the development of dedicated methods for preparing the char. In this paper, the development of a laboratory-scale test, based on a laboratory-scale spouted bed gasifier, is described that is able to prepare chars under conditions that represent those in an air-blown gasifier. The reactivity of the prepared chars is then examined to identify how the reactivity of the char varies within the envisaged operating window of the process. A feature of this apparatus is that the char formation time is known accurately, which has required the development of novel feeding and draining mechanisms. These enable the coal particles to be injected quickly into the reactor and the sand/char bed drained and quenched rapidly after a known residence time. The extent of char deactivation can be measured with residence times between 2 and 3600 s. In this paper, the validation of the experiment is described and some preliminary results are reported.
- 出版日期2006-4
