微波诱导低级醇的等离子体化学反应

微波诱导低级醇的等离子体化学反应王真，洪品杰，张承聪，戴树珊（云南大学化学系，昆明，６５００９１）关键词微波，等离子体化学，低级醇等离子体能产生大量的活性自由基、亚稳态粒子和激发态离子，它所包含的能量传递过程和反应过程不仅与反应碰撞理论有关，而且还涉...

The Microwave-induced Plasma Chemical Reaction of the Lower Alcohol

A microwave source with power 0 100 W,continuously adjustable,operating at a frequency of 2450 MHz and a surfatron discharge cavity was used for the experiment.The microwave-puncture curves of air and various alcohols(CH3OH,C2H5OH,n-C3H7OH and i-C3H7OH)observed show that the lower-pressure vapor of alcohol was dissociated easier than air,resulting in plasma.The reactor effluent gases were analyzed by gas chromatography with FI detector or TC-FI two-dimensional chromatography method on line.The electron temperature(Te)of the alcohol plasma was identified using Langmuir double-probe.The results show that the products of plasma reaction were composed of H2,H2O,CO,CH4,C2H4,C2H6,C3H6and C3H8, but C2H4 was the main product.Not only the nature of the alcohol itself,but also the microwave power was responsible for the product abundance.This kind of reaction proceeded through a free radical mechanism,so the distribution and quantity of products show the species and quantity of free radicals in plasma.The yield of C2H4 was increasing as the input-power increased,up to the maximum then followed by the decreasing,and the carbon deposit on the wall of reactor could be observed,which implied the deepdissociation took place in the case of higher power,and the higher hydrocarbon was not easily produced.