Research on Hydrogen Production from Waste Plastics Using the High Temperature Steam Reforming Process

采用间歇式热解/蒸汽重整装置，对PE、PP和PS三种纯塑料的热解/蒸汽重整性能进行了研究。阐明了三个操作参数（重整温度、重整炉内停留时间和蒸汽比[供汽摩尔/秒/热解气体中碳摩尔/秒]）对重整性能的影响。首先，在停留时间为1.5秒、蒸汽比为1的条件下，考察了重整温度对蒸汽重整反应的影响。结果表明，随着重整温度的升高，每种塑料的气体转化率和氢气产率均有所提高。在600℃的温度下，所有的塑料材料都可以完全气化，比非催化重整所需的温度低400℃左右。其次，在重整温度为600℃、蒸汽比为1的条件下，考察了重整釜中停留时间对重整反应的影响。结果表明，根据塑料材料的不同，需要1-1.5秒的停留时间才能完全气化并产生足够的氢气。将重整温度设置为600℃，重整釜停留时间设置为0.9秒，考察了蒸汽比对重整反应的影响。结果表明，每种塑料都能成功生成富氢（50-65%）的燃料气体，该工艺对于生产富氢燃料气体是有效的。最后，对热解气冷却过程中因对苯二甲酸冷凝而难以热解的PET材料进行了类似的实验。结果表明，水蒸气重整完全抑制了凝析油的生成，即使是PET材料也能产生富氢燃料气。

Pyrolysis and steam reforming performances of three pure plastic material (PE, PP and PS) were investigated using a batch-type pyrolysis/steam reforming equipment. The effects of three operating parameters (the reforming temperature, the residence time in the reformer and the steam ratio [mole/sec of steam supplied / mole/sec of carbon in the pyrolysis gas] ) on the steam reforming performance were clarified.At first, the effect of the reforming temperature on the steam reforming reaction was investigated by setting the residence time at 1.5 sec. and the steam ratio at 1. As a result, the gas conversion rate and the hydrogen yield both increased by increasing the reforming temperature for each plastic material. All the plastic material could be completely gasified at the temperature of 600℃, which is about 400℃ lower than that required for the non-catalytic reforming. Next, the effect of the residence time in the reformer on the steam reforming reaction was investigated by setting the reforming temperature at 600℃ and the steam ratio at 1. The results showed that 1-1.5 sec. residence time is required for complete gasification and sufficient hydrogen production depending on the plastic material. Then the effect of the steam ratio on the steam reforming reaction was investigated by setting the reforming temperature at 600℃ and the residence time in the reformer at 0.9 sec. As a result, it was demonstrated that hydrogen rich (50-65%) fuel gases were successfully generated for each plastic material, and that this process is effective for production of hydrogen rich fuel gases.Finally, the similar experiments were done for PET material which is hard to be pyrolyzed due to condensing of terephthalic acid in the course of cooling of the pyrolysis gas. The results showed that the steam reforming completely suppresses formation of condensates and hydrogen rich fuel gas can be produced even in the case of PET material.