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

采用间歇式热裂解/水蒸气重整装置研究了三种纯塑料（PE、PP和PS）的热裂解和水蒸气重整性能。明确了重整温度、重整器内的停留时间、水蒸气比[供给的水蒸气的摩尔/秒/热解气体中的碳的摩尔/秒]这3个操作参数对水蒸气重整性能的影响。首先，将停留时间设为1.5秒，研究了重整温度对水蒸气重整反应的影响。蒸汽比为1。结果，通过提高每种塑料材料的重整温度，气体转化率和氢产率都增加。在600℃的温度下，所有的塑料原料都可以完全气化，比非催化重整所需的温度低400℃左右。接着，通过设定重整温度为600℃和水蒸气比为1，研究了在重整器中的停留时间对水蒸气重整反应的影响。结果表明，1-1.5秒。取决于塑料材料，完全气化和足够的氢气产生需要停留时间。在此基础上，研究了水蒸气比对水蒸气重整反应的影响，设定重整温度为600℃，在重整器中的停留时间为0.9秒。实验结果表明，每种塑料原料都能成功地产生50-65%的富氢燃气，说明该工艺是生产富氢燃气的有效方法。最后，对由于对苯二甲酸在热解气体冷却过程中冷凝而难以热解的PET原料进行了类似的实验。结果表明，蒸汽重整完全抑制了冷凝物的形成，并且即使在PET材料的情况下也可以产生富氢燃料气。

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.