Today, we ran the reaction at a lower temperature than last weekend. Unfortunately, we can still not measure it, so we just kept the flame regulated a bit lower. We used 25 g of waste PP and got approximately the same amount as liquid waxy product (so we assume we got almost 100% conversion).
We got a small flame to burn at the outlet, but most of the product was liquid. This was in contract to the run we did last weekend, where we got the reactor to glow on the outside, meaning that the reaction temperature was higher than this time. With the high temperature, we produced a high amount of gas and little liquid product. A higher temperature seems to increase the fraction of gas formed, but we still need to find the right temperature to for forming diesel and gasoline fraction. We also have to investigate the influence of pressure on the products more, once we have a pressure sensor.
No plastic remained in the reactor and only a very small amount of coke was formed. All plastic was converted within 27 minutes. For heating the reactor we used about 50 g of propane gas in 10 minutes, which is very reasonable given that we have a cylinder of 9.5 kg (1 kg ~1 m3) of it.
It is important to leak-test the reactor prior to every run. We learned this the hard way. During the first run of the day, we had a leak at the top of the reactor and had to stop the experiment. It was however interesting to have a look at the inside. The gas bubbles seem to form everywhere in the molten plastic and bubble through making the plastic look spongy.