Chinese export tariffs, page-2

very interesting read, the question is what difference will it make if any? following are a couple of points i have picked up in my research in the sop space;

1. supply price likely has a floor in the marginal cost of production of sop via the mannheim process ~us$400t.
2. mannhiem furnaces are being shut down for environmental reasons, so this is likely to be reducing supply and consequently pushing up prices(?)
3. demand inside china is likely to stay the same or even grow, so where is their demand being met from?

just as an idea, is it possible that the chinese regulators have removed this tarif as they know that china is unable to export any sop due to internal supply shortages for this product, and they are using it to soften the us stance in the trade negotiations? ok so sop alone will not move us policy, but some concessions need to be made and this could just be a move by china in that direction..... has this sort of thing happened before, i.e. give someone something they don't want so that you can get what you want? i think so.