Published December 2009
In recent years, the propylene oxide (PO) industry has been quite active in researching new process technologies to manufacture PO without co-producing large amounts of styrene or t-butyl alcohol, or generating chloride-containing waste streams. Many companies have investigated PO technologies using hydrogen peroxide (HPPO process), and effective catalysts have been developed to improve the selectivity to PO. In late 2002, BASF and Dow Chemical joined forces in the development of an HPPO technology process. A 300,000 t/yr plant using this technology was completed at Antwerp, Belgium, in March 2009. In Thailand, Dow and Siam Cement group (SCG) have broken ground on a 390,000 t/yr PO facility near Map Ta Phut, using the BASF-Dow HPPO technology. The plant is expected to come online in 2011.
This review presents a conceptual design and preliminary economics for a plant producing 200,000 t/yr of PO from propylene using the HPPO process. The plant is integrated with a unit that generates hydrogen peroxide by direct reaction of hydrogen and oxygen. We also compare the economics of the HPPO technology with those of the conventional PO/SM, PO/TBA and chlorohydrin processes.
Our analysis indicates that recent patented improvements in the product recovery configuration have resulted in a significant reduction in the overall steam consumption of the HPPO process. The improved version of the technology can be cost-competitive with the PO/SM and PO/TBA processes when market prices for the styrene and TBA co-products are relatively low. One of the main benefits of the HPPO technology, which could justify new capacity additions in developing regions, is the fact that it eliminates the need for additional infrastructure or markets for co-products. However, to be competitive, the HPPO process depends on the availability of a low cost source of hydrogen peroxide.