Catalytic feedstock hydrogen content

Figure 5. Effect of feedstock hydrogen content on response to fluid catalytic...

Propylene yield is increased by processing feedstocks with high hydrogen content. Key features that allow catalytic conversion of fresh feed into propylene yields of 15-25 wt% in the DCC process are... 

Methanol synthesis Syngas (essentially hydrogen, carbon monoxide, carbon dioxide) reacts catalytically to methanol at medium pressures and medium temperatures (200-300 °C). Typical plant capacities go up to 5000 t methanol/ day a hydrogen content in the syngas of 70 % and 2520 Nm /t of syngas consumed for ammonia production result in an hourly hydrogen consumption of 370,000 Nm. Methanol serves as chemical feedstock for the production of further chemicals. 

Furnace carbon black is produced from the incomplete combustion of what is called carbon black oil feedstock, which consists of heavy aromatic residue oils. In the United States this oil is commonly the bottoms from catalytic cracker units. They are commonly referred to as cat cracker bottoms and contain relatively low hydrogen content (and conversely high carbon content). In Europe and other locations, the carbon black oil used is commonly a byproduct of high-temperature steam cracking of such products as naphtha, gas condensate, and gas oil to produce ethylene, propylene, and other olefins. Here, no catalysts are used in the cracking process. These types of carbon black oils are mainly unsaturated hydrocarbons. A third source of carbon black feedstock is coal tar, which is commonly used in China to manufacture carbon black. 

High-temperatnre pyrolysis and cracking of waste thermoplastic polymers, such as polyethylene, polypropylene and polystyrene is an environmentally acceptable method of recycling. These type of processes embrace both thermal pyrolysis and cracking, catalytic cracking and hydrocracking in the presence of hydrogen. Mainly polyethylene, polypropylene and polystyrene are used as the feedstock for pyrolysis since they have no heteroatom content and the liquid products are theoretically free of sulfur. 

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