As demand for oil and natural gas outpaces discoveries of new reserves, coal will regain its importance as a source of energy and as a chemical feedstock. At current production levels, proven coal reserves are estimated to last over a century, with recoverable reserves in around 70 countries. In contrast, proven oil and gas reserves are equivalent to around 50 years at current production levels while two-thirds of these reserves are concentrated in the Middle East and Russia. The challenge is how to harness this enormous amount of coal resource, which constitutes about 30% of world energy demand, economically without adverse impact on the environment.
Ethylene and propylene are by far the two largest-volume chemicals produced by the petrochemicals industry. In 2010, about 127 million metric tons of ethylene and 82 million metric tons of propylene were produced worldwide. The majority of light olefins are produced by the petrochemicals industry either from pyrolysis (steam cracking) of NGLs and naphtha or from fluid catalytic cracking (FCC) of naphtha. The recent dramatic increase in oil prices is reviving a strong interest in the production of light olefins from nonpetroleum sources such as coal.
In this report, we evaluate chemical applications of coal: the partial oxidation of coal to produce synthesis gas (syngas), followed by synthesis of methanol from syngas, and the catalytic conversion of methanol to light olefins. We develop and present conceptual designs and preliminary economics for the integration of GE Energy gasification technology with the UOP/Hydro methanol to olefins (MTO) process and the Shell Coal Gasification Company (SCGP) technology with the Lurgi (now Air Liquide) MTP methanol-to-propylene process.