Chemical Week 2002/6/19
The Egyptian government has approved Eatco Petrochemical’s (Cairo) $1.4-billion olefins and polyolefins project at Damietta, Egypt. Eatco says it is looking for partners for the project, which will use a new methanol-to-olefins (MTO) technology developed by UOP and Norsk Hydro. Eatco will convert methanol to ethylene and propylene, which will be supplied to plants with capacity for 300,000 m.t./year of polyethylene and 200,000 m.t./year of polypropylene. Eatco says Dow Chemical, Chevron Phillips Chemical, and Basell are competing to supply polyolefins technology. Eatco adds that it is close to appointing a financial advisor.
The MTOTM methanol to olefins process, developed by UOP and HYDRO of Norway, provides an economical means to convert methanol to olefins, primarily ethylene and propylene. Ethylene and propylene are in increasing demand worldwide and have significant financial value in the marketplace. With its higher yields, the MTO process is more economical than older technologies for indirect conversion of methane to higher value products.
The MTO process plays a key role in converting natural gas into olefins. The first step in that process, converting natural gas to methanol, has been available to the industry for some time. The second step, transforming the resulting methanol into olefins, is now available via the MTO process.
UOP/HYDRO MTO PROCESS
METHANOL TO OLEFINS CONVERSION
INTRODUCTION Changing natural gas into olefins is a two-step process
| The first
step, converting natural gas to crude methanol, has been
available to the industry for some time. The second step,
transforming the resulting methanol into olefins, has
recently been introduced by UOP and HYDRO of Norway. The
UOP/HYDRO MTO (methanol to olefins) process provides an
economical means to convert natural gas to olefins. The
UOP/HYDRO MTO process primarily converts the methanol
into ethylene and propylene. Ethylene and propylene are
in increasing demand worldwide and have significant
financial value in the marketplace. UOP and HYDRO have
developed the UOP/HYDRO MTO process for license to
Other technologies for indirect conversion of methane to higher value products do exist. These processes have lower yields than the UOP/HYDRO MTO process and are, therefore, less economical. The UOP/HYDRO MTO process offers:
|・||Exceptional value for direct conversion of methane to polymer-grade ethylene and propylene.|
|・||Direct use of ethylene and propylene in chemical-grade products with greater than 98% purity using a flowscheme that does not require expensive ethylene/ethane or propylene/propane splitters.|
|・||Limited production of by-products compared to a steam cracker, which results in a simplified product recovery section.|
|・||Easy integration into existing naphtha cracker facilities due to low paraffin yields.|
|・||Flexibility to change the ethylene to propylene product weight ratio from 1.5 to 0.75.|
The UOP/HYDRO MTO process can be utilized in locations with cheap, abundant natural gas reserves. By integrating the UOP/HYDRO MTO process into a gas to olefins (GTO) complex, feedstock prices can be held down and natural gas can be converted into a form that is more easily transported and of higher value. Existing naphtha or ethane-propane cracker facilities can increase olefin production and feedstock flexibility by installing an MTO reactor section and feeding into a revamped cracker fractionation section to minimize capital investment. Because the UOP/HYDRO MTO process produces a rich olefinic effluent containing low quantities of paraffins, the existing fractionation equipment can often be easily debottlenecked to handle the additional olefins produced. Yet another application would be downstream of an existing methanol plant with excess capacity, to meet local demands for olefins and polyolefins.
In the UOP/HYDRO MTO process, crude methanol is converted primarily to ethylene and propylene. The process can work in either a maximum ethylene or a maximum propylene production mode. The approximate purified hydrocarbon product stream compositions, on the basis of wt%, are shown below for both operating modes. By changing the reactor operating severity, the UOP/HYDRO MTO process user can switch between operation modes as market demands dictate.
Long-term methanol conversion of 99.8% and stable product selectivity have been demonstrated at HYDRO’s large process demonstration plant in Norway. This plant circulates and regenerates catalyst continuously and uses crude methanol as a feedstock at a rate of more than 0.75 MT per day.
The UOP/HYDRO MTO commercial process utilizes a fluidized bed reactor with a continuous fluidized bed regenerator. This technology is an extension of UOP’s established FCC commercial technology.
C 2 =/C 3 =
Feedstock for the UOP/HYDRO MTO process is crude, non-distilled methanol usually produced from synthesis gas (CO + H 2 ), which is produced from the reforming of abundant natural gas. Synthesis gas can also be produced by steam reforming of petroleum products such as naphtha, partial oxidation of natural gas and petroleum products, and coal gasification.
The reaction is catalyzed by the MTO-100 silicoaluminophosphate synthetic molecular sieve based catalyst. The catalyst has demonstrated the degree of attrition resistance and stability required to handle multiple regenerations and fluidized bed conditions over the long term. The catalyst is extremely selective toward the production of ethylene and propylene.