Process Design and Integration of Shale Gas to Methanol

Abstract

The substantial discoveries of shale gas present many opportunities for the chemical, petrochemical, and fuel industries. As in conventional natural gas, shale gas contains primarily methane, but some formations contain significant amounts of higher molecular weight hydrocarbons and inorganic gases such as nitrogen and carbon dioxide. These differences present several technical challenges to incorporating shale gas with the current infrastructure designed to be used with natural gas. This paper is aimed at process synthesis, analysis, and integration of the production of methanol from shale gas. The composition of the shale gas feedstock is assumed to come from the Barnett Shale play located near Fort Worth, Texas, which is currently the most active shale gas play in the United States. Process simulation using ASPEN Plus along with published data were used to construct a base-case scenario. Key performance indicators were assessed. These include overall process targets for mass and energy and economic performance. A sensitivity analysis is carried out to assess the impact of the methanol selling price and shale gas price on the profitability of the process. Energy integration including process cogeneration was carried out to enhance the sustainability and profitability of the process. Finally, a techno-economic analysis was carried out to estimate the price differential for shale gas at the wellhead compared to pipeline quality natural gas.

A Techno-Economic Comparison between Two Methanol-to-Propylene Processes

“…The first section is omitted if methanol is to be purchased and to be the feedstock to the plant. The simulation and techno-economic data for the methanol production from shale gas have been provided in literature [4]. The reaction for MTO can be shown in two steps [11].…”

“…Instead, these flowsheets were developed to capture the essence of MTO and MTG processes and to provide results for sample processing routes with typical values of key design and operating parameters used in these process. The results from the process simulation were exported to ASPEN's Process Economic Analyzer and supplemented with literature data [4,19,20]. For each process, two scenarios were considered for the feedstock: buying methanol and manufacturing methanol from natural gas.…”

“…For each process, two scenarios were considered for the feedstock: buying methanol and manufacturing methanol from natural gas. The techno-economic data for natural gas conversion to methanol were taken from literature [4]. The main feedstock and product flows for the base cases are shown by Table 1.…”

“…It is also worth noting that heat integration may be applied to both processes. A recent study [4] presented a detailed analysis of the heat integration options for the methanol-making option of the process. The same approach was extended for the methanol-buying options of the process.…”

“…These investments will be in the form of new plants, retrofitted processes, and integrated eco-industrial parks [2,3]. One of the primary products to be made from shale gas is methanol [4]. Several new methanol plants are anticipated in the US Gulf Region (especially in Texas and Louisiana) with record capacities [5].…”