Feasibility study for mega plant construction of synthesis gas to produce ammonia and methanol

This paper presents a feasibility analysis for the autothermal reforming (ATR) of methane in a fixed bed for syngas production to manufacture ammonia and methanol. The hydrocarbon feed stream of methane (in the presence or absence of ethane) are representative of the natural gas reserves recently found in the North East of Venezuela (Güiria). A packed bed reactor is modeled using published kinetics for steam reforming, catalytic partial oxidation, gas shift and carbon dioxide reforming. A set of optimum operating parameters are obtained to guarantee an ATR process using air instead of oxygen in the feed at an inlet fixed oxygen/carbon ratio of 0.575, water/carbon ratio of 1.5 and carbon dioxide/carbon ratio of 0.34 an inlet temperature of 600.15 K. These provide a 98% methane conversion with a syngas product ratio of three necessary for ammonia and methanol production. Two different processes are analyzed with the same autothermal reforming system, the first process is based on patented large scale technologies (Lurgi, Haldor Topsøe) [1,2], the second process eliminate the oven and differ in the placing of the heat exchanger to reach the desired product conditions for subsequent treatment to obtain a “dehydrated” syngas stream, preliminary feasibility analysis indicates greater saving are obtained in capital investment when air is used as oxidant instead of pure oxygen.