Optimized Process for Methanol Production via Bi-reforming Syngas

Abstract

In this work, an optimized process for methanol production using syngas from bi-reforming is proposed. The feed ratio (CH 4 /CO 2 /H 2 O) in the bi-reforming step, the purge stream quantity, and the heat recovery were optimized with the overall objective to reduce direct and indirect CO 2 emission in the process. The effect of the feed ratio on the rates of simultaneous reactions involved in bi-reforming (i.e., DR, SMR, and WGS) was investigated to understand the balance between the consumption and production of CO 2 relative to CH 4 . Compared to the conventionally used feed ratio of 3:1:2, this study found that the 1:1:2 ratio resulted in 100% CH 4 conversion and higher CO 2 consumption per mole of CH 4 in the bi-reforming step. A plantwide heat integration approach was adopted using pinch analysis to design a network of 27 heat exchangers. The implementation of a heat exchanger network resulted in the recovery of 221 MW of heat from process streams within the plant. With complementary optimization strategies, the proposed process resulted in ∼0.31 tonnes of CO 2 per tonne of methanol production, one of the lowest among the processes published in the literature.

Exploring the Methane to Methanol Oxidation over Iron and Copper Sites in Metal–Organic Frameworks

“…Remarkably, recyclability tests over five consecutive cycles also indicated only slight catalyst deactivation after the first cycle with stable methanol selectivity, and DME was not observed as a byproduct. Methanol selectivity was confirmed through isotope labeling experiments that made use of 13 C-methane as the reactant under the same conditions: 13 C-labeled methanol and 13 C-labeled CO 2 were found to be the main products with only minor amounts of 12 CO 2 being released. Increasing the methane pressure to 40 bar during the reaction step resulted in increased methanol productivity by a factor of ∼3.5, together with the formation of DME in small quantities.…”

“…Common MTM conversion routes-at an industrial scale-involve the initial transformation of methane from natural gas into syngas (a mixture of CO and H 2 ). Subsequently, syngas is converted to methanol by a heterogeneous catalytic reaction, typically conducted over a bimetallic (Cu/Zn or Cu/Cr) catalyst at 220-250 • C and high pressure (70-100 bar) [13,14]. The high temperature (>800 • C) and energy demands required by methane steam reforming are associated with elevated costs, and significant efforts have been devoted to developing alternative catalytic platforms to efficiently and sustainably accomplish the MTM oxidation reaction.…”