Techno-Economic Analysis of Biomethanol Production via Hybrid Steam Reforming of Glycerol with Natural Gas

Abstract

The present article deals with the techno-economic assessment of the hybrid steam reforming (HSR) process of glycerol (obtained via transesterification) together with natural gas to produce biomethanol via the synthesis gas route. In this techno-economic assessment, a model is developed in the UniSim Design Suite process simulator using different glycerol amounts up to ∼54% (on a carbon basis) together with natural gas to produce synthesis gas at reforming conditions of 900 °C, S/C∼3. The techno-economic analysis shows that at the current market scenario (Oct–Dec 2012) with a natural gas price of 0.2 €/Nm3 and with an assumed glycerol price of 200 €/tonne, the average cost of biomethanol is estimated as ∼433 €/tonne for a feed of ∼54 wt % of glycerol (on a carbon basis) with natural gas, which is ∼75 €/tonne higher than for the methanol obtained via only natural gas steam reforming. It is concluded that biomethanol from a HSR process becomes more attractive when the natural gas price exceeds 0.45 €/Nm3 or when glycerol is available at lesser than 90 €/tonne. Splitting the production capacity in methanol and biomethanol according to the feed composition would result in a price of 358 €/tonne and 470–500 €/tonne of methanol and biomethanol, respectively, depending on the amount of glycerol in the feed. This means that currently, biomethanol is not competitive with methanol unless special arrangements are made (regulations, subsidies) to promote the use of biomethanol. For example, the EC Renewable Energy Directive1 states that the energy content of biofuels from wastes and residues (for instance crude glycerol) counts double. From the sensitivity analysis, it is concluded that feedstock prices and total capital investment have major influence on the final product value of biomethanol. Furthermore, it is concluded that at the current price scenario, utilizing glycerol either in the furnace or in the reformer has no effect on the cost price. However, burning is not an option since the biomethanol will not contain the required C14 isotope.