The production of fuels and chemicals in the new world: critical analysis of the choice between crude oil and biomass vis-à-vis sustainability and the environment

Abstract

Abstract: Energy and the environment are intimately related and hotly debated issues. Today's crude oil-based economy for the manufacture of fuels, chemicals and materials will not have a sustainable future. The over-use of oil products has done a great damage to the environment. Faced with the twin challenges of sustaining socioeconomic development and shrinking the environmental footprint of chemicals and fuel manufacturing, a major emphasis is on either converting biomass into low-value, high-volume biofuels or refining it into a wide spectrum of products. Using carbon for fuel is a flawed approach and unlikely to achieve any nation's socioeconomic or environmental targets. Biomass is chemically and geographically incompatible with the existing refining and pipeline infrastructure, and biorefining and biofuels production in their current forms will not achieve economies of scale in most nations. Synergistic use of crude oil, biomass, and shale gas to produce fuels, value-added chemicals, and commodity chemicals, respectively, can continue for some time. However, carbon should not be used as a source of fuel or energy but be valorized to other products. In controlling CO₂ emissions, hydrogen will play a critical role. Hydrogen is best suited for converting waste biomass and carbon dioxide emanated from different sources, whether it be fossil fuel-derived carbon or biomass-derived carbon, into fuels and chemicals as well as it will also lead, on its own as energy source, to the carbon negative scenario in conjunction with other renewable non-carbon sources. This new paradigm for production of fuels and chemicals not only offers the greatest monetization potential for biomass and shale gas, but it could also scale down output and improve the atom and energy economies of oil refineries. We have also highlighted the technology gaps with the intention to drive R&D in these directions. We believe this article will generate a considerable debate in energy sector and lead to better energy and material policy across the world.

Keywords: Biomass; Energy; Environment; Hydrogen economy; Methane; Methanol economy; Petroleum; Renewable sources; Shale oil and gas; Sustainability; Valorization.

Fig.1

Carbon conversion processes to manufacture useful products. Carbon has been solely responsible for advancement in lifestyle, comfort, luxury, transport, instant communication and longevity

Fig.2

The roughly 160 year history of the oil industry can be summarized as a quest for high atom and energy economies, and wider crack spreads

Fig.3

The network of transportation pipelines in North America bears little overlap with its biomass producing belts, which raises transportation costs and lowers the ‘crack spread’ for biorefining

Fig.4

Energy and mass balances on crude oil and biomass reveal that the latter is better suited for use as a feedstock for chemical manufacturing

Fig.5

The difference between the fuel and chemical production capacities for biomass, when scaled to refinery output, is even wider, thereby corroborating our recommendation that biomass should be used to manufacture chemicals and not fuels

Fig.6

Investments by the US Department of Energy on biofuels companies have, more often than not, ended in losses. Detailed information about the companies listed in the figure is available in the Supplementary Information that accompanies this article

Fig.7

Production of selected petroleum-derived products in North America. Transportation fuels comprise nearly three quarters of the refinery output in North America, whereas ethylene and propylene account for the largest share of petrochemicals. This product distribution is similar across the world. As a comparison, North American bagasse production is estimated to be roughly 210 megatons each year

Fig.8

Methane conversion processes such the MTO process and OCM exhibit higher thermal and carbon efficiencies compared to SCE, the dominant process for ethylene production. The bubbles in the figure represent current capital costs for plants with a processing capacity of 12,000 bpd

Fig.9

Methanol is a versatile feedstock for the production of fuels and chemicals, although we advocate reserving it for chemical manufacturing

Fig.10

The levelized cost of electricity (LCoE) generated by combined cycle power plants fueled by natural gas is substantially lower than power plants that either consume biomass or employ gas turbines. The extremities of each bar represent the minimum and maximum costs, whereas the vertical black line that intersects each bar denotes the average levelized cost

Fig.11

A rich catalog of catalytic processes are available for producing value-added chemicals from biomass

Fig.12

Impact of CO₂ emissions in atmosphere if no technological intervention is done ( Source: IPCC Intergovernmental Panel on Climate Change show projected concentrations of CO₂)

Fig.13

The industrial carbon cycle

Fig.14

Hydrogen valorization pathways