Furfural manufacture from xylose : routes towards high selectivity and novel processes

Abstract

Planet Earth is facing a human-induced climate crisis. 1 Scientists from numerous nations have raised concern about this issue at various instances in the past, with one of the latest public warning having arrived in January 2020. 1 The alarming trends observed in the parameters that we use to describe climate and environment (e.g., desertification, availability of fresh water, air pollution) show that drastic, politically driven changes are urgently necessary. 1 With greenhouse gas (GHG) emissions still rapidly rising, and most public discussions focused on global surface temperature only, it is of fundamental importance to understand that this environmental crisis is related to social and economic factors embedded in our society. 1,2 In parallel, and strongly related, to the climate crisis, our society is facing an energy crisis, which is directly connected to the steep rise in energy demand. 3,4 These two crises are intertwined, since the combustion of crude oil, natural gas and coal still is the primary energy sources worldwide, both for transportation of people and goods, fueling industry and infrastructures, and for ensuring the stability of the energy grid. 4 The product of combustion of these fossil fuels is CO2, which is an important contributor to the greenhouse effect. The increased energy demand is due to worldwide industrial development, coupled with an average increase of wealth. [3][4][5] This scenario, in combination with the increasing costs of extraction and manufacture of fossil fuels, is becoming a troubling bottleneck for economic development. [3][4][5] Currently, the addition of green and/or renewable sources of energy (e.g., hydroelectric, solar, wind and nuclear energy) is rapidly growing. 5 Yet, we must realize that just compensating the growing energy demand with these 'clean' energy sources is not sufficient. Reducing the (absolute) contributions of fossil fuels to the energy palette is absolutely necessary to act on the climate crisis and reduce, for example the CO2 levels in the atmosphere. 5 Making humanity fully independent from fossil fuels is an incredibly complex task. 1,2 To do so, the chain of production and consumption of energy, at all levels, needs to be redesigned with drastic, both politically and economically driven international choices. 1,2 Next to these necessary societal changes, research is needed to explore possible alternatives for fossil fuels, which would ease this transition with the aim to avoid, or minimize, an economic crisis. [1][2][3][4][5] Particularly, some sectors of industry and transportation, e.g., heavy industry and aviation, are extremely challenging to decarbonize and cannot solely rely on solar and wind energy, requiring the development of renewable fuels and chemicals. 6 Reducing, and finally eliminating, fossil resources such as oil is exceptionally complex, as these resources are also the basis for the current petrochemical industry. 6,7 The petrochemical industry, one of the largest during the last century, continues to grow t...