Novel Solutions to Atmospheric Carbon Maintain Advantages of Petroleum

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 196109, “Promising Pathways to Lower Atmospheric Carbon Without Sacrificing the Petroleum Advantage,” by Subodh Chandra Gupta, Cenovus Energy, prepared for the 2019 SPE Annual Technical Conference and Exhibition, Calgary, 30 September-2 October. The paper has not been peer reviewed. The traditional advantages of petroleum-based transport fuels are challenged by the need to lower atmospheric carbon. Despite significant research, development, and investment during the last few decades, humanity still seeks carbon-neutral alternatives to petroleum that can be commercially viable. This paper presents novel approaches to carbon abatement using petroleum that have a strong chance to succeed in fulfilling technological and economic goals. Comparing Renewable Fuel With a Fossil-Fuel/Carbon-Offset Combination Typically, renewable liquid fuels are more expensive than their fossil-fuel counterparts on a unit-energy basis, but they result in lower carbon dioxide (CO2) addition to the atmosphere. Fossil fuels could also be used in such a way that produced CO2 is sequestered at a cost. With carbon-offset costs added to fossil fuel, both can be considered to provide carbon-neutral energy and can be compared on bases of cost and availability. Commodity prices fluctuate because of a variety of factors. Aside from the higher costs of renewables, reading too much into exact crossover points is not useful. Nonetheless, a general statement could be made that, at carbon-abatement costs of approximately $80-100/tonne of CO2, a renewable energy source can compete with fossil fuels. The cited costs of carbon capture and storage also have varied in the range of $100-150/tonne of CO2. The costs depend on emission sources and locations and the technology used for carbon capture. Even at reduced carbon costs, one would still be better off using gasoline - that is, if both commodities (renewable fuels and fossil fuels) were equally available at needed amounts. Technology for food-based bio fuels (e.g., corn-based ethanol) has advanced sufficiently and mostly is used commercially in the US for making bio ethanol for blending with gasoline. However, food-based biofuels compete with the availability of food and result in rising food prices. Data suggest that food-based biofuels are neither cost-competitive nor quantitatively sufficient to supplant fossil fuels. While they can play a role in carbon abatement to an extent if the carbon offset costs rise above $100/tonne of CO2, at present, they do not appear to be the solution to reduce emissions on their own. Can Useful Products Be Monetized From CO2 Conversion? Little other than energy is consumed in proportions greater than 4 billion tonnes/year (e.g., cement). Even if produced CO2 is converted to something that can replace cement, for example, the supply of that substance will be far greater than the amount of cement the world needs and, hence, it will not be able to retain its market - or any - price. If CO2 is converted to other substances, the quantity of products or byproducts will be on the order of 10-plus billion tonnes. This means that no prospective revenues from the useful byproducts can be relied upon, and, thus, it is prudent to only include costs involved in carbon abatement.