Petroleum refinery greenhouse gas emission variations related to higher ethanol blends at different gasoline octane rating and pool volume levels

Abstract

Refi nery GHG emissions were predicted for 10% and 30% ethanol blends at refi nery blendstock octanes between 77 and 89 AKI at any gasoline pool energy content between parity and constant gasoline pool volume. Linear programming analyzed how separate E30 blending scenarios of 2017 PADD 2-based refi neries affect greenhouse gas (GHG) emissions relative to status quo gasoline (i.e., E10, 87 AKI and 93 AKI premium). The compliance synergy of higher ethanol blends illustrated here is pertinent to national policy goals and multiple environmental objectives. Study results have implications for CAFE Standards, US EPA Tier 3 fuel standards, and Clean Air Act regulations of stationary source CO2 emissions from refi nery operations. Results varied by amounts and types of crude oil processed, refi nery operations, refi nery gasoline blendstock produced (and fuel ethanol blended), and produced refi nery product composition and properties. Signifi cant differences exist in total refi nery GHG emissions (including emissions from purchased electricity and hydrogen) with the largest differences from coke burn in the fl uidized catalytic cracker and refi nery fuel gas combustion principally related to reformer operations. The concept of refi nery GHG emissions intensity was introduced to differentiate between differences in refi nery throughput (an extensive factor) and severity of refi nery operations (intensive factors). Refi nery GHG emissions decline 12% to 27% from a 2017 base case for the various 30% ethanol cases, highlighting a signifi cant gap in current life cycle analysis (LCA) and supporting incorporation of this improved approach into LCA related to higher ethanol blends. This methodology can be adapted to other PADDs and/or for the USA. 37Modeling and Analysis: Petroleum refinery greenhouse gas emission variations V Kwasniewski, J Blieszner, R Nelson effi ciencies, a higher minimum octane fuel (well above 88 AKI) is required. For these vehicles to be accepted by consumers, that higher octane number fuel needs to be widely-available and cost-eff ective which will mean high-CR vehicles will perform adequately. Ethanol has a higher octane rating than conventional gasoline. Consequently, higher blend levels could significantly increase a fi nished gasoline's octane rating. In addition, engine researchers have determined ethanol's high heat of vaporization provides a cylinder 'charge cooling' eff ect. Due to these two desirable properties, fuels with higher levels of ethanol could allow for design and use of direct-injection, spark-ignition engines with higher CRs and greater thermal effi ciency. 7Recent studies examined increased ethanol content in gasoline and its impacts on engine performance with favorable results. Jung et al.8 tested splash-blended E10, E20, and E30 fuels in a Ford 3.5L EcoBoost direct injection turbocharged engine at CRs of 10.0:1 and 11.9:1. Results showed E30 (101 RON) at a 11.9:1 CR reduced CO 2 emissions by 5% and 7.5% on the EPA M/H (Metro Highway) cycle and US06 Highway cycles, re...

Adaptation of oil refineries to make modern fuels

“…Other challenges are emerging, particularly in the field of fuels for higher-efficiency vehicles, especially those with gasoline engines. [21][22][23][24][25] This paper is not intended to advocate any specific approach but seeks to explain the technical and practical issues around changes in the fuel quality and the integration of refined and alternative fuels. It reviews some recent examples and explores some challenges for the future using a European framework; other regions are discussed where appropriate.…”

“…The efficiency of gasoline engines can be improved by raising the compression ratio, which can be facilitated by the use of higher-octane-number road fuel. The current octane number specifications generally stem from system efficiency studies in the 1980s; 91 recent studies [20][21][22][23][24][25] have investigated the potential impact of increasing the octane number by as much as 5 or are exploring new fossil-biofuel blends such as gasoline-methanol-ethanol. 92 This article is not intended as a detailed review of these studies but instead comments on the various manufacturing strategies that they employ.…”

Refining Economics of Higher Octane Sensitivity, Research Octane Number and Ethanol Content for U.S. Gasoline

“…Several studies have examined the cost, energy and GHG impacts of producing higher RON fuels for the US market, with most finding that increasing RON by 3–5 points was technically feasible and could be done at relatively low cost, with ethanol being an attractive fuel component to increase RON. − However, there is no published literature on how an additional OS constraint would impact fuel production. This information is needed to conduct well-to-wheel (WTW) assessments that yield the impact on fuel consumption and GHG emissions associated with vehicle use and fuel production.…”

Novel Method to Estimate the Octane Ratings of Ethanol–Gasoline Mixtures Using Base Fuel Properties

“…1 Increased ethanol content has also been identified as a potential enabler to increase the octane ratings of gasoline above those in existing grades, which would in turn enable future engines to be designed and operated at higher efficiency, for example, through higher engine compression ratio. 2−5 These approaches can provide improvements in greenhouse gas emissions and crude oil consumption at refineries, 2,6 in vehicles, 3 and on a combined well-to-wheels basis. 7−12 Ethanol is generally considered a cost-effective source of octane at the levels in which it is currently used, limited by the degree of ethanol compatibility of the retail distribution system and vehicles.…”

“…Fuel suppliers (refiners, blenders, marketers) utilize ethanol’s high octane ratings to provide a portion of the octane requirements for existing gasoline grades . Increased ethanol content has also been identified as a potential enabler to increase the octane ratings of gasoline above those in existing grades, which would in turn enable future engines to be designed and operated at higher efficiency, for example, through higher engine compression ratio. − These approaches can provide improvements in greenhouse gas emissions and crude oil consumption at refineries, , in vehicles, and on a combined well-to-wheels basis. − …”