Source: DOE. Click to enlarge.

This goal reflects contributions from both improved engines (7%–14% reduction in fuel consumption) and improved fuels (including 15 billion gallons/year of advanced biofuels). At a fleet level, Optima will result in an additional 9%–14% fleet greenhouse gas (GHG) reduction by 2040.

In an article for ASME’s Mechanical Engineering magazine, Dr. Robert Wagner, director of the Fuels, Engines, and Emissions Research Center at Oak Ridge National Laboratory, who is a member of the national labs’ leadership team for Optima, observed that:

Over the past several years, road transportation has seen some significant advances in what are considered alternative technologies. Energy storage, electric drive systems, and fuel cell technology all seem to be poised to find a significant place in the automotive marketplace. But it would be a mistake to believe that such technologies will completely sweep aside what has come before. Instead, the internal combustion engine will continue to be integral to the transportation of people and goods for the foreseeable future.

That is not to say that things will stay as they are now. The engine is undergoing a significant evolution of its own, as new fuel economy and emissions standards in the light-duty and heavy-duty sectors push the development of new technologies on an unprecedented scale toward the theoretical limits of engine operation. Coupled with continuing research into fundamental engine processes, the introduction of affordable high-performance computing, and the adoption of advanced manufacturing techniques throughout industry, those new technologies are leading to potentially disruptive opportunities for the introduction of engines with extraordinarily high efficiencies. How these new engines perform and how they will be integrated into new vehicle architectures will be the story of personal mobility for this half of the 21^st century.

… The “Optima” program bridges the broad expertise and resources of the Vehicle Technologies Office and the Bioenergy Technologies Office at the DOE. The overall plan includes a near-term phase which builds upon current engine technologies with a goal of new fuel and vehicle technologies in the marketplace by 2025, together with a longer-term—and arguably more ambitious—phase focused on kinetically controlled combustion processes and fuel technologies with impact expected in the 2030 timeframe. The Optima team is working closely with a broad range of stakeholders representing vehicle and engine manufacturers, energy companies, biofuel producers, fuel distributors and retailers as well as identifying and addressing potential deployment issues to ensure maximum success.

In fiscal year 2016 (beginning October 1, 2015), BETO and VTO jointly funded a consortium of nine DOE national laboratories to begin an initial three-year effort focused on Optima. Activities funded under this initiative cover six major technology areas that leverage existing, foundational fuels and engines R&D along with initial stakeholder engagement.

The Optima project will provide DOE and stakeholders with:

1. a definitive technical assessment of biofuel options that enable advanced spark ignition (SI) engines;

2. new “market-pull” drivers that convey the value of advanced biofuels to consumers;

3. fuels that emit less GHGs and expand the stable operating conditions for advanced compression ignition (ACI) engines; and

4. a mitigation of the technical barriers required for ACI fuel and vehicle market penetration.

The Optima initiative includes two major research thrusts:

• Thrust I – Improvement of near-term conventional SI engine efficiency. High-research octane number (RON) fuels are known to enable more efficient, higher-performance SI operation via engine downsizing and boosting. Many biofuel blending components exhibit high RON and can be introduced into the market in the near- to medium-term for engines optimized to operate on those fuels. Fuel properties beyond RON, such as heat of vaporization, burn rate, viscosity, volatility, and energy density will also be characterized and the complexity of their interactions mapped to evaluate the full value opportunity. This thrust has lower risk relative to Thrust II because SI engines are in use today—but will benefit from additional optimization to take advantage of potential new fuels.

• Thrust II – Enable full operability ACI engines. Thrust II will provide the science and technology underpinnings needed to make new fuels compatible with commercially viable new ACI engine technologies. This engine platform, which includes kinetically controlled and low-temperature combustion approaches, offers the promise of significantly greater thermal efficiencies with lower criteria-pollutant emissions, and presents attractive options for both light- and heavy- duty vehicles.

  Fuel research will focus on low-GHG advanced biofuel/petroleum blends. In addition, already-efficient conventional compression ignition (CI) engines can realize fuel economy increases enabled by improved, low GHG-intensity fuels. Thrust II, to be conducted in parallel with Thrust I, presents a more complex technical challenge with higher potential risk and reward.

The research cycle for each thrust will include identifying fuel candidates, understanding their characteristics and combustion performance, and determining market transformation requirements such as cost, GHG reduction, feedstock requirements, scalability, and infrastructure compatibility, while providing feedback to stakeholders and future collaborators.

The current DOE national laboratory effort in this arena focuses on six major, interrelated areas:

1. Low Greenhouse Gas Fuels that Enable Increased Efficiency and Higher Performance.

2. Fuel Properties Characterization.

3. Advanced Engine Development.

4. Analysis of Sustainability, Scale, Economics, Risk, and Trade.

5. Market Transformation and Deployment.

6. Simulation Toolkit Development.

The purpose of this RFI is to solicit feedback from industry, academia, research laboratories, government agencies, and other stakeholders on issues related to the Optima initiative. EERE is specifically interested in information regarding additional areas of research that universities and others are interested in contributing to and collaborating on.

The RFI will help BETO and VTO understand the additional areas of research, capabilities, and yet to be addressed barriers and opportunities for stakeholder engagement relative to the co-optimization of engines and fuels.

The RFI provides stakeholders with an opportunity to provide information on:

1. perspectives and interest in co-optimization of fuels and engines;

2. technical aspects of fuel and ACI engine interactions; and

3. barriers to market acceptance and deployment of co-optimized fuels and engines.

Resources

• Optima program overview

• Robert M. Wagner (2015) “Engines of the Future” ASME Mechanical Engineering magazine