Four Alternative Fuels to Watch

According to the IEA, global energy demand is expected to grow 9% from 2021-2023, as the pandemic economy recovers. While the traditional renewable electricity share is projected to remain in the 8% range, led by wind, solar, and hydropower, these sources are not projected to meet this demand growth.

A study conducted by the IEA suggests that the demand side of the equation has provided the market pull that companies have needed to embrace large scale production of green energy in the form of alternative fuels. Government incentives for low-carbon solutions combined with this higher demand has led to an increased number of “green” commercial units being developed by mainstream energy companies and private equity firms.

Balancing pull from demand and palatable payback with governmental push, 20 states, territories, and the District of Columbia have published clean energy goals starting as early as 2030. From this dynamic, four green energy alternative fuels have emerged, bridging the gap from green energy demand to commercial adoption.

Renewable Diesel

Renewable diesel uses organic material like animal fat or vegetable oils to reduce greenhouse emissions while meeting ASTM D975 performance criteria for petroleum diesel. The feedstock is hydrotreated, meaning formulators react the fat or oil with hydrogen. Renewable diesel is chemically compatible with any diesel engine, creating a low entry barrier and transparent adaptation for consumers. Critical parameters in D975 include a 52°C minimum flash point, kinematic viscosity between 1.9-4.1 mm²/s at 40°C, and a cetane number of at least 40 with aromaticity below 35.

Despite the performance parity and chemical similarity to its petroleum-based counterpart, renewable diesel has some unique characteristics. Like any natural material, there is increased variability in the feedstock sources. As a result, the way they are harvested and processed may introduce new carbon-emitting steps into production. The entire supply chain must be carbon neutral for a zero-carbon claim.

Appreciating and balancing the relationship between technical and economic factors involved in today’s RDUs, and understanding the credit rules in place federally and within individual states, is critical in assisting clients to produce viable RDU designs. KPE is uniquely qualified to provide this assistance.

Biodiesel

Biodiesel reacts the same feedstocks used by renewable diesel with methanol in a process called transesterification. The products of this process are fatty-acid methyl esters (FAMEs). Although FAMEs are a greener option than fossil fuel-based diesel, they are not as pure as renewable diesel. Biodiesel contains oxygen as well, which poses a storage challenge due to the increased corrosion risk.

While renewable diesel adheres to the same ASTM spec as petroleum diesel, biodiesel follows ASTM D6751. This standard specifies biodiesel to have a 130°C minimum flash point, kinematic viscosity between 1.9-6.0 mm²/s at 40°C, and a cetane number of at least 47. The higher viscosity range and flash point limit how much biodiesel can be blended with petroleum diesel to 15 to 20% by volume.

Sustainable Aviation Fuel

While passenger cars dominate the transportation faction of carbon emissions, commercial aviation contributes 2-3% of global CO₂ emissions. Global demand for air travel is outpacing relatively modest improvements in fuel efficiency. Achieving carbon neutrality in aviation equates to saving over 1 billion tons of CO₂. The most impactful way to reduce this footprint may be made by expanding the use of sustainable aviation fuel (SAF).

Like renewable diesel, sustainable aviation fuel is produced by hydroprocessing sustainable feedstocks, and the end product results in a fuel chemically similar to traditional fossil fuel-based jet fuel. As a result, SAF can reduce lifecycle emissions by up to 80% over conventional jet fuel. Unlike renewable diesel, the financial incentives and carbon intensity calculations are less established but this is expected to change rapidly as numerous airlines have publicly stated carbon reduction goals and deadlines.

Green Gasoline

Green gasoline is a synthetic fuel that converts biomass and waste products into renewable fuel that performs nearly identically to traditional gasoline. The processes for producing green gasoline is significantly different from diesel and jet, which are hydroprocessed plant and animal products.

Green gasoline processes “gasify” - via partial oxidation, pyrolysis, or auto thermal reforming - organic materials to produce synthesis gas, or “syngas”. Syngas is a mixture of hydrogen and carbon monoxide, which are building blocks for a wide variety of chemicals. In this case, syngas is converted to methanol which is then, via proprietary catalytic processes, converted to gasoline.

The transportation and agriculture sectors comprise around half of the global CO₂ emissions, so using natural feedstock sources and waste products to produce renewable diesel, biodiesel, sustainable aviation fuel, and green gasoline meet the challenge of carbon emission reduction head-on. As global demand, technology innovation, and governmental push secure commercial feasibility, renewable fuels will soon become a reality. KPE will take its place among those providing the bridge from concept to execution of these key projects.

How KPE Leverages These Fuels for Production

KPE’s background in these technologies, coupled with its experience gained from renewable diesel project development makes it an ideal partner for owners and financiers of these projects. We marry technical factors, project economics, and political drivers while ensuring safety and project success.

Hydrogen and syngas production are a core competency of ours, as is the downstream syngas conversion processes. Currently, KPE is heavily involved in several green gasoline projects in varying stages of development. These projects are rooted in science, and employ industry-leading technology suppliers to deliver clear economic incentives.

KPE has made renewable diesel production a focus of its business, building on its extensive EPC background in the hydrotreating of diesel, naphtha, and gasoline. KPE has performed extensive technology comparison studies, conceptual studies, and revamp evaluations, and has executed detailed engineering and procurement for a 9,000 barrel per day grass-roots renewable diesel unit (RDU) that is now in construction. Currently, KPE is executing FEL-2 for a grassroots green fuels facility slated to be announced by the state Governor in Q3 of 2023.

Sources:

https://www.iea.org/reports/re...