From carbohydrates to hydrocarbons

While renewable energy sources such as wind and solar are contributing significantly to electricity production, liquid fuels will continue to be indispensable in areas where alternatives are not yet feasible, such as in aviation.

This article discusses the journey of converting agricultural waste into SAF, highlighting the role of technology in the aviation industry’s sustainable future. The article also explains the importance of investment in the development of technological innovations to improve capacity and efficiency, which will result in a more accessible biofuel price for a greener planet. The process of converting agricultural waste to SAF represents a significant stride towards an environmentally responsible future.

The transformation of agricultural waste into biofuels and biopolymers is paving the way for significant reductions in greenhouse gas (GHG) emissions, while also conserving valuable natural resources.

Harnessing abundant, sustainable feedstocks

Given escalating environmental concerns and the intensified search for sustainable alternatives, agricultural waste, which is abundant and rich in lignocellulosic biomass, is becoming increasingly recognised as a promising feedstock for the production of SAF. Turning this potential into reality involves an intricate series of steps that transforms complex carbohydrates into the necessary hydrocarbon molecules for fuels.

Typically, this conversion journey begins with the enzymatic hydrolysis of agricultural waste. In this crucial phase, specific enzymes act on the biomass, breaking down its cellulose and hemi-cellulose constituents into their respective simple sugars.¹ This foundational process sets the stage for the subsequent conversion stages.

Post-hydrolysis, the derived sugars enter the fermentation stage. Here, metabolic activities of specific yeasts and bacteria are leveraged to metabolise these sugars. The end products are energy-rich ethanol and carbon dioxide (CO₂), marking a significant transformation from complex carbohydrates to a simpler, potent form.² Upon successful production and thorough purification, ethanol is prepared for further transformation, proving itself as an ideal component for fuel production. This holistic process, from breakdown to transformation, underscores the potential of agricultural waste as a vital resource for sustainable fuel production.

Previously perceived as an unavoidable byproduct of farming, agricultural waste has now surfaced as a valuable resource in SAF production, courtesy of advanced conversion processes. These materials, once discarded or burned thereby contributing to pollution, have now claimed a pivotal role in green fuel production. The transformation of this ‘waste’ into wealth provides a potential solution to agricultural residue disposal, whilst simultaneously reducing the aviation sector’s carbon footprint.

Innovations

EcoCeres has been contributing towards innovations in SAF production with its own version of hydroprocessed esters and fatty acids (HEFA), which are now in full operation. Beyond HEFA, the company is developing its version of hydrolysis technology to produce cellulosic ethanol from agricultural waste, being the front-end precursor for the more customary alcohol-to-jet (ATJ) process to further transform it into SAF. This hydrocarbon, SAF, is particularly valued for its high renewable value, as it efficiently utilises sustainable resources and significantly curbs GHG emissions. EcoCeres’ hydrolysis technology starts with the process to efficiently segregate lignocellulosic biomass into its three fundamental components: hemi-cellulose, cellulose, and lignin. This is then followed by a second-stage process to further break down those polysaccharides, hemi-cellulose and cellulose, into their respective simple sugars of 5-C xylose and 6-C glucose.

This article was originally published in the November 2023 issue of Hydrocarbon Engineering magazine. To read the full article, sign in or register for a free subscription.

Written by Philip Siu, EcoCeres.

References

¹NAIK, S., GOUD, V., ROUT, R., and DALAI, A. K., ‘Production of first and second generation biofuels: A comprehensive review’, Renewable and Sustainable Energy Reviews, Vol. 14, No. 2 (2010), pp. 578 - 597.

²WANG, L., and CHEN, H. ‘Technologies for Biochemical Conversion of Biomass.’ Elsevier Science. (2010).

Read the article online at: https://www.hydrocarbonengineering.com/special-reports/29112023/from-carbohydrates-to-hydrocarbons/