IPB University Expert Explains Technology for Converting Straw into Hydrocarbon Fuel
IPB University Mechanical and Biosystems Engineering lecturer Dr Leopold Oscar Nelwan highlights the growing issue of utilizing straw as an alternative fuel
According to him, information related to this technology is still very limited. However, several sources indicate that straw is treated as lignocellulosic biomass in the conversion process.
“In this context, it is important to emphasize that the fuel in question is hydrocarbon, not ethanol or biodiesel, because only hydrocarbons meet commercial standards if marketed purely for engines,” he said.
He explained that hydrocarbons are compounds composed of carbon and hydrogen, which are generally classified into paraffins, isoparaffins, olefins, and aromatics.
According to him, the amount of carbon determines the physical properties and use of the fuel, for example, gasoline is in the range of C5–C12 and diesel is in the range of C12–C20.
Furthermore, Dr Leopold explained that there are many ways to convert lignocellulosic biomass into hydrocarbons, although most are still in the research stage.
Some of the popular methods he mentioned include thermochemical processes such as gasification followed by Fischer–Tropsch (FT) synthesis, as well as fast pyrolysis that produces bio-oil followed by a hydrotreating process.
In addition, Dr Leopold explained conversion through monosaccharide hydrolysis, both direct sugar to hydrocarbon conversion (DSHC) and via ethanol with the alcohol to hydrocarbon mechanism.
“Of all these processes, the ones closest to commercialization are gasification and FT, because the principles have already been applied to coal conversion,” he explained.
Dr Leopold elaborated that many stages of the conversion process, both thermochemical and monosaccharide hydrolysis, require special catalysts and high-temperature and high-pressure operating conditions. The cost of conversion (energy), he said, remains a major challenge.
“Some literature states that the cost of producing one liter of fuel through the FT process from coal reaches USD 0,8-1,6. In fact, the process cost can be more than four times the price of coal,” he said.
However, he emphasized that the concept of converting biomass waste into fuel is part of second-generation biofuels that support sustainability. Nevertheless, this technology has not been widely implemented due to high investment and process costs.
Dr Leopold believes that claims of low production costs need to be recalculated, including energy and investment factors. He concluded that this technology has the potential to increase its feasibility or become competitive if fossil fuel prices rise or are restricted. (dr) (IAAS/MRM)
