Patent ID: 9438 | Patent Number 10,695,745 | Status: Granted


This invention involves the design, synthesis, and application of a novel product to be used in the treatment of oil spills in aquatic environments. The product entails chemical modification of sawdust or wood flour (a cheap product of sawmills) to render it with hydrophobic, oleophilic, and buoyant properties. The resulting product is herein referred to as an aggregator. Aggregators modified with oleic acid (OA) were further modified with fatty acids (C3-C18) to cover surface hydroxyl groups on sawdust. The final products showed super hydrophobic and 44.2% enhancement of crude oil sorption relative to OA-modified aggregators. They also showed excellent stability and recyclability. The Invention Synthesis and property: Our earlier work included sawdust modification with OA (called 1st generation aggregator). The 1st generation aggregator entailed an oleic acid (OA: C18) modified 20-40 mesh pine flour. They showed 100-165% weight percent gain (WPG), excellent buoyance, and 4.17g crude oil sorption/g aggregator. Though they showed excellent properties and test results, XRD and TGA analysis suggested that improvements can be made to the aggregator to boost performance. We added second fatty acids with different alkyl chain lengths to the 1st generation aggregators, which have uncovered surface hydroxyl groups. We first prepared three base 1st generation aggregators: pine/OA-106, pine/OA-124, and pine/OA-160, where numbers indicate WPG of OA in pine sawdust. To the base aggregators, we added fatty acids with different alkyl chain lengths (C3, C6, C8, C10, C12, C14, C16, C18). We have several significant observations listed below: Pyridine is the most costly reagent in the synthesis ( >45% of the materials costs). The used pyridine solvent contains HCl and p-Tosylate (p-Ts). In fact, a tiny amount of water does not affect the reaction. We tried to recycle (vacuum distillation after treated with KOH and magnesium sulfate) pyridine and about 60% pyridine was recycled. When different fatty acids were added to the base aggregators, fatty acids with C10-C14 showed highest WPG and all mixed fatty acid-modified aggregators showed very hydrodrophobic (much more hydrophobic than the base aggregators). XRD analysis showed that (002) peak of cellulose on aggregators modified with C10-C14 fatty acids was expanded from 4.23 to 4.60Å (original pine sawdust: 3.98Å) due to more fatty acids penetrated and modified. In the FT-IR spectra of aggregators modified with C10-C14 it was hard to observe OH stretching vibration at 3500cm-1, which indicates that all aggregators are superhydrophobic. The aggregators start decomposition at 230oC though the original pine does 328oC, and they leave less than 0.1wt% ash after burned off at 700oC. Crude oil sorption test: we tested our aggregators for crude oil sorption. Three base materials showed about about 4.5g crude oil/ g aggregator, and our new aggregators sorbed 5.0 -6.4g crude oil/ g aggregator. Specifically, pine/OA-106-C14 sample (second C14 fatty acid was chemically modified on pine/OA-106 aggregator) showed 6.4g crude oil/g, which is about 44.2% enhancement relative to that of the pine/OA-106. Crude oil sorbed pine/OA-106-C14 sample was recycled (washed with CH2Cl2). It is easily washed and showed same property.

Application Number



Bonheyo,George T
Winder,Eric M

Market Sector

Energy Production and Efficiency