A study on the modified lignosulfonate from lignin

A series of modified lignosulfonates containing aliphatic amide residues were prepared from lignin (wood and straw), the by-products from pulp paper industry, via a modification route, including Mannich reaction with aliphatic polyamine, acylation with aliphatic acyl chloride and sulfomethylation. The results from performance tests show that these modified products are more active than the unmodified lignosulfonates, the surface tension of the product solution at CMC could be as low as 28-38 mN/m. Excellent activity at the interface of crude oil and the solutions was observed. Therefore, it wouldn't be necessary to add other kinds of surfactants, the ultralow interfacial tension could have achieved within a wide range of surfactant concentration and alkalinity. The modified lignosulfonates prepared were found to be the appropriate surfactants in Enhanced oil recovery industry.