The production and use of biofuel have increased under the context of sustainable development. Biofuel production from plant biomass produces not only biofuel or ethanol but also co-products containing lignin, modified lignin, and lignin derivatives. This paper discusses the utilization of lignin-containing biofuel co-product in pavement soil stabilization as a new application area. The primary experimental test plan encompassed the comparison of co-products treated soils, untreated soils as well as traditional stabilizer treated soils in terms of their strengths. The focus of the secondary experimental test plan was to investigate the effect of additive combinations on strength improvement. Laboratory test matrix in each test plan included variations in additive type, additive content, curing period, and moisture condition. Statistical analyses were performed on unconfined compression strength (UCS) test results to evaluate if the strength improvements resulting from the addition of the co-products to soils are significant. Results indicate that the biofuel co-products are effective in stabilizing the Iowa class 10 soil classified as CL or A-6(8). Strengths comparable to traditional additive (fly ash) could be obtained through the use of combined additives (co-product A + fly ash; co-product A + co-product B). Utilization of biofuel co-product as a stabilization material for soil appears to be one of many viable answers to the profitability of the biobased products and the bioenergy business.
Abstract