Techno-Economic Analysis and Life Cycle Assessment of Waste Lignin Fractionation and Valorization Using the ALPHA Process

Abstract

Techno-Economic Analysis (TEA) and Life Cycle Assessment (LCA) were performed on the Aqueous Lignin Purification with Hot Agents (ALPHA) process, which is being investigated for the fractionation and purification of raw, bulk lignins recovered from cellulosic ethanol biorefineries or Kraft pulp mills. Here, ALPHA is proposed for the isolation of lignin from a corn stover-to-ethanol plant into purified low, medium, and high molecular weight (MW) fractions for producing polyurethane foam, activated carbon, and carbon fiber, respectively. A scenario analysis was conducted to determine the effect of ALPHA solvent choice on process economics and environmental performance. Solvent choice was found to have a significant impact on ALPHA, with a minimum selling price of $838/tonne with use of acetic acid vs $463/tonne with ethanol. Conversion of the lignin, processed with ethanol solvent, to high-value products yields $151 million/year in profit, which over 30 years results in a total net present value of $533 million. A life cycle assessment was conducted to determine the "gate-to-gate" greenhouse gas emissions and energy consumption of the lignin-based products compared to fossil-based equivalents. A value allocation scenario was conducted and it was determined that products generated using the ALPHA process with ethanol have similar or lower greenhouse gas emissions than the same products from fossil feedstocks.

Technoeconomic Analysis of Multiple-Stream Ethanol and Lignin Production from Lignocellulosic Biomass: Insights into the Chemical Selection and Process Integration

“…This notable variation among scenarios is attributed to the secondstage ethanol distillation, as the lower ethanol concentration in the final stream for scenario I required more stages of the distillation column to separate ethanol from water. 81 It notably increases the distillation equipment cost for scenario I (see Tables S1−S3). Accordingly, the cost related to equipment such as process piping, instrumentation, electrical, and auxiliary facilities from scenario I is also higher than those from scenarios II and III (Table 3).…”

“…The primary unit operation for total plant direct cost within the SuperPro Designer simulation is from equipment purchase cost (Table ). This notable variation among scenarios is attributed to the second-stage ethanol distillation, as the lower ethanol concentration in the final stream for scenario I required more stages of the distillation column to separate ethanol from water . It notably increases the distillation equipment cost for scenario I (see Tables S1–S3).…”

“…Therefore, the heating and electricity requirements after energy integration are satisfied by external sources . The aqueous residues from the distillation column are subjected to wastewater treatment at an assumed cost of $6 per 1000 gallons . Second, in terms of the equipment, sizing and quantity options are based on throughput and calculated with a design mode.…”

“…80 The aqueous residues from the distillation column are subjected to wastewater treatment at an assumed cost of $6 per 1000 gallons. 81 Second, in terms of the equipment, sizing and quantity options are based on throughput and calculated with a design mode. Equipment purchase cost is obtained by using a built-in cost model from the SuperPro Designer software; the parameters of the reactors and fermenters are referred to a previous report.…”

Lignin for energy applications – state of the art, life cycle, technoeconomic analysis and future trends

“…It is widely used to estimate the environmental impact or benefit of an existing or new technology. Since the interest on lignin as an alternative to fossil-fuels based technologies has gained considerable attention recently, lignin-only LCA studies have emerged, which are either focused on lignin extraction [289][290][291][292][293][294][295][296][297][298][299] or lignin-based products (asphalt, [300][301][302][303][304] adhesives, [305][306][307] resins, 308 fine chemicals, [309][310][311][312][313][314] carbon fibres 315 and fuels. 287,[316][317][318][319][320] Lignin as a product from biorefineries is a new concept, therefore most of the LCA conducted are based on either well quantified extraction processes such as Kraft or based on experimental lab scale data which has been extrapolated.…”