A review on strategies to reduce ionic liquid pretreatment costs for biofuel production.

Worldwide demand for renewable energy has promoted the considerable exploration of biofuel production from lignocellulosic biomass. Ionic liquid pretreatment is of great interest to render biomass amenable for biofuel production, however, its unaffordable cost stimulates significant attention to the feasibility of commercialization. This review aims to compile the latest advances with respect to reducing production costs for ionic liquids-based biorefineries. Protic ionic liquids offer relatively low synthesis costs, but excessive antisolvent washing of the pretreated biomass is often inevitable. Recovering ionic liquids requires several separation and purification steps, and the reuse of ionic liquids could significantly lose functionality due to the degradation. It is promising to screen ionic liquids-tolerant enzymes and strains for one-pot saccharification and fermentation without solid-liquid separation, however, there is still a need for subsequent recovery of ionic liquids. Additionally, technoeconomic analysis and life cycle assessment are highly recommended to evaluate the economic and environmental impacts.

Quantitative assessment of wheat quality using near-infrared spectroscopy: A comprehensive review.

Wheat is one of the most widely cultivated crops throughout the world. A great need exists for wheat quality assessment for breeding, processing, and products production purposes. Near-infrared spectroscopy (NIRS) is a rapid, low-cost, simple, and nondestructive assessment method. Many advanced studies associated with NIRS for wheat quality assessment have been published recently, either introducing new chemometrics or attempting new assessment parameters to improve model robustness and accuracy. This review provides a comprehensive overview of NIRS methodology including its principle, spectra pretreatments, spectral wavelength selection, outlier disposal, dataset division, regression methods, and model evaluation. More importantly, the applications of NIRS in the determination of analytical parameters, rheological parameters, and end product quality of wheat are summarized. Although NIRS showed great potential in the quantitative determination of analytical parameters, there are still challenges in model robustness and accuracy in determining rheological parameters and end product quality for wheat products. Future model development needs to incorporate larger databases, integrate different spectroscopic techniques, and introduce cutting-edge chemometrics methods. In addition, calibration based on external factors should be considered to improve the predicted results of the model. The NIRS application in micronutrients needs to be extended. Last, the idea of combining standard product sensory attributes and spectra for model development deserves further study.

A Dynamic Shelter Location and Victim Resettlement Model Considering Equitable Waiting Costs.

Catastrophic natural disasters cause devastating damage and leave a huge number of homeless people. Waiting for resettlement in a post-disaster environment brings human suffering, which is defined by waiting cost in this paper. Taking into account waiting cost and fairness consideration simultaneously, a mixed integer linear programming model is constructed for the multiperiod location-allocation process. Two fairness indicators are incorporated to guarantee both the whole-process equity and the periodic equity. The model is implemented in the General Algebraic Modeling System (GAMS) and solved by the CPLEX solver. An illustrative example is provided to explain the model characteristics. Furthermore, a case study of the Yushu earthquake is conducted to demonstrate the applicability of the model to practical problems.

Co-fermentation of magnesium oxide-treated corn stover and corn stover liquor for cellulosic ethanol production and techno-economic analysis.

MgO is an effective catalyst to reduce the recalcitrant structure of corn stover and reduce sugar degradation during pretreatment. To evaluate the economic feasibility of MgO pretreatment, techno-economic analysis was performed at a commercial scale of 700,000 MT stover per year based on the collected experimental data. Compared to LHW pretreatment, MgO pretreatment reduced total capital investment due to elimination of solids washing and increased ethanol yield by 78.4 L/MT stover due to higher xylose yield (53.4 vs 10.9%), thus resulted in a lower minimum ethanol selling price (MESP) of $0.72/liter. Although washing of MgO-pretreated solids improved glucose (73.0 vs 69.5%) and xylose (66.0 vs 53.4%) yields, MESP did not decrease but increase by $0.08/liter due to the high capital cost of solid-liquid separation unit. Tween 80 also improved glucose (73.1 vs 69.5%) and xylose (62.6 vs 53.5%) yields. However, its high cost limited its economic feasibility in ethanol production.