Mapping the National Phosphorus Recovery Potential from Centralized Wastewater and Corn Ethanol Infrastructure.

Anthropogenic discharge of excess phosphorus (P) to water bodies and increasingly stringent discharge limits have fostered interest in quantifying opportunities for P recovery and reuse. To date, geospatial estimates of P recovery potential in the United States (US) have used human and livestock population data, which do not capture the engineering constraints of P removal from centralized water resource recovery facilities (WRRFs) and corn ethanol biorefineries where P is concentrated in coproduct animal feeds. Here, renewable P (rP) estimates from plant-wide process models were used to create a geospatial inventory of recovery potential for centralized WRRFs and biorefineries, revealing that individual corn ethanol biorefineries can generate on average 3 orders of magnitude more rP than WRRFs per site, and all corn ethanol biorefineries can generate nearly double the total rP of WRRFs across the US. The Midwestern states that make up the Corn Belt have the largest potential for P recovery and reuse from both corn biorefineries and WRRFs with a high degree of co-location with agricultural P consumption, indicating the untapped potential for a circular P economy in this globally significant grain-producing region.

Process design and techno-economic analysis of 2'-fucosyllactose enriched distiller's dried grains with solubles production in dry grind ethanol process using genetically engineered Saccharomyces cerevisiae.

2'-fucosyllactose (2'-FL) has been linked positively with piglet gut health. Genetically engineered Saccharomyces cerevisiae strains producing 2'-FL can be used in the dry grind process to enrich Distiller's dried grains with solubles (DDGS) with 2'-FL and supplement swine diets with 2'-FL. The objectives of our study were to modify dry grind ethanol process for 2'-FL enriched DDGS production and evaluate the techno-economic feasibility of the process. Concentrations of 19.8 g 2'-FL/kg dry DDGS were achieved in the dry grind process using engineered strain without negatively affecting the ethanol yield. Process models for conventional and modified dry grind processes producing 2'-FL enriched DDGS (1150 MT corn/day capacity) were developed using SuperPro Designer. Capital and ethanol production costs for modified dry grind processes were higher than the conventional process. The internal rate of return for the modified processes was higher than the conventional process for $300/MT 2'-FL enriched DDGS selling price.

Biopolymer poly-hydroxyalkanoates (PHA) production from apple industrial waste residues: A review.

Apple pomace, the residue which is left out after processing of apple serves as a potential carbon source for the production of biopolymer, PHA (poly-hydroxyalkanoates). It is rich in carbohydrates, fibers and polyphenols. Utilization of these waste resources has dual societal benefit-waste management and conversion of waste to an eco-friendly biopolymer. This will lower the overall economics of the process. A major limitation for the commercialization of biopolymer in comparison with petroleum derived polymer is the high cost. This article gives an overview of valorization of apple pomace for the production of biopolymer, various strategies adopted, limitations as well as future perspectives.

Sustainable blueberry waste recycling towards biorefinery strategy and circular bioeconomy: A review.

Waste valorization using biological methods for value addition as well as environmental management is becoming popular approach for sustainable development. The present review addresses the availability of blueberry crop residues (BCR), applications of this feedstock in bioprocess for obtaining range of value-added products, to offer economic viability, business development and market potential, challenges and future perspectives. To the best of our knowledge, this is the first article addressing the blueberry waste valorization for a sustainable circular bioeconomy. Furthermore, it covers the information on the alternative BCR valorization methods and production of biochar for environmental management through removal or mitigation of organic and inorganic pollutants from contaminated sites. The review also discusses the ample opportunities of strategic utilization of BCR to offer solutions for environmental sustenance, covers the emerging trends to produce multi-products and techno-economic prospective for sustainable agronomy.

Resource recovery and biorefinery potential of apple orchard waste in the circular bioeconomy.

In this review investigate the apple orchard waste (AOW) is potential organic resources to produce multi-product and there sustainable interventions with biorefineries approaches to assesses the apple farm industrial bioeconomy. The thermochemical and biological processes like anaerobic digestion, composting and , etc., that generate distinctive products like bio-chemicals, biofuels, biofertilizers, animal feed and biomaterial, etc can be employed for AOW valorization. Integrating these processes can enhanced the yield and resource recovery sustainably. Thus, employing biorefinery approaches with allied different methods can link to the progression of circular bioeconomy. This review article mainly focused on the different biological processes and thermochemical that can be occupied for the production of waste to-energy and multi-bio-product in a series of reaction based on sustainability. Therefore, the biorefinery for AOW move towards identification of the serious of the reaction with each individual thermochemical and biological processes for the conversion of one-dimensional providences to circular bioeconomy.

Optimization of two-stage pretreatment for maximizing ethanol production in 1.5G technology.

Two-stage pretreatment conditions were optimized to convert corn fiber, separated from whole stillage in a corn dry grind ethanol plant, to fermentable sugars via hydrolysis. Liquid hot water pretreatment (25% solids) at 180 °C for 10 min, followed by three cycles of disk milling, provided maximum glucose, xylose, and arabinose yields of 88.5%, 41.0%, and 30.4% respectively after hydrolysis with Cellulase I. The glucose, xylose, and arabinose yields with Cellulase II at optimum conditions were 94.9%, 74.2%, and 66.3%, respectively. SSF of corn fiber using engineered yeast, with both Cellulase I and II, provided maximum ethanol concentrations of 2.13% and 2.73% (v/v). The protein content in the residual solid after fermentation was 47.95% and 52.05% for Cellulase I and II, respectively. This technology provides additional ethanol in a dry grind plant by converting corn fiber into ethanol and increases the protein content of DDGS, thereby improving the quality.

Bioprocessing and technoeconomic feasibility analysis of simultaneous production of d-psicose and ethanol using engineered yeast strain KAM-2GD.

The objective of this study was to analyze the processing and technoeconomic feasibility of coproduction of d-psicose and ethanol in a modified dry grind ethanol process. The yeast strain was constructed by expressing d-psicose 3-epimerases (DPE) in Sachharomyces cerevisiae. The strain was capable of converting d-fructose to d-psicose at 55 °C with a conversion efficiency of 26.6%. A comprehensive process model for modified dry grind ethanol plant with 396,000 MT/yr corn processing capacity was developed using SuperPro Designer. Predicted ethanol and d-psicose yields were 390.4 L and 75.3 kg per MT of corn, with total annual production of 154.6 million L and 29,835 MT respectively. The capital investment for the plant was estimated as 150.3 million USD with total operating cost of 85.2 million USD/yr. The unit production cost and minimum selling price of d-psicose with an internal rate of return of 15% were calculated as $0.43/kg and $1.29/kg respectively.

Model predictive control coupled with economic and environmental constraints for optimum algal production.

Algae production process is a key cost center in production of biofuels/bioproducts from microalgae. Decline in the growth of algae in outdoor ponds during non-optimal conditions is one of the hurdles for achieving consistently high algal production rates. An optimal controller can be used to overcome this limitation and provide reliable growth in outdoor conditions. A model predictive controller (MPC) was developed to optimize the algal growth, predicted by flux balance analysis, under natural disturbances, embedding within the cost function, the economic and environmental constraints associated with the process. The model, developed in MATLAB, was validated on a 30-L continuous algal culture under light, temperature and a combination of light and temperature disturbances. The MPC proved effective in minimization of a decrease in growth under these natural disturbances. The growth rates with MPC were observed to be 79-116% higher as compared to the non-MPC growth.

Germ soak water as nutrient source to improve fermentation of corn grits from modified corn dry grind process.

Corn fractionation in modified dry grind processes results in low fermentation efficiency of corn grits because of nutrient deficiency. This study investigated the use of nutrient-rich water from germ soaking to improve grits fermentation in the conventional dry grind and granular starch hydrolysis (GSH) processes. Comparison of germ soak water with the use of protease and external B-vitamin addition in improving grits fermentation was conducted. Use of water from optimum soaking conditions (12 h at 30 °C) resulted in complete fermentation with 29 and 8% higher final ethanol yields compared to that of control in conventional and GSH process, respectively. Fermentation rate (4-24 h) of corn grits with germ soak water (0.492 v/v-h) was more than double than that of control (0.208 v/v-h) in case of conventional dry grind process. The soaking process also increased the oil concentration in the germ by about 36%, which would enhance its economic value.

Genome scale metabolic reconstruction of Chlorella variabilis for exploring its metabolic potential for biofuels.

A compartmentalized genome scale metabolic network was reconstructed for Chlorella variabilis to offer insight into various metabolic potentials from this alga. The model, iAJ526, was reconstructed with 1455 reactions, 1236 metabolites and 526 genes. 21% of the reactions were transport reactions and about 81% of the total reactions were associated with enzymes. Along with gap filling reactions, 2 major sub-pathways were added to the model, chitosan synthesis and rhamnose metabolism. The reconstructed model had reaction participation of 4.3 metabolites per reaction and average lethality fraction of 0.21. The model was effective in capturing the growth of C. variabilis under three light conditions (white, red and red+blue light) with fair agreement. This reconstructed metabolic network will serve an important role in systems biology for further exploration of metabolism for specific target metabolites and enable improved characteristics in the strain through metabolic engineering.