Techno-economic analysis of ethanol production from lignocellulosic biomass-a comparison of fermentation, thermo catalytic, and chemocatalytic technologies.

Bioethanol produced from 2nd generation biomass comprising of agricultural residues and forest wastes is a viable alternate fuel. Besides fermentation and biomass gasification to syngas and its further conversion to ethanol, a direct chemocatalytic conversion of lignocellulosic biomass into ethanol is being investigated as a viable route which avoids the emission of greenhouse gases. In this work, a detailed configuration of chemocatalytic route is simulated and optimized for minimizing the cost of ethanol production. The economic feasibility of ethanol production through the chemocatalytic pathway is analyzed. The techno-economic analysis is conducted in terms of ethanol selectivity and ethanol production cost. The obtained results show that biomass feedstock and catalyst have major contributions to the production cost. The proposed route is found to be giving a lower ethanol selling price as compared to the well-researched routes of biomass fermentation to ethanol and biomass gasification followed by syngas conversion to ethanol.

Lignocellulosic biomass: Hurdles and challenges in its valorization.

Lignocellulosic biomass (LCB) is globally available and sustainable feedstock containing sugar-rich platform that can be converted to biofuels and specialty products through appropriate processing. This review focuses on the efforts required for the development of sustainable and economically viable lignocellulosic biorefinery to produce carbon neutral biofuels along with the specialty chemicals. Sustainable biomass processing is a global challenge that requires the fulfillment of fundamental demands concerning economic efficiency, environmental compatibility, and social responsibility. The key technical challenges in continuous biomass supply and the biological routes for its saccharification with high yields of sugar sources have not been addressed in research programs dealing with biomass processing. Though many R&D endeavors have directed towards biomass valorization over several decades, the integrated production of biofuels and chemicals still needs optimization from both technical and economical perspectives. None of the current pretreatment methods has advantages over others since their outcomes depend on the type of feedstock, downstream process configuration, and many other factors. Consolidated bio-processing (CBP) involves the use of single or consortium of microbes to deconstruct biomass without pretreatment. The use of new genetic engineering tools for natively cellulolytic microbes would make the CBP process low cost and ecologically friendly. Issues arising with chemical characteristics and rigidity of the biomass structure can be a setback for its viability for biofuel conversion. Integration of functional genomics and system biology with synthetic biology and metabolic engineering undoubtedly led to generation of efficient microbial systems, albeit with limited commercial potential. These efficient microbial systems with new metabolic routes can be exploited for production of commodity chemicals from all the three components of biomass. This paper provides an overview of the challenges that are faced by the processes converting LCB to commodity chemicals with special reference to biofuels.

Alcohol Availability and Onset and Recurrence of Alcohol Use Disorder: Examination in a Longitudinal Cohort with Cosibling Analysis.

BACKGROUND: Recent reviews of associations of alcohol availability with alcohol outcomes suggest findings are highly inconsistent and highlight a lack of longitudinal and causal evidence. Effect modification (moderation or statistical interaction), which could contribute to the inconsistent picture in the existing literature, has not been systematically assessed. We examined associations of alcohol availability with onset and recurrence of alcohol use disorder (AUD) using multilevel, longitudinal population data from Sweden and tested hypothesized effect modifiers to identify groups for whom increased alcohol availability may be particularly risky. We also employed cosibling models to assess potential causality for AUD onset by accounting for genetic and shared-environment confounders. METHODS: Data come from all individuals born in Sweden between 1950 and 1975 who were registered in a residential neighborhood at the end of 2005 (N = 2,633,922). We used Cox proportional hazards models to investigate time to AUD onset and logistic regression to assess the odds of AUD recurrence over an 8-year period. RESULTS: Living in a neighborhood with at least 1 alcohol outlet of any type was associated with a small increase in the likelihood of developing AUD, with an adjusted hazard ratio (HR) of 1.16 (95% CI: 1.13 to 1.19). Among people with a prior AUD registration, alcohol availability was not significantly associated with recurrence of AUD, with an adjusted odds ratio of 1.02 (95% CI: 1.00 to 1.05). Associations of alcohol availability with AUD onset varied according to sex, age, education, neighborhood deprivation, and urbanicity. HRs from the sibling models were similar to those in the general population models, with an adjusted HR = 1.19 (95% CI: 1.15 to 1.24). CONCLUSIONS: Effects varied among neighborhood residents, but greater alcohol availability was a risk factor for AUD onset (but not relapse) in all groups examined except women. Cosibling models suggest there may be a causal relationship of greater alcohol availability with adult-onset AUD.

Comparison of Ultrasound-Guided Percutaneous Polidocanol Injection Versus Percutaneous Ethanol Injection for Treatment of Benign Cystic Thyroid Nodules.

OBJECTIVES: We compared the efficacy, safety, and cost-effectiveness of ultrasound-guided percutaneous polidocanol injection and percutaneous ethanol injection for the treatment of benign cystic and predominantly cystic thyroid nodules. METHODS: A total of 135 cystic thyroid nodules treated by percutaneous ethanol injection and 136 cystic thyroid nodules treated by percutaneous polidocanol injection were enrolled retrospectively in this study from May 2010 to March 2016. The nodules were followed after 1, 3, 6, and 12 months. Nodule volumes, symptoms scores, and cosmetic scores were assessed before treatment and at follow-up. The therapeutic success rate, safety, and cost-effectiveness between the groups were also compared. RESULTS: No significant differences in the reduction of the nodule volume, volume reduction rate, and therapeutic success were observed between the groups with cystic and predominantly cystic thyroid nodules during follow-up (P > .05). Neither the cosmetic scores (P = .59; P = .42) nor the symptom scores (P = .32; P = .73) in the cystic and predominantly cystic nodules were significantly different between the groups at the last follow-up. The complication rates for ethanol were higher than those for polidocanol (P < .05). However, the cost of polidocanol injection was higher than that of ethanol injection for cystic thyroid nodules (mean ± SD, US$97.18 ± US$22.17 versus US$43.36 ± US$5.51; P < .01). CONCLUSIONS: Ultrasound-guided percutaneous polidocanol injection can be an alternative for sclerotherapy of cystic or predominantly cystic thyroid nodules. However, its cost was higher than that of percutaneous ethanol injection.

Fed-batch hydrolysate addition and cell separation by settling in high cell density lignocellulosic ethanol fermentations on AFEX™ corn stover in the Rapid Bioconversion with Integrated recycling Technology process.

The Rapid Bioconversion with Integrated recycling Technology (RaBIT) process uses enzyme and yeast recycling to improve cellulosic ethanol production economics. The previous versions of the RaBIT process exhibited decreased xylose consumption using cell recycle for a variety of different micro-organisms. Process changes were tested in an attempt to eliminate the xylose consumption decrease. Three different RaBIT process changes were evaluated in this work including (1) shortening the fermentation time, (2) fed-batch hydrolysate addition, and (3) selective cell recycling using a settling method. Shorting the RaBIT fermentation process to 11 h and introducing fed-batch hydrolysate addition eliminated any xylose consumption decrease over ten fermentation cycles; otherwise, decreased xylose consumption was apparent by the third cell recycle event. However, partial removal of yeast cells during recycle was not economical when compared to recycling all yeast cells.

Episodic Future Thinking: Expansion of the Temporal Window in Individuals with Alcohol Dependence.

BACKGROUND: Episodic future thinking (EFT) requires an individual to vividly pre-experience a realistic future event. Inspired by previous reports of reducing delay discounting following EFT in other populations, we examined the effects of engaging alcohol-dependent individuals in EFT or episodic recent thinking (ERT; control) to examine its effects on delay discounting and alcohol purchasing. METHODS: Participants (n = 50) with alcohol dependence were allocated into EFT or ERT groups and asked to generate positive future or recent past events for each of 5 time points. Participants then completed a delay-discounting task, during which event cues were displayed, and a hypothetical alcohol purchase task. RESULTS: EFT significantly increased valuation of future monetary rewards, while decreasing initial consumption (Q0 ) of alcoholic drinks indicative of lower demand intensity. Two additional findings suggest potential moderators of this effect. EFT more readily influenced individuals with lower Alcohol Use Disorders Identification Test scores, and self-reported cue valence differed between groups. CONCLUSIONS: Together, these results suggest a widening of alcohol-dependent individuals' temporal window following engagement of EFT. While our data suggest that EFT may be moderated by certain susceptibility criteria, exercises such as EFT could be easily adaptable as a potential therapeutic tool for use in rehabilitation programs.

Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

Estimating the economic effects of reduced drinking in Japan based on the methodologies of cost-of-illness studies on alcohol in Japan and overseas.

One of the alcohol-related goals in Japan's health promotion campaign called Health Japan 21 (secondary term) is to reduce the number of high-risk drinkers (20 years old or above) who consume 40g or more pure alcohol/day in men and 20g or more in women by year 2022. To achieve this goal, it is important for both the government and clinicians to understand the cost-of-illness associated with harmful drinking in Japan and .effectively reflect it into related poli- cies. In this study, direct and indirect costs attributable to alcohol based on conventional cost-of-illness study methodologies were estimated to be approximately 9.9 trillion yen using 2012 data. Furthermore, economic effects brought by achieving the goal of Health Japan 21 (seconda'ry term) were further analyzed by incorporating parameters such as employment rates, drinking volume and frequency by age group and gender. The authors.had previously estimated possible savings of as much as 381.3 billion yen, before subtracting associated intervention costs and decreased tax revenue from purchasing alcohol beverages. The scenario analysis in this study provided lower savings of approximately 158.4-194.6 billion yen. However, the estimates excluded high-risk drinkers in their 20s, early 30s and over 70, who account for a good part of high-risk drinkers in Japan. Furthermore, considerations of employment rates and average annual salaries into the calculations of economic loss due to premature mortality tend to ignore productivity loss (absenteeism and presentism) of high-risk drinkers and opportunity costs of home-makers or care-givers. Thus, possibly underestimated 158.4 billion yen was considered as realistic as possibly overestimated 381.3 billion yen. Despite such variations, economic effects brought by achieving reduced drinking among high-risk drinkers seemed to support related policies and disease management in Japan.

Cost of abating greenhouse gas emissions with cellulosic ethanol.

We develop an integrated framework to determine and compare greenhouse gas (GHG) intensities and production costs of cellulosic ethanol derived from corn stover, switchgrass, and miscanthus grown on high and low quality soils for three representative counties in the Eastern United States. This information is critical for assessing the cost-effectiveness of utilizing cellulosic ethanol for mitigating GHG emissions and designing appropriate policy incentives to support cellulosic ethanol production nationwide. We find considerable variations in the GHG intensities and production costs of ethanol across feedstocks and locations mostly due to differences in yields and soil characteristics. As compared to gasoline, the GHG savings from miscanthus-based ethanol ranged between 130% and 156% whereas that from switchgrass ranged between 97% and 135%. The corresponding range for GHG savings with corn stover was 57% to 95% and marginally below the threshold of at least 60% for biofuels classified as cellulosic biofuels under the Renewable Fuels Standard. Estimates of the costs of producing ethanol relative to gasoline imply an abatement cost of at least $48 Mg(-1) of GHG emissions (carbon dioxide equivalent) abated and can be used to infer the minimum carbon tax rate needed to induce consumption of cellulosic ethanol.

Assessing Patterns of Alcohol Taxes Produced by Various Types of Excise Tax Methods--A Simulation Study.

AIM: To examine patterns of tax burdens produced by specific, ad valorem, and various types of combination taxations. METHOD: One hundred unique hypothetical alcoholic beverages were mathematically simulated based on the amount of ethanol and perceived-qualities contained. Second, beverages were assigned values of various costs and tax rates, and third, patterns of tax burden were assessed per unit of ethanol produced by each type of tax method. RESULT: Different tax methods produced different tax burdens per unit of ethanol for different alcoholic beverages. The tax burden produced by the ad valorem tax resulted in a lower tax burden for low perceived-quality alcoholic beverages. The specific tax method showed the same tax burden for both low and high perceived-quality alcoholic beverages. However, high perceived-quality beverages benefited from a lower tax burden per beverage price. Lastly, the combination tax method resulted in a lower tax burden for medium perceived-quality alcoholic beverages. CONCLUSION: Under the oligopoly market, ad valorem taxation encourages consumption of low perceived-quality beverages; specific taxation encourages consumption of high perceived-quality beverages; and combination tax methods encourage consumption of medium perceived-quality beverages.

Impacts of retrofitting analysis on first generation ethanol production: process design and techno-economics.

More than half of the bioethanol plants in operation today use corn or grains as raw materials. The downstream processing of mash after fermentation to produce ethanol and distiller grains is an energy-demanding process, which needs retrofitting for optimization. In addition, the fluctuation in the ethanol and grain prices affects the overall profitability of the plant. For this purpose, a process simulation was performed in Aspen Plus(®) based on an existing industrial plant located in Sweden. The simulations were compared using different scenarios including different concentrations of ethanol, using the stillage for biogas production to produce steam instead of distiller grains as a by-product, and altering the purity of the ethanol produced. Using stillage for biogas production, as well as utilizing the steam, reduced the overall energy consumption by 40% compared to the plant in operation. The fluctuations in grain prices had a high impact on the net present value (NPV), where grain prices greater than 349 USD/ton reached a zero NPV. After 20 years, the plant in operation producing 41,600 tons ethanol/year can generate a profit of 78 million USD. Compared to the base case, the less purified ethanol resulted in a lower NPV of 30 million USD.

Tradeoffs and Synergies between biofuel production and large solar infrastructure in deserts.

Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large solar installations. However, for efficient power generation, solar infrastructures use large amounts of water for construction and operation. We investigated the water use and greenhouse gas (GHG) emissions associated with solar installations in North American deserts in comparison to agave-based biofuel production, another widely promoted potential energy source from arid systems. We determined the uncertainty in our analysis by a Monte Carlo approach that varied the most important parameters, as determined by sensitivity analysis. We considered the uncertainty in our estimates as a result of variations in the number of solar modules ha(-1), module efficiency, number of agave plants ha(-1), and overall sugar conversion efficiency for agave. Further, we considered the uncertainty in revenue and returns as a result of variations in the wholesale price of electricity and installation cost of solar photovoltaic (PV), wholesale price of agave ethanol, and cost of agave cultivation and ethanol processing. The life-cycle analyses show that energy outputs and GHG offsets from solar PV systems, mean energy output of 2405 GJ ha(-1) year(-1) (5 and 95% quantile values of 1940-2920) and mean GHG offsets of 464 Mg of CO2 equiv ha(-1) year(-1) (375-562), are much larger than agave, mean energy output from 206 (171-243) to 61 (50-71) GJ ha(-1) year(-1) and mean GHG offsets from 18 (14-22) to 4.6 (3.7-5.5) Mg of CO2 equiv ha(-1) year(-1), depending upon the yield scenario of agave. Importantly though, water inputs for cleaning solar panels and dust suppression are similar to amounts required for annual agave growth, suggesting the possibility of integrating the two systems to maximize the efficiency of land and water use to produce both electricity and liquid fuel. A life-cycle analysis of a hypothetical colocation indicated higher returns per m(3) of water used than either system alone. Water requirements for energy production were 0.22 L MJ(-1) (0.28-0.19) and 0.42 L MJ(-1) (0.52-0.35) for solar PV-agave (baseline yield) and solar PV-agave (high yield), respectively. Even though colocation may not be practical in all locations, in some water-limited areas, colocated solar PV-agave systems may provide attractive economic incentives in addition to efficient land and water use.

Impact of air pollution control costs on the cost and spatial arrangement of cellulosic biofuel production in the U.S.

Air pollution emissions regulation can affect the location, size, and technology choice of potential biofuel production facilities. Difficulty in obtaining air pollutant emission permits and the cost of air pollution control devices have been cited by some fuel producers as barriers to development. This paper expands on the Geospatial Bioenergy Systems Model (GBSM) to evaluate the effect of air pollution control costs on the availability, cost, and distribution of U.S. biofuel production by subjecting potential facility locations within U.S. Clean Air Act nonattainment areas, which exceed thresholds for healthy air quality, to additional costs. This paper compares three scenarios: one with air quality costs included, one without air quality costs, and one in which conversion facilities were prohibited in Clean Air Act nonattainment areas. While air quality regulation may substantially affect local decisions regarding siting or technology choices, their effect on the system as a whole is small. Most biofuel facilities are expected to be sited near to feedstock supplies, which are seldom in nonattainment areas. The average cost per unit of produced energy is less than 1% higher in the scenarios with air quality compliance costs than in scenarios without such costs. When facility construction is prohibited in nonattainment areas, the costs increase by slightly over 1%, due to increases in the distance feedstock is transported to facilities in attainment areas.

Pretreatment solution recycling and high-concentration output for economical production of bioethanol.

The purpose of this study was to enhance the economic efficiency of producing bioethanol. Pretreatment solution recycling is expected to increase economic efficiency by reducing the cost of pretreatment and the amount of wastewater. In addition, the production of high-concentration bioethanol could increase economic efficiency by reducing the energy cost of distillation. The pretreatment conditions were 95 °C, 0.72 M NaOH, 80 rpm twin-screw speed, and flow rate of 90 mL/min at 18 g/min of raw biomass feeding for pretreatment solution recycling. The pretreatment with NaOH solution recycling was conducted five times. All of the components and the pretreatment efficiency were similar, despite reuse. In addition, we developed a continuous biomass feeding system for production of high-concentration bioethanol. Using this reactor, the bioethanol productivity was investigated using various pretreated biomass feeding rates in a simultaneous saccharification and fermentation (SSF) process. The maximum ethanol concentration, yield, and productivity were 74.5 g/L, 89.5%, and 1.4 g/L h, respectively, at a pretreated biomass loading of approximately 25% (w/v) with an enzyme dosage of 30 FPU g/cellulose. The results presented here constitute an important contribution toward the production of bioethanol from Miscanthus.

Associations Between COVID-19 Alcohol Policy Restrictions and Alcohol Sales in British Columbia: Variation by Area-Based Deprivation Level.

OBJECTIVE: Government alcohol sales data were used to investigate associations between estimates of per capita age 15+ alcohol consumption, policy restrictiveness, and area-level deprivation. METHOD: We analyzed weekly consumption data (expressed as per capita age 15+ Canadian standard drinks [13.45 g of pure ethanol]) collected from all 89 local health areas in British Columbia, Canada, between April 2017 and April 2021. Our analyses were stratified by outlet type (total, on-premise, and off-premise). Our intervention was alcohol policy restrictiveness (operationalized by the Restrictiveness of Alcohol Policy Index), and our moderator was area-level deprivation (Canadian Index of Multiple Deprivation). The Restrictiveness of Alcohol Policy Index included hours of trading, the number of people permitted on site for on-premise venues, the proportion of outlets in operation, and the extent of permissible home delivery. RESULTS: Higher policy restrictiveness was associated with decreased consumption across all outlet types (ps < .001): when the most restrictive policies were implemented, consumption was reduced by 9% and 100% in off- and on-premise outlets, respectively. Area-based deprivation level modified the effect of policy restriction on per capita alcohol consumption (ps < .007): for total and off-premise consumption, the decrease was greatest among more economically deprived areas (ps < .001); for on-premise outlets, areas with a high proportion of racial and ethnic minorities increased their consumption (ps < .001). CONCLUSIONS: Alcohol-specific policy restrictions implemented in response to the COVID-19 pandemic were associated with reduced consumption. However, the magnitude and direction of change was moderated by area-based deprivation level, albeit inconsistently across various deprivation measures.

Mortality of harmful drinkers increased after reduction of alcohol prices in northern Finland: a 10-year follow-up of head trauma subjects.

OBJECTIVE: Alcohol-related mortality may be influenced by the level of alcohol consumption. We investigated the effect of alcohol price reduction on mortality in a cohort of 827 subjects with head injury. METHODS: We used the Finnish National Hospital Discharge Register to identify all diagnoses recorded during hospital and health center visits for survivors of the index injury during a follow-up of 10 years. Mortality data were gathered from death records obtained from the Official Cause-of-Death Statistics. Cox proportional hazards model was used to identify independent predictors for death. Kaplan-Meier survival curves were used to characterize the effect of alcohol price reduction on mortality of harmful and non-harmful drinkers. RESULTS: Alcohol-related deaths increased after the reduction of alcohol prices on March 1, 2004. Subjects recorded as harmful drinkers during the follow-up period were significantly (p < 0.001) more likely than others to die after the price reduction. Older age (HR 1.06, 95% CI 1.05-1.07), moderate-to-severe brain injury (HR 2.39, 95% CI 1.59-3.60) and harmful drinking recorded after the index trauma (HR 2.59, 95% CI 1.62-4.62) were significant (p < 0.001) predictors for death. CONCLUSION: We conclude that a political decision to lower the price of alcohol may cause a significant increase in the death rate of harmful drinkers.

The challenge of enzyme cost in the production of lignocellulosic biofuels.

With the aim of understanding the contribution of enzymes to the cost of lignocellulosic biofuels, we constructed a techno-economic model for the production of fungal cellulases. We found that the cost of producing enzymes was much higher than that commonly assumed in the literature. For example, the cost contribution of enzymes to ethanol produced by the conversion of corn stover was found to be $0.68/gal if the sugars in the biomass could be converted at maximum theoretical yields, and $1.47/gal if the yields were based on saccharification and fermentation yields that have been previously reported in the scientific literature. We performed a sensitivity analysis to study the effect of feedstock prices and fermentation times on the cost contribution of enzymes to ethanol price. We conclude that a significant effort is still required to lower the contribution of enzymes to biofuel production costs.