The role of chemical engineering in the organic waste-based circular bioeconomy: what has been done and what still needs to be done. A perspective

The persistent organic pollutants (POPs) waste take the main place in the group of organic industrial waste and the residues of the POPs waste generated in the processes of the chemical industry. There are green chemistry methods and some other treatment approaches for decreasing the quantity of the organic industrial waste, but currently thermic treatment processes are the most popular alternatives. This paper summarises thermic utilisation processes with a comparison between the different technologies, stressing factors affecting their applicability and operational suitability. The Life Cycle Assessment (LCA) can play an important role in such research. With the application of LCA for the Waste-to-Energy (WtE) technologies, their economic and environmental efficiency can be determined. Their advantages and disadvantages are examined in such a multi-component matrix. The LCA software GaBi 5 Professional is the basis for life-cycle impact assessment. The research can set up prognoses and models with LCA analyses and the conscious application of scientific methods, which can offer a prognosis for untested situations. While examining the above viewpoints, it worked out a new mathematical method which, in addition to the LCA, takes time and probability into consideration with the combination of a programming language, and which may mark a new direction for solutions and decision making in waste management. Despite the fact that chemical industry and environmental protection are closely interlocked, there is fairly poor national and international professional literature available about the two connected professions.

Life cycle assessment (LCA) and techno-economic analysis (TEA) models are developed for a tertiary wastewater treatment system that employs a biochar-integrated reactive filtration (RF) approach. This innovative system incorporates the utilization of biochar (BC) either in conjunction with or independently of iron-ozone catalytic oxidation (CatOx)-resulting in two configurations: Fe-CatOx-BC-RF and BC-RF. The technology demonstrates 90%-99% total phosphorus removals, adsorption of phosphorus to biochar for recovery, and >90% destructive removal of observed micropollutants. In this work, we conduct an ISO-compliant LCA of a 49.2 m3 /day (9 gpm) field pilot-scale Fe-CatOx-BC-RF system and a 1130 m3 /day (0.3 MGD) water resource recovery facility (WRRF)-installed RF system, modeled with BC addition at the same rate of 0.45 g/L to quantify their environmental impacts. LCA results indicated that the Fe-CatOx-BC-RF pilot system is a BC dose-dependent carbon-negative technology at -1.21 kg CO2 e/m3 , where biochar addition constitutes a -1.53 kg/m3 CO2 e beneficial impact to the process. For the WRRF-installed RF system, modeled with the same rate of BC addition, the overall process changed from 0.02 kg CO2 e/m3 to a carbon negative -1.41 kg CO2 e/m3 , demonstrating potential as a biochar dose-dependent negative emissions technology. Using the C100 100-year carbon accounting approach rather than Cnet reduces these CO2 e metrics for the process by about 25%. A stochastic TEA for the cost of water treatment using this combinatorial P removal/recovery, micropollutant destructive removal, and disinfection advanced technology shows that at scale, the mean cost for treating 1130 m3 /day (0.3 MGD) WRRF secondary influent water with Fe-CatOx-BC-RF using the C100 metric is US$0.18 ± US$0.01/m3 to achieve overall process carbon neutrality. Using the same BC dose in an estimation of a 3780 m3 /day (1 MGD) Fe-CatOx-BC-RF facility, the carbon neutral cost of treatment is reduced further to US$0.08 ± $0.01 with added BC accounting for US$0.03/m3 . Overall, the results demonstrate the potential of carbon negativity to become a water treatment performance standard as important and attainable as pollutant and pathogen removal. PRACTITIONER POINTS: Life cycle assessment (LCA) of a pilot scale tertiary biochar water treatment process with or without catalytic ozonation at a WRRF shows a carbon negative global warming potential of -1.21-kg CO2e/m3 while removing 90%-99% TP and >90% of detected micropollutants. Biochar-integrated reactive filtration use can aid in long-term carbon sequestration by reducing the carbon footprint of advanced water treatment in a dose-dependent manner, allowing an overall carbon-neutral or carbon-negative process. A companion paper to this work (Yu et al., 2023) presents the details related to the process operation and mechanism and evaluates the pollutant removal performance of this Fe-CatOx-BC-RF process in engineering laboratory pilot research and field WRRF pilot-scale water resource recovery trials. Techno-economic analysis (TEA) of this biochar catalytic oxidation reactive filtration process using Monte Carlo stochastic modeling shows a forecasted carbon-neutral process cost with low P and micropollutant removal as US$0.11/m3 ± 0.01 for a 3780-m3/day (1 MGD) scale installation with BC cost at US$0.03/m3 of that total. The results demonstrate the potential of carbon negativity to become a water treatmentperformance standard as important and attainable as pollutant and pathogen removal.

Advanced technologies on the sustainable approaches for conversion of organic waste to valuable bioproducts: Emerging circular bioeconomy perspective

Integration of LCA, TEA, Process Simulation and Optimization: A systematic review of current practices and scope to propose a framework for pulse processing pathways

Abstract. In this paper, adhesives made either from fossil fuels or biological sources were examined. The purpose of this review was to investigate the development, processing, and production of bio-adhesives, especially key information about environmental and economic impacts of these types of adhesives. Specifically, the literature was reviewed in terms of life cycle assessment (LCA) and techno-economic analysis (TEA) in order to evaluate the environmental effects, economic performance and potential market acceptance. Several key parameters for life cycle analysis will be compared, such as resource consumption, ecosystem quality and human health; As for TEA, capital costs, operational costs, and unit costs will be explored, as well as the breakeven points. Underlying issues in LCA and TEA will be discussed, and we will examine areas needed for improvement for emerging biobased adhesives.

Integration of techno-economic analysis and life cycle assessment for sustainable process design – A review

Municipal and agricultural organic waste can be treatedto recoverenergy, nutrients, and carbon through resource recovery and carboncapture (RRCC) technologies such as anaerobic digestion, struviteprecipitation, and pyrolysis. Data science could benefit such technologiesby improving their efficiency through data-driven process modelingalong with reducing environmental and economic burdens via life cycleassessment (LCA) and techno-economic analysis (TEA), respectively.We critically reviewed 616 peer-reviewed articles on the use of datascience in RRCC published during 2002–2022. Although applicationsof machine learning (ML) methods have drastically increased over timefor modeling RRCC technologies, the reviewed studies exhibited significantknowledge gaps at various model development stages. In terms of sustainability,an increasing number of studies included LCA with TEA to quantifyboth environmental and economic impacts of RRCC. Integration of MLmethods with LCA and TEA has the potential to cost-effectively investigatethe trade-off between efficiency and sustainability of RRCC, althoughthe literature lacked such integration of techniques. Therefore, wepropose an integrated data science framework to inform efficient andsustainable RRCC from organic waste based on the review. Overall,the findings from this review can inform practitioners about the effectiveutilization of various data science methods for real-world implementationof RRCC technologies.

Addressing global food security is a paramount challenge that necessitates a shift towards enhanced food self-sufficiency. The escalating demand for animal-derived proteins, such as meat and dairy, underscores the critical role of livestock farming in meeting the nutritional needs of the global population. To sustain this, protein-rich feed, essential for livestock production, consumes a considerable share of agricultural resources. Concurrently, urban expansion significantly increases organic waste, undermining both economic and environmental sustainability. This highlights the urgent need for innovative waste management solutions that bolster sustainability. Microbial protein (MP), produced by methane-oxidizing bacteria (MOB), presents a promising solution. It offers a land-independent method for producing feed for livestock and aquaculture, potentially alleviating the pressure on agricultural lands. Despite its advantages, reliance on natural gas for MP production raises sustainability concerns when compared to traditional feeds like fishmeal and soybean meal. Recent research focuses on valorizing waste materials using high-protein microorganisms for animal feed production, thereby addressing these concerns. Aerobic fermentation of methane to produce MP, utilizing methanotrophic microbes, showcases distinct advantages. These microbes produce a protein-rich biomass, containing over 75% protein, offering a viable alternative to conventional protein sources. This review explores the potential of urban biowaste valorization for MP production through the integration of anaerobic digestion (AD) and subsequent fermentation of biogas. It delves into the valorization mechanisms of biogas from AD to MP, highlighting methane's value in MP production for environmental and economic sustainability. Despite advancements, challenges such as inefficient fermenters, MOB inhibition, and safety issues hinder large-scale MP production. Further investigation into the life cycle assessment (LCA) and techno-economic analysis (TCA) of these integrated technologies is essential for enhancing and establishing a sustainable MP production system.

Hybrid processing of cellulosic biomass, composed of thermochemical-based pyrolysis of biomass into fermentative substrates followed by biochemical-based algal fermentation into lipid-rich biomass was developed. The hybrid process has proven an effective way for producing biofuel from lignocellulosic biomass. In this work, life cycle assessment and techno economic analysis were performed for algal fermentation of the acetic-acid rich stage fraction of bio-oil under different scales and fermentation conditions. These results will provide guidance for choosing optimal algal fermentation parameters. Moreover, with more biodiesel produced, increased environmental and economic benefits per gallon of biodiesel can be expected.

Life-cycle assessment (LCA) presents a relatively new approach, which allows comprehensive environmental consequences analysis of a product system over its entire life. This analysis is increasingly being used in the industry, as a tool for investigation of the influence of the product system on the environment, and serves as a protection and prevention tool in ecological management. This method is used to predict possible influences of a certain material to the environment through different development stages of the material. In LCA, the product systems are evaluated on a functionally equivalent basis, which, in this case, was 1000 cubic centimeters of an alloy. Two of the LCA phases, life-cycle inventory (LCA) and life-cycle impact assessment (LCIA), are needed to calculate the environmental impacts. Methodology of LCIA applied in this analysis aligns every input and output influence into 16 different categories, divided in two subcategories. The life-cycle assessment reaserch review of the leadfree solders Sn-Cu, SAC (Sn-Ag-Cu), BSA (Bi-Sb-Ag) and SABC (Sn-Ag-Bi-Cu) respectively, is given in this paper, from the environmental protection aspect starting from production, through application process and finally, reclamation at the end-of-life, i.e. recycling. There are several opportunities for reducing the overall environmental and human health impacts of solder used in electronics manufacturing based on the results of the LCA, such as: using secondary metals reclaimed through post-industrial recycling; power consumption reducing by replacing older, less efficient reflow assembly equipment, or by optimizing the current equipment to perform at the elevated temperatures required for lead-free soldering, etc. The LCA analysis was done comparatively in relation to widely used Sn-Pb solder material. Additionally, the impact factors of material consumption, energy use, water and air reserves, human health and ecotoxicity have been ALSO considered including the potentials for dissolution and recycling processes.

Life cycle assessment and techno-economic analysis of maleic anhydride hydrogenation to 1,4-butanediol through biomass gasification coupling with chemical looping hydrogen production

Life cycle assessment is a fundamental tool used to evaluate the environmental impact of products. Standard life cycle assessment methodology ignores the impact of greenhouse gases relative to when they are emitted. In this paper, we present a method for leveraging the social cost of greenhouse gases to account for the temporal impacts of emissions in life cycle assessment and techno-economics. To demonstrate, we use this method to analyze the present value of the monetized impacts of emissions across multiple electricity generation technologies. Results show that accounting for time increases the present value across all but one of the technologies considered. Carbon intensive technologies show the highest increase, with coal rising between 26% and 62% depending on social cost scenario. Additionally, we demonstrate a second method that combines temporally resolved greenhouse gas emissions with techno-economic analysis. Considering temporal impacts of emissions within techno-economic analysis increases the levelized cost of electricity (LCOE) across all technologies considered. Carbon intensive technologies increase significantly, with the LCOE from coal rising between 37% and 263% depending on the social cost scenario. The proposed methods show that temporal resolution in life cycle assessment is critical for comparing the monetized impacts of greenhouse gas emissions across technologies.

Various technologies and strategies have been proposed to decarbonize the chemical industry. Assessing the decarbonization, environmental, and economic implications of these technologies and strategies is critical to identifying pathways to a more sustainable industrial future. This study reviews recent advancements and integration of systems analysis models, including process analysis, material flow analysis, life cycle assessment, techno-economic analysis, and machine learning. These models are categorized based on analytical methods and application scales (i.e., micro-, meso-, and macroscale) for promising decarbonization technologies (e.g., carbon capture, storage, and utilization, biomass feedstock, and electrification) and circular economy strategies. Incorporating forward-looking, data-driven approaches into existing models allows for optimizing complex industrial systems and assessing future impacts. Although advances in industrial ecology-, economic-, and planetary boundary-based modeling support a more holistic systems-level assessment, more efforts are needed to consider impacts on ecosystems. Effective applications of these advanced, integrated models require cross-disciplinary collaborations across chemical engineering, industrial ecology, and economics.

Abstract. Aquaponics is the system combining hydroponic and aquaculture, in which fish and plants are raised together, and they can be beneficial from each other as well as to each other. When the system is maintained properly and is in a balance status, aquaponics will mimic the natural ecosystem, use much less water than traditional aquaculture, and have almost no effluent. As a result, it is thought more environmentally friendly and sustainable. In this study, both Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) of a tilapia and basil aquaponic system were conducted. Three scales, including a truly running system, pilot scale, and commercial scale of aquaponics were considered and analyzed. This study provided environmental impacts and profitability for operating aquaponics in the Midwest of U.S. It also showed that the operating scale and basil price had obvious effect on profits. When the scale was large enough, such as with the grow bed area of 75.6 m2 and when the basil price equals to or is great than $60/kg, operating aquaponics was profitable.

<abstract> <bold>Abstract.</bold> DDGS could have higher market price and wider use if it could be separated into higher protein and higher fiber fractions. In our work, DDGS was firstly sieved into three size categories, and one category was further separated into light, midlight, midheavy and heavy fractions using a gravity separator. This process was effective in getting enhanced DDGS with increased protein and oil. In this study, both Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) of our approach to DDGS fractionation were conducted. Three scales, including lab scale, pilot scale, and commercial scale of DDGS fractionation were considered and analyzed. All equipment parameters were obtained from industrial manufacturers. Both the environmental impact and the cost per unit of DDGS fractionation decreased as the fractionation scale expanded.