Low stabilization pathways: Economic and technical feasibility

The production of chemicals from renewable feedstocks is becoming an attractive area of investment for industries in the framework of a more sustainable economy. From a technical point of view, a large fraction of industrial chemicals and materials from fossil resources can be replaced by their bio‐based counterparts. Nevertheless, fossil‐based chemistry is still dominant because of optimized production processes and lower costs. The best approach to maximize the valorization of biomass is the processing of biological feedstocks in integrated biorefineries where both bio‐based chemicals and energy carriers can be produced, similar to a traditional petroleum refinery. The challenge is to prove, together with the technical and economic feasibility, an environmental feasibility, in terms of lower impact over the entire production chain. In this review, potential renewable substrates, conversion pathways, and target molecules are carefully investigated with reference to the most recent technological advancements. Potential environmental impacts and benefits over the life cycle of products are also reviewed. While an economic and technical feasibility can be, and sometimes has been already, reached, the same is not true yet for environmental feasibility, where several issues still need to be explored and the risk for burden shift is not negligible. The aim of this review is to provide an overview of the opportunities and constraints related to the transition from petroleum to biomass chemistry and to draw a roadmap of the most sustainable technologies and promising biomass value chains, screening in parallel their environmental implications, toward a market implementation of bio‐based chemistry. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

BackgroundItaly can augment its profit from biorefinery products by altering the operation of digesters or different designs to obtain more precious bioproducts like volatile fatty acids (VFAs) than biogas from organic municipal solid waste. In this context, recognizing the process stability and outputs through operational interventions and its technical and economic feasibility is a critical issue. Hence, this study involves an anaerobic digester in Treviso in northern Italy.ObjectiveThis research compares a novel line, consisting of pretreatment, acidogenic fermentation, and anaerobic digestion, with single-step anaerobic digestion regarding financial profit and surplus energy. Therefore, a mass flow model was created and refined based on the outputs from the experimental and numerical studies. These studies examine the influence of hydraulic retention time (HRT), pretreatment, biochar addition, and fine-tuned feedstock/inoculum (FS/IN) ratio on bioproducts and operational parameters.MethodsVFA concentration, VFA weight ratio distribution, and biogas yield were quantified by gas chromatography. A t test was then conducted to analyze the significance of dissimilar HRTs in changing the VFA content. Further, a feasible biochar dosage was identified for an assumed FS/IN ratio with an adequately long HRT using the first-order rate model. Accordingly, the parameters for a mass flow model were adopted for 70,000 population equivalents to determine the payback period and surplus energy for two scenarios. We also explored the effectiveness of amendments in improving the process kinetics.ResultsBoth HRTs were identical concerning the ratio of VFA/soluble chemical oxygen demand (0.88 kg/kg) and VFA weight ratio distribution: mainly, acetic acid (40%), butyric acid (24%), and caproic acid (17%). However, a significantly higher mean VFA content was confirmed for an HRT of 4.5 days than the quantity for an HRT of 3 days (30.77, SD 2.82 vs 27.66, SD 2.45 g–soluble chemical oxygen demand/L), using a t test (t8=−2.68; P=.03; CI=95%). In this research, 83% of the fermented volatile solids were converted into biogas to obtain a specific methane (CH4) production of 0.133 CH4-Nm3/kg–volatile solids. While biochar addition improved only the maximum methane content by 20% (86% volumetric basis [v/v]), the FS/IN ratio of 0.3 volatile solid basis with thermal plus fermentative pretreatment improved the hydrolysis rate substantially (0.57 vs 0.07, 1/d). Furthermore, the biochar dosage of 0.12 g-biochar/g–volatile solids with an HRT of 20 days was identified as a feasible solution. Principally, the payback period for our novel line would be almost 2 years with surplus energy of 2251 megajoules [MJ] per day compared to 45 years and 21,567 MJ per day for single-step anaerobic digestion.ConclusionsThis research elaborates on the advantage of the refined novel line over the single-step anaerobic digestion and confirms its financial and technical feasibility. Further, changing the HRT and other amendments significantly raised the VFA concentration and the process kinetics and stability.

Technical, economic, and environmental feasibility of alternative fuel heavy-duty vehicles in Iceland

The urgently needed phasing out of fossil resources requires that we should critically assess for which applications (virgin) carbon-based materials are essential and in which cases it is possible to dematerialise. Nevertheless, it is anticipated that a large fraction of the functionalities that are currently supplied by carbon-based materials will remain essential in the decades to come. Therefore, a transition to new high performance materials and products made from non-fossil renewable feedstock needs to be realized. In the past decade, various studies have pointed out that this transition can be realised by the utilisation of three particular alternative sources, exclusively. These are biomass, recycled materials and carbon dioxide (CO2). Out of these three pathways, the development of processes for the conversion of CO2 into polymers that can be used for plastics is lagging behind. This lag can largely be explained by the technical challenges that still exist for sourcing and subsequent conversion of CO2. As a result, the currently available technologies are not yet cost-effective. Nevertheless, driven by the increasing demand for fossil-free resources and increasing levels of CO2 taxation, a wide range of new chemical and microbial conversion technologies have been developed in the past decade, some of which are currently being investigated at an industrial level. This study identifies and assesses the most relevant sources and conversion routes for CO2-based materials from a technical perspective. A specific focus is placed on the conversion of CO2 into polymers that can be used in packaging, building and textile applications. The present study identifies specific CO2-to-product pathways and the five parameters that determine the technical, economic and ecologic feasibility of these routes, those being: • The CO2 content of the polymer, i.e., the fraction of carbon that originates from CO2 • The energy required for the conversion process(es) • The technical feasibility and yield of the conversion process which is reflected in the technology readiness level (TRL) number • The oxidation state of the carbon within the target polymer • The lifetime of a product that determines the potential of CO2 capture and storage. Based on the performed assessment, the electrochemical conversion of CO2 can be considered one of the most promising routes. Furthermore, all ‘CO2-to-product’ routes score low on the energy required. Currently, most CO2 conversion processes have a low TRL, which is not surprising given the relative new research area. Although multiple polymers (polyethylene, polypropylene and polyglycolic acid) score excellent on the CO2 content in the polymer, only applications in building and construction have a high CO2 capture potential due to their long lifespan. Fast moving consumer goods, like clothing and food packaging, have a short lifespan, and although these materials are partially recycled, there are inherent recycling losses. Overall, these products are considered to be a less effective carbon sink and as such, using CO2 as feedstock will have a lower impact for these applications. Finally, it is concluded that the economic potential of each of the identified CO2 conversion methods heavily relies on whether the technology can mature quickly and significantly, and on the extent to which they can be coupled to excess renewable energy streams in the future. Additionally, a heavy driver in the economics of these solutions will depend on the taxation of the carbon offset that is mitigated by a specific route and whether the potential for long term carbon capture will be taken into account for such taxation.

The Clean Air Act Amendments of 1970 established a national program of pollution control to be administered jointly by the states and the Federal Environmental Protection Agency. National air quality standards have not yet been attained, however, because the legality of EPA approval and enforcement of state antipollution plans that impose economic hardship on industry is still undetermined. In this article, the author argues that Congress intended air quality standards to be met even at significant cost to industry, including shutdown, and develops a framework for decision making in challenges to administrative action under the Clean Air Act. Economic and technical feasibility, he concludes, is generally irrelevant to Federal approval of state implementation plans and does not constitute a defense to Federal or state enforcement of those plans.

Nowadays, as the technology behind solar photovoltaic systems has been significantly improved, along with a significant decrease in costs, grid-connected photovoltaic systems are becoming an important option to reach a low-carbon energy transition. The high cost of electricity consumed at the Technical University of Cluj-Napoca represented a good reason for the university to increase its energy efficiency by adopting and increasing energy consumption from renewable energy sources. This paper assesses the technical, economic, and environmental feasibility of deploying four photovoltaic systems at the aforementioned university situated in the Northwestern part of Romania, according to the Romanian renewable energy legislation. PVSOL software has been used to estimate the performance of photovoltaic installations. The results indicated that the most viable distributed generation system is the one with a capacity of 100 kW, meeting approximately 23 percent of university electricity needs, and at the same time, reducing carbon dioxide emissions by approximately 460 tons. A sensitivity analysis has been performed to evaluate the effect of several critical parameters on the PV system’s economic feasibility. The results provide valuable decision-making information regarding the buildings’ solar potential for other universities, supporting the transition to solar energy.

The conversion of wood into chemicals for the production of most of our synthetic plastics, fibers, and rubbers is technically feasible. With refinements in technology a large integrated plant utilizing all components of the wood for production of ethanol (to be further processed to ethylene and butadiene), phenols and furfural would be approaching economic feasibility as well at current petrochemical prices. If crude oil prices continue to climb at a faster rate than wood costs, the economic feasibility of chemicals for polymers from wood would become certain. Although technical feasibility has not been established, synthetic oils from liquefaction of wood might serve as feedstocks for cracking to chemicals in the same way that crude oil is presently used. The fulfillment of all our polymer needs from wood as a raw material should not place an impossible burden on our wood supply, but might actually improve the availability of wood for lumber, plywood and pulp by providing a use for less valuable wood which would allow reforestation and improved forest management.

The purpose of the study is to single out the research management and administration strategies that are used at the USA universities and evaluate their feasibility in Ukraine. The method of descriptive content analysis was applied to analyse the relevant literature sources found using the keyword-based strategy. The review process included five basic phases such as preparation, retrieval, appraisal, synthesis, and reporting. The review found three eligible strategies used in research management and administration in the USA universities. These were as follows: the strategy that is based on the Supply Chain Management concept, the strategy that is based on promoting a project management community, the strategies of internationalization: the (research-related) study abroad programs recruiting international students (as a financial source to fund the research), and internationalizing the faculty through the scholarship programmes. While evaluating the strategies using the criteria, the experts rated the project management community-based strategy the highest (45 %), while the Supply Chain Management concept-based strategy scored the least (22 %). Concerning feasibility in Ukraine, the project management community-based strategy scored the highest technical feasibility, legal compatibility, and economical feasibility. The internationalisation strategies showed the greatest values for economical feasibility but moderate scores for other criteria. The Supply Chain Management concept-based strategy showed the largest values for technical feasibility, but the legal compatibility, economical feasibility and stakeholder benefits and ensuring competitive advantage were rated by the experts the lowest.

The cost of compound feed is a constraint in intensive fish and poultry farming, contributing 60-80% of the total production costs, 70% of which is due to fish and soy meal used as protein source. This review presents the extent to which insects have been utilised as an alternative protein source in feed in sub-Saharan Africa (SSA). A key word search of agricultural, biological and multi-disciplinary databases and academic search engines was conducted for literature on the extent of research and utilisation of insects in poultry and fish feed in SSA. There is limited published information on the practice as well as technical and economic feasibility of the use of insects as alternative protein ingredients in compound feed. This is likely because research on the subject is fairly recently initiated and yet to be published. Excluding South Africa, rearing, processing and use of insects is still at experimentation level at laboratory scale. Insects (grasshoppers, house fly maggots, Westwood larvae, termites and garden snail) meal replaced conventional protein sources by 10-100% without affecting the growth performance of fish and poultry. In some cases, insect based feed performed better than conventional feed. Nutritional composition data of insects published for SSA majorly focused on proximate composition and not characterisation of the nutritional quality. Several research and development projects on the technical and economic feasibility, social acceptability and potential social-economic impact are ongoing and expected to increase available data when completed. Published research confirms the potential of insects for use in poultry and fish production systems and mass production and processing of target insects is the next necessary step. Based on available and ongoing research, piloting and up-scaling the use of insects as alternative protein sources in animal feed in partnership with private sector in SSA is necessary. This will confirm and enhance the technical and economic feasibility of using of insects as an alternative protein source on a commercial scale.

Brazil has a high co-processing potential and a large part of its Municipal Solid Waste (MSW) is destined to landfills. Thus, in order to bring economic and environmental improvements to the city of Campo Largo, an analysis was performed in one of the recycling associations of the city to verify the possibility of sending waste to co-processing instead of landfills. The methodology was a study based on structured and participant observation. Information and data were collected in the association to be able to perform an analysis of the current situation. In the sequence, the possible cement industries were identified. From the information gathered in the previous stages, it was possible to elaborate a proposal with technical and economic feasibility for the city. The technical feasibility was confirmed by a report issued by a specialized company, and for the economic analysis, the gains were calculated as well as the necessary adaptations were proposed. The estimated annual gain for the city is around R$51,000 considering all 4 associations of the city.KeywordsMunicipal solid wasteCo-processingRecyclingEnvironmental and economic improvements

The technical and economic feasibility of using night-effect rock bed cooling as a means of building air conditioning has been evaluated for the various climatic regions existing in the United States. The night-effect concept has been found to be a technically viable means of achieving resonable levels of human thermal comfort in wide regions of the country. Use of a night-effect rock bed cooling system may result in excessive humidity in humid northern and northeastern regions while occasional undesirable building temperature extremes may occur in western regions because of practical control difficulties. The night-effect system is not technically feasible in the South Central and Southeast. (MOW)

Decarbonising aquaculture support vessels is pivotal to reducing greenhouse gas (GHG) emissions across both the aquaculture and maritime sectors. This study evaluates the technical and economic feasibility of deploying hydrogen as a marine fuel for a 14.95 m net cleaning vessel (NCV) operating in Tasmania, Australia. The analysis retains the vessel’s original layout and subdivision to enable a like-for-like comparison between conventional diesel and hydrogen-based systems. Two options are evaluated: (i) replacing both the main propulsion engines and auxiliary generator sets with hydrogen-based systems—either proton exchange membrane fuel cells (PEMFCs) or internal combustion engines (ICEs); and (ii) replacing only the diesel generator sets with hydrogen power systems. The assessment covers system sizing, onboard hydrogen storage integration, operational constraints, lifecycle cost, and GHG abatement. Option (i) is constrained by the sizes and weights of PEMFC systems and hydrogen-fuelled ICEs, rendering full conversion unfeasible within current spatial and technological limits. Option (ii) is technically feasible: sixteen 700 bar cylinders (131.2 kg H2 total) meet one day of onboard power demand for net-cleaning operations, with bunkering via swap-and-go skids at the berth. The annualised total cost of ownership for the PEMFC systems is 1.98 times that of diesel generator sets, while enabling annual CO2 reductions of 433 t. The findings provide a practical decarbonisation pathway for small- to medium-sized service vessels in niche maritime sectors such as aquaculture, while clarifying near-term trade-offs between cost and emissions.

This study presents a preliminary evaluation of the technical and economic feasibility of selected conceptual processes for pyrolytic conversion of organic feedstocks or the decomposition/detoxification of hazardous wastes by coupling the process to the geopressured-geothermal resource. The report presents a detailed discussion of the resource and of each process selected for evaluation including the technical evaluation of each. A separate section presents the economic methodology used and the evaluation of the technically viable process. A final section presents conclusions and recommendations. Three separate processes were selected for evaluation. These are pyrolytic conversion of biomass to petroleum like fluids, wet air oxidation (WAO) at subcritical conditions for destruction of hazardous waste, and supercritical water oxidation (SCWO) also for the destruction of hazardous waste. The scientific feasibility of all three processes has been previously established by various bench-scale and pilot-scale studies. For a variety of reasons detailed in the report the SCWO process is the only one deemed to be technically feasible, although the effects of the high solids content of the geothermal brine need further study. This technology shows tremendous promise for contributing to solving the nation's energy and hazardous waste problems. However, the current economic analysis suggests that it is uneconomical at this time. 50 refs., 5 figs., 7 tabs.

This paper offers an investigation of the technical and economic feasibility of using standard utility-grade coal burning equipment and electrical generation equipment in an offshore installation. An investigation of design parameters including siting, configuration, use of conventional power equipment, undersea power cables, fuel transport, construction, and environmental impact has been made. Three possible configurations and an economic comparison between a barge type floating power plant and a land plant are given. The conclusion is that an offshore plant is technically feasible, is economically comparable to a land plant, and offers greater environmental benefits. This paper is a summary of a report sponsored in part by the NOAA Office of Sea Grant.

A Midwest Appropriate Technology Grant was awarded to determine the technical and economic feasibility of producing mineral-fiber insulation directly from extensive deposits of basaltic sand produced during former mining and milling operations in the Keweenaw Peninsula region of Michigan's Upper Peninsula. The amounts of local basaltic sands available and representative chemical compositions were determined. The variation of viscosity with temperature and chemical composition was estimated. Samples were melted and either pulled or blown into fiber. In all cases fiber could be made with a reasonable tensile strength to ensure usefulness. It was concluded that it was technically feasible to produce fibers from basaltic stamp sands of the Upper Peninsula of Michigan. A technical feasibility study using published data, a cost and design analysis of a basalt fiber production plant, a market survey of fiber needs, and an economic analysis for investing in a basalt fiber venture was undertaken. These studies concluded that the local production of basaltic insulation was both feasible and economically reasonable. It was suggested that the plant be located in a region of greater population density with lower utility costs. A representative one-third of these studies is included as appendices A, B, C, and D.