Assessing the Suitability of DME for Powering SI Engines by Analyzing In-Cylinder Pressure Change

This article discusses an analysis of in-cylinder pressure change during combustion of LPG-DME fuel in IC engines. The aim of the study is to present a method for assessing the possibility of using DME as a combustion activator, and to establish its impact on the process. The study proposes a method for assessing the shift of the maximum value of cylinder pressure as a parameter which enables the impact of DME on the combustion process to be evaluated. The method was developed on the basis of bench tests carried out on an SI engine with a capacity of 1.6 dm³.

LCA and LCC of dried and shredded food waste as an alternative fuel for the cement industry

The scope of this paper is to examine the environmental and economic performance of an alternative household fermentable waste (HFW) management paradigm, developed within the framework of the HORIZON 2020 project Waste4think. In Greece, the business-as-usual scheme for the management of HFW is its disposal in landfills as part of mixed waste. Waste4think developed an alternative approach based on the benefits of source separation. Specifically, source separated HFW is taken to a drying/shredding plant, located in the municipality, for the production of a high-quality biomass product called FORBI. Alternative approaches have been examined for the exploitation of FORBI. In this work, the use of FORBI as an alternative fuel for the cement industry is assessed using life cycle assessment (LCA) and life cycle costing (LCC) tools. The results show that the proposed HFW management framework performs better than the baseline scenario both in economic and environmental terms. However, focus should be given to the optimisation of the drying/shredding process in order to reduce its energy intensity and environmental loadings.

Lignocellulosic Bioethanol and Biobutanol as a Biocomponent for Diesel Fuel

In this paper, the fuel properties of mixtures of diesel fuel and ethanol and diesel fuel and butanol in the ratio of 2.5% to 30% were investigated. The physicochemical properties of the blends such as the cetane number, cetane index, density, flash point, kinematic viscosity, lubricity, CFPP, and distillation characteristics were measured, and the effect on fuel properties was evaluated. These properties were compared with the current EN 590+A1 standard to evaluate the suitability of the blends for use in unmodified engines. The alcohols were found to be a suitable bio-component diesel fuel additive. For most physicochemical properties, butanol was found to have more suitable properties than ethanol when used in diesel engines. The results show that for some properties, a butanol–diesel fuel mixture can be mixed up to a ratio of 15%. Other properties would meet the standard by a suitable choice of base diesel.

Analysis of rejects from waste printed circuit board processing as an alternative fuel for the cement industry

Waste Printed circuit boards (PCBs) are one of the most valuable and recycled components of electronic waste due to the presence of precious metals such as copper, silver, gold and palladium. The rejects of the PCB recycling process, named non-metal fraction (NMF) have continuously been sent to landfills. Several researchers have proposed alternative use of NMF as secondary materials such as fillers in composites or as adsorbent. This study is focused on the potential application of the PCB recycling rejects as waste-derived fuel or alternative fuel in the cement industry. Approximately 2 million metric tonnes (Mt) of this waste was produced in 2014 globally and estimated to reach 6.5 million Mt in 2050. The presence of high organic matter in the NMF renders it useful as an alternative fuel. The organic content of the NMF could also potentially be increased using gravity separation and thus increasing its net calorific value. The study showed that the NMF could provide up to 21 MJ kg^-1 of heating value with low heavy metal and ash concentration. A comparison with other waste-derived fuel sources is also presented in the paper.

Impact of utilizing solid recovered fuel on the global warming potential of cement production and waste management system: A life cycle assessment approach

Cement production is responsible for a significant share of global greenhouse gas (GHG) emissions. A potential option to reduce the cement production emissions is to use alternative fuels which can have also an impact on emissions from the waste management sector. This work investigates the change in global warming potential (GWP) of ordinary Portland cement (OPC) production and affected waste management systems when conventional fuels are partially replaced by solid recovered fuel (SRF) made from commercial and industrial waste (C&IW). A life cycle assessment (LCA) was conducted with a functional unit of 1 metric tonne of OPC production and treatment of 194 kg of C&IW. Data from an existing cement plant have been used, where the share of SRF from total fuel energy demand increased from 0% to 53% between 2007 and 2016. Four scenarios were established with varying waste treatment methods and SRF share in the thermal energy mix of cement production. It was found that GHG emissions decreased by 20% from 1036 kg carbon dioxide (CO2), eq. (functional unit)-1 in Scenario 1 to 832 kg CO2, eq. (functional unit)-1 in Scenario 3. Furthermore, it is possible to reach a reduction of 30% to 725 kg CO₂, eq. (functional unit)-1 in Scenario by increasing the share of SRF to 80%. In conclusion, significant GHG emissions reduction can be achieved by utilizing SRF in cement production. Especially in the middle-income and low-income countries where waste is dumped to the open landfills, emissions could be reduced without huge investments to waste incineration plants.

Physicochemical Properties of Biobutanol as an Advanced Biofuel

Biobutanol is a renewable, less polluting, and potentially viable alternative fuel to conventional gasoline. Biobutanol can be produced from same sources as bioethanol, and it has many advantages over the widespread bioethanol. This paper systematically analyzes biobutanol fuel as an alternative to bioethanol in alcohol–gasoline mixtures and the physicochemical properties. Based on the conducted analyses, it was found that biobutanol mixtures have a more suitable behavior of vapor pressure without the occurrence of azeotrope, do not form a separate phase in lower temperature, it has higher energy density, but slightly reduce the octane number and a have higher viscosity. However, in general, biobutanol has many advantageous properties that could allow its use in gasoline engines instead of the commonly used bioethanol.

Environmental levels and human health risks of metals and PCDD/Fs near cement plants co-processing alternative fuels in Catalonia, NE Spain: a mini-review

This paper was aimed at reviewing recent studies related with the impact on environment and human health of metals and PCDD/Fs near cement plants. It has been particularly focused on the impact of cement plants located in Catalonia, Spain, which have been monitored by our research for more than ten years. Environmental monitoring studies were performed under different cement plant conditions. While some of our studies examined temporal trends of the levels of the above indicated pollutants, the main goal of other surveys was to assess the impact of implementing alternative fuels in the facilities. Even one of the studies was performed before and after the cement plant temporally ceased its industrial activity. The impact of cement plants burning alternative fuels on the emissions of metals and PCDD/Fs elsewhere was also reviewed. Regarding the cement plants in Catalonia, no significant differences were found, neither in the long-term follow-up studies, nor when alternative fuels are used, nor when a cement plant temporally stopped its activity. These results are in agreement with those reported for several stack emissions of other cement plants working under different conditions. We conclude that emissions of metals and PCDD/Fs by cement plants working with the best available techniques (BAT), should not cause a significant negative impact neither on the surrounding environment, nor on the human health of the population living in the neighborhood.

Impact of Calcium Oxide on Hygienization and Self-Heating Prevention of Biologically Contaminated Polymer Materials

During the storage of spent polymer materials derived from municipal solid waste, which contain biodegradable impurities, an intense growth of microorganisms takes place. The aerobic metabolism of microorganisms may cause these materials to combust spontaneously and to become a real epidemiological risk for humans. The aim of the research is to determine the optimal addition of calcium oxide (CaO), which effectively reduces the number of selected microorganism groups populating the analyzed materials, in which spent polymers represent a significant fraction: refuse-derived fuel (RDF) and an undersize fraction of municipal solid waste (UFMSW). The main novelty of the experiments is to assess the benefits of using the commonly available and cheap filler (CaO), to hygienize the material and to reduce the fire hazard arising from its storage. During the mixing of spent polymer materials with pulverized CaO (mass shares: 1, 2, and 5% CaO), temperature changes were monitored using thermography. Moisture content (MC), pH, respiration activity (AT4) and bacterial count were determined before and after the experiment. During the addition of CaO (especially when the content was at 5%) to the UFMSW, higher maximum temperatures were obtained than in the case of RDF analyses, which may be the result of a high percentage of the biodegradable fraction and higher MC of the UFMSW. In all cases the waste temperature did not increase again after 3 min. CaO used in the experiment effectively limited the number of microorganisms. The addition of 5% of CaO has showed the strongest antimicrobial properties, and it can be recommended for hygienization of the analyzed materials and for the reduction of the risk of self-heating during their storage in windrows.

Health Benefits from Upgrading Public Buses for Cleaner Air: A Case Study of Clark County, Nevada and the United States

Public transit buses, which move more than 5 billion passengers annually in the United States (U.S.), can contribute substantially to the environmental health burden through emitted air pollutants. As a leader in transforming to cleaner bus fleets, the Regional Transport Commission of Southern Nevada (RTC) has been transitioning from diesel to compressed natural gas (CNG) transit buses since 1999. By 2017, ~75% of RTC's buses operating in Clark County, Nevada were CNG-powered. This study assesses the health benefits of the venture using the US Environmental Protection Agency's (EPA) Co-Benefits Risk Assessment (COBRA) model, considering the emission and exposure changes from the 2017 baseline for two hypothetical scenarios: (1) no transition (CC_D) and (2) complete transition (CC_N). The CC_D scenario shows realized health benefits, mostly due to avoided mortality, of $0.79⁻8.21 million per year for 2017 alone, while CC_N suggests an additional $0.88⁻2.24 million annually that could be achieved by completing the transition. The wide range of estimates partly reflects uncertainties in determining diesel bus emissions under business-as-usual. These health benefits were not limited locally, with ~70% going to other counties. Two national-scale scenarios, US_D and US_N, were also constructed to explore the health impact of transitioning from diesel to CNG buses across the U.S. As of 2017, with CNG powering only ~20% of transit bus mileages nationwide, there could be massive unrealized health benefits of $0.98⁻2.48 billion per year including 114⁻258 avoided premature deaths and >5000 avoided respiratory and cardiovascular illnesses. Taking into account the health benefits, economic costs, and the inter-state nature of air pollution, expanding federal assistances to accelerate a nationwide transition to cleaner bus fleets is highly recommended.

Multi-dimensional Roles of Ketone Bodies in Fuel Metabolism, Signaling, and Therapeutics

Ketone body metabolism is a central node in physiological homeostasis. In this review, we discuss how ketones serve discrete fine-tuning metabolic roles that optimize organ and organism performance in varying nutrient states and protect from inflammation and injury in multiple organ systems. Traditionally viewed as metabolic substrates enlisted only in carbohydrate restriction, observations underscore the importance of ketone bodies as vital metabolic and signaling mediators when carbohydrates are abundant. Complementing a repertoire of known therapeutic options for diseases of the nervous system, prospective roles for ketone bodies in cancer have arisen, as have intriguing protective roles in heart and liver, opening therapeutic options in obesity-related and cardiovascular disease. Controversies in ketone metabolism and signaling are discussed to reconcile classical dogma with contemporary observations.

Refuse derived fuel (RDF) plasma torch gasification as a feasible route to produce low environmental impact syngas for the cement industry

Plasma torch gasification (PTG) is currently researched as a technology for solid waste recovery. However, scientific studies based on evaluating its environmental implications considering the life cycle assessment (LCA) methodology are lacking. Therefore, this work is focused on comparing the environmental effect of the emissions of syngas combustion produced by refuse derived fuel (RDF) and PTG as alternative fuels, with that related to fossil fuel combustion in the cement industry. To obtain real data, a semi-industrial scale pilot plant was used to perform experimental trials on RDF-PTG.The results highlight that PTG for waste to energy recovery in the cement industry is environmentally feasible considering its current state of development. A reduction in every impact category was found when a total or partial substitution of alternative fuel for conventional fuel in the calciner firing (60 % of total thermal energy input) was performed. Furthermore, the results revealed that electrical energy consumption in PTG is also an important parameter from the LCA approach.

Market-driven considerations affecting the prospects of alternative road fuels

Without significant intervention, demand for crude oil could rise by a further 25% by 2035, stemming from its use for transportation, particularly road transport. Many technologies for alternative fuels and substitute transport energy carriers are being researched, but successful implementation of these technologies at scale will require attention to consumer-behavioural and policy challenges as well as adapting existing or introducing new commercial value chains. In particular, there will be new capital-intensive roles for which there are no obvious contenders as yet. The legacy of diverse urban planning and fuel taxation policies and varying degrees of consumer inertia will lead to different rates of adoption of different alternative technologies in regional markets. In the absence of technology that provides a compelling consumer proposition, substitution of crude demand in mature markets will be challenging, as will be channelling exponential growth from growing markets like China into less crude-intensive road transport solutions.

Atmospheric chemistry and air pollution

Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozone and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.

Enthalpy of Combustion of Microcrystalline Cellulose

A test substance with characteristics and properties similar to those of cellulose-based solid waste products is needed to calibrate calorimeters and combustors which will be routinely burning these materials to determine their calorific values precisely for use in commerce. Microcrystalline cellulose was found to be a good calibrant for this purpose. The enthalpy of combustion of microcrystalline cellulose Δ H c o at (25 °C), and its estimated uncertainty, was determined to be -2812.401±1.725 kJ/mol based upon the sample mass. A calculated heat of wetting correction of 1.514 kJ/mol was applied to the combustion data.