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Cement production has advanced greatly in the last few decades. The traditional fuels used in traditional kilns include coal, oil, petroleum coke, and natural gas. Energy costs and environmental concerns have encouraged cement companies worldwide to evaluate to what extent conventional fuels can be replaced by waste materials, such as waste oils, mixtures of non-recycled plastics and paper, used tires, biomass wastes, and even wastewater sludge. The paper aims to discuss these issues.

The work is based on literature review.

The clinker firing process is well suited for various alternative fuels (AF); the goal is to optimize process control and alternative fuel consumption while maintaining clinker product quality. The potential is enormous since the global cement industry produces about 3.5 billion tons that consume nearly 350 million tons of coal-equivalent fossil and AF. This study has shown that several cement plants have replaced part of the fossil fuel used by AF, such waste recovered fuels. Many years of industrial experience have shown that the use of wastes as AF by cement plants is both ecologically and economically justified.

The substitution of fossil fuels by AF in the production of cement clinker is of great importance both for cement producers and for society because it conserves fossil fuel reserves and, in the case of biogenic wastes, reduces greenhouse gas emissions. In addition, the use of AF can help to reduce the costs of cement production.

There are a number of impediments to consumer adoption of alternative fuel vehicles (AFVs), including regulatory barriers, resources, infrastructure and vehicle characteristics themselves. These impediments also impact on other stakeholders, such as government, producers (i.e. corporations), suppliers (collaborators), competition (i.e. alternative products) and activist groups. The inter‐relationships amongst all stakeholders are complex, as one group may initiate actions that serve as impediments for others. Developing systems‐based sustainable alternatives to traditional, environmentally‐harmful automobiles requires the network of relationships between stakeholders and impediments to be considered. This paper looks at the various impediments as well as how they can affect various stakeholders. It then posits a broad based integrative approach to provide the most favourable environment for consumers to consider AFVs.

The declared aim of this paper is to explore the possible effects of the need for energy conservation (and in particular the need for economy in the use of oil‐based fuels) on road vehicle development in the UK over the next few decades. In the absence of the author, his colleague, R J Francis, also of Harwell, presented this paper at the conference held by the Institute of Management Services in London, September 1980. He stressed the fact that the views here are those of ETSU, and may not necessarily be regarded in any way as “government policy”. ETSU is the Energy Technology Support Unit, which is based at Harwell, and was established in 1974 to formulate and manage research, development and demonstration programmes in the technology of renewable energy sources and conservation under contract to the Department of Energy. There are approximately 45 professional staff at ETSU (mainly scientists and engineers) working in three main areas: strategic planning of research and development, management of R&D on the renewable energy sources, and research, development and demonstration in energy conservation. When introducing this paper, Richard Francis said that it set out to establish the need for conservation in general, as well as to explain how this is to be achieved in practice. This subject, he commented, leads on to the special task of improving fuel economy and achieving wider fuel flexibility within road transport, which itself has wide implications for road vehicle technology. This paper reviews all the more realistic alternatives, and then attempts to identify those which seem most promising and also to quantify the impact they might have in reducing our dependence on oil‐based fuels.

This article seeks to address aviation as an emerging biofuel consumer and to discuss sustainability issues and consequences for feedstock production concepts. Biojet fuels have been identified as a promising, readily deployable alternative to fossil‐based aviation fuels. At the same time they are highly criticised as their production may have negative social and environmental impacts. Therefore, the paper aims to identify major sustainability issues and assessment challenges and relate these to the production of biojet fuel feedstock.

Two plant oil production concepts are presented that address the sustainability issues discussed. Both concepts are being investigated within the research project “Platform for Sustainable Aviation Fuels”. A literature‐based overview of sustainability issues and assessment challenges is provided. Additionally, conceptual insights into new plant oil production concepts are presented.

The use of biojet fuels is often hailed as a strategy for the aviation industry to become more sustainable. However, biofuels are not necessarily sustainable and their potential to reduce GHG emissions is highly debated. Several unresolved sustainability issues are identified highlighting the need for improved assessment methods. Moreover, the two concepts presented have the potential to provide sustainably grown feedstock, but further empirical research is needed.

This article addresses researchers and practitioners by providing an overview of sustainability issues and assessment challenges related to biojet fuels. Consequences are identified for two plant oil feedstock concepts: catch cropping in temperate regions and silvopastoral systems in tropical and subtropical regions.

There is growing apprehension about climate change and the role played by fossil fuels. Exploration of renewable sources of energy as an alternative to fossil fuels reveals that there is no path forward toward a true green economy that does not have negative environmental side effects. Thus, the improvement of managerial and financial accounting to provide more environmental information and accountability by governmental and nongovernmental institutions is increasingly important in guiding us toward wiser choices. Since the 1970s, the increasing concerns about the environment in the United States have led to improved regulation and more comprehensive environmental reporting requirements and accounting standards. Also, global institutions have been created to foster voluntary reporting of both direct and indirect environmental impacts of their activities by institutions. However, evidence suggests that, while some large global firms have found it useful to engage in sustainability reporting throughout their operations, in general, the US organizational environmental reporting is not strong and is oriented toward the legal minimum when present. If we are to take account of the many direct and indirect ways in which our production choices affect our environment, then our institutions need to play a larger role in informing our choices. Both the Environmental Managerial Accounting Initiative and an enhanced balanced scorecard approach are recommended as frameworks for future efforts; public and private institutions must also include life cycle analysis in decision-making systems in order to enhance their ability to help achieve sustainable economic progress.

This study seeks the effect on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions of euro diesel-hydrogen dual-fuel combustion in a small turbojet engine.

Experimental studies are performed in a JetCat P80-SE type small turbojet engine. Euro diesel and hydrogen is fed through two different inlets in a common rail distributing fuel to the nozzles. Euro diesel fuel is fed by a liquid fuel pump to the engine, while hydrogen is fed by a fuel-line with a pressure of 5 bars from a gas cylinder with a pressure of approximately 200 bars.

At different engine speeds, it is found that there is a decrease at the TSEC between a range of 1% and 4.8% by different hydrogen energy fractions (HEF).

The amount of hydrogen is adjusted corresponding to a range of 0–20% of the total heat energy of the euro diesel and hydrogen fuels. The small turbojet engine is operated between a range of 35,000 and 95,000 rpm engine speeds.

On the other hand, remarkable improvements in exhaust emissions (i.e. CO, CO₂, HC and NO_x) are observed with HEFs.

This is through providing improvements in performance and exhaust emissions using hydrogen as an alternative to conventional jet fuel in gas turbine engines.

The International Maritime Organization has decided that as of 1.1.2020, SOx content in a ship’s emissions should be no more than 0.5 per cent. The purpose of this paper is to address the various challenges expected to arise from the enforcement of the global cap sulfur regulation.

The authors outline various enforcement options and present a model that calculates the profits from noncompliance in the high seas, so as to help determine the level of fines that could be imposed in case of violation.

The main finding is that a harmonized system of fines, which are more than potential savings from cheating, would be a strong deterrent for compliance.

To the authors’ knowledge, no paper in the maritime literature on sulfur regulations has focused on enforcement as of yet.