Biodiesel is a renewable fuel made from vegetable oils and animal fats. Compared with fossil fuels, it has the potential to alleviate environmental pressures and achieve sustainable development. In this paper, 1660 patents related to biodiesel production were reviewed. They were published between January 1999 and July 2018 and were retrieved from the Derwent Innovation patent database. The patents were grouped into five categories depending on whether they related to starting materials, pre-treatment methods, catalysts, reactors and processing methods, or testing methods. Their analysis shows that the availability of biodiesel starting materials depends on climate, geographical location, local soil conditions, and local agricultural practices. Starting materials constitute 75% of overall production costs and, therefore, it is crucial to select the best feedstock. Pre-treatment of feedstock can improve its suitability for processing and increase extraction effectiveness and oil yield. Catalysts can enhance the solubility of alcohol, leading to higher reaction rates, faster biodiesel production processes, and lower biodiesel production costs. Moreover, the apparatus and processes used strongly affect the oil yield and quality, and production cost. In order to be commercialized and marketed, biodiesel should pass either the American Society for Testing and Materials (ASTM) standards or European Standards (EN). Due to increases in environmental awareness, it is likely that the number of published patents on biodiesel production will remain stable or even increase.

Patent landscape review on biodiesel production: Technology updates

The composition of VOC (volatile organic compounds) emissions from in-use passenger cars with different engine types, ie cars with diesel engines, cars with petrol engines equipped with three-way-catalysts, and cars with petrol engines without catalysts was determined. Five cars of each engine type have been measured on a chassis dynamometer under conditions of the US FTP 75 test procedure and the "Autobahn" test developed by TUV Rheinland. Measurements of C2 and C10 hydrocarbons were made with a GC-FID system. In addition, samples on DNPH cartridges were taken and analysed by means of a HPLC-system for the determination of aldehydes and ketones. The influence of cold/warm-conditions on the VOC composition was determined. In the case of cars with diesel engines as well as for the petrol driven cars without exhaust treatment, the effect caused by the cold start only led to minor changes in the VOC composition. A similar behaviour was observed for these car types at higher speeds. In contrast to the cars without catalysts the cars with three-way-catalysts showed a great variability of the VOC composition. During the cold start phase the aromatic compounds and the alkanes yielded the main fraction of the VOC. During the warm phase the less reactive alkanes were predominant. With increasing mean velocities the VOC composition changed in favour of the more reactive compounds. (A) For the covering abstract see IRRD E101903.

Determination of voc-components in the exhaust of gasoline and diesel passenger cars

There are some challenges about NOX emissions exhausted from diesel engines fueled with biodiesel. Due to increasingly stringent emission regulations, the different methods such as varying the engine operating parameters, treatment with antioxidant additive and blending fuels have been adapted to reduce emissions of biodiesel combustion. One of the effective methods is the combustion of dual or blending fuels. Various fuels such as gasoline, hydrogen, natural gas, biogas, different types of alcohols and also fuel additives have been used to reduce biodiesel disadvantages. This study reviews the potential of the different fuels as an additive in biodiesel fuel in correspond to reduce NOX emissions. The general reduction of NOX has been observed with the presence of gasoline, biogas and alcohols in biodiesel blends. The reduction of NOX in biodiesel-hydrogen, biodiesel-diesel or biodiesel–CNG combustion has not been observed through all engine conditions. Moreover the retarding injection timing, the lower injection pressure, EGR higher than 30% can result in the reduced NOX emissions. However it seems the decrease in NOX emissions can be achieved by the use of most fuels in blending with biodiesel under all engine operating conditions, if only the proper injection parameters and blending proportions of fuels are set.

NOX emissions of compression ignition engines fueled with various biodiesel blends: A review

Air pollutants such as volatile organic compounds (VOCs), nitrogen oxides (NOx), and sulfur dioxide (SO2), as well as water pollutants (e.g., heavy metals phosphorous, fluoride, boron, phenolic compounds, and dyes), are harmful to humans and the environment. Effective control and reduction of their pollution is therefore an important topic for today’s scientists. Fly ash (FA) is a type of industrial waste that can cause multiple environmental problems if discharged into the air. On the other hand, because of its high porosity, large specific surface area, and other unique characteristics, FA can also be used as a low-cost and high efficient adsorbent for treatment of environment pollutants. This paper reviews the effects of FA on treatment of the air and water pollution, including to the current status of global FA utilization, physicochemical properties, principle of adsorption, and the application direction of FA in the future. Since most researchers only studied the adsorption capacity of pure FA or zeolite (synthesized from FA), the research on the fabrication of nanofiber membranes using FA is still lacking, especially the adsorption of VOCs from air and heavy metals from wastewater using FA nanofiber membranes. Therefore, in this paper, we focus on reviewing and summarizing that FA can be spun into a fiber membrane via electrospinning with the ability to adsorb VOCs and heavy metals from air and wastewater. Moreover, we also evaluate the future application value of FA nanofiber membranes in the field of environmental pollution control. Utilization of nanofiber technology to fabricate multi-functional FA emerging composite materials to mitigate air and water pollution has great potential in the future, especially the use of pollutant materials to control other pollutants.

Application of Fly Ash as an Adsorbent for Removal of Air and Water Pollutants

Pollution profiles of volatile organic compounds from different urban functional areas in Guangzhou China based on GC/MS and PTR-TOF-MS: Atmospheric environmental implications

Sam Ki Yoon

Papers

Reducing volatile organic compound emissions from diesel engines using canola oil biodiesel fuel and blends