Showing papers by "Razif Harun published in 2013"

Impact of excessive nitrogen fertilizers on the environment and associated mitigation strategies

Abstract: (Received 12 March, 2013; Accepted 30 March, 2013)Key words: Atmospheric deposition, Wet deposition, Watershed, Nitrate, Excessive-fertilizationAbstract - The soaring rise in the anthropological production of nitrogen (N) fertilizers has been notablein the field of crop production Despite several advantages the world is deriving from the use ofreactive N, many environmental hazards including water and soil acidification, pollution ofgroundwater surface and other water mineral resources and accelerated ozone depletion have arisenas a result of the recurring use of excessive environmental N The purpose of this paper is to highlightthe impact of N in the environment In addition, mention is made of management practices, such asmanure storage and handling solutions, livestock management, pasture management for reduced Nlosses, balanced N application rates, proper irrigation strategies, efficient N cycling at the field level,runoff, drainage and wastewater management and other mitigation strategies Conclusively, the use ofVarian’s Mathematical model, a model that dutifully delineates system theory in deterring over-fertilization will be considered*Corresponding author’s email: mie@engupmedumy (Salmiaton Ali, B- 16-16,Vista Pinggiran Putra -1, SeriKembangan, Selangor Malaysia

Bioprocess Engineering Aspects of Biodiesel and Bioethanol Production from Microalgae

Abstract: Rapid increase of atmospheric carbon dioxide together with depleted supplies of fossil fuel has led to an increased commercial interest in renewable fuels. Due to their high biomass productivity, rapid lipid accumulation and high carbohydrate storage capacity, microalgae are viewed as promising feedstocks for carbon-neutral biofuels. This chapter discusses process engineering steps for the production of biodiesel and bioethanol from microalgal biomass (harvesting, dewatering, pre-treatment, lipid extraction, lipid transmethylation, anaerobic fermentation). The suitability of microalgal lipid compositions for biodiesel conversion and the feasibility of using microalgae as raw materials for bioethanol production will also be evaluated. Specific to biodiesel production, the chapter provides an updated discussion on two of the most commonly used technologies for microalgal lipid extraction (organic solvent extraction and supercritical fluid extraction) and evaluates the effects of biomass pre-treatment on lipid extraction kinetics.

Process Economics and Greenhouse Gas Audit for Microalgal Biodiesel Production

Abstract: With the current global drive towards a low-emission economy, countries need to take a stance. For example, Australia, which is one of the world’s largest polluters, has made a commitment that before 2020 its overall emissions would be reduced by 5–15% below the levels registered in the year 2000. To realise these targets, processes which capture carbon dioxide will prove critically important. One of such emerging processes is carbon dioxide capture for microalgae cultivation and subsequent downstream biomass processing for biodiesel production. This chapter will entail engineering scale-up, economic analysis and carbon audit to ascertain the viability of an industrial scale microalgal biodiesel production plant. This will involve the development of an industrial scale model to determine the feasibility of a real large-scale plant. Data from each process step (cultivation, dewatering, lipid extraction and biodiesel synthesis) will be presented individually and integrated into the overall process framework.