Energy content of biofuel (J/kg) or equivalent units. Energy density is the amount of energy stored in a fuel per unit volume, expressed in SI units as joule per litre (J/L) or equivalent units. The table below includes entries for popular substances already used for their energy, or being discussed for such use. The second column shows specific energy, the energy content in megajoules per unit of mass in kilograms, useful in understanding the energy that can be extracted from the fuel. The third column in the table lists energy density, the energy content per liter of volume, which is useful for understanding the
Energy & Environmental Science journals in the category "Engineering, Chemical", and first among 225 journals in the category "Environmental Sciences". "Energy & Environmental Science" publishes the following types of articles: Research Papers (original scientific work); Review Articles, Perspectives, and Minireviews (feature review-type articles of broad interest); Communications (original scientific work of an urgent nature), Opinions (personal, often speculative, viewpoints or hypotheses on a current topic), and Analysis Articles (in-depth examination of energy and environmental technologies, strategies, policies, and general conceptual frameworks of general interest). According to the Thomson Reuters Master Journal List and CASSI, this journal is indexed by the following services: Energy &