• M85
    An alcohol fuel mixture containing 85 percent methanol and 15 percent gasoline by volume. Methanol is typically made from natural gas, but can also be derived from the fermentation of biomass.

  • Mains
    A system of pipes for transporting gas within a distributing gas utility's retail service area to points of connection with consumer service pipes.

  • Major fuels
    Fuels or energy sources such as: electricity, fuel oil, liquefied petroleum gases, natural gas, district steam, district hot water, and district chilled water.

  • Merchant MTBE plants
    MTBE (methyl tertiary butyl ether) production facilities primarily located within petrochemical plants rather than refineries. Production from these units is sold under contract or on the spot market to refiners or other gasoline blenders.

  • Methane
    Methane (CH4) is commonly known as natural gas. It is colorless and burns efficiently without many byproducts. Natural gas has odor added as a safety measure since it is naturally odorless.

  • Methanol
    Methyl alcohol, also known as "wood alcohol," is commonly used in biodiesel for its reactivity. Generally, it is easier to find than ethanol. Sustainable methods of production are currently not economically viable. Usually, methyl alcohol is a by-product of the petroleum industry, and is often used as a "racing fuel."

  • Methanol blend
    Mixtures containing 85 percent or more (or such other percentage, but not less than 70 percent) by volume of methanol with gasoline. Pure methanol is considered an "other alternative fuel."

  • Middle distillates
    Products heavier than motor gasoline/naphtha and lighter than residual fuel oil. This range includes heating oil, diesel, kerosene, and jet kero.

  • mmcf
    million cubic feet.

  • mmcfd
    million cubic feet per day.

  • MMgal/d
    One million gallons per day.

  • mmmcf
    Mediterranean Sea

  • mmscfd
    million standard cubic feet per day.

  • Modified diesel engine
    Traditional diesel engines must be modified to heat the oil before it reaches the fuel injectors in order to handle straight vegetable oil. Modified, any diesel engine can run on veggie oil. Without modification, the oil must first be converted to biodiesel.

  • Module
    The box or package containing equipment for installation on a production platform. Each self-containing unit is constructed a shore and serves a specific purpose.

  • Mole Percent
    Mole is a short form of molecular weight. Mole fraction or mole percent is the number of moles of a component of a mixture divided by the total number of moles in the mixture.

  • MON/RON
    Motor Octane Number/Research Octane Number.

  • MPG
    Miles per gallon.

  • MToe/Toe
    Million Tonnes of oil equivalent/Tonnes of oil equivalent.

  • MTPA Million
    Tons per Annum. Tons or Metric Ton is approximately 2.47 cubic meter of LNG.

  • Multiple completion well
    A well equipped to produce oil and/or gas separately from more than one reservoir. Such wells contain multiple strings of tubing or other equipment that permit production from the various completions to be measured and accounted for separately. For statistical purposes, a multiple completion well is reported as one well and classified as either an oil well or a gas well. If one of the several completions in a given well is an oil completion, the well is classified as an oil well. If all of the completions in a given well are gas completions, the well is classified as a gas well.

  • Mutagenicity
    The property of chemical or physical agents inducing changes in genetic material that are transmitted during cell division. Fundamentally, a measure of cancer risk. The mutagenicity of biodiesel emissions is 75% - 90% less than its petroleum counterpart.