Abstract: A Diesel Exhaust Fluid (DEF) that includes urea, demineralized water and between 5 and 300 ppm formaldehyde, acetaldehyde, propianaldehyde, or butyraldehyde, and this formulation of DEF include less than 0.6 ppm of phosphates, calcium, iron, aluminum, magnesium, sodium, and potassium, the formulation also includes less than 0.3 ppm copper, zinc, chromium, and nickel. This formulation of DEF reduces the accumulation of urea deposit in the diesel exhaust system relative to other formulation of specification grade DEF that include less formaldehyde.

Abstract: A Diesel Exhaust Fluid (DEF) that includes urea, demineralized water and between 5 and 300 ppm formaldehyde, this formulation of DEF include less than 0.6 ppm of phosphates, calcium, iron, aluminum, magnesium, sodium, and potassium, the formulation also includes less than 0.3 ppm copper, zinc, chromium, and nickel. This formulation of DEF reduces the accumulation of urea deposit in the diesel exhaust system relative to other formulation of specification grade DEF that include less formaldehyde.

Abstract: A Diesel Exhaust Fluid (DEF) that includes urea, demineralized water and between 5 and 300 ppm formaldehyde, this formulation of DEF include less than 0.6 ppm of phosphates, calcium, iron, aluminum, magnesium, sodium, and potassium, the formulation also includes less than 0.3 ppm copper, zinc, chromium, and nickel. This formulation of DEF reduces the accumulation of urea deposit in the diesel exhaust system relative to other formulation of specification grade DEF that include less formaldehyde.

Abstract: A Diesel Exhaust Fluid (DEF) that includes urea, demineralized water and between 5 and 300 ppm formaldehyde, acetaldehyde, propianaldehyde, or butyraldehyde, and this formulation of DEF include less than 0.6 ppm of phosphates, calcium, iron, aluminum, magnesium, sodium, and potassium, the formulation also includes less than 0.3 ppm copper, zinc, chromium, and nickel. This formulation of DEF reduces the accumulation of urea deposit in the diesel exhaust system relative to other formulation of specification grade DEF that include less formaldehyde.

Abstract: A mixture of urea, water and ammonium carbamate is formulated for use in the catalytic reduction of oxides of nitrogen in diesel exhaust. The mixtures may be formulated to optimize the amount of reductant in the mixture and the freezing point of the formulation. These formulations are especially useful in combination with Selective Catalytic Reduction systems and are well suited for use on heavy-duty trucks and heavy duty equipment used off-road. Some of these formations include between about 15.0 wt. % to about 40.0 wt. % urea; between about 15.0 wt. % to about 40.0 wt. % ammonium carbamate; and between about 40.0 wt. % to about 60.0 wt. % water. The formulation may be monitored for ammonia content and/or freezing point and the composition of the formulation may be adjusted to optimize the freezing point and ammonia content.