Abstract: An improved exhaust system and catalytic converter element for a diesel engine wherein the improvement comprises: holding means for restricting the movement of catalytic converter elements in an overhead exhaust manifold; an improved catalytic converter element having at least one retaining rod extending through the catalyst substrate and/or having at least one retaining lip projecting into the substrate; a stabilizer projecting from the cover for the element insertion slot for receiving an end portion of the catalytic converter element to restrict the movement of the converter element in the exhaust manifold; perforated flow distribution elements provided upstream of the catalytic converter elements; and/or vertical coupling manifolds which each receive exhaust from a pair of engine cylinders and then deliver the combined exhaust stream to a separate one of the inlet openings in the bottom of the overhead exhaust manifold.

Abstract: An improved exhaust system and catalytic converter element for a diesel engine wherein the improvement comprises: holding means for restricting the movement of catalytic converter elements in an overhead exhaust manifold; an improved catalytic converter element having at least one retaining rod extending through the catalyst substrate and/or having at least one retaining lip projecting into the substrate; a stabilizer projecting from the cover for the element insertion slot for receiving an end portion of the catalytic converter element to restrict the movement of the converter element in the exhaust manifold; perforated flow distribution elements provided upstream of the catalytic converter elements; and/or vertical coupling manifolds which each receive exhaust from a pair of engine cylinders and then deliver the combined exhaust stream to a separate one of the inlet openings in the bottom of the overhead exhaust manifold.

Abstract: A method of utilizing kraft black liquor by converting the black liquor to "green liquor" and then oxidizing the green liquor with air in the presence of a quinone compound or spent liquor from the kraft process, the soda semi-chemical process or the neutral sulfite semi-chemical process as a catalyst. A marked improvement in the rate of oxidation is obtained. The thus oxidized green liquor is then able to be used as part at least of the digestion liquor in the NSSC process.

Abstract: A process for the delignification of lignocellulosic material is described wherein the lignocellulosic material is cooked with an alkaline or neutral sulphite pulping liquor, and there is added to the pulping liquor at least 0.001% by weight of an additive compound or mixture of additive compounds selected from quinones and hydroquinones.

Abstract: A delignification process using amine cooking liquors which also contain a quinoid or hydroquinoid compound. The process also encompasses a pretreatment step using the quinoid or hydroquinoid compounds.

Abstract: A process for the delignification of .Iadd.softwood .Iaddend.lignocellulosic material is described wherein the lignocellulosic material is cooked with .[.an alkaline or.]. .Iadd.a .Iaddend.neutral sulphite pulping liquor, and there is added to the pulping liquor at least 0.001% by weight of an additive compound or mixture of additive compounds selected from quinones and hydroquinones.