Process for the recovery of oil from waste oil sludges

A process for the recovery of oil, useful for further processing as refinery feed stock, from two or more waste oil sludges containing oil, water, and solids, at least one said sludge being fluid waste oil sludge and the other sludge being a thick waste oil sludge, comprising:

• (a) treating said sludge to substantially separate free oil and free water from the solids,
• (b) heating by indirecting heat exchange solids having entrained oil and water from the treatment step in (a) at a temperature sufficient to volatilize all entrained oil and water, and recovering solids, said solids being classified nonhazardous by EP toxicity test procedure,
• (c) condensing said oil and water from step (b),
• (d) treating the resulting condensate from step (c) and free oil and water from step (a) to separate oil from water and any entrained solids,
• (e) recovering oil from step (d), and
• (f) recovering water from step (d), whereby said water is sufficiently clean for further treatment in a conventional water treatment facility to lower the Chemical Oxygen Demand to an acceptable limit.

A process for the recovery of oil, useful for further processing as refinery feed stock, from two or more waste oil sludges containing oil, water, and solids, at least one said sludge being fluid waste oil sludge and the other sludge being a thick waste oil sludge, comprising:

• (a) treating said fluid sludge to substantially separate free oil and free water from solids and recovering the oil and water,
• (b) heating by indirect heat exchange said thick sludge and the resulting solids from step (a) containing oil and water at a temperature sufficient to volatilize oil and water, said resultant solids being classified nonhazardous by EPA toxicity test procedure;
• (c) condensing the oil and water from step (b) and recovering the condensate,
• (d) treating the free oil and water from step (a) and the condensate from step (c) to separate the oil from water and any entrainded solids, and
• (e) recovering oil from step (d).

A process for the recovery of oil, useful for further processing as refinery feed stock, from waste oil sludge containing oil, solids, and a substantial amount of water, comprising:

• (a) treating said sludge to substantially separate free oil and free water from the solids,
• (b) passing the oil and water from step (a) to a (settler) separator means,
• (c) heating by indirect heact exchange the solids from step (a) at a temperature
• sufficient to volatilize entrained oil and water, said resulting solids being classified nonhazardous by EPA toxicity test procedure
• (d) condensing said oil and water from step (c) and passing the condensate to said (settler) separator means of step (b),
• (e) collecting the resulting (settler) separator overflow and separating oil from water and any entrained solids, and
• (f) recovering oil from step (e).

A process for the recovery of oil, useful for further processing as refinery feed stock, from waste oil sludge containing oil, solids, and a substantial amount of water, comprising:

• (a) treating said sludge to substantially separate free oil and free water from the remaining sludge,
• (b) admixing the resulting sludge from the treatment step (a) with a base in sufficient quantity to render the sludge pH at least about neutral to basic and heating by indirect exchange product the resulting admixture at a temperature sufficient to volatilize entrained oil and water and leaving partially dewatered and deoiled sludge,
• (c) heating by indirect heat exchange the resulting sludge from step (b) at a higher temperature than in step (b) to further volatilize oil and water from said sludge, thereby resulting in solids free of oil and water, said solids being classified nonhazardous by EPA toxicity test procedure,
• (d) condensing said oil and water from both steps (b) and (c),
• (e) treating the resulting condensates from step (d) and said oil and water from step (a) to separate oil from water and any entrained solids, and
• (f) recovering oil from said treating of step (e).

A process for the recovery of oil, useful for further processing as refinery feed stock, from waste oil sludge containing oil, solids, and a substantial amount of water, comprising:

• (a) treating said sludge with a base in sufficient quantity to render the sludge pH at least about neutral to basic and heating the resulting admixture at a temperature sufficient to volatilize entrained oil and water and leaving partially dewatered and deoiled sludge,
• (b) heating by indirect exchange product the resulting sludge from step (a) at a higher temperature than in step (a) to further volatilize oil and water from said sludge, thereby resulting in solids free of oil and water, said solids being classified nonhazardous by EPA toxicity test procedure,
• (c) condensing said oil and water from both steps (a) and (b),
• (d) treating the resulting condensates from step (c) to separate oil from water and any entrained solids, and
• (f) recovering oil from said treating of step (d).

A process for the recovery of oil, useful for further processing as refinery feed stock, from waste oil sludge containing oil, water and at least 5% by weight solids, and from which the oil and water cannot be separated by mechanical means, comprising:

• (a) heating by indirect heat exchange said sludge in the essential absence of oxygen at a temperature ranging from about 225.degree. F. to 1150.degree. F. to volatilize the oil and water in said sludge, and recovering solids exhibiting more than about 98% volatilization of organic material, said solids being classified nonhazardous by EPA toxicity test procedure;
• (b) condensing said oil and water;
• (c) separating oil from water and entrained solids from the condensate from step (b);
• (d) recovering oil from step (c) as a valuable oil product;
• and (e) recovering the water, whereby said water is sufficiently clean for further treatment in a conventional water treatment facility to lower the Chemical Oxygen Demand to an acceptable limit.