Decontamination of soil

A system for decontaminating contaminated solids from hydrocarbon compounds, the system comprising:

• at least one thermal hydrocarbon removal unit, which extends from a first edge to a second edge, and comprises:
• an elongated inner tube, which defines an inner space therein, the inner tube comprising
• a solids inlet opening proximal to the first edge;
• a solids outlet opening proximal to the second edge;
• and
• a vapor outlet opening positioned longitudinally between the first edge and the second edge;
• and
• a transportation means, disposed within the inner space of the elongated inner tube, and configured to transport solids in the direction from the first edge towards the second edge of the thermal hydrocarbon removal unit;
• at least one heating device configured to apply indirect heat to the inner space of the elongated inner tube;
• and
• a cooling unit connected to the vapor outlet opening of the inner tube, through an outlet line, wherein the outlet line is oriented so that the cooling unit is positioned above the vapor outlet opening.

A system for decontaminating contaminated solids from hydrocarbon compounds, the system comprising:

• (a) at least one thermal hydrocarbon removal unit comprising transportation means disposed therein, and a solid inlet, a solid outlet, a liquid outlet, and a vapor outlet coupled thereto, wherein the at least one thermal hydrocarbon removal unit is configured to apply indirect heat to the contaminated solids, while said transportation means is configured to convey the contaminated solids therethrough, and wherein the indirect heat generates volatile hydrocarbon vapors within the at least one thermal hydrocarbon removal unit;
• (b) at least one outlet line in solid-fluid communication with the vapor outlet of the thermal hydrocarbon removal unit, wherein said at least one outlet line enables hydrocarbon vapors flow therethrough;
• and
• (c) at least one cooling unit in solid-fluid communication with the at least one outlet line, configured to condense a first portion of the hydrocarbon vapors entering thereto, wherein a first fraction of the condensed hydrocarbon vapors is released out therefrom to produce a first hydrocarbon liquid product,
• wherein a second fraction of the condensed hydrocarbon vapors is recirculated back into the outlet line to form a reflux stream flowing back into the thermal hydrocarbon removal unit, and
• wherein a second portion of the hydrocarbon vapors which does not condense is released as vapors to the external environment,
• wherein the reflux stream flows downwards within the thermal hydrocarbon removal unit and dissolves at least partially the contamination from the solids conveyed therethrough, thus enabling to produce and release decontaminated solids via the solid outlet of the thermal hydrocarbon removal unit, and to produce a second hydrocarbon liquid product via the liquid outlet thereof.

A method for recovering hydrocarbon compounds from contaminated solids, the method comprising:

• (a) providing contaminated solids into a system comprising at least one thermal hydrocarbon removal unit which is in solid-fluid communication with at least one cooling unit via at least one outlet line;
• (b) conveying the contaminated solids through the at least one thermal hydrocarbon removal unit;
• (c) evaporating volatile hydrocarbon compounds from the solids within the thermal hydrocarbon removal unit into the cooling unit, thus at least partially decontaminating the solids;
• (d) condensing a first portion of the hydrocarbon vapors within the cooling unit;
• (e) conveying a first fraction of the condensed hydrocarbon vapors of step (d) into a liquid tank, thereby forming a first hydrocarbon liquid product therein;
• (f) conveying a second fraction of condensed hydrocarbon vapors of step (d) back into the thermal hydrocarbon removal unit, thereby recirculating a reflux stream which flows downwards into the thermal hydrocarbon removal unit;
• (g) transporting the solids from a first edge of the thermal hydrocarbon removal unit upwards towards a second edge thereof while washing the solids with the reflux stream of step (f) flowing downwards therein, thus at least partially decontaminating the solids;
• (h) discharging the reflux stream out from the thermal hydrocarbon removal unit following step (g), thus providing a second hydrocarbon liquid product;
• and
• (i) discharging the decontaminated solids out from the thermal hydrocarbon removal unit, following the decontamination performed during steps (c) and (g), thus providing a decontaminated solid product.