US2201050A - Process for producing carbonaceous material - Google Patents

Description

Patented May 14, 1940 UNITED, STATES PATENT OFFICE Alfred Oberle, Edgcmoor, Md; Grace Oberle administratrix c! said Alfred Oberle, deceased No Drawing. Original application August 11,

1928, Serial No. 299,100. Divided and this application April 17, 1933, Serial No. 668,629. Renewed September 28, 1939 5 Claims.

This invention relates to improvements in carbonaceous material and a process for making the same, and is a division of Serial Number 299,100 (filed August 11, 1928) which is a continuation in part of a prior application Serial Number 672,648, filed November 3, 1923. It refers more particularly to the treatment of potroleum carbon resulting as a residue from the treatment of mineral oils or their gaseous, liquid or solid derivatives, in the form of carbon, collecting during the destructive distillation or cracking and partial or complete combustion of mineral oils or their derivatives, and carbon separated by distilling, filtering, centrifuging, burning, evaporating, heating in general, oxidizing, extracting, refining, precipitating and flotating residual and light mineral oils or their derivatives inthe form of a powder, a hard spongelike material, or a semi-liquid pasty mass, or irregular masses to produce active carbon.

Among the salient objects of the invention is to provide a process in which carbonaceous material of this character is relieved of any gaseous, volatile, liquid, tarry, and pitchy hydrocarbons or impurities such as sulphur or sulphur compounds and innumerable other materials, by heat treatment under atmospheric or superatmospheric pressures, or in vacuum in the presence of water, activating gases, activating salts, activating metals or their oxides, chlorides or hydroxides, silicious and calcareous material, mineral acids, and solvents in order to produce a highly active carbon.

The process for the treatment of the carbonaceous material will vary due to impurities present, the purpose for which the product is to be used and the relative cost of treatment.

The temperatures used in this process vary from a minimum of about 100 C. to a maximum of about 2000 C. Very wet carbonaceous material will stand a maximum temperature, especially if the time factor is short. Maximum temperatures are also advantageously used where steam is employed. Minimum temperatures are indicated in cases where hot air is used to initiate combustion in the pores of relatively dry, porous carbonaceous material, 'such as is obtained from oil burners or in vapor-phase cracking, in the form of pumice-stone-like chunks. Low temperatures are also sufiicient where the carbonaceous material is treated with sulphuric acid, nitric acid, or mixtures of the two. In this case reaction will set in, almost immediately, accompanied by more or less foaming and boiling and lasting for quite some time. carbonaceous material which has been produced under conditions of high temperature needs often only a mild but prolonged temperature treatment such as afterglowing.

It may be said, in general, that dry heat treatment has to be carried out at considerably lower temperatures than steam heat treatment and that prolonged treatment must be carried out at minimum temperatures whereas very short treat,- ments maybeneflt by the use of maximum temperatures. It is important that temperatures, at which the particular carbonaceous material undergoing treatment may change to graphitic or coke form, be avoided.

Wherever there is a possibility of the volatiles present in the carbonaceous material breaking down into secondary carbons, temperatln'es should be kept below 300 C. until such volatiles are removed. This may be ascertained by the use or a suitable condenser.

In cases where the carbonaceous material has been acid-treated prior to heat treatment without complete elimination of the acid, temperatures as low as 100 C. are efiectively used. Where phosphoric acid has been used to activate the carbonaceous material, it is of special importance to regulate the temperature applied, since phosphoric acid at temperatures below 600 C. will dehydrate the carbonaceous material while at about 800 C. reduction takes place, whereas at about 1000 C. formation of phosphorus begins. Reduction in this case takes place at the cost of hydrogen complexes present in the carbonaceous material.

Where superheated steam is decomposed it'is important to regulate the temperature so that the carbon will have an ailinity for hydrogen, but not for oxygen.

The heat treatment may be carried out under superatmospheric pressure, at atmospheric pressure, or under a vacuum. A superatmospheric pressure ranging from 50 to 500 pounds may be maintained by means of extraneous inert gases, or gases having a catalytic or activating efiect on the material under treatment. The greater part of the carbonaceous material available for the carrying out of this process is in the form of a fairly dry, spongy petroleum coke, and needs,

after reduction in size, a treatment with superheated steam, followed by a gradual building up of pressure by means of steam, this pressure mixed with sand, slacked or unslacked lime, oyster or clam shells and other calcareous material, salts containing chlorine, such as zinc chloride, calcium chloride,.magnesium chloride, iron chloride, molybdenum chloride, tin chloride, aluminum chloride also the chlorides of nickel, cobalt, manganese, lead, thallium, etc. especially the oxides or chlorides derived from the elements included in the fifth group of Mendelejefis table. It is understood, however, that the activating material is not limited, as different types of carbonaceous material will require different activating material. Iron, nickel, cobalt, copper, zinc,

sodium, potassium, calcium, etc. may be used.

Prior or subsequent to or during the heating or heat and pressure treatment the carbonaceous material may be subjected to a treatment with a mineral acid or mixture thereof, such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acids. With some of the carbonaceous material a violent reaction will take place during the first stages of the acid treatment, particularly where nitric acid, sulphuric acid, or a mixture of the two is being used. Where the carbonaceous product is used in the manufacture of electrical appliances, or for certain catalytical processes, it is of distinct advantage that the removal of excess acids by water-washing, or heat treatment, is incomplete, since a certain degree of acidity prior to the final heat treatment is advantageous. In all other instances where acid treatment is resorted to, the acidtreated material is water-washed until neutral, with orwithout the application of heat. The acid treatment may be substituted, preceded or followed by an alkali treatment. The alkali metals or ,their compounds may be used. Sodium, potassium, or calcium or their compounds are used advantageously.

By the uses of centrifuges, filter presses, vaporizers, or the like, the acid or alkali may be recovered and reused.

Some types of carbon require a treatment with suitable solvents of the aliphatic or aromatic hydrocarbon series and the generally known extracting agents, such as, gasoline, benzol, carbon bisulfide, xylol, anilines, pyridine, alcohols, phenols, carbon tetra-chloride, ethers, chloroform, acetone, etc. or mixtures thereof. Treatment with solvents is preferably carried out before any heat and pressure treatment, but not necessarily Such gases as, carbon monoxide, carbon dioxide, oxygen hydrogen, water-gas, fiue gases, nitrogen, chlorine, air, wet and dry steam, or decomposed steam, or mixtures of the aforementioned, or gases containing same, may be introduced into the carbonaceous material undergoing treatment, preferably through a perforated tube arranged in such a manner in the treating vessel to bring about a maximum of turbulence in the material to be treated. These gases may serve as a vehicle for furnishing the necessary heat, for building up pressure to drive off and remove impurities, to initiate or carry out oxidation, or to function as activating or catalytic agents. 3 E

The material to be treated may be charged continuously through a hopper or grinder into the top of a. still where it undergoes the necessary treatment, after which, it may be removed from the still for further treatment, if necessary.

The gases, vapors and volatile material given off are preferably led through a condenser and may be reused. The treating vessel, or still, should be provided with valves to keep the still under pressure and also with such appliances as manometers, safety valves, charging and discharging tubes, thermometer wells, or pyrometer appliances, which are generally used on apparatuses of this kind where pressure or vacuum is applied. The carbonaceous material can be retreated, if necessary, and the process may be carried out continuously. The materials used in treating the carbonaceous matter are subsequently removed. The product is a high quality active carbon, adapted especially for the'following uses:

1. Decolorizing carbons. 2. Medicinal carbons.

. Condensation carbons. Contact carbons.

Gas mask carbons.

. Catalytic carbons.

. Colloidalcarbons.

amyla e:

1. Origin of crude material. (Hydrocarbons) 2. Method of production of carbonaceous material to be activated.

3. Purpose for which finished product is used.

4. Facilities and relative cost.

The product obtained by this process has been used successfully for refining of sugar, water purification, treatment of casinghead gas, refining and treatment of petroleum and its products such as, motor fuels, heavy oils, lubricating oils, medicinal oils, for purifying gases, in making gas masks, in the treatment of edible oils. organic liquids and mineral acids, also in the treatment of waxes, glycerine, gelatine, glue, as a substitute for lamp black and as a filler.

I claim as my invention:

1. A continuous process for treating carbonaceous material of a mineral oil origin, consisting in treating the carbonaceous material under superatmospheric pressure at temperatures above C. but not above 2000 C. with decomposed steam, withdrawing volatile material, moisture and impurities.

2. A process for producing carbon from carbonaceous material, consisting in distilling off gaseous and volatile material from the material undergoing treatment under a vacuum, releasing the vacuum, introducing an aqueous fiuid into the still, maintaining a temperature on the still sufiicient to drive off by distillation, or otherwise, remaining gases, volatiles, liquids and impurities, treating the residual carbon with a purifying fluid, while at an elevated temperature, removing the treating fiuid and impurities and again imposing a vacuum to further remove undesirable matter and recovering a carbon product.

3. A process for producing carbon from carbonaceous material containing oil such as described, consisting in heating the material to a temperature above 100 C., building up a pressure up to 500pounds, imposed by means of the gases and vapors given of! by the material undergoing treatment, releasing the pressure and introducing a suitable gas, removing the gases, volatiles, liquids, dissolved material and recovering a carbon prodnet.

4. The process of treating carbonaceous material which comprises subjecting the carbonaceous material to treatment with superheated steam under superatmospheric pressure, releasing the pressurmand subjecting the treated material to a vacuum treatment.

5. The method of treating petroleum coke which comprises subjecting such coke to treatment with superheated steam under superatmospheric pressure, releasing the pressure andsubjecting the treated coke to vacuum.

men 013mm.